DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CDT WED JUN 27 2012 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER NRN MN.... ...NRN/CNTRL MN... WATER VAPOR IMAGERY SHOWS AN INTENSE UPPER LOW OVER SRN SASKATCHEWAN THAT IS FORECAST TO MOVE MAINLY EWD ACROSS THE CANADIAN PRAIRIE PROVINCES THROUGH TONIGHT. AS THE SYSTEM MOVES EWD...WEAK MID LEVEL HEIGHT FALLS ARE EXPECTED ACROSS EXTREME NRN MN WITH THE BULK OF THE DYNAMIC FORCING FOR LARGE SCALE ASCENT REMAINING NORTH OF THE US/CANADA BORDER. 12Z REGIONAL RAOBS INDICATED AN EXPANSIVE AREA OF VERY WARM 700 MB TEMPERATURES OF 16-18C ASSOCIATED WITH AN EML/CAPPING INVERSION THAT HAS SPREAD OVER THE UPPER MS VALLEY AND TOWARD THE UPPER GREAT LAKES. THIS WILL LIKELY INHIBIT SURFACE-BASED CONVECTION ALONG A COLD FRONT MOVING INTO THE UPPER MS VALLEY DESPITE A GRADUAL INCREASE IN LOW LEVEL MOISTURE INTO THE MN AREA. MODEL GUIDANCE INDICATES CONSIDERABLE UNCERTAINTY IN THE LIKELIHOOD OF CONVECTIVE DEVELOPMENT NEAR THE FRONT OVER NRN/CNTRL MN LATER THIS AFTERNOON AND EVENING...BUT THE PRESENCE OF STEEP LAPSE RATES/MODERATE INSTABILITY AND FAVORABLE DEEP LAYER SHEAR SUPPORTS A CONDITIONAL RISK OF SEVERE STORMS FOR ANY SUSTAINED UPDRAFTS THAT DEVELOP. RELATIVE PROXIMITY OF THE CANADIAN UPPER LOW SUGGESTS THE PROBABILITY OF DEEP CONVECTION MAY BE HIGHER CLOSER TO THE NRN MN BORDER...AND HAVE MAINTAINED CURRENT SLIGHT RISK AREA IN THIS REGION WITH LOWER /5%/ HAIL AND WIND PROBABILITY VALUES SWD INTO CENTRAL MN. ...CENTRAL ROCKIES INTO HIGH PLAINS A RELATIVELY NARROW PLUME OF MID LEVEL MOISTURE IS EVIDENT IN WATER VAPOR IMAGERY AND SOUNDER/GPS PW DATA FROM SERN AZ INTO THE CENTRAL ROCKIES WHERE SCATTERED HIGH-BASED CONVECTION IS OCCURRING THIS MORNING. ADDITIONAL CONVECTION IS EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF CENTRAL CO THIS AFTERNOON. THIS ACTIVITY IS EXPECTED TO SPREAD EWD INTO PARTS OF THE CENTRAL HIGH PLAINS LATE THIS AFTERNOON AND EVENING ALONG/NORTH OF A COLD FRONT MOVING SWD OVER THE AREA. SWLY MID LEVEL WINDS OF 25-30 KT WILL CONTRIBUTE TO SUFFICIENT VERTICAL SHEAR FOR A FEW MULTICELL CLUSTERS TO FORM. SOME STORMS MAY BE CAPABLE OF PRODUCING STRONG WIND GUSTS GIVEN THE PRESENCE OF A DEEP WELL-MIXED BOUNDARY LAYER. ...SRN FL... IN THE WAKE OF TD DEBBY NOW OFF THE NERN FL COAST...WSWLY DEEP LAYER WINDS ARE EVIDENT IN RAOB AND LOCAL VAD PROFILES OVER SRN FL. 12Z MFL RAOB EXHIBITED POTENTIAL INSTABILITY AND CONTINUED HEATING SOUTH OF A BAND OF CONVECTION ALONG A FMY-PBI LINE MAY PROMOTE DEVELOPMENT OF A FEW THUNDERSTORMS THIS AFTERNOON. INCREASING MID/UPPER LEVEL DRYING AS SEEN IN WATER VAPOR IMAGERY AND MODERATELY STRONG UNIDIRECTIONAL WSWLY FLOW ALOFT SUGGEST RISK OF ISOLATED STRONG WIND GUSTS WITH MORE INTENSE CONVECTIVE CELLS INTO THE EVENING. ..WEISS/LEITMAN.. 06/27/2012 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z CURRENT UTC TIME: 1631Z (11:31AM), RELOAD THIS PAGE TO UPDATE THE TIME "INFORMS YOU ON WEATHER" THIS BLOG WILL INFORM ON WEATHER MOSTLY FOR NORTHERN ILLINOIS AND SURROUNDING AREAS. ALSO MOST AREAS DURRING SEVERE WEATHER.
Wednesday, June 27, 2012
[UPDATED]THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTHERN MINNESOTA FOR TODAY
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