I'm an undergraduate meteorology student at the University of Oklahoma and these are my storm chasing accounts.
REVISED Chase Outlook for Sunday March 30, 2008
Published Saturday, March 29, 2008 by Alex Lamers.
Chase Target: Woodward, OK.
Status: Uncertain
Plan of Action: Head to Woodward via I-35/I-40/US-281 Spur/US-183 around Noon and set up shop and wait to see what happens. Would want to arrive in the mid-late afternoon.
Projected Chasing Conditions: Road network will be excellent as usual. The possibility of a late start to the convection would be a huge negative - thus the uncertainty and late arrival time if I do chase.
It seems like I always get stuck being able to chase the events that seem great 2-3 days out, look really terrible one day out and then surprise me the "day of". This one looks to be no different. The new 12z NAM run shows next to NOTHING occurring except maybe in far southern Kansas in the evening hours. Even then, I don't see any QPF in the 00-06z timeframe exceeding 0.25". This is a big change from the 00z run where it broke out a significant amount of evening convection. The GFS and NGM still both develop some thunderstorms in NW Oklahoma. Recent 4km WRF ARW and NMM cores from NCEP come up dry in this region though.
The question is...is it worth the gamble of NOTHING happening in order to potentially see something SIGNIFICANT. The parameters are maxed out. If something develops, some violent supercells are likely. That is not in question. What appears to be in question is whether or not storms will develop at all...except far to the north and east in elevated waa regimes.
This reminds me a lot of the Greensburg, KS event from last year. This is not to say that we'll experience a lot of violent tornadoes on Sunday evening. But the model forecasts remind me a lot of that event. Leading up to the Greensburg event, models depicted NO precipitation in the warm sector except closer to the warm front across Northern Kansas and north and east of there in elevated waa regimes. Below is a 00z May 4th 30hr forecast from the NAM. 6-hr convective precipitation is filled and contoured.
Not until the 12z run THAT DAY, did the models even show small amounts of precipitation in NW OK and SC KS (0.01-0.05"). The atmosphere was primed though, just like it will be on Sunday. 0-1km EHI values on Sunday are bullseyed at nearly 7 m2/s2 near Woodward! MLCAPE values at this same time (10 pm) will be nearly 2500 j/kg! Significant Tornado Parameter and Supercell Composite Parameter are both off the charts. The LLJ will crank up to about 50-60 knots at 850 mb and with the decoupling of the boundary layer, surface flow will back. The result will be richly curved hodographs. Butterflying jet structure aloft should aid in vertical motion across the area.
Bottom line, if something develops, it will be significant. And if I'm not there I'll kick myself. However, there's also a good chance nothing will happen. So chase status is still uncertain, but I'll keep my eye on things through the day...
Status: Uncertain
Plan of Action: Head to Woodward via I-35/I-40/US-281 Spur/US-183 around Noon and set up shop and wait to see what happens. Would want to arrive in the mid-late afternoon.
Projected Chasing Conditions: Road network will be excellent as usual. The possibility of a late start to the convection would be a huge negative - thus the uncertainty and late arrival time if I do chase.
It seems like I always get stuck being able to chase the events that seem great 2-3 days out, look really terrible one day out and then surprise me the "day of". This one looks to be no different. The new 12z NAM run shows next to NOTHING occurring except maybe in far southern Kansas in the evening hours. Even then, I don't see any QPF in the 00-06z timeframe exceeding 0.25". This is a big change from the 00z run where it broke out a significant amount of evening convection. The GFS and NGM still both develop some thunderstorms in NW Oklahoma. Recent 4km WRF ARW and NMM cores from NCEP come up dry in this region though.
The question is...is it worth the gamble of NOTHING happening in order to potentially see something SIGNIFICANT. The parameters are maxed out. If something develops, some violent supercells are likely. That is not in question. What appears to be in question is whether or not storms will develop at all...except far to the north and east in elevated waa regimes.
This reminds me a lot of the Greensburg, KS event from last year. This is not to say that we'll experience a lot of violent tornadoes on Sunday evening. But the model forecasts remind me a lot of that event. Leading up to the Greensburg event, models depicted NO precipitation in the warm sector except closer to the warm front across Northern Kansas and north and east of there in elevated waa regimes. Below is a 00z May 4th 30hr forecast from the NAM. 6-hr convective precipitation is filled and contoured.
Not until the 12z run THAT DAY, did the models even show small amounts of precipitation in NW OK and SC KS (0.01-0.05"). The atmosphere was primed though, just like it will be on Sunday. 0-1km EHI values on Sunday are bullseyed at nearly 7 m2/s2 near Woodward! MLCAPE values at this same time (10 pm) will be nearly 2500 j/kg! Significant Tornado Parameter and Supercell Composite Parameter are both off the charts. The LLJ will crank up to about 50-60 knots at 850 mb and with the decoupling of the boundary layer, surface flow will back. The result will be richly curved hodographs. Butterflying jet structure aloft should aid in vertical motion across the area.
Bottom line, if something develops, it will be significant. And if I'm not there I'll kick myself. However, there's also a good chance nothing will happen. So chase status is still uncertain, but I'll keep my eye on things through the day...
Chase Outlook for Sunday March 30, 2008
Published Friday, March 28, 2008 by Alex Lamers.
Sounding at Altus, OK for 00z Monday. This was the 00z Friday March 28th NAM run.Chase Target: Altus, OK.
Plan of Action: Head southwest on I-44 towards Lawton and then head west to Altus sometime in the late morning or early afternoon. Monitor data until storm initiation. Believe best tornado threat to be somewhere within a 30 mile radius of Altus as of the latest model runs (00/06z) this morning.
Projected Chasing Conditions: Road network will be excellent as usual. A potential negative would be the possibility of a low stratus deck that could be somewhat slow to mix out. Another negative is the possibility of late initiation and quick transition to multicellular convective modes.
Remarkably, this Sunday's chase looks potentially a lot like a chase day EXACTLY 4 weeks ago! Similar setups aloft and in the lower levels. Cold front over NW/NC Oklahoma, a dryline near the TX Panhandle/Oklahoma border down into West Texas that is bulging into the Altus area. Steep LCL gradient just north of the Red River. Models peg storm initiation late in the afternoon just north of the dryline bulge. Aloft, there should be a butterflying jet structure, which will enhance divergence, with the strongest flow arriving right around 00z. The two events are very similar.
Therefore, based on a similar structure to the event, I have initially pegged my target as Altus, the same target as four weeks ago. However, the only tornado in that event 4 weeks ago was north of Watonga, so I may need to revise that target as the event draws closer.
All that being said, there are a few differences. First, this event seems as though it will have far more moisture to work with and the moist layer should be much deeper than last time (extending up to nearly 800 mb). Secondly, as a result of the deeper moisture, both the NAM and GFS project SBCAPE values on the order of 2500-3500 j/kg! Thus the air mass associated with this event should be far more moist and unstable.
Some negatives need to be addressed though, and any one of these could wind up marginalizing this event. (1) Potential for late initiation. Neither the GFS or the NAM has much QPF prior to 00z. Therefore, we could be racing twilight on this chase. (2) Potential for a quick transition to a multicellular mode. Both the NAM and the GFS show a big QPF bullseye in the 00-06z Monday timeframe. Values in the maximum exceed 1". I'd be hard pressed to find many events where there was such a localized maximum of QPF and storms remained discrete for a long time. (3) Potential for a more stubborn cap/low stratus deck eroding slower. This could wind up decreasing instability levels. It also could tie into number 1, and delay initiation until after dark, when the LLJ will increase.
That being said, the event still does look chaseable. We'd be in an area with an awesome road network and it looks likely there will be storms. Basically, we'll wait and see later model runs and try to position north of the dryline bulge where surface flow is more likely to be backed to a southeasterly direction. This will increase convergence along the dryline and cold front as well as contribute to large looping hodographs (see sounding above). By positioning north of the dryline bulge, we will also stay to the north of the sharp LCL gradient, something we failed to do last time, and missed the only tornado of the day.
I'll close with a few numbers. 1km EHI values look to be on the order of 3-4 at 00z. 3km CAPE values could peak in the 200-300 j/kg range. Effective shear values could peak at just over 50 knots. Overall, some excellent shear parameters to suggest supercells will be likely once initiation occurs. All we can do now is watch and wait!
Chase Account - March 2, 2008
Published Sunday, March 02, 2008 by Alex Lamers.
Kiowa County, OklahomaMarch 2, 2008
This chase event went about as well as could be expected for an early season chase (especially the first few days in March). Typically Oklahoma sees its primary severe weather season from April through early June. So, seeing the potential for some supercells to fire along the dryline in the afternoon, we decided to head southwest to the Altus area. We departed Norman at 11 AM and wound up in Altus around 1:15 PM. We ate a quick lunch and looked at some data a bit north of the main downtown area in Altus before we noticed storms starting to develop around 2:45 PM just to our southwest.
Some of the initial development in our area. From our position at the Days Inn in Altus looking NW at 3:00 PM.We watched the storms, waiting for one to kind of take hold, but didn't really see all that much that impressed us. There was a storm that seemed decent that was headed towards Altus and our general area that we decided we would follow, as nothing else seemed to warrant us going out of our way to speed to try and intercept.
The storm passed through the Altus area at about 3:30 PM and began to weaken considerably. We decided to let this storm go and wait for another more interesting cell that essentially paralleled the track of the first storm, just a bit further south. We drove back through Altus and headed east on Highway 62 to try and get out ahead of both of these storms a bit. We then took N2100 Rd north putting us a few miles east of Altus Air Force Base where we sat and observed the storms rolling in, initially the weakening one and then the other one that pushed in from the southwest.
The above pictures were taken from a point a few miles east of Altus Air Force Base. The first one is of the storm "of interest" approaching from the southwest. The second one is of the interesting rain-free updraft base that we saw on the storm as it passed closer to our location, with a picturesque rain/hail foot on the right.
After the storm looked like it was beginning to pull just north of our location we had to act quickly to get out ahead of it again. We drove north on N2100 Road, through the town of Friendship until we got to Highway 19 and the small town of Warren. As we were driving north on N2100 Road, we could look almost straight up and see a wonderful back edge to the storm. We also could look to our right (east) and see the hail shaft, obvious from some brilliant white streaks highlighted against the dark clouds in the background. It could have been a good photo opportunity, but we had to try and get out ahead of this thing before it strengthened any more.
Turning east onto Highway 19, we headed into the teeth of the storm. For those of you who don't know, Highway 19 "stair-steps" its way east, then north, then east, and...well you get the picture. As a result, we core punched this thing about 2 or 3 times, getting penny to nickel size hail each time, extremely gusty winds and torrential downpours that reduced the visibility to near zero at times. I probably would have hung back in most cases, but the most we were hearing about on warnings was nickel size or quarter size hail, and the WxWorx radar that Sam had in his vehicle was just spitting out 1.00" size hail most of the time...generally under the threshold that will dent your car.
We turned onto Highway 54/19 north through the small town of Cooperton and then took the next major right turn, continuing on Highway 19 west. Looking in our rear-view mirrors, the storm had turned into a beast, and a broad, ragged wall cloud had begun to form. We decided to pull off on the side of the road on a small gravel road (N2370 Rd) just south of Highway 19 and watch what happened. The wall cloud became more compact as the rotation seemed to tighten up.
Above is a side by side base reflectivity and velocity image two panel (courtesy UCAR) at 5:08 PM. The rotation to the southeast of Hobart is obvious. Visually, the supercell had a classic, nice "mother-ship" mesocyclone. The rotation eventually increased to the point where we could see tendrils of condensed scud rotating quickly around each other. It wasn't the most classic funnel I've ever seen, but a funnel nonetheless. Below is a series of pictures of the happenings at this location.
The nice "mothership" mesocyclone with a rotating wall cloud and a funnel trying to form.
The same wall cloud, only about a minute later and zoomed down a bit more.
Zoomed in on the funnel even further.The funnel cloud and wall cloud gradually dissipated and the rotation weakened. We decided to follow this storm as we figured it had the best chance of producing a tornado of any storm in our general vicinity. We continued east on Highway 19, eventually pulling off in a gravel turnaround off the side of the road near the intersection of Highway 19 and Highway 58. This put us about 15 miles west of Apache, OK.
We watched the storm continue to develop, but it definately took on more of an HP appearance as the circulation got rain-wrapped and occluded and we noticed more of a gust front/bowed appearance to the storm. This storm began to be overtaken by another storm from the southwest and we saw a bit of a rain-free base on it, so we sat and watched some spectacular lightning and a shelf cloud with a greenish hue for awhile while we waited for the other storm to approach. However, it didn't do anything terribly impressive. Below are a series of pictures at this location.
Supercell becoming HP. Old wall cloud broadening out.
Shelf cloud on the leading edge of the HP supercell. Actually could have been a combination of the FFD off the approaching cell and the RFD of the cell we were previously on.
A view to the west-southwest. A new rain-free base with a broad lowering has emerged.
HP supercell shelf cloud and low hanging scud underneath. Heavy precipitation core visible behind the shelf cloud.After we determined that this new storm wasn't going to do very much at all, we decided to hop south on another storm, that had yet another wall cloud - but again the rotation was very broad and disorganized. So alas, we didn't see much of anything else.
All in all, I consider it a very successful chase for the first chase of the season, and having been in the first week of March. Hopefully this bodes well for the remainder of the spring!
Chase is a GO for Sunday March 2, 2008
Published by Alex Lamers.
Chase Target: Altus, OK.
Departure Time: (From Norman OK) 1100-1130 CST
Arrival Time: (approximate) 1300-1400 CST
Plan of Action: Will sit at a wi-fi hotspot in Altus and watch the latest weather data through the afternoon. Altus gives good road options to either get south into far Northern Texas, north towards I-40 or either east or west depending on the position of the dryline.
The last few runs of the NAM, in addition to the 12Z RUC look extremely favorable for Southwest Oklahoma. If these models verify, I would expect to see some vigorous supercells with nice structure and at the very least some good photography opportunities if we don't bag a tornado.
Based on the latest RUC and NAM (both 12Z runs), CAPE should be pushing 2000 j/kg in a small corridor of Southwest Oklahoma centered on the Altus area by 21-00Z. Also the NAM and RUC show potentially 20-30 knots of 0-1km shear values along with effective SRH values of 250-350 m2s-2. Effective wind shear should be on the order of 45-55 knots. All of this is extremely supportive of supercell development and would expect to see a few nice cells along the dryline especially in the 21-01z timeframe.
Hodographs really broaden and curve more between 21z and 00z so would expect an attendant increase in the tornado threat in that timeframe as well. LCLs won't be dragging the ground but would be low enough to support tornado development. Main threat from the supercells will still likely be large hail and damaging winds.
There looks to be a really nice dryline bulge per the RUC and NAM that will set up in Southwest Oklahoma in this same timeframe as the surface cyclone deepens in the southeastern Texas Panhandle. The result should be a backing of the wind flow across SW OK, an increase in SRH and increased forcing for ascent along the dryline.
Therefore, we will wind up in Altus between 1 and 2 pm and watch the latest data. This area is being downplayed at the moment. Perhaps that's good. All the big events that I've been a part of were downplayed.
Departure Time: (From Norman OK) 1100-1130 CST
Arrival Time: (approximate) 1300-1400 CST
Plan of Action: Will sit at a wi-fi hotspot in Altus and watch the latest weather data through the afternoon. Altus gives good road options to either get south into far Northern Texas, north towards I-40 or either east or west depending on the position of the dryline.
The last few runs of the NAM, in addition to the 12Z RUC look extremely favorable for Southwest Oklahoma. If these models verify, I would expect to see some vigorous supercells with nice structure and at the very least some good photography opportunities if we don't bag a tornado.
Based on the latest RUC and NAM (both 12Z runs), CAPE should be pushing 2000 j/kg in a small corridor of Southwest Oklahoma centered on the Altus area by 21-00Z. Also the NAM and RUC show potentially 20-30 knots of 0-1km shear values along with effective SRH values of 250-350 m2s-2. Effective wind shear should be on the order of 45-55 knots. All of this is extremely supportive of supercell development and would expect to see a few nice cells along the dryline especially in the 21-01z timeframe.
Hodographs really broaden and curve more between 21z and 00z so would expect an attendant increase in the tornado threat in that timeframe as well. LCLs won't be dragging the ground but would be low enough to support tornado development. Main threat from the supercells will still likely be large hail and damaging winds.
There looks to be a really nice dryline bulge per the RUC and NAM that will set up in Southwest Oklahoma in this same timeframe as the surface cyclone deepens in the southeastern Texas Panhandle. The result should be a backing of the wind flow across SW OK, an increase in SRH and increased forcing for ascent along the dryline.
Therefore, we will wind up in Altus between 1 and 2 pm and watch the latest data. This area is being downplayed at the moment. Perhaps that's good. All the big events that I've been a part of were downplayed.
REVISED Chase Outlook for Sunday March 2, 2008
Published Friday, February 29, 2008 by Alex Lamers.
A Tale of Two Numerical Models
Chase Target: Seymour, TX.
Time to Target: (From Norman OK) 3 hours
Plan of Action: Head southwest on I-44 to US277/82. Estimated departure time would be around 9 to 10 AM, given expected storm initiation shortly after the noon hour.
Two different models would present two entirely different possibilities as far as the potential severe weather event on Sunday. The GFS certainly would present greater concern, for its stronger mid to upper tropospheric flow over the warm sector contributes to much larger looping hodographs and thus stronger low-level wind shear. The NAM presents two areas of stronger shear, one to the north across Oklahoma and Kansas, and one to the south in the southern half of Texas with the butterflying jet structure. In fact the NAM puts upper level winds in the hole over Northwest Texas below 30 knots. This seems slightly impractical. I will break down what I think will happen and why I think each model is wrong on certain aspects. In any case, the differences among the models certainly casts doubt upon any chase potential.
The situation is incredibly complex and any variations will throw a wrench into the mix. Anyways, back to Sunday. It appears as though there will be a nice Gulf air mass surging north albeit modifying as it goes along. This is the first difference that is noted. The NAM tends to want to surge the mT air mass as far west as the New Mexico border, while the GFS hangs it up somewhere in the West-Central Texas rolling plains and the Edwards Plateau. I would imagine the GFS would be more reasonable in this regard for several reasons. (1) the persistent drought and dry soil and vegetation across the western half of Texas should allow for relatively quick modification and drying of the air mass, especially prior to the bulk of the spring green-up AND (2) low level cyclogenesis should provide more of a westerly component to the winds off the higher elevations in New Mexico and into far West Texas. Therefore, we could see compressional warming and some drier air emanating from the plateaus. As a result, I would expect the dryline to sharpen up somewhere along the edge of the Caprock escarpment.
The "main show", as far as coverage of convection goes, will be along the cold front which should reach a BVO-CDS line by 00Z Monday. Storms will initially fire along the cold front in the early afternoon in Northwest Oklahoma, but warm, moist air mass will likely advect up and over the cold dome and produce a backbuilding effect. The cold front will be surging southeast faster than mean storm motion IN THAT DIRECTION, which will allow the cold front to overtake the storms by late in the afternoon, allowing them to become progressively more elevated. Therefore, I don't see much of a tornado threat in Oklahoma, mainly just a marginal hail threat.
Further south, things become more interesting. There are several factors to consider. The first is a relatively stable environment caused by a pronounced elevated mixed layer that will hopefully erode as the late morning and early afternoon hours wear on. The source region for this air would be the arid Mexican plateaus. However, as the afternoon progresses, a shortwave trough is progged to eject northeastward from ~Southeast New Mexico to just northwest of the DFW metro area. The result should be a cooling of the layer and perhaps some induced vertical motion...both would act to destabilize the environment.
Interestingly enough, both of the models tend to agree on where the best instability will be in the afternoon hours. They project the best instability to be over Western North Texas, which makes sense as coldest air aloft will be able to overlap with the relatively homogeneous warm air over the entire warm sector. Because logic and all the models support the most unstable surface-based CAPE to reside over Western North Texas, this puts it at the top of my list as a general chasing target.
Concerns exist then about several things: shear and timing/initiation. I believe the NAM is woefully underdoing the amount of vertical shear because of the nearly calm winds it is depicting aloft. I would think bulk shear values would at least be in the 25-30 knot range, which would be marginally supportive of supercells. If one believes the GFS, then bulk shear could be as high as 50 knots with 0-1km SRH values approaching 300m2s-2.
So what will happen? Right now I'm thinking increasingly elevated storms will occur during the afternoon and evening over Oklahoma behind the surface cold front. There should be a low cloud deck during the morning over most of the warm sector, but this will erode near the dryline with mixing influences, etc. Further east, strong warm advection will persist as the boundary layer remains more decoupled and thus I think we'll see the soupy strands of weak-moderate elevated convection developing in the late morning and early afternoon from Southern Oklahoma into Central Texas. Not much should arise out of this, until stronger height falls arrive overnight to cool the column and destabilize the environment, which would then support more vigorous convection. This pretty much restricts chasing opportunities close to the dry line where hopefully clouds will clear out later in the morning, and sufficient shear and instability will exist to support supercells. Best overlap of shear and instability seems to be over Western North Texas so at the moment, that's what I have down as a target area.
Hopefully models converge on a solution soon! It would at least be nice to pin down a general area where initial convection will occur and the best threat will be, but current model spread makes that a bit difficult.
Chase Outlook for Sunday March 2, 2008
Published Thursday, February 28, 2008 by Alex Lamers.
Chase Target: Lawton, OK.
Plan of Action: Head southwest on I-44 towards Lawton around Noon on Sunday. This will give us time to review data during the mid-late morning here in Norman and evaluate if bust potential is high. Some wi-fi hotspots in Lawton and we would get there around 1:30 PM. Good major highway options in any direction out of Lawton.
Projected Chasing Conditions: POSITIVES: High visibility, good road network, IN OKLAHOMA! NEGATIVES: Relatively fast storm motion, eventual linearization, the Wichitas.
Not much talk yet about the severe weather potential in any discussions, but it seems like a fairly good setup (especially before the main tornado season which runs typically from April through early June down here). This is alright though, because I tend to like the downplayed events. They can surprise and you don't get your hopes up astronomically high. Granted this won't be a classic Spring dry line event but it has enough potential and is close enough to home to merit a chase.
SBCAPE values look to be on the order of 1000-1500 j/kg which is quite impressive for the first couple days in March. The NAM model (perhaps a bit too robustly) draws up 55-60F dewpoint temperatures, but would expect mid-50s dewpoints to at least make it close to the Red River, given that the Gulf will be opening up sometime early Saturday.
40-50 knots of bulk shear and 200-300 m2s-2 of 0-3km SRH bode well for some supercells. QPF fields in the model forecasts are pretty bullish in C & NE Oklahoma, so would expect things to line out rather quickly up there. However, there is better potential for things to stay more isolated further southwest, coincidentally where the better instability and low level shear will be located.
It's a forecast that will need to be fine tuned in the next couple days, but at this point I'm planning on a chase!
NEWS: Damage in Tulia, Texas rated as EF-2
Published Friday, April 27, 2007 by Alex Lamers.
The damage that we accidentally happened upon as a result of our storm chasing endeavors on April 21, 2007 in Tulia, Texas was rated as EF-2 by meteorologists with the National Weather Service in Lubbock. We got into the town maybe 10 minutes after the tornado went through, but quickly left so that we wouldn't hamper any rescue efforts. Below is an image the National Weather Service posted on their website. I provided a link in the picture caption to their website damage report which is very thorough and well-done.
Image from the National Weather Service website. Click here for a link to their damage writeup.
Image from the National Weather Service website. Click here for a link to their damage writeup.As the aerial survey indicated, the tornado seemed to move from south to north across the city and in fact spun up just east of Interstate-27, probably narrowly avoiding what could have been a very dangerous situation.
And now, time to give some other chasers, at least the ones with video or pictures that I could find, the glory for being on the storm as it spawned the tornado. Dustin Wilcox has a good writeup. Reed Timmer, as usual, had good video. Jason Boggs had video but I couldn't find a chase writeup and didn't want to link straight to a video.
That's all I have for now! Interesting storm though. Too bad we just couldn't quite get there to see the tornado. Definately didn't want to core-punch right into a tornado. I'm still waiting on the official word from the Wichita NWS office on their website as to how many tornadoes occurred on the Reno County storm on April 24th, and when I do, I will post that chase account.
And now, time to give some other chasers, at least the ones with video or pictures that I could find, the glory for being on the storm as it spawned the tornado. Dustin Wilcox has a good writeup. Reed Timmer, as usual, had good video. Jason Boggs had video but I couldn't find a chase writeup and didn't want to link straight to a video.
That's all I have for now! Interesting storm though. Too bad we just couldn't quite get there to see the tornado. Definately didn't want to core-punch right into a tornado. I'm still waiting on the official word from the Wichita NWS office on their website as to how many tornadoes occurred on the Reno County storm on April 24th, and when I do, I will post that chase account.
LATE Chase Account - April 21, 2007
Published Thursday, April 26, 2007 by Alex Lamers.
Hereford and Tulia, Texas
April 21, 2007
All videos with the copyright logo on the lower left hand corner were taken by Brandon Smith in my chase crew for the day. Also, the overcontrast image was his as well, just modified with photo editing software. Thanks to him for allowing me to use the pictures in my writeup!
This particular day - a Saturday in late April - was very promising, not only to me but to a great number of chasers. It was on a weekend, and the SPC had a nice elongated Moderate Risk along the High Plains. That meant that people were out in abundance, especially in the Texas Panhandle where the threat was advertised to be particularly high for tornadoes, some strong.
The 1300 UTC (8 am) outlook from the Storm Prediction Center.
If you look back at my chase outlook for the day, I had picked out Happy, Texas as a preliminary target. That would turn out to be in the vicinity of some very interesting supercells later in the day. The chase crew for this event consisted of myself, Sam Dienst, his girlfriend Cassie and Brandon Smith. We departed Norman early in the morning at 8 AM in order to get to Amarillo around noon. The other half of our chase crew - Andrew Starnes, Mike Kahle, DJ Gagne and Doug Lang - left later due to time conflicts, around 1 PM. We made great time to Amarillo and got into town around noon. The entire way there we were driving in miserable conditions. Low stratus and fog that reduced visibilities under a mile and obscured the tops of antennas. In addition it was drizzling. This had us doubting how good the heating would be for later in the day. However as we neared Amarillo, the cloud deck began to break up and this encouraged us. By the time we stopped at a hotel in Amarillo, the stratus had broken up into small cumulus clouds.
Good news for heating, and instability later in the day. Best Western parking lot in Amarillo.
We looked at data for about 15 minutes when suddenly the internet stopped working. It may have been just a glitch but I suspect that an ornery old lady who was working the front desk cut us off. Who knows, but in any event we decided to head south to Canyon, Texas which is about a 20 minute drive from Amarillo. We arrived at about 1:20 pm and sat in another Best Western parking lot right adjacent to a Holiday Inn Express on the main east-west drag through the town. We sat there for a little over an hour when suddenly the DOW (doppler-on-wheels) crew rolled up and parked on the street between the two hotels. This gave us a momentary reprieve in our boredom waiting for the cap to break. Shortly thereafter there was a chaser convergence on the area and we went over to talk to some of the guys we knew.
The DOW crew with the Tornado Intercept Vehicle to the left and one of the trucks with all the observation equipment strapped on the back.
(Left to Right) Sam, Brandon and I pictured in front of the Tornado Intercept Vehicle. Yes, they try to drive this through tornadoes.
After we were done with that we went back to the Best Western to get internet. With the other half of our chase crew en-route, we finally got the Tornado Watch for the area at about 3:51 pm on our computer. It was a PDS ("particularly dangerous situation") Tornado Watch indicating the potential for strong tornadoes. This got us encouraged and excited to say the least. Looking off to the west, we began to see cumulus towers after 4 pm. The DOW crew rolled out around 5 pm, and we decided to make a break for it at 5:30 pm into Eastern Deaf Smith County (one county to the west) when a few echoes finally appeared on Sam's WxWorx radar that we could track. They quickly intensified and we went for the one that was headed off to the northwest side of Hereford, Texas.
The supercell viewed from a distance as we just turn onto US Highway 60 to the west.
Getting closer to the supercell, photo from Brandon Smith.
Zoomed shot of the sun poking out behind the anvil. Photo from Brandon Smith.
We broke off north on Highway 809 just into Eastern Deaf Smith County to get a better look at the storm, and then west on Highway 1062 towards the storm to get a little closer. We wound up stopping at the intersection of Highway 1062 and Highway 385 or 11 miles due north of Hereford, Texas for those of you keeping track at home. We tried to evaluate the situation. On one hand, the storm we were on had a tightening reflectivity gradient on the southeast edge and we could see some scud ascending into the cloud base. It had promise. On the other hand, there was a storm exploding to the south of Hereford that had unobstructed inflow from the south and was "living in a juicy environment" as they like to say.
The view from radar. The storm to the south looked increasingly impressive.
Difficult to see low scud clouds and the sun breaking through the back edge of the anvil.
We could see the crisp anvil of the supercell to the south.
The sun on the edge of the anvil...beautiful!
We sat debating this for awhile, but finally Sam made a quick decision - and I agreed - to head for the southern storm. Not wanting to core punch a storm that was getting golf ball size hail reports, we decided to head around the forward flank downdraft to the east, jog south for a way, and then cut back to the west and intercept where the circulation would be. Also, the other half of our chase team finally caught up and were a bit east on Highway 1062. So we decided to pick them up on our intercept path. As we headed east on Highway 1062, we encountered hail being lofted out of the core of the storm and that was falling out of the anvil of the storm! The largest hailstones were quarter to half dollar sized or about 1.00 to 1.25" in diameter. I shot video of us going through the hail.
Mammatus on the underside of the anvil after the hail stopped.
We cut to the south on Highway 809 again, basically retracing our route in, and then we took Highway 60 further to the west-southwest. As we did, the storm's appearance on radar got much better and in a few minutes the rain-free base of the supercell came into view. We saw the wall cloud with striations from the wall cloud up the base of the storm clouds.
The wall cloud forming as we head west-southwest on Highway 60.
As we got much closer to the circulation we decided to cut north on County Highway CC and stopped a little north of Highway 60 at the intersection of CC and County Road 14. This put our exact location as 11.4 miles northwest of Hereford, Texas. As we sat and watched the wall cloud we noticed a funnel forming at about 6:28 pm. It formed quickly! Timestamps from the photos indicated it only took about a minute to become completely formed when it nearly touched the ground. Below is a series of pictures of what we saw.
The funnel - looking into a field past a crop irrigation system.
An enhanced photo for contrast that shows the two vorticies at the base of the funnel that were rotating around each other and what appears to be a tube extending down a bit.
The funnel beginning to lift again.
Continuing to lift, still very impressive.
Of course since we had no conclusive evidence that a tornado touched the debate raged - had we seen a tornado? Well, there were other chasers in the area, some of them said they were going to count this as a tornado and others said no, just a very low funnel. What do I think? Personally I think there was a brief spinup back in a field that nobody but the farmer will ever know about. It was probably only a few seconds but circulation on the ground is in fact a tornado. The rate at which the funnel descended and the enhanced image showing the two vorticies suggests to me that it briefly came in contact with the surface. We will probably never know for sure! Officially (NWS Storm Data) it was not a tornado. But in my honest opinion, we saw a brief spinup.
The other thing to note about all this was there was impressive rotation in the wall cloud, and the inflow winds to the storm were exceptionally strong. We were unable to stand still at points because the wind was blowing so hard. I thought that was one of the more impressive things about the storm. In response to the wind gusts you could see tumbleweed and dust blowing across streets and fields.
Zig-zagging across country roads we attempted to follow the storm as it headed northeast in the hopes of seeing another, more impressive tornado spinup. We stopped at one point and I took another video showing the impressive structure of the storm and the mesocyclone.
Little, small vorticies rotating under the mesocyclone in the center of the picture.
The storm eventually lost its organization although it still had small funnels that occasionally retreated back and forth, in and out of the cloud base. We followed it basically all the way to Interstate-40, close to 20 miles from where we initially saw the tornado spinup. It was a difficult chase too as earlier rainfall had made the dirt roads muddy and we were slipping and sliding all over the place. We thought we saw another tornado spinup behind us as we were driving but the visibility was low enough to make it inconclusive as we were in hail and rain with a few hailstones perhaps up to ping pong ball or golf ball size (1.50 to 1.75" in diameter).
We lost WxWorx radar for a bit due to a data feed problem at the National Weather Service. We thought it was something wrong with Sam's system so as we approached the west side of Amarillo, we stopped at a Barnes and Noble for a bathroom stop and to try and raise an internet connection to re-evaluate the situation. Of course after about 5 minutes the data was back and we realized there was a nice storm headed straight for Tulia, Texas in Swisher County. We kicked ourselves for stopping as we would need to book it down Interstate-27 to try and catch this massive supercell.
The supercell nearly over Tulia, Texas at 7:52 pm CDT.
We were nearly to the storm, as you can see above, when it spawned a tornado. We knew it had a Tornado Warning on it, but we didn't know of the actual tornado until Brandon heard reports of people trapped in homes on his scanner. At that point we all turned to each other and exchanged concerned glances. We rolled into Tulia, exiting onto Highway 87 south, and we saw the damage and immediately knew it had been a strong tornado. One of those grain trailers was tossed into the middle of the Highway. Trees had all the branches ripped off and metal was twisted around a few. A truck had its back window frame twisted and all the windows were busted out. A brick building had two walls collapse. We knew it would be impossible to keep up with the storm as it was headed into Caprock Canyon State Park where the road network is, to say the least, horrible. So we got out momentarily and looked at the damage.
Hard to see the damage. You can see the metal twisted around the tree to the left of the building in the far right of the picture.
Emergency vehicles swarmed the scene.
Not wanting to get in the way of search and rescue efforts, and not having lights on our cars like some other storm chasers, we headed back up Highway 87 and then south on I-27 to the Highway 86 exit just southwest of town to fuel up and perhaps get some nighttime shots of an approaching supercell and a squall line right behind that. A lot of things happened while we were there. First, we warned a trucker not to drive south to Plainview lest he be blown off the road by the approaching squall line. Second, we did see some amazing lightning. Then, they issued a tornado warning for the northern half of Swisher County for the supercell out ahead of the line. Alarmed, we pointed our car north to try and get a view of the cloud base. No sooner had a cloud-to-ground lightning strike illuminated the cloud base revealing a nice cone funnel than we heard from the other half of our chase group that had got seperated. They were apparently headed right past us on the Interstate and unaware of the Tornado Warning and the funnel. We told them to pull over to the side of the road and wait, which they did. We didn't see a tornado spinup though.
We then drove down Highway 86 to the west for a couple miles and parked in a prison parking lot, letting the squall line overtake us. Vivid cg lightning illuminated the underside of the shelf cloud and we could see the turbulent cloud formations there. Then it got windy with some small hail around 1/2" in diameter. The car rocked a bit but the winds probably weren't quite severe levels.
For the final act, after stopping to eat in Canyon again, we drove back through the squall line on the way back just before reaching the Oklahoma border. We encountered constant lightning, downpours reducing the visibility to nearly zero and wind gusts of 60 to 65 mph. The combination of wind and rain caused a semi to jack-knife which we passed with little congestion, probably meaning it occurred just ahead of us on the interstate.
All in all a successful chase. An unofficial tornado. Another nice supercell. The damage in Tulia. A funnel cloud at night. And let's not forget a nice squall line...twice. I'll post the Tulia, Texas damage survey results in a future post.
April 21, 2007
All videos with the copyright logo on the lower left hand corner were taken by Brandon Smith in my chase crew for the day. Also, the overcontrast image was his as well, just modified with photo editing software. Thanks to him for allowing me to use the pictures in my writeup!
This particular day - a Saturday in late April - was very promising, not only to me but to a great number of chasers. It was on a weekend, and the SPC had a nice elongated Moderate Risk along the High Plains. That meant that people were out in abundance, especially in the Texas Panhandle where the threat was advertised to be particularly high for tornadoes, some strong.
The 1300 UTC (8 am) outlook from the Storm Prediction Center.If you look back at my chase outlook for the day, I had picked out Happy, Texas as a preliminary target. That would turn out to be in the vicinity of some very interesting supercells later in the day. The chase crew for this event consisted of myself, Sam Dienst, his girlfriend Cassie and Brandon Smith. We departed Norman early in the morning at 8 AM in order to get to Amarillo around noon. The other half of our chase crew - Andrew Starnes, Mike Kahle, DJ Gagne and Doug Lang - left later due to time conflicts, around 1 PM. We made great time to Amarillo and got into town around noon. The entire way there we were driving in miserable conditions. Low stratus and fog that reduced visibilities under a mile and obscured the tops of antennas. In addition it was drizzling. This had us doubting how good the heating would be for later in the day. However as we neared Amarillo, the cloud deck began to break up and this encouraged us. By the time we stopped at a hotel in Amarillo, the stratus had broken up into small cumulus clouds.
Good news for heating, and instability later in the day. Best Western parking lot in Amarillo.We looked at data for about 15 minutes when suddenly the internet stopped working. It may have been just a glitch but I suspect that an ornery old lady who was working the front desk cut us off. Who knows, but in any event we decided to head south to Canyon, Texas which is about a 20 minute drive from Amarillo. We arrived at about 1:20 pm and sat in another Best Western parking lot right adjacent to a Holiday Inn Express on the main east-west drag through the town. We sat there for a little over an hour when suddenly the DOW (doppler-on-wheels) crew rolled up and parked on the street between the two hotels. This gave us a momentary reprieve in our boredom waiting for the cap to break. Shortly thereafter there was a chaser convergence on the area and we went over to talk to some of the guys we knew.
The DOW crew with the Tornado Intercept Vehicle to the left and one of the trucks with all the observation equipment strapped on the back.
(Left to Right) Sam, Brandon and I pictured in front of the Tornado Intercept Vehicle. Yes, they try to drive this through tornadoes.After we were done with that we went back to the Best Western to get internet. With the other half of our chase crew en-route, we finally got the Tornado Watch for the area at about 3:51 pm on our computer. It was a PDS ("particularly dangerous situation") Tornado Watch indicating the potential for strong tornadoes. This got us encouraged and excited to say the least. Looking off to the west, we began to see cumulus towers after 4 pm. The DOW crew rolled out around 5 pm, and we decided to make a break for it at 5:30 pm into Eastern Deaf Smith County (one county to the west) when a few echoes finally appeared on Sam's WxWorx radar that we could track. They quickly intensified and we went for the one that was headed off to the northwest side of Hereford, Texas.
The supercell viewed from a distance as we just turn onto US Highway 60 to the west.
Getting closer to the supercell, photo from Brandon Smith.
Zoomed shot of the sun poking out behind the anvil. Photo from Brandon Smith.We broke off north on Highway 809 just into Eastern Deaf Smith County to get a better look at the storm, and then west on Highway 1062 towards the storm to get a little closer. We wound up stopping at the intersection of Highway 1062 and Highway 385 or 11 miles due north of Hereford, Texas for those of you keeping track at home. We tried to evaluate the situation. On one hand, the storm we were on had a tightening reflectivity gradient on the southeast edge and we could see some scud ascending into the cloud base. It had promise. On the other hand, there was a storm exploding to the south of Hereford that had unobstructed inflow from the south and was "living in a juicy environment" as they like to say.
The view from radar. The storm to the south looked increasingly impressive.
Difficult to see low scud clouds and the sun breaking through the back edge of the anvil.
We could see the crisp anvil of the supercell to the south.
The sun on the edge of the anvil...beautiful!We sat debating this for awhile, but finally Sam made a quick decision - and I agreed - to head for the southern storm. Not wanting to core punch a storm that was getting golf ball size hail reports, we decided to head around the forward flank downdraft to the east, jog south for a way, and then cut back to the west and intercept where the circulation would be. Also, the other half of our chase team finally caught up and were a bit east on Highway 1062. So we decided to pick them up on our intercept path. As we headed east on Highway 1062, we encountered hail being lofted out of the core of the storm and that was falling out of the anvil of the storm! The largest hailstones were quarter to half dollar sized or about 1.00 to 1.25" in diameter. I shot video of us going through the hail.
Mammatus on the underside of the anvil after the hail stopped.We cut to the south on Highway 809 again, basically retracing our route in, and then we took Highway 60 further to the west-southwest. As we did, the storm's appearance on radar got much better and in a few minutes the rain-free base of the supercell came into view. We saw the wall cloud with striations from the wall cloud up the base of the storm clouds.
The wall cloud forming as we head west-southwest on Highway 60.As we got much closer to the circulation we decided to cut north on County Highway CC and stopped a little north of Highway 60 at the intersection of CC and County Road 14. This put our exact location as 11.4 miles northwest of Hereford, Texas. As we sat and watched the wall cloud we noticed a funnel forming at about 6:28 pm. It formed quickly! Timestamps from the photos indicated it only took about a minute to become completely formed when it nearly touched the ground. Below is a series of pictures of what we saw.
The funnel - looking into a field past a crop irrigation system.
An enhanced photo for contrast that shows the two vorticies at the base of the funnel that were rotating around each other and what appears to be a tube extending down a bit.
The funnel beginning to lift again.
Continuing to lift, still very impressive.Of course since we had no conclusive evidence that a tornado touched the debate raged - had we seen a tornado? Well, there were other chasers in the area, some of them said they were going to count this as a tornado and others said no, just a very low funnel. What do I think? Personally I think there was a brief spinup back in a field that nobody but the farmer will ever know about. It was probably only a few seconds but circulation on the ground is in fact a tornado. The rate at which the funnel descended and the enhanced image showing the two vorticies suggests to me that it briefly came in contact with the surface. We will probably never know for sure! Officially (NWS Storm Data) it was not a tornado. But in my honest opinion, we saw a brief spinup.
The other thing to note about all this was there was impressive rotation in the wall cloud, and the inflow winds to the storm were exceptionally strong. We were unable to stand still at points because the wind was blowing so hard. I thought that was one of the more impressive things about the storm. In response to the wind gusts you could see tumbleweed and dust blowing across streets and fields.
Zig-zagging across country roads we attempted to follow the storm as it headed northeast in the hopes of seeing another, more impressive tornado spinup. We stopped at one point and I took another video showing the impressive structure of the storm and the mesocyclone.
Little, small vorticies rotating under the mesocyclone in the center of the picture.The storm eventually lost its organization although it still had small funnels that occasionally retreated back and forth, in and out of the cloud base. We followed it basically all the way to Interstate-40, close to 20 miles from where we initially saw the tornado spinup. It was a difficult chase too as earlier rainfall had made the dirt roads muddy and we were slipping and sliding all over the place. We thought we saw another tornado spinup behind us as we were driving but the visibility was low enough to make it inconclusive as we were in hail and rain with a few hailstones perhaps up to ping pong ball or golf ball size (1.50 to 1.75" in diameter).
We lost WxWorx radar for a bit due to a data feed problem at the National Weather Service. We thought it was something wrong with Sam's system so as we approached the west side of Amarillo, we stopped at a Barnes and Noble for a bathroom stop and to try and raise an internet connection to re-evaluate the situation. Of course after about 5 minutes the data was back and we realized there was a nice storm headed straight for Tulia, Texas in Swisher County. We kicked ourselves for stopping as we would need to book it down Interstate-27 to try and catch this massive supercell.
The supercell nearly over Tulia, Texas at 7:52 pm CDT.We were nearly to the storm, as you can see above, when it spawned a tornado. We knew it had a Tornado Warning on it, but we didn't know of the actual tornado until Brandon heard reports of people trapped in homes on his scanner. At that point we all turned to each other and exchanged concerned glances. We rolled into Tulia, exiting onto Highway 87 south, and we saw the damage and immediately knew it had been a strong tornado. One of those grain trailers was tossed into the middle of the Highway. Trees had all the branches ripped off and metal was twisted around a few. A truck had its back window frame twisted and all the windows were busted out. A brick building had two walls collapse. We knew it would be impossible to keep up with the storm as it was headed into Caprock Canyon State Park where the road network is, to say the least, horrible. So we got out momentarily and looked at the damage.
Hard to see the damage. You can see the metal twisted around the tree to the left of the building in the far right of the picture.
Emergency vehicles swarmed the scene.Not wanting to get in the way of search and rescue efforts, and not having lights on our cars like some other storm chasers, we headed back up Highway 87 and then south on I-27 to the Highway 86 exit just southwest of town to fuel up and perhaps get some nighttime shots of an approaching supercell and a squall line right behind that. A lot of things happened while we were there. First, we warned a trucker not to drive south to Plainview lest he be blown off the road by the approaching squall line. Second, we did see some amazing lightning. Then, they issued a tornado warning for the northern half of Swisher County for the supercell out ahead of the line. Alarmed, we pointed our car north to try and get a view of the cloud base. No sooner had a cloud-to-ground lightning strike illuminated the cloud base revealing a nice cone funnel than we heard from the other half of our chase group that had got seperated. They were apparently headed right past us on the Interstate and unaware of the Tornado Warning and the funnel. We told them to pull over to the side of the road and wait, which they did. We didn't see a tornado spinup though.
We then drove down Highway 86 to the west for a couple miles and parked in a prison parking lot, letting the squall line overtake us. Vivid cg lightning illuminated the underside of the shelf cloud and we could see the turbulent cloud formations there. Then it got windy with some small hail around 1/2" in diameter. The car rocked a bit but the winds probably weren't quite severe levels.
For the final act, after stopping to eat in Canyon again, we drove back through the squall line on the way back just before reaching the Oklahoma border. We encountered constant lightning, downpours reducing the visibility to nearly zero and wind gusts of 60 to 65 mph. The combination of wind and rain caused a semi to jack-knife which we passed with little congestion, probably meaning it occurred just ahead of us on the interstate.
All in all a successful chase. An unofficial tornado. Another nice supercell. The damage in Tulia. A funnel cloud at night. And let's not forget a nice squall line...twice. I'll post the Tulia, Texas damage survey results in a future post.
About me
- I'm Alex Lamers
- From Wisconsin/Oklahoma, United States
- My profile
Last posts
- REVISED Chase Outlook for Sunday March 30, 2008
- Chase Outlook for Sunday March 30, 2008
- Chase Account - March 2, 2008
- Chase is a GO for Sunday March 2, 2008
- REVISED Chase Outlook for Sunday March 2, 2008
- Chase Outlook for Sunday March 2, 2008
- NEWS: Damage in Tulia, Texas rated as EF-2
- LATE Chase Account - April 21, 2007
- LATE Chase Account - April 23, 2007
- Chase Outlook for Saturday April 21, 2007
Archives
Links
- The Storm Source
- Wikipedia Microbursts
(They have everything) - StormTrack Forums and more!
- Mesoscale Analysis Archive
- SPC's Event Archive
- Plymouth State Archives
- Huge Reanalysis Archive
Archived Data
ATOM 0.3