SPC AC 150522
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1122 PM CST THU JAN 14 2010
VALID 151200Z - 161200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
SPLIT-FLOW PATTERN NOW PREVAILS OVER CENTRAL/WRN CONUS BECAUSE OF
BROAD MID-UPPER CYCLONE NOW ANALYZED OVER NRN MEX. NRN STREAM
SHORTWAVE TROUGH -- EVIDENT ATTM IN MOISTURE CHANNEL IMAGERY OVER WY
AND ERN MT -- IS FCST TO TURN SSEWD ACROSS CENTRAL HIGH
PLAINS...REACHING PORTIONS SRN KS...WRN OK AND TX PANHANDLE BY
16/12Z. THOUGH REASONABLY CONSISTENT IN TRACK...CONSIDERABLE
VARIATION EXISTS AMONG OPERATIONAL/DETERMINISTIC MODELS REGARDING
INTENSITY OF THIS PERTURBATION BY END OF PERIOD. 15/00Z WRF
EXHIBITS DISCRETE AND NEARLY CLOSED LOW...IN AGREEMENT WITH PRIOR
ECMWF. HOWEVER...MOST SREF MEMBERS...ALONG WITH LATEST OPERATIONAL
SPECTRAL...FCST OPEN-WAVE TROUGH WITH ONLY WEAK EMBEDDED LOW AT
BEST. CONSENSUS SOLUTION WEIGHTED TOWARD SREF RESEMBLES OPERATIONAL
SPECTRAL THROUGH PERIOD...ALTHOUGH SPECTRAL BECOMES MORE OF AN
OUTLIER AFTER THIS PERIOD.
AS GREAT PLAINS TROUGH APCHS SRN HIGH PLAINS...MEX CYCLONE IS
EXPECTED TO PIVOT/REDEVELOP NEWD ACROSS NERN MEX TOWARD LOWER/MIDDLE
TX COAST...SURROUNDED BY BROAD BELT OF CYCLONIC FLOW ARCHING ACROSS
WRN/CENTRAL MEX AND WRN GULF. AS THIS OCCURS...SFC PRESSURE FALLS
NOW OCCURRING OVER LEE SIDE OF SIERRA MADRE ORIENTAL ARE EXPECTED TO
CONSOLIDATE INTO DISTINCT SFC CYCLONE OVER LOWER RIO GRANDE VALLEY
AREA BETWEEN 15/12Z-15/18Z. LOW WILL INTENSIFY AS IT MOVES EWD THEN
ENEWD ACROSS NWRN GULF...POSSIBLY OCCLUDING WITH TRIPLE-POINT
CYCLONE DEVELOPING S OR SE OF LA COAST. EVERY PROG KEEPS LOW AND
ATTACHED WARM FRONT WELL S OF CENTRAL GULF COAST REGION UNTIL AFTER
DAY-1 PERIOD.
...S TX...
MRGL/CONDITIONAL TORNADO AND SVR GUST POTENTIAL EXPECTED TO CARRY
OVER FROM END OF PRIOR OUTLOOK PERIOD INVOF LOWER TX COAST BEFORE
ABOUT 15/18Z. COOLING ALOFT AND RELATED STEEPENING OF LAPSE RATES
OVER THIS REGION DURING LATE MORNING/MIDDAY HOURS WILL KEEP MLCAPES
AROUND 1000 J/KG...BUT WITH MORE VERTICALLY COMPRESSED BUOYANT
PROFILES THAN AT 15/12Z. POTENTIAL BRIEFLY MAY EXIST FOR ISOLATED
HAIL NEAR SVR LEVELS. THEN ANY REMAINING SVR THREAT SHOULD SHIFT
OFFSHORE WITH DEEPENING SFC LOW...THOUGH SVR POTENTIAL WILL INCREASE
CONSIDERABLY ACROSS OPEN GULF WATERS...OUTSIDE OUTLOOK DOMAIN.
OVER LAND...DURING FIRST FEW HOURS OF PERIOD...ENLARGED LOW LEVEL
HODOGRAPHS WILL BE PRESENT IN SFC WARM FRONTAL ZONE S OF CRP...INVOF
PADRE ISLAND AND IN REMAINING WARM SECTOR AIR ACROSS LOWEST VALLEY
REGION...WITH 0-1 KM SRH 150-250 J/KG POSSIBLE. HOWEVER...KINEMATIC
PROFILES WILL INCLUDE BACKING AND SOMEWHAT WEAKENING FLOW WITH
HEIGHT FROM LOW-MIDDLE LEVELS OVER THIS AREA...INDICATING POTENTIAL
FOR MOSTLY LINEAR CONVECTIVE MODE AND LIMITED DEEP-LAYER
SHEAR...I.E. EFFECTIVE SHEAR MAGNITUDE LESS THAN 30 KT IN MOST FCST
SOUNDINGS.
..EDWARDS.. 01/15/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
|
