The SPC is forecasting ...severe thunderstorms expected over parts of the northeast us later today and tonight.... Please read the latest public statement about this event.
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SPC AC 061300 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 AM CDT SUN JUN 06 2010 VALID 061300Z - 071200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID ATLANTIC STATES AND SRN NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TN VLY THROUGH THE CNTRL APPALACHIANS INTO THE NORTHEAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF S GA/NRN FL... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HI PLNS... ...SYNOPSIS... LWR GRT LKS SHORTWAVE TROUGH WILL FURTHER AMPLIFY AS IT CONTINUES ESE OFF THE NEW ENGLAND CST EARLY MON...WHILE CNTRL/NRN RCKYS RIDGE PROGRESSES E INTO THE HI PLNS. IN THE WEST...SEVERAL LOW AMPLITUDE DISTURBANCES WILL TRACK ENE ACROSS THE PACIFIC NW/NRN GRT BASIN AS UPR HIGH HOLDS FIRM OVER SRN NM. SE OF THE HIGH...ELONGATED TROUGH WITH AT LEAST TWO EMBEDDED IMPULSES WILL PERSIST FROM THE NWRN GULF TO NRN FL. AT LWR LVLS...SEASONABLY STRONG SFC LOW NOW OVER S CNTRL NY WILL CONTINUE E INTO SRN NH BY EARLY AFTN...AND INTO THE GULF OF ME BY EVE. ASSOCIATED COLD FRONT SHOULD PROGRESS STEADILY E/SE ACROSS THE ERN THIRD OF THE NATION THROUGH THE PERIOD. THE WRN PORTION OF THE FRONT...MEANWHILE...WILL BECOME STNRY OVER N TX LATER TODAY...AND WILL REDEVELOP N TO THE CNTRL HI PLNS EARLY MON. ...CNTRL APPALACHIANS/MID ATLANTIC TO SRN/CNTRL NEW ENGLAND... A SUBSTANTIAL SVR WEATHER EVENT /DAMAGING WINDS AND A FEW TORNADOES/ REMAINS POSSIBLE TODAY FROM SERN NY AND CNTRL/SRN NEW ENGLAND SW THROUGH ERN PA/NJ TO THE CHESAPEAKE BAY REGION... BAND OF SCTD TSTMS...INCLUDING SEMI-DISCRETE SUPERCELLS AND BROKEN LINES...EXPECTED TO PERSIST THROUGH LATER THIS MORNING ALONG AND AHEAD OF AFOREMENTIONED COLD FRONT FROM SRN NY SW INTO SRN/CNTRL OH. DESPITE UNFAVORABLE TIME OF DAY...COMBINATION OF 50-60 KT DEEP WSWLY SHEAR AND FAIRLY RICH MOISTURE RETURN WILL MAINTAIN THREAT FOR OCCASIONAL TORNADOES AND LOCALLY DMGG WINDS. THIS THREAT SHOULD BE GREATEST ALONG AND JUST S OF SFC WAVE ALONG THE NY/PA BORDER. IN RESPONSE TO SFC HEATING AND CONTINUED EWD MOTION/AMPLIFICATION OF UPR TROUGH...EXPECT THE FRONTAL STORMS TO INCREASE IN NUMBER AND STRENGTH LATER THIS MORNING AND EARLY THIS AFTN OVER PARTS OF PA/WV AND SRN OH. OTHER STORMS SHOULD FORM BY MIDDAY ALONG PREFRONTAL CONFLUENCE AXIS/LEE TROUGH FROM THE CHESAPEAKE BAY NE INTO NEW ENGLAND. STRONG WIND FIELD ASSOCIATED WITH GRT LKS TROUGH /WITH 700 MB SPEEDS OF 50-70 KTS/...AND INCREASING SFC-BASED INSTABILITY /SBCAPE TO 2000 J PER KG IN MD/VA...AND 1000 J PER KG IN NEW ENGLAND/...SHOULD PROVE FAVORABLE FOR SCTD SUPERCELLS/SUSTAINED STORMS WITH DMGG WIND AND A FEW TORNADOES. THIS THREAT WILL BE GREATEST FROM THE PHILADELPHIA AREA NE INTO SRN AND PERHAPS CNTRL NEW ENGLAND THROUGH EARLY EVE. ...TN VLY/SRN APPALACHIANS INTO ERN KY...NC...SRN VA... MODERATE TO STRONG INSTABILITY WILL DEVELOP WITH DAYTIME HEATING ALONG PORTION OF COLD FRONT CROSSING PARTS OF KY/TN...AND ALONG PREFRONTAL TROUGH OVER VA/NC. MID/UPR LVL FLOW AND ASCENT WILL INCREASE OVER THESE AREAS AS REGION IS GLANCED BY SRN FRINGE OF GRT LKS TROUGH. 35-40 KT WNWLY 700 MB WINDS COULD SUPPORT ORGANIZED STORMS WITH DMGG WIND/HAIL...ESPECIALLY OVER NRN PARTS OF THE REGION. THE SVR THREAT COULD PERSIST INTO MID EVE IN VA/NC. ...NW TX TO CNTRL HI PLNS... SFC HEATING EXPECTED TO GENERATE STRONG INSTABILITY /SBCAPE TO 3000 J PER KG/ IN ZONE OF WEAK DEEP SHEAR ALONG AND JUST S OF STALLING FRONT OVER NW TX LATER TODAY. SOMEWHAT LESSER CAPE /AROUND 2000 J PER KG/ BUT GREATER DEEP SHEAR WILL EXIST FARTHER NW INTO ERN CO...ON NE EDGE OF NM UPR HIGH. UPSLOPE OVER THE CO FOOTHILLS...AND WEAK CONVERGENCE NEAR FRONT IN TX...EXPECTED TO SUPPORT SCTD STRONG AFTN STORMS OVER BOTH REGIONS. PULSE ACTIVITY IN TX MAY YIELD SVR HAIL/LOCALLY DMGG WIND. DESPITE ABSENCE OF APPRECIABLE LARGE SCALE FORCING FOR ASCENT...A FEW SUPERCELLS COULD FORM IN ERN CO...GIVEN 40+ KT DEEP WNWLY SHEAR WITH A SUBSTANTIAL VEERING COMPONENT IN THE VERTICAL AND SUSTAINED UPSLOPE FLOW. LATE TODAY OR EARLY THIS EVE...ADDITIONAL STORMS SHOULD FORM OVER WRN NEB...IN AREA OF STRENGTHENING WAA ASSOCIATED WITH NOCTURNALLY-ENHANCED LLJ AND PASSING DISTURBANCES IN WNW FLOW OVER THE UPR MS VLY. THIS ACTIVITY COULD EVOLVE INTO A LATE NIGHT MCS POSING A THREAT FOR SVR HAIL AND POSSIBLY DMGG WIND. ...S GA/FL... ERN MEMBER OF ELONGATED UPR DISTURBANCE OVER THE GULF STATES LIKELY WILL AFFECT LOCATION/TIMING OF DIURNALLY ENHANCED STORMS OVER FL/S GA AND POSSIBLY CSTL SC. 25-30 KT WNWLY MID LVL FLOW ON S SIDE OF TROUGH MAY YIELD A FEW ORGANIZED STORMS WITH LOCALLY DMGG WINDS THROUGH EARLY EVE. ..CORFIDI/STOPPKOTTE.. 06/06/2010 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z