227
ACUS01 KWNS 210054
SWODY1
SPC AC 210052
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0752 PM CDT SAT MAR 20 2010
VALID 210100Z - 211200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
WATER VAPOR IMAGERY/00Z UPPER AIR ANALYSIS SHOWS A DEEPENING
SHORTWAVE TROUGH/CLOSED LOW TRACKING EWD ALONG THE RED RIVER /OK/TX
BORDER/...WITH 100 METER 500 MB HEIGHT FALLS OBSERVED AT OUN SINCE
12Z TODAY. MODELS REMAIN CONSISTENT INDICATING FURTHER
INTENSIFICATION OF THIS SYSTEM TONIGHT WITH 180 METER HEIGHT FALLS
INTO THE LOWER MS VALLEY. CLOSED LOW PROGGED TO REACH THE ARKLATEX
REGION BY 12Z SUNDAY. EARLY EVENING SURFACE ANALYSIS SHOWED AN AREA
OF LOW PRESSURE OVER AR WITH A COLD FRONT TRAILING SSWWD THROUGH LA
INTO THE WRN GULF OF MEXICO. THE SURFACE LOW SHOULD SLOWLY DEEPEN
AND SHIFT NEWD INTO NERN AR THIS FORECAST PERIOD... WHILE THE COLD
FRONT PUSHES EWD INTO ERN MS TO SWRN AL BY 12Z SUNDAY.
MEANWHILE...THE TSTM ACTIVITY LOCATED OVER FAR SERN LA INTO THE
NORTH CENTRAL GULF EARLY THIS EVENING APPEARS TO BE ATTENDANT TO A
WEAKER SRN STREAM SHORTWAVE TROUGH EXPECTED TO REACH GA BY 12Z
SUNDAY. GIVEN THE TRACK OF THIS IMPULSE AND INCREASING LOW LEVEL
WAA INTO SRN AL/FL PANHANDLE OVERNIGHT...THE GENERAL TSTM LINE HAS
BEEN EXTENDED EWD.
...MS DELTA/CENTRAL GULF COAST...
MODELS SUGGEST A SUB-SYNOPTIC SURFACE LOW WILL TRACK ENEWD ACROSS
FAR SERN LA LATE THIS EVENING/EARLY OVERNIGHT AND REACH SWRN AL
COAST BY THE END OF THE PERIOD. THIS SECONDARY LOW SHOULD MARK THE
NRN EXTENT OF GREATER LOW LEVEL MOISTURE /SURFACE DEWPOINTS AROUND
60/ WHICH ARE CURRENTLY LOCATED OFFSHORE. SLY LLJ STRENGTHENING
INTO CENTRAL GULF COAST REGION TONIGHT IN RESPONSE TO APPROACH OF
DEEPENING MID-UPPER LEVEL LOW WILL ADVECT MOISTURE NWD TO THE
COASTAL AREAS OF SERN LA TO SWRN AL/FAR WRN FL PANHANDLE. THIS
COMBINED WITH INCREASING LOW LEVEL WAA WILL AID IN DESTABILIZATION
FOR CONVECTIVE DEVELOPMENT...BUT WEAK LAPSE RATES WILL CONTINUE TO
LIMIT THE DEVELOPMENT OF STRONGER INSTABILITY.
ALTHOUGH FORECAST SOUNDINGS SUGGEST STORMS NEAR AND INLAND OF THE
COAST SHOULD BE PRIMARILY ELEVATED...INCREASING HODOGRAPH CURVATURE
ALONG LLJ WITH 0-1 KM SHEAR AROUND 25-30 KT WOULD SUPPORT AN
ISOLATED SEVERE THREAT/NON-ZERO POTENTIAL FOR LOW LEVEL STORM
ROTATION. THUS...WILL KEEP VERY LOW TORNADO AND WIND PROBABILITIES
IN THE 01Z OUTLOOK ISSUANCE.
..PETERS.. 03/21/2010
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