SWODY1
SPC AC 120546
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1146 PM CST FRI JAN 11 2008
VALID 121200Z - 131200Z
..NO SVR TSTM AREAS FORECAST...
..SYNOPSIS...
IN MID/UPPER LEVELS...MEAN TROUGHING OVER CENTRAL CONUS WILL
MAINTAIN BROAD ZONE OF CYCLONIC FLOW FROM ROCKIES EWD. EMBEDDED
SHORTWAVE TROUGH -- NOW APPARENT IN MOISTURE CHANNEL IMAGERY OVER
CENTRAL ROCKIES -- IS FCST TO CONTINUE DIGGING SEWD AND AMPLIFYING
UNTIL 13/00Z-13/06Z TIME FRAME....WHEN IT WILL PIVOT EWD ACROSS
CENTRAL/E TX AND WRN LA. MEANWHILE...ANOTHER PERTURBATION NOW OVER
SD/NEB SHOULD FOLLOW NEARLY PARALLEL CYCLONIC PATH ACROSS MID/UPPER
MS VALLEY...REACHING LOWER MI...LM AND SERN MO BY END OF PERIOD.
ALTHOUGH BOTH PERTURBATIONS SHOULD RESULT IN SFC CYCLOGENESIS TO
THEIR ESE/SE...ONLY SRN TROUGH MAY HAVE ACCESS TO SUFFICIENT LOW
LEVEL MOISTURE FOR TSTMS.
AT SFC...DIFFUSE LOW INITIALLY ANALYZED OVER NE TX IS FCST TO
STRENGTHEN/CONSOLIDATE WITH APCH OF MID/UPPER PERTURBATION...MOVING
FROM N-CENTRAL TX AT 12/12Z TO VICINITY BPT/LCH AT 13/06Z. ATTACHED
COLD FRONT WILL MOVE SEWD OVER NWRN GULF BY END OF
PERIOD...OVERTAKING WRN PORTION OF QUASISTATIONARY FRONTAL ZONE NOW
ANALYZED OVER NERN/N-CENTRAL GULF.
..CENTRAL/SE TX TO ARKLATEX REGION...
WIDELY SCATTERED...HIGH BASED TSTMS MAY DEVELOP ACROSS PORTIONS
E-CENTRAL...SE AND NE TX THIS AFTERNOON...BEFORE SPREADING/MOVING
ENEWD ACROSS ARKLATEX REGION...THEN WEAKENING BY LATE EVENING. A
FEW OF THESE TSTMS MAY PRODUCE HAIL OR STG GUSTS...ATOP RELATIVELY
DRY BOUNDARY LAYER. ORGANIZED SVR POTENTIAL APPEARS TOO LOW FOR
CATEGORICAL OUTLOOK BECAUSE OF LIMITATIONS ON BUOYANCY IMPOSED BY
WEAK MOISTURE.
THIS REGION WILL EXPERIENCE VERY STRONG LARGE SCALE
ASCENT/DESTABILIZATION ALOFT THAT SHOULD SPREAD OVER PREFRONTAL
SECTOR. IN BOUNDARY LAYER...RICH MARINE MOISTURE IS FCST TO REMAIN
OVER GULF. INLAND THETAE ACROSS CENTRAL/E TX WILL BE LOW AS A
RESULT...WITH SFC DEW POINTS GENERALLY MID 30S F WHERE OPERATIONAL
MODELS AND SREF GUIDANCE PACKAGES ARE INDICATING CONVECTIVE
POTENTIAL. DESPITE MEAGER LOW LEVEL MOISTURE...EXPECT STEEPENING
LOW-MIDLEVEL LAPSE RATES...WEAK CINH AND CONVERGENCE NEAR FRONT/LOW
TO SUPPORT CONVECTIVE DEVELOPMENT...WITH ENOUGH SFC HEATING TO ALLOW
MLCAPES IN 100-500 J/KG RANGE. 0-6 KM SHEAR OF 50-70 KT IN FCST
SOUNDINGS SUGGESTS SOME POTENTIAL FOR ORGANIZED TSTMS...HOWEVER LACK
OF MORE ROBUST MOISTURE IS A SIGNIFICANT LIMITING FACTOR FOR SVR
POTENTIAL. LAPSE RATES ALOFT WILL WEAKEN WITH SWD EXTENT TOWARD
COAST...WHILE LOW LEVEL MOISTURE WILL BECOME EVEN MORE SCANT WITH
NWD EXTENT PAST ABOUT I-20.
..NRN FL/EXTREME SRN GA...
ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE INVOF
DIFFUSE/QUASISTATIONARY SFC FRONTAL ZONE. GREATEST TSTM POTENTIAL
INLAND SHOULD BE DURING EARLY-MID AFTERNOON WHEN SFC HEATING SHOULD
OFFSET VERY WEAK LAPSE RATES ALOFT...JUST ENOUGH TO GENERATE
BUOYANCY THAT PENETRATES UPWARD INTO ICING LAYERS SUITABLE FOR
LIGHTNING PRODUCTION. ALTHOUGH MID/UPPER LEVEL FLOW WILL REMAIN
FAVORABLE FOR SOME STORM ORGANIZATION...OFFSETTING FACTORS INCLUDE
WEAKNESS OF LOW LEVEL WINDS/SHEAR AND OF CONVERGENCE. LESS VEERED
SFC WINDS IN WARM SECTOR WOULD INCREASE LOW LEVEL SHEAR BUT ALSO
WOULD BRING RELATIVELY DRY AND EASILY MIXED AIR MASS NOW OVER
PENINSULA INTO INFLOW LAYER. SVR POTENTIAL APPEARS TOO CONDITIONAL
AND WEAK TO OUTLINE PROBABILISTIC OR CATEGORICAL AREAS ATTM.
.EDWARDS.. 01/12/2008
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