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| Probabilistic Tornado Graphic | |||||||||
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| 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 | |||||||||
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| 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 | |||||||||
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| 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 261254 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0754 AM CDT SUN MAY 26 2013 VALID 261300Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE HIGH PLNS AND PARTS OF THE CNTRL/NRN PLNS... ...SYNOPSIS... BC/WA UPR LOW WILL DEVOLVE INTO A SOMEWHAT MORE PROGRESSIVE OPEN TROUGH THIS PERIOD AS UPSTREAM JET STREAK IN THE NE PACIFIC BEGINS TO CARVE A LARGER-SCALE NEGATIVE TILT TROUGH OVER THE REGION. DOWNSTREAM ACROSS THE REMAINDER OF THE CONUS...PLNS/UPR MS VLY RIDGE WILL EDGE SLOWLY E...WHILE SEASONABLY STRONG LOW RETREATS SLOWLY NE TOWARD THE GULF OF ST LAWRENCE. SEVERAL WEAK DISTURBANCES WILL MOVE FROM THE GRT BASIN/NW U.S. INTO THE CNTRL/NRN HIGH PLNS AND UPR MS VLY...IN MODERATE SW TO WSW FLOW ON ERN SIDE OF BC/WA LOW. AT THE SFC...AN ELONGATED AREA OF LOW PRESSURE WILL PERSIST FROM SE MT THROUGH ERN CO INTO ERN NM AND THE WRN OK/TX PANHANDLES. A DRY LINE/LEE TROUGH WILL ACCOMPANY THE ELONGATED LOW OVER THE CNTRL/SRN HIGH PLNS....AND A FRONT WILL REMAIN MORE OR LESS QSTNRY FROM SRN SD/NRN NEB SEWD INTO MID MS/LWR OH VLYS. BOTH THE LEE TROUGH AND THE FRONT WILL ONCE AGAIN SERVE TO FOCUS STRONG TO SVR TSTM DEVELOPMENT THIS PERIOD. ...CNTRL/NRN PLNS THIS AFTN THROUGH TNGT... PERSISTENT SSELY LOW-LVL FLOW EAST OF ELONGATED LOW/LEE TROUGH WILL FURTHER MOISTEN BOUNDARY LAYER FROM THE NRN HIGH PLNS SSE INTO THE CNTRL PLNS TODAY...WITH DEWPOINTS IN THE MID TO UPR 60S F EXPECTED OVER NEB/KS AND UPR 50S/LOW 60S IN SD. AT THE SAME TIME...WSWLY UPR FLOW WILL MAINTAIN EML OVER REGION...CONTRIBUTING TO 2000-3000 J/KG MLCAPE FROM ERN MT AND WRN/SRN SD SWD INTO WRN/CNTRL PORTIONS OF NEB/KS. TSTMS SHOULD ONCE AGAIN FORM WITH AFTN HEATING ALONG THE LEE TROUGH IN NEB/KS...OVER THE BLACK HILLS/NE WY MOUNTAINS...AND IN CONVERGENT LOW-LVL FLOW E OF LOW/NEAR STNRY FRONT IN ERN MT/SD. THE STORMS SHOULD STRENGTHEN AS THEY MOVE ENE DEEPER INTO LOW-LVL MOIST AXIS. AMPLE /35-40 KT/ SWLY DEEP SHEAR SHOULD EXIST DOWNSTREAM FROM BC/WA UPR LOW TO SUPPORT SUSTAINED STORMS/SUPERCELLS...WITH SELY NEAR-SFC WINDS ENLARGING LOW-LVL HODOGRAPHS. THIS SETUP MAY YIELD A FEW ARCS/SHORT BANDS OF FAIRLY NUMEROUS STORMS POSING A RISK FOR VERY LARGE HAIL....LOCALLY DMGG WIND AND TORNADOES. IT SEEMS LIKELY THAT SOME OF THE STORMS...ESPECIALLY IN NEB AND WRN/SRN SD...WILL EVOLVE INTO ONE OR MORE SIZABLE CLUSTERS GIVEN BROAD NATURE OF MOIST AXIS AND NOCTURNAL STRENGTHENING OF SLY LLJ. THESE SYSTEMS MAY POSE A CONTINUED RISK FOR SVR HAIL/WIND INTO EARLY MON. ...SRN HIGH PLNS THIS AFTN/EVE... ISOLD TO WDLY SCTD STORMS SHOULD ONCE AGAIN FORM IN RESPONSE TO SFC HEATING ALONG DRY LINE FROM WRN KS SSW INTO W TX. THE STORMS LIKELY WILL INTENSIFY AS THEY MOVE INTO LOW-LVL MOIST AXIS...WHERE 2000-3000 J/KG MLCAPE WILL EXIST. 30-35 KT WSWLY DEEP SHEAR ASSOCIATED PRIMARILY WITH THE SRN BRANCH OF THE UPR JET SHOULD PROMOTE BOTH MULTICELLS AND SUPERCELLS CAPABLE OF LARGE HAIL...DMGG WIND...AND PERHAPS A TORNADO THROUGH MID-EVE. ..CORFIDI/BOTHWELL.. 05/26/2013 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z |