SPC AC 230054
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 PM CDT TUE APR 22 2008
VALID 230100Z - 231200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF LOWER MS VALLEY
WNWWD THROUGH RED RIVER VALLEY TO W TX...
...ERN OK/WRN AND SRN AR SWD TO PARTS OF E TX TO MS...
WATER VAPOR IMAGERY INDICATED A LEAD IMPULSE MOVING SSEWD ACROSS THE
MS DELTA REGION INTO THE NRN GULF OF MEXICO AND A MESOSCALE
CONVECTIVE SYSTEM TRACKING SEWD IN ITS WAKE ACROSS SERN AR/CENTRAL
MS. THESE SYSTEMS ARE SUPPORTING A ZONE OF 30-40 KT NWLY MID LEVEL
WINDS EXTENDING FROM SWRN MO INTO THE LOWER MS VALLEY. THIS FLOW
REGIME ATOP GENERALLY WEAK OR WEAKENING LOW LEVEL WINDS WILL TEND TO
MAINTAIN 30-35 KT OF DEEP LAYER SHEAR ALONG CORRIDOR OF STRONGER MID
LEVEL WINDS. LOSS OF DAY TIME HEATING WILL ALLOW FOR INCREASING
SURFACE BASED INHIBITION AND EVENTUAL LOSS OF SUPPORT FOR DEEP MOIST
CONVECTION AND ATTENDANT THREATS OF HAIL AND STRONGER WIND GUST
WITHIN MODERATELY UNSTABLE AIR MASS. FOR MESOSCALE DETAILS...REFER
TO SPC MESOSCALE DISCUSSIONS 693 AND 694.
...SRN OK/NRN TX WWD TO SRN HIGH PLAINS...
WATER VAPOR IMAGERY SHOWED AN APPARENT LEAD IMPULSE/JET STREAK
MOVING ENEWD ACROSS SRN NM/NORTH CENTRAL MEXICO EARLY THIS
EVENING...WITH A STRONGER UPSTREAM IMPULSE APPROACHING THE CENTRAL
BAJA REGION. THIS LATTER FEATURE IS EXPECTED TO REACH SRN NM/FAR W
TX BY 12Z WEDNESDAY. WSWLY FLOW ALOFT WILL ADVECT A PLUME OF STEEP
LAPSE RATES NEWD INTO THE SRN/CENTRAL HIGH PLAINS OVERNIGHT ATOP
INCREASING BOUNDARY LAYER MOISTURE WITHIN ZONE OF STRENGTHENING
SSELY LOW LEVEL WINDS IN RESPONSE TO APPROACHING BAJA TROUGH. THIS
WILL SUPPORT ELEVATED MUCAPE RANGING FROM 1000-2000 J/KG.
EARLY EVENING SURFACE ANALYSIS SHOWED SWRN EXTENT OF QUASISTATIONARY
BOUNDARY EXTENDING FROM SOUTH CENTRAL OK INTO WRN N TX AND TO THE S
PLAINS OF W TX. A DRY LINE EXTENDED SWWD FROM JUST SW OF SPS TO
VICINITY OF TX BIG BEND REGION. RECENT TRENDS IN VISIBLE IMAGERY
SHOWED DRY LINE BEGINNING TO RETREAT WWD. ASCENT ATTENDANT TO LEAD
IMPULSE...NOW APPROACHING W/SW TX...APPEARS TO BE AIDING IN
SUSTAINING CU FIELD DEVELOPING WNWWD WITHIN VICINITY OF SJT.
ELSEWHERE...CU/TCU ALONG NWD EXTENT OF DRY LINE AND SURFACE BOUNDARY
IN SRN OK SHOULD CONTINUE TO DIMINISH AS SURFACE BASED INHIBITION
STRENGTHENS WITH LOSS OF DAY TIME HEATING. AS LLJ STRENGTHENS OVER
WRN TX TONIGHT...DRY LINE WILL RETREAT WWD INTO W TX...WHILE
QUASISTATIONARY BOUNDARY DEVELOPS NWWD INTO CENTRAL OK AND THE TX
PANHANDLE. INCREASING WAA REGIME ALONG/N OF RETREATING BOUNDARIES
COMBINED WITH MODERATE INSTABILITY AND ASCENT/STRENGTHENING SWLY
FLOW/DEEP SHEAR ATTENDANT TO BAJA TROUGH ARE EXPECTED TO SUPPORT
MAINLY ELEVATED TSTMS TONIGHT FROM W TX NWD THROUGH TX PANHANDLE/WRN
OK AND POTENTIALLY FAR SERN CO/SWRN KS. HAIL IS EXPECTED TO BE THE
PRIMARY THREAT WITH THIS OVERNIGHT ACTIVITY.
..PETERS.. 04/23/2008
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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