The SPC is forecasting ...major tornado and severe weather outbreak expected over parts of the lower mississippi...mid mississippi...and lower ohio valleys this afternoon and tonight.... Please read the latest public statement about this event.
| Categorical Graphic |
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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. |
| 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. |
| 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. |
SPC AC 260056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT WED MAY 25 2011 VALID 260100Z - 261200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN OH...CENTRAL/SRN INDIANA...EXTREME ERN IL...KY...WRN-MID TN...NRN MS...EXTREME SERN AR... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE IN CORRIDOR FROM SE TX TO WRN NY...SRN LOWER MI AND NERN IL.... ...SYNOPSIS... PROGRESSIVE UPPER-AIR PATTERN OVER CONUS FEATURES HIGH-AMPLITUDE SHORTWAVE TROUGHS OVER NRN CA AND LOWER MO/MID MS RIVER VALLEY REGION. AS STG RIDGING BETWEEN THEM SHIFTS EWD...COMPACT CYCLONE EMBEDDED WITHIN ERN TROUGH WILL DO LIKEWISE...ITS CENTER MOVING EWD ACROSS STL AREA BY END OF PERIOD. ASSOCIATED SFC CYCLONE...ANALYZED AT 23Z OVER NRN MO...IS FCST TO MOVE EWD TO ESEWD OVER PORTIONS CENTRAL/SRN IL BY 26/12Z...WITH QUASISTATIONARY SYNOPTIC FRONTAL ZONE NEWD ACROSS SERN ONT AND ST LAWRENCE VALLEY. SFC COLD FRONT -- ANALYZED FROM LOW SEWD OVER ERN OZARKS THEN SWWD ACROSS E TX -- IS EXPECTED TO REACH WRN TN...SERN AR...NRN LA AND S-CENTRAL TX BY END OF PERIOD. ...GREAT LAKES TO LOWER MS VALLEY... SVR TSTM OUTBREAK...INCLUDING SEVERAL TORNADIC AND POTENTIALLY TORNADIC SUPERCELLS...PERSISTS FROM SRN AR TO IL ASSOCIATED WITH PRE-COLD FRONTAL CONVERGENCE ZONE...WITH LOBE EXTENDING EWD INTO OH S OF QUASISTATIONARY FRONT. NRN PORTION OF MS VALLEY/IL BAND IS UNDERGOING QLCS TRANSITION WITH ENHANCED DAMAGING GUST THREAT...WHILE EMBEDDED SUPERCELLS/MESOCIRCULATIONS STILL CAN PRODUCE TORNADOES. ENHANCED DAMAGING WIND THREAT EXISTS WITH QLCS NEAR AND S OF OUTFLOW BOUNDARY THAT WAS ANALYZED FROM CENTRAL IL ACROSS S-CENTRAL INDIANA TO SWRN OH. MEANWHILE MORE DISCRETE OR CLUSTERED STORM MODES SHOULD PERSIST FOR LONGER PERIOD OF TIME FARTHER S. REF SPC WWS 370...371...AND 373-375...AS WELL AS ACCOMPANYING MESOSCALE DISCUSSIONS...FOR LATEST NEAR-TERM FCST GUIDANCE ON THIS EVENT. SVR THREAT WILL SHIFT EWD AHEAD OF COLD FRONT AND EXTEND THROUGH MOST OF TONIGHT...WITH ONLY GRADUAL SFC COOLING OVER THOSE PORTIONS OF WARM SECTOR NOT STABILIZED BY EXTENSIVE CONVECTION. RICH MOISTURE AND HIGH THETAE WILL PERSIST IN PRE-STORM INFLOW REGION...HELPING TO MAINTAIN EFFECTIVELY SFC-BASED INFLOW PARCELS IN ENVIRONMENT CHARACTERIZED BY VERY FAVORABLE DEEP-LAYER SHEAR. MOREOVER...LLJ IS FCST TO INTENSIFY SOMEWHAT THIS EVENING FROM TN VALLEY REGION NEWD OVER OH...FURTHER STRENGTHENING 0-1 KM AGL SHEAR/SRH AND ENLARGING HODOGRAPHS IN SUPPORT OF SIGNIFICANT-SVR THREAT. ..EDWARDS.. 05/26/2011 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z