SWODY1
SPC AC 261630
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT MON MAR 26 2012
VALID 261630Z - 271200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NORTHERN
PLAINS...
...NRN PLAINS...
A PROGRESSIVE UPPER TROUGH WILL CROSS THE ROCKIES AND EJECT IN
NEGATIVE TILT FASHION ACROSS THE NRN PLAINS THIS PERIOD. IN RESPONSE
TO THIS DISTURBANCE AND ITS ASSOCIATED 75-90KT FOCUSED MID LEVEL
SPEED MAX CURRENTLY CROSSING THE FOUR CORNERS REGION...DOWNSTREAM
LEE CYCLOGENESIS WAS ALREADY UNDERWAY ACROSS ERN WY/MT. AS PRIMARY
SURFACE CYCLONE CONSOLIDATES ACROSS MT AND MOVES INTO ND THROUGH
TONIGHT...SECONDARY/TRIPLE POINT LOW NEAR HIGH PLAINS DRYLINE/LEE
TROUGH AND COLD FRONT INTERSECTION WILL TRACK RAPIDLY NEWD FROM ERN
WY INTO NERN NEB AND SD THROUGH THIS EVENING.
DYNAMIC FORCING FOR ASCENT AND RAPID TRANSLATION/EVOLUTION OF THE
LARGE SCALE FLOW FIELDS WITH THIS SYSTEM ARE SUBSTANTIAL. AS
SUCH...PLAINS LOW LEVEL JET WILL CONTINUE TO INTENSIFY THROUGH THE
DAY AND CONTRIBUTE TO AT LEAST A MODEST INCREASE IN MOISTURE ACROSS
AREAS OF THE PLAINS THAT ARE CURRENTLY QUITE DRY /PW UNDER 0.75
INCH/. THIS INCREASE IN MOISTURE...HOWEVER...WILL TAKE PLACE AMIDST
SIGNIFICANT CONVECTIVE INHIBITION DUE TO STOUT EML PLUME SITUATED
ACROSS THE CNTRL AND NRN PLAINS. WHILE SURFACE-BASED INSTABILITY
NEAR THE TRIPLE POINT LOW AND SURGING FRONT ACROSS NE/SD LATER TODAY
MAY EXCEED 1000 J/KG...INHIBITION IN THIS REGIME WILL REMAIN QUITE
STRONG.
THUS...EXPECT POTENTIAL FOR NEAR SURFACE-BASED STORM INITIATION TO
OCCUR WHERE STRONGEST DYNAMIC AND DIABATIC INFLUENCES CAN ACT IN
CONCERT TO BREACH THE CAP. THIS MAY OCCUR LATE IN THE DAY...OR BY
EARLY EVENING...NEAR LEE LOW AND COLD FRONT/DRYLINE TRIPLE
POINT...FROM ERN WY ACROSS NEB PNHDL TO SWRN SD. EXPECT ISOLATED
HIGH BASED STORMS IN THESE AREAS TO TRACK NEWD AND POSSIBLY
CONSOLIDATE INTO A FAST-MOVING ARC OF SEVERE STORMS ACROSS SD. GIVEN
POTENT EFFECTIVE SHEAR ON THE ORDER OF 50-60KT AND RAPID COOLING
ALOFT...SEVERE THREAT WITH THIS INITIAL ACTIVITY WOULD BE THE
POTENTIAL FOR AN LP SUPERCELL OR TWO WITH LARGE HAIL. TORNADO
POTENTIAL WILL BE CONDITIONAL ON TRUE SURFACE-BASED STORM
DEVELOPMENT BUT SUFFICIENT LOW LEVEL FORCING AND SHEAR WILL BE IN
PLACE ACROSS A RELATIVELY NARROW CORRIDOR IN SPACE AND TIME TO
SUPPORT SOME TORNADO POSSIBILITY NEAR THE TRIPLE POINT LOW BETWEEN
00Z AND 03Z. IF STORMS CAN INCREASE IN COVERAGE ACROSS SD THIS
EVENING...SOME DAMAGING WIND POTENTIAL SHOULD ENSUE GIVEN FAVORABLE
ORIENTATION OF THE 75-90KT MID LEVEL JET STREAK AND POTENTIAL ARC OF
STORMS OVER THIS AREA. AS SMALL MCS RACES NEWD...EXPECT STORM
UPDRAFTS TO BECOME MORE REMOVED FROM THE BOUNDARY LAYER WITH A
SUBSEQUENT TRANSITION BACK TO MORE OF A HAIL THREAT AS ACTIVITY
MOVES ACROSS ND THROUGH LATE TONIGHT/EARLY TUESDAY.
...WEST TX...
FARTHER SOUTH...NO CHANGE FROM PRIOR OTLK...STRONG DAYTIME HEATING
WILL LEAD TO DEEP MIXING ALONG THE DRYLINE OVER WEST TX LATER TODAY.
A FEW OF THE OPERATIONAL MODEL SOLUTIONS SUGGEST THAT ISOLATED
THUNDERSTORMS WILL DEVELOP ALONG THE DRYLINE DURING THE LATE
AFTERNOON AND EARLY EVENING. EFFECTIVE SHEAR VALUES WILL BE SOMEWHAT
MARGINAL FOR ORGANIZED STORMS. RELATIVELY STEEP MID LEVEL LAPSE
RATES AND DEEPLY MIXED BOUNDARY LAYER MAY BE SUFFICIENT TO PROMOTE
HAIL AND GUSTY WINDS IN A COUPLE STRONGER STORMS.
..CARBIN/GARNER/GUYER.. 03/26/2012
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