Yesterday's Results / Chase Today

We intercepted a very nice supercell yesterday south of Cordell, OK. Incredible structure and Baseball sized hail were observed! We witnessed some damage to the town of Rocky and I added a few new dents as well. I'll have a full report with pictures up on website later this (busy) week.

Today the potential exist for more severe storms and possibly tornadoes across eastern OK and northeast TX. Haven't dug into forecasting too much but I'll likely head east and south of Norman later on today. Expectations aren't high because of the dense forest/mountains/crappy road network but I'll give it a shot.

Getting Ready for Today

Will likely meet up with a few people in a couple of hours and head west around noon. Plan is to stop in Clinton or Weatherford and sit and wait for a while.

Chase Day - Sunday March 30th

Looks like a decent setup tomorrow but still some questions. In the upper levels, 500mb SW flow around 40kts will spread over much of the southern plains with main trough/vorticity maxima centered further north. 250mb jet streak will likely be entering west TX and TX panhandle late Sunday afternoon. At the surface, warm moist air will begin its return from the gulf today and continue overnight and into tomorrow morning. Further north, sfc cold front slides south throughout the day eventually stalling across northern OK into southern KS and possibly drifting back to the north a little Sunday night. A dryline will mix east across the TX panhandle and likely intersect the stalled front in the far eastern TX panhandle where strengthening sfc low seems to setup in the afternoon/evening. 850mb winds seem to remain out of the south-southwest throughout much of the day on Sunday contributing to warm layer overspreading much of the warm sector resulting in stout cap and delayed initiation. Without the upper support from 500mb wave, sfc features will have to overcome the warm layer to provide initiation in the late afternoon. This remains the biggest question with this setup. With this being said, models seem to back 850mb winds to a southerly direction and really kick-in as evening approaches and LLJ cranks to around +40kts. QPF fields are very reluctant to fire any convection due to capping as well. However, I'll be out chasing this event. My hopes are that one or two storms fire along stationary front near sfc low/dry line intersection during the evening before it gets dark. If this could happen, storms would likely have a nice environment to thrive in. Dewpoints into the mid 60's and CAPE values ~2000j/kg will provide nice instability to any storm that goes. 0-6km shear will be ample so any storms along or south of front will likely be supercells. Along the previously mentioned stationary front, sfc winds may have an easterly component and when coupled with strong LLJ, there may be favorable low-level winds to sustain mesocyclones and tornadoes into the evening hours. If cap holds strong then the majority of this chase may occur into Sunday evening. Good Luck to those heading out. Stay tuned for updates...

Pics fron 27th

A drove east a bit from Norman to get some structure shots, here is one of them:

Mid-week Update

Not much to get excited about as a slow end of March pattern continues. With that being said, I'm still watching Sunday 30th as a possible chase day. 12Z NAM shows great moisture/instability for this time of year but wind profiles aren't exactly what I'd like to see for tornadoes. Being on a Sunday though, I will watch closely and probably head somewhere in central Oklahoma. More on to come on Saturday with forecast and target....

Upcoming Storm Chances

Looks like this Wed. and Thurs. will both likely not be anything major or chase worthy. I'm keeping an eye on this weekend (Sunday 30th) heading into next week as there are hints of mid-upper level southwest flow across the plains and possibility of shortwaves coming through. Will update on Wednesday as to what the models are trending towards.

Back in Town

I'm finally back to Norman after a few days in Houston. Pattern has been and still is relatively slow. Looks like a possible setup on Thursday March 27th but just glancing at some data looks like capping may be issue. Not sure of anything after that. I'll keep an eye on stuff an update when necessary.

Report: March 17, 2008

Today we targeted Wichita Falls to Abilene, TX. Day started early with convection around Abilene about 1pm. On storm quickly went tornado warned while we were on our way there. Got there 5 minutes after a small reported tornado and saw a leftover wall cloud that was rotating and beginning to tighten up. It eventually crapped out and we st back for a while til around 530pm when another round fired off this time a bit south of Abilene. We got on a severe T-storm south of Abilen near Taylor/Runnels co. line This storm presented nice structure but not much of a tornado threat the storm ended up splitting and we followed it north. Encountered some nice hail with the right split then later the left split became tornado warned and tracked right toward downtown Abilene. We followed it through the city with no confirmed touchdowns. We stayed on this storm until just after dark shooting some nice CG lightning then returned back north making it back to Norman right at midnight.

Storm 1: Wall cloud near I-20 just west of Abilene.

Storm 2: Hail Producer near Taylor /Runnels County line.

Chase Today

Leaving for the National Weather Service building in a while to look over data and meet some people there. Gonna be hard in determining what will exactly happen today. Still have a general target from Abilene-Wichita Falls-Lawton. Maybe more later...

Chase Monday 17th

Looks like a chase is on for tomorrow but the details are still sketchy. As of now, there are two options I am thinking about:

Option 1: Venturing into west central TX, maybe Abilene, and starting from there.
Option 2: Staying in central/south-central Oklahoma and starting around Lawton area.

Depending on what the remaining model runs show and how things unfold early tomorrow morning, I will decide from there where to go.

Report: March 14, 2008

Me and Cassie ventured out to Woodward, OK early and watched things unfold. It became clear by 2pm or so that dewpoints were really struggling and wouldn't make the advertised return. A storm went up right on top of us about 4:30pm and we followed it north and then east across Woods and Alfalfa counties. It was extremely high based (given upper 30's -low 40's Td's) but was actually more impressive than I thought it would be given that environment. We met up with Brandon Lawson and Brett Roberts while we were out there and shot a few pics:

Heading out the door

Just about to leave. I always leave too damn early. Heading for Woodward to watch data for a long time. Probaly will work north and/or east from there.

Chase Today

Currently I'm still in Norman but plan on heading out to the OK/KS border (Harper/Barber/Woods/Alfalfa county) at about 11am or so. Biggest problem today will be low-level moisture. Deepening sfc low over eastern Colorado will move southeastward and eventually east later today. Hopefully winds will back to an ese direction and pull some decent moisture into the region. Good directional and speed shear will likely exist but moisture is still key. Right now, latest guidance shows 50F Td may be hard to achieve but I will monitor this closely. Still, both high-resolution WRF & NSSL models show cell firing in the above mentioned area around 4pm. I don't expect much in the way of tornado potential but a sculpted supercell would be nice. Will likely follow the storms east after sunset as long as road networks remain good. Will update later, either before leaving or on the road. Good luck to others heading out!

Time Lapse from Today

First real attempt at time lapse piece....

Thoughts for Friday 14th

Still planning on heading somewhere tomorrow midday. Right now, I am interested in the area from Stillwater to Ponca City as a starting point. Pretty complicated situation but my hopes are that decent moisture will advect back into parts of central/north central Oklahoma by midday due to a deepening surface low taking shape across western OK/TX panhandle. Left exit region of strong upper jet will be crossing the state in the late afternoon and this coupled with hopefully enough convergence along sfc low/frontal intersection may be enough to provide thunderstorm initiation in north central or northeast OK by late afternoon. 12Z NAM simulated reflectivity shows possibility of supercells forming at or near dark in that region then moving east into a favorable environment. Not expecting much at all but I'll be out there if anything exciting does happen.

Upcoming Storm Chases

Friday 14th
Don't know how this event will unfold but I'll be out there regardless. Right now, believing what the NAM is showing, I'll likely be hugging the sfc low across north-central OK into northeast Oklahoma. If the cap is an issue, this area near sfc low and frontal boundary intersection may provide the sufficient lift need to overcome the warm layer when coupled with a strong jet max and decent boundary layer moisture. Still going with current thinking of an area from Ponca City-Stillwater to Bartlesville-Tulsa as a starting point.

Monday 17th
Medium-long range models still with some differences but I am fairly confident I'll be on the plains Monday. Strong western US trough will begin to move east effecting the southern and central plains. Moisture may be a problem but looks like at least 1 full day of good flow off the gulf. No definite target area as of now.

Chase Oppurtunities Thurs-13th/Fri-14th

-Basing both of these forecasts off 12Z NAM/WRF from March 11, 2008-

-Both are likely to change!-

Thursday 13th
Shortwave trough crossing the central/southern plains Thursday afternoon could set off a few storms from Kansas to Texas. Area of interest would likely be in Ardmore, OK / Gainesville, TX area. At the surface, NAM forecasts ample moisture return into the area (50~55Td) with a sfc low developing in west TX ending up near Childress-Abilene-Wichita Falls region by late afternoon. Sfc winds may back to a southeasterly direction in response to deepening sfc low (<1000mb) while 850mb winds are decent at ~25kts from ssw. 500mb flow with associated trough will likely be in 40kt range. This should result in ample deep-layer shear (~45kts) over the area of interest. With decent moisture in place, sfc temperatures from 70-75F, and mid-level cooling with mid/upper level trough, CAPE values of 750-1200j/kg may be achieved over much of se OK and eastern TX. Currently, NAM does not break out any precip in the region until near dark on Thursday evening because of capping/subsidence issues but synoptic features could come together to allow storms to fire before dark if the trend in the models hold. Will update tomorrow...

Friday 14th
Strong, persistent westerly flow at mid/upper levels will continue to send disturbances into the central and southern plains extending into the Mississippi valley. At the sfc, another low will likely form somewhere in western OK. Much of the evolution for this day depends on how the Thursday event turns out. If moisture is not pushed to far south/east, deepening sfc low in OK may pull decent moisture back into regions of central/north-central/northeast OK with almost easterly sfc winds along KS/OK border midday. Current area of interest would be in the Ponca City-Bartlesville region near a possible occlusion point from sfc low, dryline, and warm front. (Main sever threat would likely be centered in a se OK/Arkansas/n Louisiana area but terrain is horrible there and this forecast is aimed more toward chaseable areas.) Wherever the warm/occluded frontal boundaries end up will likely be an area of interest. Flow at 500mb and up is very strong and directional wind shear profiles will likely be conducive to rotating storms. Will update tomorrow...

Testing...

Current Location

Long Range

Keeping an eye on a possibly active pattern from March 15th-18th. Below is 12z runs of GFS and ECMWF showing 500mb flow for Sunday morning the 16th.

Classic Tornado Videos

Andover, KS 1991

May 3, 1999 Fort Cobb, OK


Laverne, OK


Pampa, TX

Tornado Watch for Texas Coastal Plain

Thunderstorm are rapidly developing generally south of I-10 to the coastline ahead of an approaching upper trough swinging in from the west. At the surface a cold front extends across central TX moving southward toward the region. CAPE values from 500-1000 j/kg and deep layer shear generally around 50kts will allow some thunderstorms to develop and maintain supercell characteristics. +200 m2s2 0-1km SRH values and 0-1km vertical shear values of ~20kts may pose a tornado threat with any defined supercell. Currently, thereare 2 T-warnings: one in Goliad and one in Jim Wells Co, both of which are showing rotation in the low levels on radar.

Tornado Warnings above and 4 cells showing supercell characteristics on radar below...

NAM Snow on Thursday

The 12z run of the NAM from this morning shows much more accumalting snow from the system set to move across the area on Thursday. I hate to be talking snow right now but someone may see some significant totals. It will be interseting to see how this unfolds.

Latest total accumulations from this model are shown below...

March 2, 2008 Pictures

Here are a few video grabs from yesterday's chase in sw OK. Probaly won't write a full length report on website for this chase though.

I might get a video of the tornado warned storm we were on from Sean Waugh. He had his camera on the tripod for the duration and I might try to put together a timelapse piece of it to show the true rotation!

Also, Alex Lamers was with my group and he has a more detailed report here...

http://themicroburst.blogspot.com/

Almost..

Almost bagged a tornado today as a tornado warned supercell we where on looked like it would produce for a while. No luck but still a good chase! Have pics/report tomorrow hopefully. Right now I'm preparing for the snow...

About to Head Out

Things are looking fairly decent and I'll be heading out towards western/southwestern Oklahoma around 11am. Much of the warm sector is already filled with a low stratus deck already but that was expected. According to latest visible satellite, there are some areas near and south of Childress, TX with clear skies this morning. This may be a good sign that all the areas won't be under heavy cloud cover all day and that there will be pockets of nice heating along the dryline as it mixes east. I may update mid-day when I find a nice wi-fi spot.

Storm Chase Sunday March 2nd

I'll definitely be chasing tomorrow likely somewhere in western or north Texas. I'm not going to make a detailed forecast because the models are having quite a bit of difficulty in timing and placement of a lead shortwave that will eject out across the target area Sunday afternoon/evening. But I'm gonna look at things real closely in the morning and watch how it unfolds throughout the day and decide on a more precise target then. Right now I'm planning on leaving from Norman around 8-9am and heading down to Wichita Falls area and possibly then to Abilene region. I'll post again in the morning.