Happy Thanksgiving and Something Unexpected...

Happy Thanksgiving everyone! A potent Arctic cold front was moving through our area this morning. Around 4am isolated thunderstorms began to pop up on radar in Archer, Baylor, Clay, Jack, Montague, Throckmorton, and Wichita counties. These storms were forming just ahead of the cold front. One of these storms formed right over Wichita Falls and dropped pea-size hail, moderate rain, and frequent wind gusts around 40mph.

 HRRR Surface temperature analysis. I overlayed the approximate location of the front. You can see temperatures south of the from are in the 70's north and along the front it drops significantly (upper 40's).

Base reflectivity from KFDR. This isolated storm formed right over us.

I was surprised to see hail with the storm. The VIL was only around 12 kg/m2.

Echo Tops

HRRR surface CAPE. There is very little instability over our area at this time, but the strong forcing from the front/trough was enough to generate lift and spawn off a few storms.

Snowing in the Panhandle???...

A potent cold front made its way through western TX and OK yesterday. Surprisingly areas of the TX panhandle have reported snow accumulation. Here's the preliminary storm reports from NWS in Amarillo, TX.

000
NWUS54 KAMA 122032
LSRAMA
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE AMARILLO TX
232 PM CST FRI NOV 12 2010
..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..
0931 PM     FLASH FLOOD      1 W AMARILLO            35.20N 101.83W
11/11/2010                   POTTER             TX   BROADCAST MEDIA
            INTERSTATE 27 BEING CLOSED FROM GEORGIA TO HILLSIDE DUE
            TO NUMEROUS STRANDED CARS IN HIGH WATER. NUMEROUS HIGH
            WATER RESCUES ACROSS CENTRAL AND SOUTHERN AMARILLO.
0700 AM     SNOW             5 NNE ADRIAN            35.35N 102.65W
11/12/2010  M4.5 INCH        OLDHAM             TX   CO-OP OBSERVER
0700 AM     SNOW             3 NW VEGA               35.28N 102.46W
11/12/2010  M5.0 INCH        OLDHAM             TX   CO-OP OBSERVER
0710 AM     SNOW             HEREFORD                34.82N 102.40W
11/12/2010  M2.0 INCH        DEAF SMITH         TX   CO-OP OBSERVER
0800 AM     SNOW             6 SW AMARILLO           35.14N 101.91W
11/12/2010  M3.0 INCH        RANDALL            TX   NWS EMPLOYEE
0800 AM     SNOW             1 WSW BUSHLAND          35.19N 102.08W
11/12/2010  M5.5 INCH        POTTER             TX   CO-OP OBSERVER
0800 AM     SNOW             1 NE GRUVER             36.26N 101.41W
11/12/2010  M4.0 INCH        HANSFORD           TX   CO-OP OBSERVER
0825 AM     SNOW             7 SW AMARILLO           35.14N 101.90W
11/12/2010  M3.0 INCH        RANDALL            TX   BROADCAST MEDIA
            LOCAL BROADCAST METEOROLOGIST MEASURED 3 INCHES OF SNOW
            IN THE SLEEPY HOLLOW AREA.
0830 AM     SNOW             2 WSW BORGER            35.65N 101.43W
11/12/2010  M2.5 INCH        HUTCHINSON         TX   CO-OP OBSERVER
0905 AM     SNOW             6 WNW AMARILLO          35.23N 101.91W
11/12/2010  M4.5 INCH        POTTER             TX   NWS EMPLOYEE
0905 AM     SNOW             5 W AMARILLO            35.21N 101.91W
11/12/2010  M5.0 INCH        POTTER             TX   NWS EMPLOYEE
0928 AM     SNOW             1 NW PAMPA              35.55N 100.97W
11/12/2010  M2.0 INCH        GRAY               TX   CO-OP OBSERVER
0954 AM     SNOW             7 ENE AMARILLO          35.24N 101.70W
11/12/2010  M3.0 INCH        POTTER             TX   PUBLIC
            REPORTED 3 INCHES OF SNOW FROM NE 14TH AVENUE IN
            AMARILLO.
1000 AM     SNOW             DUMAS                   35.86N 101.97W
11/12/2010  E2.0 INCH        MOORE              TX   LAW ENFORCEMENT
1015 AM     SNOW             6 S WILDORADO           35.13N 102.24W
11/12/2010  M5.0 INCH        DEAF SMITH         TX   PUBLIC
1100 AM     SNOW             6 WSW AMARILLO          35.17N 101.92W
11/12/2010  M3.0 INCH        RANDALL            TX   NWS EMPLOYEE
1100 AM     SNOW             SPEARMAN                36.20N 101.19W
11/12/2010  E4.5 INCH        HANSFORD           TX   FIRE DEPT/RESCUE
1240 PM     SNOW             PANHANDLE               35.35N 101.38W
11/12/2010  M4.0 INCH        CARSON             TX   PUBLIC

Areas around Amarillo are expected to have lows in the mid to upper 20's tonight through Thursday.

Thursday Forecast Update...

Looking over the latest NAM/GFS runs I am not convinced for Thursday. Also I am working so I will not be able to participate. The general lack of instability is the biggest problem with this setup.

Though the newest NAM is showing a little hope with an isolated pocket of MLCAPE around 400-500 J/kg. Everything else looks good for this. Decent moisture return (55-60 DP's), good midlevel support (50kts), and nice curving with the hodographs.

Judging by the model runs if I was able to chase my target would probably be on the TX/OK border just north of I-40. I'll just say Sayre, OK. Maybe we'll get the chance for some lightning photography at least.

Wild Weather this Week?...

It looks as though we might have an interesting weather pattern approaching us this week. From freezing temperatures tomorrow night, extreme wildfire hazards on Sat/Sun, and a potential for severe thunderstorms, this next week will be something to keep an eye on.

Read on to learn more about the forecasts.

-Ben

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...THROUGH TONIGHT...

THUNDERSTORM OUTLOOK...
NO THUNDERSTORMS ARE EXPECTED THROUGH TONIGHT.

DISCUSSION...
THE AIRMASS OVER THE AREA WILL REMAIN TOO DRY AND STABLE FOR
THUNDERSTORM DEVELOPMENT.


OTHER HAZARDOUS WEATHER...
FREEZING TEMPERATURES WILL BE POSSIBLE ACROSS PORTIONS OF OKLAHOMA
AND NORTH TEXAS LATE TONIGHT AND EARLY SATURDAY MORNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

THUNDERSTORM OUTLOOK...
THUNDERSTORM CHANCES ARE IN THE FORECAST TUESDAY NIGHT THROUGH
THURSDAY AS A COUPLE OF STORM SYSTEMS MOVE FROM THE WESTERN UNITED
STATES INTO THE PLAINS.

OTHER HAZARDOUS WEATHER...
WARM... DRY AND WINDY CONDITIONS ARE EXPECTED SATURDAY THROUGH
MONDAY CREATING VERY HIGH TO EXTREME FIRE WEATHER CONDITIONS EACH
AFTERNOON... ESPECIALLY IN WESTERN OKLAHOMA AND WESTERN NORTH TEXAS
WHERE THE WIND SPEEDS WILL BE THE HIGHEST. A FIRE WEATHER WATCH IS
IN EFFECT FOR BOTH SATURDAY AND SUNDAY AFTERNOONS IN THE WEST.

 First off we have a Freeze warning in effect until Saturday morning. Low temperatures are expected to reach near to below freezing levels.

 Also a fire weather watch has been issued for Western OK as well as western TX.

Wildfire potential graph for NWS Norman county warning area. Note how Sunday has an "Extreme" wildlife potential. The sustained southerly winds at  20-25mph and RH in the 30-40% range are ideal situations for wildfires.



 Lastly, we have a chance for thunderstorms from Thursday into Friday.



This unseasonal storm system is forecast to make its way into central KS by 00z Friday. A strong midlevel jet (55kts) maxing out over western OK and western north TX and the neutral tilt of the trough could result in organization the the thunderstorm's updrafts.

 Another interesting feature are the H5 (500mb) temps. Very cold air aloft with areas reaching almost -25 degrees Celsius! Maybe a cold-core setup like 03/08/10?

 Moisture return isn't too bad with dewpoints in the upper 50's to low 60's.

 This is the only problem I have with this is the general lack of instability. Hopefully the strong forcing of the trough/dryline will generate enough lift for thunderstorms.

 If that does happen then the storms will need to beat out a pretty stout cap.



It is still a while off and the models can change completely, but right now it looks like we have a decent chance for thunderstorms. Now I just need to know my next weeks work schedule.

10/22 Chase Report...

SPC Day 1 Outlook. Slight risk over TX, OK, and KS.

There is just something about the last chase of the year. It motivates us to get out there and witness what mother nature can do. October 22 is probably our last chase for this year and it was well worth it. A strong midlevel jet was maxing out right over western north Texas during the peak heating hours. Strong curving in hodographs showed rotation in the lowest 0-6km of the atmosphere. Lingering precipitation/cloud cover limited sunshine and decreased instability. There were a few breaks in the clouds and thunderstorms fired up in western north Texas. I coordinated with James Langford and Zack Biggs to meet up in Wichita Falls and we chased together. It always nice when its  a local "backyard" chase. It was an excellent chase, as we intercepted a few supercells. Check out the full report down below.

Thanks for the support.

-Ben

SPC Tornado graphic for Day 1. We had awesome shear with these storms, but due to the lack of instability and cold air constantly undercutting the updrafts we did not see any tornadoes.

SPC Hail graphic for Day 1.

SPC Wind graphic for Day 1.

Thunderstorms with explosive development over Knox and Haskell counties. Note how I am back in Wichita Falls. I was waiting for James and Zack to arrive.

Tornado watch issued for target area.

I meet up with James and Zack and we get out of Wichita Falls on Highway US 277 S and turn on Highway 25 to head north towards Electra, TX. Both storms have a hook appearance to them.

So our northern cell begins to wither away and the southern cell explodes (this is what happens during the entire chase) our next goal is to go back out of Mankins, TX, hook back up on 277, then go north on 183. Luckily the storms were moving at reasonable speeds and we blast our way on 183 to intercept.

Radar image as we turn on 183. The storm is intensifying and is maintaining the hook appearance.

On our way north on 183. You can see the mesocyclone/wall cloud as well as a beaver tail going into the storm.

Still driving on 183 the storm starts to look better and better. Its around this time that we actually witness a few possible funnels (one of which I captured on video).

We find a nice place to pull over and watch as the storm puts on a show for us.

This storm had some great structure on it.

So our main storm starts to dies out and a new cell develops just to our west. The lowering on this storm, while impressive looking, was not rotating. The cell to our southwest starts to become the more dominant storm. We leave 183 and head back on 277 to get in position for the storm.

We are in an excellent spot for some photography. No power lines or nothing.

More great structure on this storm.

This is a capture of the storms anvil (left portion of the photo). You can see the edges a very sharp. This updraft was moving some serious air!

This storm's wall cloud was rotating albeit fairly slow, it did have some incredible rising motion in it, however.

Radar image of our location in position to the storm.

The storms updraft base passes just to our northeast and shortly after the RFD.

The storm is occluding and we need to get to the northeast.

What? The TIV II out on a chase in October? We were actually quite surprised that there were some many chasers out on this storm. We expected everyone to target the triple point in western KS.

We had back east on 277 and watch as this storm occludes itself. But to our surprise another cell forms the south and actually doesn't look bad--visually.

New supercell to our southwest.

The storm is starting to approach us...

Incredible sunset with some awesome colors!

What is left of our northern cell is bathed in the pinkish light from the sunset.

It was just a great chase. We saw a few supercells, met some other chasers, and got some great photos. I would call it a success. To see more from this chase watch the video down below.

Rain, Rain Go Away: A Forecast Update...

I was just looking over the 00z NAM to see how the models are playing Friday out. So far we've got excellent vertical/directional shear and good moisture return. However, something that has me worried about this setup (and was mentioned in my earlier post) is the lingering precipitation over the target area. So storms are going to push through TX/OK late Thurs night into Fri morning (most likely forming an MCS). But as this storm system approaches lift will generate showers/thunderstorms throughout the morning into afternoon. This precipitation can stabilize the environment which can limit instability.

 00z WRF/NAM 6hr Precipitation graphic for 18z (1p.m.) Friday.

ML CAPE for 18z Friday. The precipitation is stabilizing the target area, thus low values of instability are expected.

Now does this mean I will be sitting Friday out? Heck no! This just means that there are some obstacles to overcome before we see any severe weather. If there can be a break in the cloud cover where some areas can get some good ol' sunshine, maybe we can see ML CAPE values closer to 1500 J/kg. Then we would be in business. This is too good of a setup and too close not to chase. Not to mention I have the day off! So everyone keep your fingers crossed and think "sunny skies'!

Be sure to subscribe/follow so you can get the latest updates.

-Ben

Monday's Forecast Falls Through, Hopes for this Weekend...

SPC Outlook for Monday. No severe thunderstorms are forecast.



So it looks like the forecast for Monday fell through. The NAM is showing the storm system hanging out farther west.  

 The lack of upper level winds will limit the severe potential for Monday. You can see the storm system out in the west coast of CA.

Another turn off is the general lack of instability and a stout cap.

 Probably the only thing that will spawn off thunderstorms is the cold front that is forecast to move through the area. I am looking forward to the fall temperatures that it is supposed to bring, however.

There are some higher hopes for Friday, however. The GFS is showing a low pressure trough digging into the TX panhandle/western OK around 18z. Upper level support is better with this system and the combination of A sharpening dryline, moderate instability, and a mild cap are a good sign. It is still a little far off, but I have confidence in this system.

 500mb chart for 18z Friday.

 Surface temps and wind for 7p.m. Friday.



 Nice dryline setting up right over the TX/OK border.

CAPE chart for Friday (18z). There is also a relatively weak cap in place over the area.

I hope these next few model runs will slow down the progress of this system. If it moves too far east, then we could see storms fire up east of I-35. I usually try to stay away from that area, the road networks aren't that great and there are more trees and hills there as well. The good news is that I have Friday off, but I was hoping for more of a "local" chase. Will keep y'all updated.

Thanks.

-Ben