Apr 13, 2014 0100 UTC Day 1 Convective Outlook | |||||||||
Updated: Sun Apr 13 01:04:37 UTC 2014 ( | ) | |||||||||
Probabilistic to Categorical Outlook Conversion Table |
Categorical Graphic | |||||||||
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Probabilistic Tornado Graphic | |||||||||
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. |
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Probabilistic Damaging Wind Graphic | |||||||||
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point. |
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Probabilistic Large Hail Graphic | |||||||||
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point. |
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SPC AC 130101 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0801 PM CDT SAT APR 12 2014 VALID 130100Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS...LOWER MO VALLEY AND MID TO UPPER MS VALLEY... ...CNTRL PLAINS/MID TO UPPER MS VALLEY... THE LATEST WATER VAPOR IMAGERY SHOWS A SUBTLE SHORTWAVE TROUGH FROM CNTRL KS EXTENDING SWD INTO WRN OK. THIS FEATURE WILL CONTINUE TO MOVE EWD THIS EVENING AS A COLD FRONT ADVANCES SWD ACROSS THE CNTRL PLAINS. THUNDERSTORMS ARE INCREASING IN COVERAGE JUST AHEAD OF THE FRONT EXTENDING NEWD ACROSS ECNTRL KS TO CNTRL IA. SFC DEWPOINTS TO THE EAST OF THE FRONT ARE GENERALLY IN THE MID TO UPPER 50S F AND THIS IS CONTRIBUTING TO MODERATE INSTABILITY WITH OBJECTIVE ANALYSIS ESTIMATING MLCAPE IN THE 1500 TO 2500 J/KG RANGE. DUE TO LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE TROUGH...INCREASING LOW-LEVEL FLOW AND THE MODERATE INSTABILITY...THUNDERSTORMS SHOULD CONTINUE TO EXPAND IN COVERAGE EARLY THIS EVENING. THUNDERSTORMS SHOULD ORGANIZE INTO SEVERAL LARGE CLUSTERS AND MOVE EWD ACROSS THE SLIGHT RISK AREA THROUGH THE MID TO LATE EVENING. IN ADDITION TO MODERATE INSTABILITY...THE 00Z SOUNDING AT TOPEKA KS SHOWS 0-6 KM SHEAR OF 35 KT AND 850 TO 500 MB LAPSE RATE OF 8.2 C/KM. THIS ENVIRONMENT SHOULD BE FAVORABLE FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. THE GREATEST THREAT FOR LARGE HAIL SHOULD BE FROM NE KS EXTENDING NEWD INTO SRN AND CNTRL IA WHERE HAILSTONES OF GREATER THAN 2 INCHES WILL BE POSSIBLE. IN ADDITION TO THE LARGE HAIL THREAT...THE WIND DAMAGE THREAT SHOULD GRADUALLY INCREASE AS THUNDERSTORMS EXPAND IN COVERAGE. 0-3 KM LAPSE RATES AROUND 8.0 C/KM EVIDENT ON THE TOPEKA 00Z SOUNDING SHOULD ENHANCE DOWNDRAFT SPEEDS ESPECIALLY WITH SHORT LINE SEGMENTS THAT CAN ORGANIZE OVER THE NEXT FEW HOURS. ...SRN WI/LOWER MI... NUMEROUS THUNDERSTORMS ARE ONGOING FROM NE IA EXTENDING EWD ACROSS SRN WI INTO SRN LOWER MI JUST TO THE NORTH OF A SLOW-MOVING FRONTAL BOUNDARY. THE AIRMASS NORTH OF THE BOUNDARY IS COOL WITH A SFC INVERSION PRESENT. ABOVE THE SFC INVERSION...FORECAST SOUNDINGS SHOW MODERATE INSTABILITY WITH MUCAPE AROUND 1000 J/KG. THIS COMBINED WITH 40 KT OF EFFECTIVE SHEAR SHOULD BE SUFFICIENT FOR AN ISOLATED SEVERE THREAT OVER THE NEXT FEW HOURS. ISOLATED LARGE HAIL WILL BE THE PRIMARY THREAT BUT A FEW STRONG WIND GUSTS CAN NOT BE RULED OUT. WEAKER INSTABILITY IS EVIDENT FURTHER TO THE EAST ACROSS LOWER MI WHERE A MARGINAL HAIL AND WIND DAMAGE THREAT MAY CONTINUE THROUGH THE MIDDLE EVENING. ...WRN KS/NRN OK... THE LATEST SFC ANALYSIS SHOWS A 996 MB LOW OVER SW KS WITH A WELL-DEFINED DRYLINE EXTENDING SWD ACROSS WRN OK. WEAK INSTABILITY IS ANALYZED ACROSS WRN KS EXTENDING SWD ALONG THE DRYLINE WHERE OBJECTIVE ANALYSIS SHOWS MLCAPE VALUES IN THE 500 TO 1000 J/KG RANGE. MODEL FORECASTS SUGGEST THAT A FEW THUNDERSTORMS MAY DEVELOP NORTH OF THE SFC LOW AND SWD ALONG THE DRYLINE EARLY THIS EVENING AS A VORTICITY MAX MOVES INTO WRN KS. FORECAST SOUNDINGS AT GOODLAND KS AND GAGE OK SHOW VERY STEEP LAPSE RATES OF 8.5 C/KM FROM THE SFC UP TO ABOVE 500 MB. DUE TO THIS...A FEW STRONG WIND GUSTS WILL BE POSSIBLE WITH THUNDERSTORMS THAT INITIATE AND PERSIST EARLY THIS EVENING. ...SW TX... THE LATEST SFC ANALYSIS SHOWS A WELL-DEFINED DRYLINE IN PLACE FROM JUST EAST OF MIDLAND EXTENDING SWD TO JUST EAST OF THE BIG BEND. WATER VAPOR IMAGERY SHOWS A WELL-DEFINED VORTICITY MAX MOVING INTO FAR WEST TX. LARGE-SCALE ASCENT ASSOCIATED WITH THIS FEATURE SHOULD ENCOURAGE CONVECTIVE DEVELOPMENT ALONG THE DRYLINE DURING THE MID TO LATE EVENING. THE AIRMASS EAST OF THE DRYLINE IS MODERATELY UNSTABLE WITH MID-LEVEL LAPSE RATES AROUND 8.0 C/KM EVIDENT ON THE DEL RIO 00Z SOUNDING. THIS ALONG WITH SFC DEWPOINTS NEAR 60 F SHOULD BE ENOUGH FOR MARGINALLY SEVERE WIND GUSTS. AN ISOLATED HAIL THREAT MAY ALSO DEVELOP. ..BROYLES.. 04/13/2014 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z |