SPC AC 161223
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0723 AM CDT MON OCT 16 2006
VALID 161300Z - 171200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO THE
CENTRAL GULF COAST/MID SOUTH...
...SYNOPSIS...
UPPER TROUGH NOW MOVING INTO THE SRN HIGH PLAINS WILL EJECT RAPIDLY
TODAY AND TONIGHT AS A NEGATIVELY-TILTED SHORTWAVE TROUGH INTO THE
MID SOUTH. AHEAD OF THIS FEATURE...SURFACE LOW CENTER NEAR JCT AT
11Z IS EXPECTED TO LIFT NEWD INTO NERN TX ALONG QUASI-STATIONARY
FRONT/TROUGH NOW EXTENDING TOWARDS TKX/CENTRAL AR WITH LOW CENTER
EXPECTED TO WEAKEN AS IT LIFTS TOWARDS THE MID SOUTH LATER TONIGHT.
A PAIR OF WARM FRONTS HAVE EVOLVED EARLY THIS MORNING ACROSS THE
TX/LA COAST WITH PRIMARY MARINE FRONT ANALYZED FROM CENTRAL TX NEWD
INTO FAR SERN LA AT 11Z...WHILE SECONDARY WARM FRONT DEVELOPING FROM
THE MS COAST NWWD TO NEAR TKX. IN ADDITION...WEAK COLD FRONT IS
EXPECTED TO BECOME BETTER DEFINED TO THE S-SW OF NEWD MOVING LOW
CENTER...THOUGH FRONT WILL LIKELY MOVE VERY LITTLE AND PERHAPS STALL
FROM NERN INTO CENTRAL TX TODAY. THIS WILL LEAVE A VERY MOIST AIR
MASS IN PLACE THROUGH THE PERIOD FROM THE TX COAST INTO THE LOWER MS
RIVER VALLEY.
...SERN TX INTO THE LOWER MS RIVER VALLEY...
SUPERCELLS HAVE REMAINED INTENSE WITH PERSISTENT LOW LEVEL ROTATION
FROM THE UPPER TX COAST INTO SRN LA/FAR SRN MS EARLY THIS MORNING...
ESPECIALLY NEAR THE MARINE FRONT. AREA VWP/S SUPPORT MODEL GUIDANCE
IN SUSTAINING VERY STRONG LLJ ACROSS THIS REGION FOR MUCH OF THE
DAY...WITH 11Z WNF PROFILER REVEALING 70 KT WINDS AT 1KM. THIS
LEAVES EXTREME LOW LEVEL SHEAR / EVIDENT THIS MORNING WITH OBSERVED
0-1 KM SRH IN EXCESS OF 400 M2/S2 AT KHGX AND KLCH / OVERSPREADING A
RICH TROPICAL BOUNDARY LAYER CHARACTERIZED BY SURFACE DEW POINTS IN
THE MID/UPPER 70S. WITH DIURNAL HEATING INCREASING POTENTIAL FOR
ROTATING STORMS TO ROOT INTO THIS RICH BOUNDARY LAYER...TORNADO
THREAT WILL REMAIN ENHANCED OVER THE REGION AND ISOLATED SIGNIFICANT
TORNADOES MAY OCCUR. THE LLJ WILL GRADUALLY VEER AND 50-70 KT
MAXIMUM IS FORECAST TO LIFT NNEWD INTO THE TN VALLEY LATER THIS
EVENING. HOWEVER...CONTINUED FEED OF TROPICAL AIR OFF THE GULF
COULD SUSTAIN A TORNADO THREAT ALONG THE GULF COAST FOR MUCH OF THE
PERIOD AS FORECAST SOUNDINGS MAINTAIN SFC-1 KM SRH IN EXCESS OF 150
M2/S2 UNDER 40+ KT SSWLY H85 FLOW THROUGH AT LEAST 06Z TONIGHT.
...CENTRAL TX INTO THE MID SOUTH...
SEVERE THREAT WILL BECOME MORE CONDITIONAL AWAY FROM THE GULF AS
INSTABILITY REMAINS WEAKER. HOWEVER...SURFACE DEWPOINTS NEAR 70F
AND EXTREME SHEAR WILL CONTINUE AHEAD OF EJECTING UPPER WAVE AND
ASSOCIATED LOW CENTER THROUGH THE PERIOD FROM CENTRAL TX INTO THE
MID SOUTH. SMALL LINES AND SUPERCELLS WILL LIKELY EVOLVE THROUGH
THE DAY AND MOVE RAPIDLY NEWD...WITH SEVERE THREAT INCREASING WHERE
HEATING CAN MIX INTO VERY MOIST SURFACE LAYER. PRIMARY SEVERE
THREAT MAY BE FROM LARGE HAIL AS STORMS REMAIN SLIGHTLY ELEVATED
ACROSS TX INTO THE EARLY AFTERNOON. HOWEVER...ONCE SUFFICIENT
MIXING OCCURS DAMAGING WIND AND ISOLATED TORNADO THREAT WILL
LIKEWISE INCREASE.
..EVANS/GUYER.. 10/16/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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