Chase 2011 - Day 23 Discussion

[icbinb]

New MD

MESOSCALE DISCUSSION 0861

NWS STORM PREDICTION CENTER NORMAN OK

0347 PM CDT SUN MAY 22 2011

AREAS AFFECTED...N-CNTRL TX...S-CNTRL OK

CONCERNING...TORNADO WATCH 326...

VALID 222047Z - 222145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 326 CONTINUES.

INITIAL TSTM DEVELOPMENT HAS RECENTLY OCCURRED ACROSS JACK COUNTY TX

WITH NUMEROUS CB/TCU DEEPENING GENERALLY S OF THE RED RIVER THROUGH

W-CNTRL TX. FARTHER N IN S-CNTRL OK...CU FIELD IS NOT QUITE AS

DEVELOPED. HOWEVER...SURFACE THERMAL AXIS CHARACTERIZED BY

TEMPERATURES IN THE MIDDLE TO UPPER 90S IS OVERLAPPING THE DRYLINE

HERE...WITH SUBTLE BACKING OF SURFACE WINDS IN THE MOIST SECTOR

ENHANCING CONVERGENCE. AS SUCH...AT LEAST ISOLATED TSTM DEVELOPMENT

APPEARS PROBABLE BETWEEN 22-23Z.

AIR MASS WITHIN MUCH OF WW 326 REMAINS EXTREMELY UNSTABLE WITH

SURFACE DEW POINTS IN THE LOWER TO MIDDLE 70S CONTRIBUTING TO MLCAPE

OF 4500 TO 6000 J/KG PER OBJECTIVE ANALYSIS AND MODIFIED 18Z FWD

RAOB. MEANWHILE...VAD WIND PROFILE AT FWS CONTINUES TO SAMPLE AROUND

25 KT LOW-LEVEL FLOW WHICH HAS NOW BACKED FROM THE SW TO THE S/SW AT

1 KM AGL. LATEST RUC SUGGESTS LOW-LEVEL FLOW WILL STRENGTHEN

SLIGHTLY AFTER 00Z. WITH EFFECTIVE SHEAR ALREADY AROUND 40

KT...ENVIRONMENT WILL BE QUITE SUPPORTIVE OF SUPERCELLS PRODUCING

TORNADOES AND VERY LARGE HAIL.

[Arron]

Still sat just over the OK border waiting. See no reason to move yet considering the latest MD that's been issued

[Roger J Smith]

From radar and your live shots, looks as though a severe cell may be developing right overhead in about 20-30 mins.

http://radar.weather.gov/radar.php?rid=FWS&product=NCR&overlay=11101111&loop=yes

Note also more cells in the frontal zone further west, one particularly strong one around Abilene TX. A slight southward move might be required at some point.

[Arron]

On the move north to a cell that's exploded, always have the option to drop south again should we need to and catch storms coming towards us.

[dallas]

Great looking cloud

[Paul]

Team under the anvil currently - taken from the stream

[nsrobins]

Cells fired right down the line of the initial cu/DL field. Upper vectors WNW looking at the anvils. Plenty of directional shear in place.

[NL]

Team are going to get pummeled pretty soon.

Latest satellite image.

[Arron]

Taking some BIG hail off this cell!

[Roger J Smith]

For team, and other chasers in area, cell northeast Abilene looks to have best potential and would be near Decatur TX about 2300-2315z or one hour from now. That one could go tornadic from its current appearance.

[Arron]

Heading east from Ardmore to get out of the precip

[dallas]

21 tornado reports so far mainly from Minnestota

[Tom Lynch]

Hi team

hope you all are doing well and the weather gods are kind to you

I would like to thank all the people I met over the the last two tours . it was a pleasure chasing with you all.

May I wish the best for tours 3 & 4 and that they bag some good storms.

Condolences to Blackpool

Johnny H I love you baby but you is gonna have to get someone to make your coffee

Bruce

[Arron]

Cheers Tom, was a pleasure to chase with y0ou again this year! John said "go ..... ........" I mean he said he loves you

Head north again to try and get under the base of this cell

[dallas]

weather.gov

National Weather Service

Watches, Warnings & Advisories

Local weather forecast by "City, St" or zip code

Tornado Warning

--------------------------------------------------------------------------------

TORNADO WARNING

TXC237-497-222330-

/O.NEW.KFWD.TO.W.0082.110522T2242Z-110522T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE FORT WORTH TX

542 PM CDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* TORNADO WARNING FOR...

EAST CENTRAL JACK COUNTY IN NORTH CENTRAL TEXAS...

WESTERN WISE COUNTY IN NORTH CENTRAL TEXAS...

* UNTIL 630 PM CDT

* AT 542 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A

DEVELOPING TORNADO 6 MILES NORTH OF JACKSBORO...MOVING EAST AT 15

MPH.

* THE TORNADO WILL BE NEAR...

CHICO...LAKE BRIDGEPORT AND RUNAWAY BAY AROUND 630 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

[Paul]

TIV on the stream just then.

[Arron]

Yea just passed reed and his team in the Dominator, we've parked up watching some TCU because the cell we were on is just moving too quick.

[Arron]

Just passed Sean Casey and the TIV now too

Looking at a LP cell now that's going up fast. Anvil going out right over our head.

[dallas]

Play 18 holes with taht hail!

[icbinb]

New MD

MESOSCALE DISCUSSION 0869

NWS STORM PREDICTION CENTER NORMAN OK

0634 PM CDT SUN MAY 22 2011

AREAS AFFECTED...SRN/SERN OK...NRN TX

CONCERNING...TORNADO WATCH 326...

VALID 222334Z - 230030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 326 CONTINUES.

AXIS OF UPPER 60S DEWPOINTS RESIDES AHEAD OF A LARGE CLUSTER OF

STORMS...SOME SUPERCELLS...OVER NRN TX. THIS MOISTURE COMBINED WITH

STEEP MIDLEVEL LAPSE RATES IS CONTRIBUTING TOWARD MLCAPE VALUES FROM

3000-4000 J/KG...WHILE OBJECTIVE ANALYSIS INDICATES EFFECTIVE BULK

SHEAR VALUES FROM 40-50 KT. THIS ENVIRONMENT FAVORS SUPERCELLS

POSING A THREAT FOR LARGE/VERY LARGE HAIL. THOUGH AREA VWP/S AND RUC

SOUNDINGS INDICATE WEAKNESS IN THE LOW-LEVEL FLOW...A TORNADO THREAT

STILL EXISTS...PARTICULARLY FOR STRONGLY DEVIANT RIGHT MOVERS. AS

EVENING APPROACHES...LATEST HRRR INDICATES THAT STORMS OVER N TX MAY

EVOLVE UPSCALE INTO A QLCS...WHICH APPEARS REASONABLE GIVEN THE

CLOSE SPACING OF ONGOING ACTIVITY...AS WELL AS EXPECTED

INTENSIFICATION OF THE NOCTURNAL LLJ. OTHERWISE IN THE SHORT

TERM...ADDITIONAL COUNTIES MAY NEED TO BE ADDED S OF WW 326 AS RIGHT

MOVING STORM EXITS BROWN COUNTY TX AND MOVES ACROSS COMANCHE COUNTY

AND LOCATIONS FARTHER DOWNSTREAM.

FARTHER N OVER PORTIONS OF SRN OK...LEFT MOVING SUPERCELL WILL

CONTINUE TO POSE A THREAT FOR LARGE HAIL. OTHER STORMS MAY DEVELOP

OFF OF THE WWD RETREATING DRYLINE...THOUGH IT IS UNCERTAIN IF SVR

STORM POTENTIAL WILL BE MITIGATED BY OUTFLOW FROM THE LEFT MOVER AND

N TX ACTIVITY.

[Roger J Smith]

Current radar analysis, tornadic cell moving ENE to the north of Decatur TX at about 30 knots and backbuilding, while second supercell further north is racing towards team location (Ardmore OK) from a position about 40 miles WSW of them, estimated time of arrival 0020z (7:20 pm CDT) and this cell could go tornadic, as it interacts with the other cell to its south. I think there is F3 potential in this cell, and very fast forward motion, watch out for the RFD guys.

[weatherobsuk]

Not sure where in KS this cam is located, but a eerie skyline, streaming live.

http://www.fox4kc.com/news/livestreaming/

[Arron]

Heading back south towards the Ardmore stuff. They're chanting "we want hail!"

[icbinb]

Thats some big hail in there! You shouldn't have encouraged them. Look what you've started :lol:

[Nick F]

Tornado Watch for N-central TX and central OK, relevant for where team are headed. Don't think I've seen so many tornado watches out all the way from Texas up to Great Lakes:

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 326

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CDT SUN MAY 22 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

CENTRAL OKLAHOMA

NORTH-CENTRAL TEXAS

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 150 PM UNTIL 900

PM CDT.

TORNADOES...HAIL TO 4 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHWEST OF

MCALESTER OKLAHOMA TO 40 MILES SOUTH SOUTHWEST OF MINERAL WELLS

TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 321...WW 322...WW

323...WW 324...WW 325...

DISCUSSION...ISOLATED STORM DEVELOPMENT IS ANTICIPATED ALONG THE

DRYLINE BY LATE AFTERNOON AS CONTINUED DAYTIME HEATING ERODES

REMAINING CONVECTIVE INHIBITION. 18Z FWD SOUNDING SHOWED THAT THE

WARM SECTOR IS ALREADY EXTREMELY UNSTABLE WITH MLCAPE VALUES

APPROACHING 5000 J/KG. THIS DEGREE OF INSTABILITY COUPLED WITH

35-40 KT OF DEEP-LAYER SHEAR WILL SUPPORT INTENSE SUPERCELLS CAPABLE

OF DESTRUCTIVE HAIL. THE THREAT FOR TORNADOES WILL INCREASE THIS

EVENING AS LOW-LEVEL SHEAR INTENSIFIES IN RESPONSE TO THE

DEVELOPMENT OF A SLY LLJ.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 27020.

...MEAD

Hail to 4 inches, that's grapefruit size!!!