The SPC is forecasting ...severe thunderstorms expected over a broad swath of the southern and central plains today through tonight.... Please read the latest public statement about this event.
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SPC AC 261625
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1125 AM CDT SUN APR 26 2009
VALID 261630Z - 271200Z
...THERE IS A HIGH RISK OF SVR TSTMS OVER PORTIONS OF SOUTH CENTRAL
KS AND WESTERN OK...
...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK FROM
EASTERN AND CENTRAL KS...ACROSS CENTRAL OK...THE EASTERN TX
PANHANDLE...AND WESTERN NORTH TX...
...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE
CENTRAL/SOUTHERN PLAINS AND UPPER MS VALLEY...
A COMPLICATED...YET SIGNIFICANT SEVERE WEATHER EVENT APPEARS TO BE
DEVELOPING OVER PARTS OF THE CENTRAL AND SOUTHERN PLAINS TODAY.
WATER VAPOR IMAGERY CONTINUES TO SHOW A PRONOUNCED SHORTWAVE TROUGH
ADVANCING EASTWARD ACROSS EASTERN NM. THIS FEATURE WILL MOVE INTO
THE TX PANHANDLE BY THIS AFTERNOON...WITH LARGE SCALE ASCENT
OVERSPREADING MUCH OF NORTH TX/OK/KS. THE RESULT WILL BE A LARGE
AREA OF CONCERN FOR SCATTERED INTENSE THUNDERSTORMS. THE GREATEST
CONCENTRATION WILL LIKELY BE ALONG THE SURFACE DRYLINE/ COLD FRONT
FROM CENTRAL KS...ACROSS WESTERN OK...INTO WESTERN NORTH TX.
HOWEVER...POTENTIAL FOR SIGNIFICANT SEVERE WILL BE PRESENT OVER A
MUCH LARGER AREA.
...KS/NEB/IA...
MORNING THUNDERSTORMS CONTINUE TO INTENSIFY AND EXPAND IN COVERAGE
ACROSS PARTS OF EASTERN KS/SOUTHEAST NEB/MUCH OF IA IN REGION OF
STRONG LOW LEVEL WARM ADVECTION AND LIFT. AIRMASS IS RECOVERING
QUICKLY IN THIS REGION...WITH SUFFICIENT INSTABILITY FOR A RISK OF
LARGE HAIL AND DAMAGING WINDS. RADAR TRENDS AND MODEL GUIDANCE
SUGGEST THE POTENTIAL FOR MULTIPLE EPISODES OF STRONG CONVECTION IN
THIS AREA TODAY.
...SOUTH CENTRAL KS/WESTERN OK/EASTERN TX PANHANDLE...
A VOLATILE ENVIRONMENT IS EXPECTED TO DEVELOP BY MID AFTERNOON
ACROSS THIS REGION WITH MLCAPE VALUES OF 2000+ J/KG AND DEWPOINTS IN
THE MID 60S. MORNING RAOBS AND MODEL FORECAST SOUNDINGS SHOW A
RATHER WEAK CAPPING INVERSION OVER THIS AREA...ALLOWING SHOWERS AND
THUNDERSTORMS TO DEVELOP THIS MORNING. MORE INTENSE STORMS WILL
OCCUR LATER THIS AFTERNOON ALONG THE DRYLINE OVER THE EASTERN TX
PANHANDLE AS SHORTWAVE TROUGH OVER NM APPROACHES. GIVEN THE WEAK
CAP...IT APPEARS THAT BROKEN CLOUD COVER AND SCATTERED SHOWERS WILL
HELP TO LIMIT THE NUMBER OF STORMS AND REDUCE VERTICAL MIXING OF LOW
LEVEL MOISTURE. THIS WILL LEAD TO A VERY FAVORABLE THERMODYNAMIC
ENVIRONMENT FOR SUPERCELLS CAPABLE OF VERY LARGE HAIL AND TORNADOES.
KINEMATIC FIELDS WILL ALSO BE VERY FAVORABLE WITH LARGE...CURVED
HODOGRAPHS AND EFFECTIVE HELICITY VALUES OVER 500 M2/S2. MODEL
GUIDANCE IS VERY INCONSISTENT IN TIMING AND EVOLUTION OF CONVECTIVE
ACTIVITY. HOWEVER...THE COMBINATION OF A POTENT
ENVIRONMENT...APPROACHING UPPER TROUGH...AMPLE MOISTURE IN
PLACE...AND MULTIPLE OBJECTIVE GUIDANCE MEASURES INDICATING A
WIDESPREAD RISK OF SIGNIFICANT TORNADOES...FEEL THERE IS SUFFICIENT
CONFIDENCE TO UPGRADE TO HIGH RISK FROM SOUTH CENTRAL KS INTO
WESTERN OK.
...WEST TX...
STRONG HEATING AND A VERY UNSTABLE AIRMASS WILL BE PRESENT THIS
AFTERNOON AND EVENING ALONG THE DRYLINE FROM WESTERN NORTH TX INTO
SOUTHWEST TX. SCATTERED SUPERCELLS ARE EXPECTED TO DEVELOP ALONG
THIS AXIS WITH A RISK OF VERY LARGE HAIL...ISOLATED TORNADOES...AND
LOCALLY DAMAGING WINDS.
..HART/HURLBUT.. 04/26/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z