SPC AC 100714
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0214 AM CDT FRI APR 10 2009
VALID 121200Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SOUTH CENTRAL U.S....
...SOUTH CENTRAL U.S...
POWERFUL SRN STREAM UPPER LOW WILL SHIFT EAST ACROSS THE SRN ROCKIES
INTO THE SRN PLAINS BY LATE AFTERNOON EASTER SUNDAY AS STRONGEST
FLOW ALOFT TRANSITIONS INTO THE SERN-ERN PERIPHERY OF CYCLONE...H5
FLOW OF 80-90KT....FROM EAST TX INTO NWRN MS.
ADDITIONALLY...STRONGLY DIFFLUENT HIGH LEVEL FLOW WILL OVERSPREAD
THE SCNTRL U.S. IN CONJUNCTION WITH RAPIDLY MODIFYING BOUNDARY
LAYER.
MODELS ARE IN GENERAL AGREEMENT THAT STRONG WARM ADVECTION...ALONG
WITH ASCENT AHEAD OF UPPER VORT...WILL ENCOURAGE A BROAD ZONE OF
WIDESPREAD STRONG CONVECTION ACROSS THE SRN PLAINS EARLY IN THE
PERIOD...MUCH OF IT ELEVATED IN NATURE. THIS ACTIVITY WILL
PROPAGATE/DEVELOP EWD ACROSS TX/OK INTO THE LOWER MS VALLEY...AND
EVENTUALLY THE CNTRL GULF COAST REGION BY 12Z MONDAY AS LARGE SCALE
ASCENT SPREADS DOWNSTREAM.
GIVEN THE STRENGTH OF THE LOW PRESSURE SYSTEM...SHEAR PROFILES WILL
BE VERY STRONG ACROSS THE OUTLOOK REGION...CLEARLY SUPPORTIVE OF
ORGANIZED UPDRAFTS WHERE INSTABILITY IS SUFFICIENT. ALTHOUGH
BUOYANCY WILL BE AT A MINIMUM EARLY IN THE PERIOD...SEVERE
THUNDERSTORMS MAY BE ONGOING AHEAD OF COLD FRONT FROM PORTIONS OF
CNTRL TX...NWD TO THE RED RIVER. WITH TIME A NARROW AXIS OF
INSTABILITY WILL DEVELOP AHEAD OF THIS CONVECTION IN THE WAKE OF
WARM FRONT THAT WILL STRUGGLE TO MOVE BEYOND THE RED RIVER/ARKLATEX
DUE TO EXTENSIVE CONVECTION/PRECIPITATION. MODELS INSIST PRIMARY
SFC LOW WILL LAG SOMEWHAT OVER NCNTRL TX DURING THE LATE AFTERNOON
HOURS. THIS MAY ALLOW SOMEWHAT HIGHER INSTABILITY TO BE GENERATED
AHEAD OF COLD FRONT ACROSS ERN TX IN THE WAKE OF WARM FRONTAL
PRECIPITATION. IF MARITIME AIRMASS IS ABLE TO WARM SUFFICIENTLY
THEN A POTENTIALLY MORE VOLATILE SCENARIO MAY EVOLVE OVER ERN TX
INTO LA AS FORECAST SOUNDINGS STRONGLY SUPPORT SUPERCELL
DEVELOPMENT. AT THIS TIME WILL MAINTAIN A SLIGHT RISK DUE TO THE
UNCERTAINTY OF INSTABILITY. HOWEVER...AN UPGRADE TO MODERATE RISK
MAY BE REQUIRED FOR TORNADOES IN LATER OUTLOOKS.
..DARROW.. 04/10/2009
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
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