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April 21-24th Severe Weather


SEMIweather

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Great point, now that's going to annoy the living hell out of me. I struggle with change. :P

I guess I can talk myself into this making more sense though. Green, yellow, red (then pink) progression for elevating thunderstorm risk like a traffic light's go, yield, stop.

I always thought yellow meant speed up .........or thats what is seems to mean to everybody cuz thats what they do. :P

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day2probotlk_1730_any.gif

Looks like they expanded the hatched area further NE to include SW IN, NW KY and all of southern IL ...........wonder if we will get a mdt out of this. just no more bow echos for a while please that one that came through here tuesday night was a dooseyyikes.png

OF MORE CONCERN WILL BE THE POSSIBILITY FOR SFC BASED CONVECTIVE DEVELOPMENT ALONG/AHEAD OF THE COLD FRONT ACROSS MO INTO IL/IND. SUBSTANTIAL MOISTENING/DESTABILIZING IS EXPECTED ACROSS THIS REGION BY 18Z AND LATEST INDICATIONS ARE THAT MODEST INSTABILITY WILL BE IN PLACE BY MID AFTERNOON FOR ROBUST THUNDERSTORM DEVELOPMENT ACROSS MO WITHIN A STRONGLY SHEARED ENVIRONMENT FOR SUPERCELLS...INCLUDING THE POSSIBILITY FOR A FEW TORNADOES...VERY LARGE HAIL AND DAMAGING WINDS. THIS ACTIVITY SHOULD SPREAD DOWNSTREAM INTO THE LOWER OH VALLEY INTO A RECOVERING AIRMASS IN THE WAKE OF NWD SHIFTING WARM FRONT.

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TORNADO WARNING

TXC371-443-212215-

/O.NEW.KMAF.TO.W.0001.110421T2118Z-110421T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX

418 PM CDT THU APR 21 2011

THE NATIONAL WEATHER SERVICE IN MIDLAND HAS ISSUED A

* TORNADO WARNING FOR...

SOUTHERN PECOS COUNTY IN SOUTHWEST TEXAS...

NORTH CENTRAL TERRELL COUNTY IN SOUTHWEST TEXAS...

* UNTIL 515 PM CDT

* AT 414 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO OVER CENTRAL

PECOS COUNTY...OR 23 MILES SOUTHEAST OF FORT STOCKTON...ALONG HIGHWAY

285...MOVING SOUTHEAST AT 25 MPH.

* THE TORNADO WILL AFFECT THE FOLLOWING LOCATIONS...

OPEN COUNTRY OF SOUTHERN PECOS COUNTY...HIGHWAY 285 SOUTHEAST

OF FORT STOCKTON...OPEN COUNTRY OF WEST CENTRAL TERRELL COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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Yeah this setup looks pretty similar to last Tuesday's. Less instability, but the wind shear looks better though. If I could chase tomorrow I'd definitely head out. Probably head down to the same area as Tuesday. If instability ends up being higher than what's currently forecast there could be some very nice action over the southern half of Illinois and surrounding areas.

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Supercell northwest of Abilene TX... warning from NWS San Angelo. A different warning format than most offices.

-- also, Andy Gabrielson is on this storm: http://www.severestudios.com/cgi-bin/player-full.pl?username=andy.gabrielson&uid=140

NOLAN TX-JONES TX-FISHER TX-TAYLOR TX-

806 PM CDT THU APR 21 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR

NORTHWESTERN TAYLOR...SOUTHEASTERN FISHER...SOUTHWESTERN JONES AND

NORTHEASTERN NOLAN COUNTIES...

AT 800 PM CDT...THE MOST DANGEROUS PART OF THE STORM WAS LOCATED 6

MILES NORTHWEST OF TRENT...OR 15 MILES NORTHEAST OF SWEETWATER...

MOVING EAST AT 15 MPH.

STORM HAZARDS INCLUDE...

DANGEROUS TORNADIC WINDS.

DAMAGING WINDS IN EXCESS OF 60 MPH.

WITH POSSIBLE STORM IMPACTS...

OVERTURNED VEHICLES...

DAMAGE TO TREES...SOME MAY BE UPROOTED...

DAMAGE TO HOMES...MAY DESTROY MANUFACTURED HOMES.

DAMAGE TO TREE LIMBS...

LIGHT OBJECTS BLOWN AROUND.

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You know I'm in. Only problemo will be the fact that I'm going to be tied up until around noon.

Yea, that could be an issue.

My overall concern is that morning activity will linger into the afternoon for most areas north of STL. On the other hand the 18z GFS looked good for the Galesburg/Peoria/Macomb areas tomorrow evening...if that morning/early afternoon stuff is not an issue.

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Yeah this setup looks pretty similar to last Tuesday's. Less instability, but the wind shear looks better though. If I could chase tomorrow I'd definitely head out. Probably head down to the same area as Tuesday. If instability ends up being higher than what's currently forecast there could be some very nice action over the southern half of Illinois and surrounding areas.

The similarities are eerie, although less instability as you said. I expect another threat of damaging winds and brief tornadoes by the time the storms move in.

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The SREF is still very bullish later tomorrow over central/southern Illinois and eastern Missouri. Wind shear is pretty damn impressive. SREF and NAM both forecast cape values in excess of 1500j/kg in that highly sheared environment south of the warm front north of St. Louis. That's less instability compared to Tuesday, but that's still not bad. I'm sure by morning the RUC will be forecasting cape in that area between 2000-3000j/kg lol. I think the big key will be if and how soon the elevated convection and associated clouds leave that area. If things clear out sooner than forecast then watch out, it's gonna be HUGE. If I didn't have work obligations tomorrow I'd be heading down towards Litchfield again.

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Yea, that could be an issue.

My overall concern is that morning activity will linger into the afternoon for most areas north of STL. On the other hand the 18z GFS looked good for the Galesburg/Peoria/Macomb areas tomorrow evening...if that morning/early afternoon stuff is not an issue.

I'd be in as well. I have a business luncheon in Streamwood at noon. If you guys hang back a bit, keep in touch. In the meantime I have learned to keep an eye on those helicity and theta-e values.

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I'd be in as well. I have a business luncheon in Streamwood at noon. If you guys hang back a bit, keep in touch.

Some of the models show the surface front making it far enough north that it wouldn't take too long to get to a good spot in just a few hours from Chicago. Some of the forecast soundings near Peoria on the GFS aren't too bad. Instability will be less than areas further south, but there will be extremely nice shear near that warm front late tomorrow.

Edit:

Just west of Peoria per 00z GFS

GFS_3_2011042200_F24_40.5000N_90.0000W.png

GFS_3_2011042200_F24_40.5000N_90.0000W_HODO_SM.png

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At this point I have diminished confidence in anything affecting Norman tomorrow...seems like the last few model cycles have continued to trend faster with the frontal/dryline passage...and the general trend with the last few systems is for the dryline to move through even faster than what's modeled.

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DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1251 AM CDT FRI APR 22 2011

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS OH WWD TO MO THEN SWWD TO

PORTIONS CENTRAL TX....

..SYNOPSIS

IN MID-UPPER LEVELS...INITIALLY STRONGER SHORTWAVE TROUGH NOW MOVING

EWD OVER ID IS FCST TO WEAKEN...MOVE SLOWLY SEWD TO WY AND BECOME

STRONGLY POSITIVELY-TILTED. MEANWHILE...LEADING SHORTWAVE TROUGH --

NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN WY...WILL BECOME

DOMINANT PERTURBATION...EVOLVING INTO CLOSED 500-MB LOW CENTERED

OVER NWRN SD BY 22/18Z. THIS FEATURE THEN SHOULD ACCELERATE ENEWD

TO LS BY END OF PERIOD...EITHER AS MRGL CLOSED CYCLONE OR STG

OPEN-WAVE TROUGH.

LEE-SIDE SFC CYCLONE -- INITIALLY ANALYZED OVER SERN CO -- IS

EXPECTED TO LIFT NEWD ALONG STRENGTHENING FRONTAL ZONE FROM SRN KS

TO WRN IL BY 23/00Z...EVOLVING INTO TRIPLE-POINT CYCLONE FOR

OCCLUDED SFC LOW OVER SD MORE CLOSELY ASSOCIATED WITH UPPER TROUGH.

THIS SHOULD BECOME DOMINANT CYCLONE...OCCLUDE...AND REACH SSM AREA

BY END OF PERIOD. MEANWHILE...COLD FRONT WILL SWEEP EWD ACROSS

MO/IL/OH BY 23/12Z...STALLING OVER SE OK AND NW TX AS SECONDARY/WEAK

LOW DEVELOPS INVOF SPS. ADVECTION AND MIXING SHOULD FORCE DRYLINE

EWD ACROSS W-CENTRAL/NW TX AND SWRN OK DURING DAY...REACHING FROM

CENTRAL OK SWWD ACROSS W-CENTRAL TX TO EXTREME NRN COAHUILA BY

23/00Z. COLD FRONT WILL OVERTAKE DRYLINE OVER CENTRAL/SWRN OK PRIOR

TO AFOREMENTIONED SFC LOW DEVELOPMENT...WHERE FRONT/DRYLINE TRIPLE

POINT SHOULD SET UP BY END OF PERIOD.

IN GENERAL...WARM FRONT SHOULD MOVE NEWD ACROSS SERN MO/SRN IL EARLY

IN PERIOD...INTO CENTRAL PORTIONS IL/INDIANA AND SWRN OH BY LATE

AFTERNOON. HOWEVER...EFFECTIVE BAROCLINIC ZONE MAY BECOME

WAVY/SEGMENTED DUE TO CONVECTIVE EFFECTS ALONG AND N OF IT.

..OH VALLEY AND ADJOINING STATES

MULTIPLE ROUNDS OF TSTMS MAY AFFECT THIS AREA...BEGINNING WITH

CARRY-OVER CONVECTION FROM PRIOR PERIOD MOVING EWD ACROSS PORTIONS

IL/INDIANA/OH DURING DAY. THIS ACTIVITY LARGELY WILL OCCUR ALONG

AND N OF NEWD-MOVING WARM FRONT WITH ELEVATED EFFECTIVE INFLOW

PARCELS...AND MRGL HAIL THREAT. EITHER BACKBUILDING/TRAILING

PORTION OF THAT ACTIVITY...OR NEWER DEVELOPMENT OVER SERN KS/MO

BEHIND IT...SHOULD MOVE EWD INTO WARM SECTOR OVER OH VALLEY REGION.

FOREGOING/PRECONVECTIVE AIR MASS WILL DESTABILIZE INTO AFTERNOON

FROM COMBINATION OF DIABATIC HEATING AND BOUNDARY-LAYER THETAE

ADVECTION. WEAK MLCINH SHOULD YIELD EFFECTIVE SFC-BASED PARCELS BY

MIDDAY...WHILE LAPSE RATES INCREASE STRONGLY WITH SWWD EXTENT FROM

OH TO ERN MO. CORRESPONDINGLY...MLCAPE SHOULD RANGE FROM 1000 J/KG

NEAR ERN INDIANA/OH WARM-FRONTAL SEGMENT TO NEARLY 3000 J/KG OVER

SRN MO.

SRN RIM OF SUBSTANTIAL HEIGHT FALLS ASSOCIATED WITH NRN PLAINS/UPPER

MIDWEST SHORTWAVE TROUGH ARE EXPECTED TO REMAIN N OF UNDISTURBED

WARM SECTOR. HOWEVER...TIGHTENING HEIGHT GRADIENTS ALOFT...ALONG

WITH LOW-LEVEL MASS RESPONSE AND ISALLOBARIC FORCING...SHOULD RESULT

IN FAVORABLE LOWER-MIDDLE TROPOSPHERIC SHEAR FOR SVR. TORNADO

PROBABILITY ALONG/S OF WARM FRONT APPEARS SUFFICIENT BY ITSELF TO

WARRANT SLGT CATEGORICAL OUTLOOK...BUT ANYTHING BEYOND THAT WILL

DEPEND STRONGLY ON MOST PROBABLE CONVECTIVE MODE...WHICH APPEARS TOO

UNCERTAIN OR MIXED ATTM TO CONCENTRATE ANY CORRIDOR OF GREATER

THREAT. EXPECT FAVORABLY LARGE HODOGRAPHS...WITH 0-1 KM AGL SRH

COMMONLY 200-400 J/KG ALONG AND S OF WARM FRONT. DAMAGING WIND IS

LIKELY...AND THREAT FOR LARGE HAIL WILL INCREASE SWWD IN STEP WITH

HIGHER LAPSE RATES/BUOYANCY.

..OZARKS TO CENTRAL/SW TX

TSTMS ARE EXPECTED TO DEVELOP INVOF COLD FRONT AND DRYLINE DURING

AFTERNOON...OFFERING VERY LARGE/DAMAGING HAIL AND SVR GUSTS.

TORNADO POTENTIAL IS CONDITIONAL ON STORM-SCALE PROCESSES...GIVEN

MORE DEEPLY MIXED SUBCLOUD LAYERS AND HIGHER LCL THAN FARTHER NE.

EXPECT 8-9 DEG C/KM 700-500 MB LAPSE RATES...STG SFC HEATING AND DEW

POINTS COMMONLY 60S F...YIELDING PRE-STORM MLCAPE 2500-3500 J/KG.

CONVECTIVE COVERAGE SHOULD BECOME MORE WIDELY SCATTERED TO ISOLATED

WITH SWWD EXTENT...BUT ALSO WITH DISCRETE TSTMS FOR LONGER PERIODS

OF TIME IN SUPPORT OF SUPERCELL POTENTIAL. ALTHOUGH LOW-LEVEL FLOW

AND HODOGRAPH SIZE SHOULD WEAKEN FROM SRN OK SWD...DEEP-LAYER SHEAR

STILL MAY FAVOR SUPERCELLS...WITH INCREASING POTENTIAL FOR STRONGLY

DEVIANT MOTIONS INTO CENTRAL TX.

THREAT S OF RED RIVER WILL BE MORE STRONGLY TIED TO DIURNAL HEATING

THAT FARTHER NE...AND AS SUCH...SHOULD WANE AFTER ABOUT 03Z.

CONVECTION OVER OH VALLEY AND OZARKS MAY PERSIST IN PROGRESSIVELY

MORE LINEAR FORM OVERNIGHT...WITH HAIL/TORNADO THREATS BECOMING MORE

MRGL AND WIND BECOMING DOMINANT SVR RISK.

..EDWARDS/ROGERS.. 04/22/2011

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I don't follow TX weather at all, but this seems very unique to me?

BULLETIN - EAS ACTIVATION REQUESTED

SEVERE THUNDERSTORM WARNING

NATIONAL WEATHER SERVICE FORT WORTH TX

342 AM CDT FRI APR 22 2011

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

SOUTHERN MCLENNAN COUNTY IN NORTH CENTRAL TEXAS...

* UNTIL 415 AM CDT

* AT 339 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED

DAMAGING WINDS...IN EXCESS OF 60 MPH...ASSOCIATED WITH

DISSIPATING THUNDERSTORMS. THE DAMAGING WINDS WERE LOCATED NEAR

HEWITT...AND MOVING NORTHEAST AT 30 MPH.

* THE DAMAGING WINDS WILL BE NEAR...

ROBINSON BY 345 AM

RIESEL BY 355 AM

HALLSBURG BY 400 AM

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WIND DAMAGE MAY OCCUR IN THE ABSENCE OF ANY RAIN OR LIGHTNING. DO NOT

WAIT FOR THE SOUND OF THUNDER BEFORE TAKING COVER. SEEK SHELTER

IMMEDIATELY INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

AREAS IN THE WARNING MAY ALSO EXPERIENCE A RAPID RISE IN TEMPERATURE.

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