SPC AC 251620
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1120 AM CDT TUE JUL 25 2006
VALID 251630Z - 261200Z
...THERE IS A SLGT RISK OF SVR TSTMS NORTH CENTRAL STATES...
...NCENTRAL U.S...
SERIES OF S/WV TROUGHS MOVING IN THE WNWLY FLOW FROM SRN CANADA TO
NEW ENGLAND. ONE IMPULSE CURRENTLY MOVING ESEWD CANADIAN PRAIRIE
PROVINCES REACHING WRN GREAT LAKES BY 12Z WED. SURFACE FEATURES OF
IMPORTANCE ARE THE TROUGH LOCATED FROM ERN SD SWWD INTO NWRN KS AND
A WEAK COOL FRONT NOW PUSHING EWD ACROSS WRN ND INTO ERN WY AHEAD OF
THE S/WV TROUGH.
A WARM AND POTENTIALLY MDT TO VERY UNSTABLE AIR MASS IS IN PLACE
ACROSS MUCH OF THE NCENTRAL U.S. WITH DEWPOINTS IN THE MID 60S TO
NEAR 70F COMMON FROM ERN DAKOTAS/NEB TO WRN GREAT LAKES. WITH
STRONG DAYTIME HEATING MUCH OF AREA...THUNDERSTORMS WILL DEVELOP
VICINITY OF BOTH THE FRONTAL SYSTEM AND SURFACE TROUGH BY MID
AFTERNOON.
WITH MLCAPES RANGING UPWARDS TO 2500 J/KG AND LAPSE RATES GENERALLY
7C/KM OR GREATER...LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE.
IDENTIFYING THE MOST FAVORABLE REGION FOR THE HIGHER SEVERE
POTENTIAL IS DIFFICULT WITH THE GENERALLY WEAK LOW LEVEL FLOW AND
CONVERGENCE OVER MUCH OF THE NCENTRAL STATES. HOWEVER AS THE UPPER
TROUGH APPROACHES...CONDITIONS WOULD FAVOR MORE ORGANIZED SEVERE
POTENTIAL DEVELOPING BY LATE THIS AFTERNOON ACROSS SRN MN/NRN IA IN
AREA OF POOLED MOISTURE/INSTABILITY. AN MCS COULD THEN PROPAGATE
INTO WI THIS EVENING WITH ASSOCIATED SEVERE THREAT.
...NEW ENGLAND...
BAND OF CLOUDINESS/PCPN THAT HAS SPREAD EWD ACROSS NRN NH/VT AND
MAINE...EXPECTED TO LIMIT HEATING/DESTABILIZATION THIS AFTERNOON IN
AREA OF EARLIER SLIGHT RISK. S/WV TROUGH SWINGING EWD ACROSS QUEBEC
HAS ENHANCED SHEAR PROFILES ACROSS MUCH OF NEW ENGLAND. THINNING OF
CLOUDS WILL ALLOW SOME HEATING THIS AFTERNOON NRN NEW ENGLAND.
HOWEVER STILL EXPECT INSUFFICIENT INSTABILITY TO DEVELOP TO SUPPORT
ORGANIZED SEVERE THREAT. A FEW STRONG/SEVERE STORMS ARE
LIKELY...PARTICULARLY ACROSS WRN/NRN NY EWD ALONG THE SRN EDGE OF
CURRENT CLOUDINESS.
...SWRN U.S...
GULF SURGE UNDERWAY WITH VERY MOIST AIR MASS SPREADING NWD ACROSS
SERN CA DESERTS AND MUCH OF SRN AZ. WITH STEEP LAPSE RATES IN PLACE
THE LOW LEVEL MOISTURE INCREASE SHOULD RESULT IN A SUBSTANTIALLY
MORE UNSTABLE AIR MASS THIS AFTERNOON S OF MOGOLLON RIM WWD TO SRN
CA MTS. WITH MLCAPES OVER THE DESERTS RISING TO WELL ABOVE 2000 J/KG
THE PRIMARY QUESTION REGARDING A SEVERE THREAT IS STORM INITIATION.
STEERING FLOW IS GENERALLY WEAK ELY TO THE S OF 4 CORNERS UPPER
HIGH. STORMS WILL DEVELOP OVER HIGHER TERRAIN DURING AFTERNOON AND
SLOWLY PROPAGATE TOWARD LOWER ELEVATIONS. IF THE STEERING FLOW WAS
STRONGER WOULD CONSIDER A SLIGHT RISK...BUT FOR NOW WILL JUST ADD
LOW PROBABILITIES OF BOTH WIND AND HAIL.
..HALES/JEWELL.. 07/25/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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