SPC AC 141608
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1108 AM CDT THU SEP 14 2006
VALID 141630Z - 151200Z
...NO SVR TSTM AREAS FORECAST...
...ND TONIGHT...
AMPLIFICATION OF THE FLOW REGIME IS UNDERWAY OVER THE CONUS AS A
DEEP MID LEVEL TROUGH DIGS SEWD OVER THE PAC NW AND HEIGHTS RISE
OVER MS VALLEY. AT THE SURFACE...LEE CYCLOGENESIS IS OCCURRING OVER
THE WRN DAKOTAS...DOWNSTREAM FROM THE AMPLIFYING PAC NW TROUGH.
HOWEVER...THE INDUCED SLY FLOW ACROSS THE PLAINS CONSISTS OF
RESIDUAL BOUNDARY LAYER MOISTURE /GENERALLY MID-UPPER 50S/...WITH
THE MARITIME TROPICAL AIR MASS CONFINED TO S OF A STALLED FRONT
ACROSS THE NRN GULF OF MEXICO. A WARM ELEVATED MIXED LAYER IS ALSO
OVERSPREADING THE NRN PLAINS...THUS THE BOUNDARY LAYER WILL REMAIN
CAPPED THROUGH THE MAJORITY OF THE PERIOD. THE MORE PROBABLE AREA
FOR CONVECTIVE INITIATION WILL BE FROM 06-12Z ALONG THE BAROCLINIC
ZONE /NE OF THE SFC LOW/ IN N AND NW ND...WHERE ASCENT MAY BE
SUFFICIENT FOR SATURATION AND RELEASE OF MODERATE ELEVATED
INSTABILITY. THUS...WILL INTRODUCE A CONDITIONAL LOW PROBABILITY
HAIL THREAT TO THIS AREA FOR LATE TONIGHT.
...SRN HIGH PLAINS THIS AFTERNOON/EVENING...
THE REMNANTS OF THE PREVIOUS CLOSED LOW OVER AZ ARE EJECTING NEWD
OVER NM AS A WEAKENING OPEN WAVE THIS MORNING. 12Z SOUNDINGS ACROSS
THE SRN HIGH PLAINS...MODIFIED FOR AFTERNOON TEMPERATURES IN THE 80S
WITH BOUNDARY LAYER DEWPOINTS OF 56-60 F...SHOW THE POTENTIAL FOR
MLCAPE OF 500-1000 J/KG WITH LITTLE CONVECTIVE INHIBITION. A FEW
STORMS SHOULD FORM INVOF THE LEE TROUGH NEAR THE TX/NM BORDER THIS
AFTERNOON BEFORE THE MID LEVEL WAVE PASSES...AND THIS CONVECTION
WILL SPREAD EWD/NEWD INTO W TX/WRN TX PANHANDLE. THE COMBINATION OF
MODEST INSTABILITY AND FORECAST WIND PROFILES APPEAR MARGINALLY
FAVORABLE FOR STORMS WITH SUPERCELL STRUCTURES...THE STRONGEST OF
WHICH COULD PRODUCE HAIL AND WIND GUSTS NEAR SEVERE LIMITS.
...NW AZ INTO UT THIS AFTERNOON/EVENING...
AS THE MID LEVEL TROUGH AMPLIFIES OVER THE PAC NW...HEIGHT
GRADIENTS/FLOW WILL INCREASE OVER THE SRN GREAT BASIN BY LATER TODAY
INTO TONIGHT. ALSO...A SEPARATE SHORTWAVE TROUGH NOW OVER THE SRN
SIERRAS WILL MOVE EWD OVER SRN NV/NW AZ/SRN UT. SCATTERED
THUNDERSTORMS ARE ALREADY DEVELOPING OVER THIS AREA...AND STORM
COVERAGE WILL INCREASE THIS AFTERNOON AS THE LOW LEVELS DESTABILIZE
WITH SURFACE HEATING IN CLOUD BREAKS. THE INCREASING FLOW FIELDS
AND TYPICALLY STEEP LOW-MID LEVEL LAPSE RATES COULD SUPPORT ISOLATED
STRONG/DAMAGING GUSTS...AND PERHAPS MARGINALLY SEVERE HAIL WITH THE
MORE INTENSE STORMS.
..THOMPSON/JEWELL.. 09/14/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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