SPC Day 3 Convective Outlook Issued on 12 October 2014

Heat Continues for the East and South-Central U.S.; Strong to Severe Storms Across the Mid-Atlantic and Northeast

The extremely dangerous heat wave continues across the East Coast and much of the South-Central U.S. today. Record high temperatures are expected for some areas especially across the Mid-Atlantic where extreme heat risk conditions reside. There is a Slight Risk (level 2 of 5) of severe thunderstorms today for the northern Mid-Atlantic into portions of southern New England. Read More >

SPC AC 120730 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0230 AM CDT SUN OCT 12 2014 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE GULF COASTAL STATES INTO THE TN VALLEY AND SRN APPALACHIANS... ...SUMMARY... A FEW STRONG TO SEVERE STORMS WITH A THREAT FOR MAINLY DAMAGING WIND AND PERHAPS A COUPLE OF TORNADOES WILL REMAIN POSSIBLE TUESDAY MAINLY OVER A PORTION OF THE SOUTHEASTERN STATES INTO THE SOUTHERN APPALACHIANS. SEVERE THREAT APPEARS MORE LIMITED WITH NORTHWARD EXTENT INTO THE OHIO VALLEY. ...SYNOPSIS... MODELS HAVE TRENDED TOWARD ECMWF WITH A SLOWER AND MORE AMPLIFIED SOLUTION AND CLOSING OFF THE UPPER LOW OVER THE MIDDLE MS VALLEY REGION TUESDAY AND CONTINUING ONLY SLOWLY EAST DURING THE DAY. BY TUESDAY MORNING A COLD FRONT WILL EXTEND FROM A SFC LOW OVER IL SWD THROUGH THE TN VALLEY AND WRN AL. THE SFC LOW WILL OCCLUDE OVER IL WHILE TRAILING FRONT ADVANCES THROUGH THE TN VALLEY AND GULF COAST STATES. ...GULF COASTAL STATES THROUGH THE SRN APPALACHIAN AREA... AXIS OF RICHER GULF MOISTURE WITH NEAR 70 DEWPOINTS WILL HAVE ADVECTED THROUGH THE PRE-FRONTAL WARM SECTOR INTO A PORTION OF THE SERN STATES. HOWEVER...WIDESPREAD CLOUDS AND WEAK MID-LEVEL LAPSE RATES WILL RESULT IN MODEST INSTABILITY WITH MLCAPE REMAINING AOB 1000 J/KG. LINE OF STORMS WILL BE ONGOING FROM THE TN VALLEY SWD THROUGH AL. THIS ACTIVITY WILL REMAIN EMBEDDED IN NEARLY PARALLEL DEEP LAYER WINDS...ADVANCING SLOWLY EAST DURING THE DAY. STRONG WINDS ALOFT WILL PERSIST WITHIN ERN SECTOR OF THE UPPER LOW CIRCULATION WITH VERTICAL SHEAR REMAINING SUPPORTIVE OF ORGANIZED STORMS WITHIN THE LINE. A FEW STORMS MAY ALSO DEVELOP AHEAD OF THE LINE...ESPECIALLY WHERE BOUNDARY-LAYER WARMING OCCURS. POTENTIAL WILL EXIST FOR EMBEDDED LEWP AND SUPERCELL STRUCTURES WITH DAMAGING WIND THE PRIMARY THREAT...THOUGH A COUPLE OF TORNADOES CANNOT BE RULED OUT OVER THE GULF COASTAL STATES. ...OH VALLEY... INSTABILITY WILL REMAIN VERY LIMITED /AOB 500 J/KG/ IN THIS REGION. A FORCED LOW-TOPPED SQUALL LINE WILL LIKELY DEVELOP SLOWLY EAST DURING THE DAY. WHILE SOME POTENTIAL WILL EXIST FOR STRONG WIND GUSTS GIVEN THE STRONG KINEMATIC ENVIRONMENT...OVERALL THREAT SHOULD REMAIN LIMITED BY THE MARGINAL THERMODYNAMIC ENVIRONMENT. ..DIAL.. 10/12/2014 CLICK TO GET WUUS03 PTSDY3 PRODUCT NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z