SPC AC 010534
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1234 AM CDT THU MAY 01 2008
VALID 011200Z - 021200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
CNTRL/SRN PLAINS AND MID MS VALLEY...
...CENTRAL/SOUTHERN PLAINS...MID MS VALLEY...
LATEST MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH LEADING
PORTION OF UPPER SPEED MAX DIGGING SEWD ACROSS THE 4-CORNERS REGION
BEFORE EJECTING NEWD ACROSS THE CNTRL PLAINS DURING THE DAYLIGHT
HOURS. THIS LEAD FEATURE WILL LIKELY DRAW INITIAL SFC LOW NWD INTO
NEB BEFORE OCCLUDING OVER SD...WHILE SECONDARY PRESSURE FALLS SHOULD
RESULT IN ANOTHER SFC CYCLONE AHEAD OF ADVANCING COLD FRONT OVER KS
BY PEAK HEATING.
DESPITE SUSTAINED STRONG LLJ ACROSS THE SRN PLAINS BOUNDARY LAYER
MOISTURE IS ONLY NOW BEGINNING TO RETURN IN EARNEST ACROSS THE WRN
GULF OF MEXICO AND SOUTH TX WHERE MID-UPPER 60S SFC DEW POINTS ARE
NOW OBSERVED. SLOW MOISTURE RETURN WILL PROVE SOMEWHAT PROBLEMATIC
FOR DIURNAL THUNDERSTORM DEVELOPMENT ALONG THE DRYLINE OVER OK...BUT
TO A LESSER DEGREE OVER KS WHERE STRONG FORCING WILL ENSURE DEEP
CONVECTION BY 23Z-01Z TIME FRAME.
LATEST THINKING IS DRYLINE WILL MIX TO A POSITION NEAR I-35 ACROSS
KS/OK AS FLOW ATOP THE BOUNDARY LAYER IS INITIALLY SOMEWHAT VEERED.
HOWEVER...PRESSURE FALLS ACROSS KS SHOULD RESULT IN THIS BOUNDARY
BECOMING A BIT MORE CONVERGENT BY SUNSET. AS TEMPERATURES SOAR INTO
THE 80S VERY STEEP LAPSE RATES WILL DEVELOP WITHIN POST DRYLINE
AIRMASS ULTIMATELY REMOVING INHIBITION FOR THOSE PARCELS RESIDING
NEAR DRYLINE/COLD FRONT. IT APPEARS THUNDERSTORMS WILL INITIALLY
DEVELOP ACROSS KS INTO SERN NEB WITH THIS ACTIVITY EXPERIENCING
UPWARD GROWTH/EXPANSION AS STRONG FORCING SPREADS EAST ACROSS THE
PLAINS LATE IN THE PERIOD. INITIAL STORM MODE SHOULD BE HIGH-BASED
SUPERCELLS...THOUGH STORM MERGERS AND FRONTAL FORCING SHOULD ENHANCE
SQUALL LINE POTENTIAL LATE AS CONVECTION SPREADS INTO THE MS VALLEY.
WHILE DRYLINE DEVELOPMENT INTO NRN OK IS POSSIBLE BEFORE
SUNSET...IT APPEARS GREATEST THREAT FOR CONVECTION ACROSS SRN
PORTIONS OF THE OUTLOOK WILL BE ALONG THE COLD FRONT AS IT SURGES
SOUTHEAST DURING THE OVERNIGHT HOURS.
GIVEN THE RETARDED MOISTURE RETURN THE GREATEST SEVERE THREAT SHOULD
BE LARGE HAIL...ESPECIALLY WITH SUPERCELLS ACROSS KS/NEB INTO SWRN
IA AND WRN MO. AS OVERALL CONVECTIVE MODE EVOLVES INTO A SQUALL
LINE THERE MAY BE AN INCREASED RISK OF DAMAGING WINDS DURING THE
OVERNIGHT HOURS.
..DARROW.. 05/01/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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