SWODY1
SPC AC 241936
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0236 PM CDT WED MAR 24 2010
VALID 242000Z - 251200Z
...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND EVE ACROSS
PARTS OF W CNTRL/N CNTRL TX INTO PARTS OF S CNTRL/SE OK...
...20Z UPDATE...CNTRL TX INTO PARTS OF EXTREME SRN OK...
THE MAIN SEVERE POTENTIAL FOR THIS PERIOD STILL APPEARS LIKELY TO BE
CONFINED TO THE LATE AFTERNOON AND EARLY EVENING HOURS ACROSS THE
SOUTHERN PLAINS. CLOUD COVER AND PRECIPITATION ACCOMPANYING A
MID/HIGH LEVEL CONVECTIVE BAND...ASSOCIATED WITH REMNANTS OF A
CLOSED LOW THAT MIGRATED INLAND ACROSS NORTHERN BAJA YESTERDAY...
HAVE STABILIZED THE PRE-COLD FRONTAL LOW-LEVEL ENVIRONMENT ACROSS
MUCH OF CENTRAL THROUGH NORTHEASTERN OKLAHOMA. BUT...SURFACE
HEATING ALONG A DEVELOPING DRY LINE NEAR OR JUST EAST OF SAN ANGELO
AND ABILENE IS CONTRIBUTING TO THERMODYNAMIC PROFILES THAT ARE
EXHIBITING INCREASING CONDITIONAL AND CONVECTIVE INSTABILITY ACROSS
PARTS OF WEST CENTRAL THROUGH NORTH CENTRAL TEXAS.
AS A SIGNIFICANT CLOSED MID-LEVEL LOW GRADUALLY BEGINS TO TURN
EASTWARD OUT OF CENTRAL NEW MEXICO...BOUNDARY LAYER BASED STORM
STILL APPEAR LIKELY TO INITIATE NEAR THE DRY LINE BETWEEN NOW AND
22-23Z...BEFORE DEVELOPING EAST NORTHEASTWARD THROUGH THE REMAINDER
OF THE AFTERNOON. THIS PROBABLY WILL IMPACT MUCH OF THE INTERSTATE
35 CORRIDOR OF CENTRAL/NORTH CENTRAL TEXAS...INCLUDING THE
DALLAS/FORT WORTH METROPLEX. STRENGTHENING OF SOUTHERLY 850 MB FLOW
IS NOT PROGGED UNTIL LATE THIS EVENING ACROSS EASTERN TEXAS INTO THE
LOWER MISSISSIPPI VALLEY. BUT...DEEP LAYER SHEAR BENEATH 50 KT
SOUTHWESTERLY 500 MB FLOW WILL BE MORE THAN SUFFICIENT TO CONTRIBUTE
TO MID-LEVEL UPDRAFT ROTATION...ENHANCING THE RISK FOR LARGE HAIL IN
STRONGEST STORMS. SIZABLE SUB-CLOUD TEMPERATURE/DEW POINT SPREADS
MAY ALSO SUPPORT LOCALIZED STRONG DOWNBURSTS...PERHAPS EVOLVING
SURFACE COLD POOLS...AT LEAST FROM THE DRY LINE EASTWARD INTO THE
INTERSTATE 35 CORRIDOR.
..KERR.. 03/24/2010
.PREV DISCUSSION... /ISSUED 1049 AM CDT WED MAR 24 2010/
...SRN PLAINS TOWARDS THE LOWER MS RIVER VALLEY...
MORNING ANALYSES AND MODELS ARE IN LINE WITH EARLIER FORECASTS
ACROSS THIS AREA THROUGH TONIGHT. INTENSE MID/UPPER LOW NOW OVER
SRN CO/NRN NM WILL PROGRESS STEADILY ESEWD ACROSS THE SRN PLAINS
WITH ASSOCIATED TROUGH GRADUALLY TAKING ON A MORE NEGATIVE-TILT BY
THE END OF THE PERIOD. SURFACE LOW OVER CENTRAL/SWRN OK THIS
MORNING /ALONG A FRONT EXTENDING FROM NWRN MO/SERN KS INTO W-CENTRAL
TX AT 15Z/ WILL LIKELY BECOME BETTER DEFINED LATER TODAY AND TONIGHT
INTO WRN AR/SRN MO. THIS WILL OCCUR AS COLD FRONT SURGES SEWD OUT
OF THE SRN HIGH PLAINS...ESPECIALLY ONCE UPPER SYSTEM BEGINS
ACCELERATING EWD LATER TODAY AND OVERNIGHT. AHEAD OF THIS
IMPULSE...MODEST WARM SECTOR WILL REMAIN IN PLACE CHARACTERIZED BY
SURFACE DEW POINTS IN THE MID TO UPPER 50S INTO CENTRAL OK.
COMBINATION OF STOUT CAPPING EVIDENT ON 12Z SOUNDINGS AND SLOW
EROSION/NEWD ADVECTION OF MORNING STRATUS OVER N-CENTRAL TX/CENTRAL
OK SHOULD DELAY DESTABILIZATION INTO THE LATE AFTERNOON. EXCEPTION
APPEARS TO BE OVER NWRN TX/SWRN OK WHERE GREATER HEATING SHOULD
DEVELOP GIVEN MORE LIMITED CLOUDS. FORECAST OF MLCAPE UPWARDS OF
500-1000 J/KG STILL APPEARS ON TRACK ALONG AND JUST AHEAD OF THE
SHALLOW COLD FRONT BY THE MID TO LATE AFTERNOON OVER NWRN TX INTO
CENTRAL OK...WHERE EFFECTIVE SHEAR FROM 30-40 SHOULD SUPPORT SOME
ORGANIZATION AS STORMS DEVELOP BETWEEN 21Z-00Z. THIS ACTIVITY IS
EXPECTED TO SHIFT EWD AND EXPAND NEWD AND SSWWD ALONG THE FRONT AS
INCREASED ASCENT AIDS IN ADDITIONAL DEVELOPMENT THROUGH THE EVENING.
ATTM...PRIMARY THREAT WILL LIKELY BE FROM LARGE HAIL AS STORMS TEND
TO BE UNDERCUT AND/OR DEVELOP ATOP CAPPED BOUNDARY LAYER. HOWEVER
AS FRONTAL LIFT DEEPENS AND SLOPE STEEPENS WITH TIME THIS EVENING
AHEAD OF MAIN UPPER SYSTEM...ACTIVITY SHOULD ACCELERATE EWD ACROSS
CENTRAL OK-TX/RED RIVER VALLEY AND INTO AR/WRN LA OVERNIGHT.
THUS...WILL MAINTAIN LOW WIND AND TORNADO PROBABILITIES GIVEN
STRENGTH OF UPPER SYSTEM AND POTENTIAL FOR INCREASED ORGANIZATION
OVERNIGHT.
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