SPC AC 271608
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1108 AM CDT THU JUL 27 2006
VALID 271630Z - 281200Z
...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF NEW ENGLAND...
...THERE IS A SLGT RISK OF SVR TSTMS OHIO VALLEY AREA...
...THERE IS A SLGT RISK OF SVR TSTMS ARIZONA AND ADJACENT PORTIONS
OF CA AND SRN NV...
...SYNOPSIS...
WESTERLIES CONFINED TO NRN TIER OF CONUS WITH SEVERAL S/WV TROUGHS
MIGRATING EWD IN THE FLOW. MUCH OF THE ENERGY ASSOCIATED WITH THE
S/WVS REMAINS IN CANADA...HOWEVER THERE IS SOME ENHANCEMENT OF THE
SHEAR PROFILES S OF THE BORDER...PARTICULARLY GREAT LAKES EWD.
WEAK TROPICAL-LIKE SYSTEM CONTINUES TO LIFT NEWD ACROSS WRN AR AT
THIS TIME WHILE ANOTHER WEAK MID LEVEL VORT IS DROPPING SWD THRU
CENTRAL ROCKIES ON THE E SIDE OF UPPER HIGH CENTER OVER NV.
AIR MASS MUCH OF CONUS CHARACTERIZED BY VERY WARM AND MOIST
CONDITIONS AND GENERALLY WEAK SHEAR IN THE LOW LEVELS.
BOUNDARIES/FRONTS ARE DIFFICULT TO IDENTIFY.
...NERN U.S..
S/WV TROUGH CURRENTLY LOCATED FROM WRN QUEBEC TO CENTRAL NY WILL
LIFT NEWD ACROSS NEW ENGLAND TODAY. THE PRIMARY EFFECTS WILL BE TO
ENHANCE THE SHEAR PROFILES IN AN AREA OF MOIST AND UNSTABLE AIR THAT
RESIDES ACROSS THE NERN U.S. WITH MINIMAL CIN AND MLCAPES CLIMBING
TO 2000 J/KG AND ABOVE...THUNDERSTORMS WILL BE COMMON BY MID
AFTERNOON MUCH OF NERN U.S. SEVERE THREAT...I.E...WET MICRO BURSTS
AND MARGINAL HAIL...EXPECTED TO INCREASE NWD WHERE SHEAR SHOULD BE
25-30KT. STORM MODE WILL BE MULTI-CLUSTER GIVEN THE MARGINAL SHEAR
AVAILABLE. SEVERE THREAT SHOULD END AFTER 00Z WITH LOSS OF HEATING.
...OHIO VALLEY,..
CURRENT MID CLOUDINESS EXPECTED TO DECREASE ALLOWING THE MOIST AIR
MASS IN PLACE TO RAPIDLY DESTABILIZE ACROSS MUCH OF OH VALLEY
REGION BY MID AFTERNOON. WITH DEWPOINTS GENERALLY AOA 70F...
TEMPERATURES IN THE MID 80S WILL REMOVE MUCH OF CINH AND ALLOW
THUNDERSTORMS TO DEVELOP. PRIMARY SEVERE THREAT WILL BE LOCATED
WHERE STRONGEST HEATING CAN OCCUR IN CONJUNCTION WITH AREA OF 30KT
DEEP LAYER SHEAR. MODELS SUGGEST THIS WOULD BE MOST LIKELY FROM
CENTRAL/NRN IL EWD ACROSS IN AND OH. WITH MODEST LAPSE RATES AND
SHEAR...PRIMARY STORM MODE WILL BE MULTICELLULAR WITH POTENTIAL FOR
WET DOWNBURSTS AND MARGINAL HAIL.
...SOUTHWESTERN U.S..
WITH TWO FULL DAYS OF A SURGE...AIR MASS OVER SRN AZ MORE LIKE SRN
FL WITH PW/S AOA 2 INCHES AND WEAK LAPSE RATES. THERE IS A WELL
DEFINED VORT NOTED IN W/V IMAGERY OVER WRN CO HEADING S...THEN
EVENTUALLY SW TOWARD AZ THAT WILL ENHANCE MID LEVEL N/NELY WINDS
ACROSS THE STATE. ALONG WITH DRYING FROM THE N...AIRMASS OVER NRN
AZ AND CENTRAL MOUNTAINS WILL RAPIDLY DESTABILIZE THIS AFTERNOON
ALLOWING WIDESPREAD THUNDERSTORMS TO DEVELOP. WITH CAPES CLIMBING TO
AROUND 2000 J/KG AND LAPSE RATES STEEPENING TO 7C/KM LARGE HAIL AND
WET DOWNBURST WINDS ARE LIKELY OVER HIGHER TERRAIN. STEERING FLOW
SHOULD ALLOW STORMS TO MOVE/PROPAGATE S/SW INTO THE LOWER ELEVATIONS
WHERE IT CURRENTLY IS CLOUD COVERED. PRIMARY THREAT IN THE DESERTS
VALLEYS WOULD BE AGAIN LARGE HAIL AND WET DOWNBURSTS MORE LIKELY
VICINITY LOWER CO RIVER VALLEY NWD TO EXTREME SRN NV WHERE HEATING
POTENTIAL GREATEST AND LAPSE RATES ARE STEEPER.
...S FLORIDA...
WEAK TROUGH DROPPING SWD THRU FL RESULTED IN SOME MID LEVEL DRYING
SPREADING ACROSS FL PENINSULA. WITH LAPSE RATES NEAR 7C/KM AND
SBCAPES CLIMBING TO NEAR 3000 J/KG...A FEW STRONG/SEVERE
THUNDERSTORMS ARE LIKELY SRN HALF OF PENINSULA. MOST FAVORED AREA
WOULD INITIALLY BE ALONG E COAST SEA BREEZE FRONT AND THEN INLAND
WHERE HEATING IS STRONGEST BY MID AFTERNOON.
..HALES/JEWELL.. 07/27/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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