ZCZC MKCSWODY1 000 ACUS1 KMKC 310632 SWODY1 MKC AC 310632 CONVECTIVE OUTLOOK...REF AFOS NMCGPH94O. VALID 311200Z - 011200Z REF WW NUMBER 0471...VALID TIL 1000Z REF WW NUMBER 0472...VALID TIL 1000Z REF WW NUMBER 0473...VALID TIL 1100Z THERE IS A HIGH RISK OF SVR TSTMS OVER PARTS OF NY/PA AND WRN VT/MA. THIS AREA LIES TO THE RIGHT OF A LINE FROM MSS PBG 15 S RUT 20 W BAF 15 E AVP DUJ ERI. SURROUNDING THIS REGION...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF WRN NEW ENGLAND/CNTRL AND SRN PA/OH/IND/KY AND TN. THIS AREA LIES TO THE RIGHT OF A LINE FROM 35 NW EFK EEN BDR TTN 15 SE LBE 20 NW PKB 40 NW HTS JKL 30 W TRI TYS 20 SE BNA 35 S CKV 40 NE DYR 15 N PAH EVV 10 S MIE JXN 45 NNE MTC. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 E ECG 35 NE RWI 25 SSW ROA AVL CHA 20 N MSL 20 NE MEM ARG 15 WNW CGI DEC 20 NW LAF SBN GRR 20 ENE OSC. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 SW HUM GPT 45 SSW SEM 25 S AUO ANB 20 S MSL UOX 30 ESE PGO MLC 20 NW MKO UMN JEF UIN CID 20 SSW MCW 30 NNW OMA 10 N GRI 25 SE MCK 50 ENE 4LJ 20 W LIC LAR 15 SE RKS SLC U31 35 WSW BIH 15 N SAC 30 W MHS 30 ESE SLE PDT 30 E EPH 45 ENE BLI ...CONT... 35 NNE CTB LWT 30 SSE MLS 25 ESE REJ 15 ESE P05 40 SW MHE 30 NE FSD AXN TVF 65 W D45. MANITOBA SHORTWAVE TROF EXPECTED TO CONTINUE DROPPING SEWD INTO THE UPPER GREAT LAKES THIS PERIOD...RESULTING IN CONTINUED DEEPENING OF SURFACE LOW NOW OVER WI /WELL-SHOWN IN CURRENT PRESSURE CHANGE DATA/. THE SEWD MOVEMENT OF THE CANADIAN SYSTEM EXPECTED TO ALSO RESULT IN SIGNIFICANT STRENGTHENING OF THE MID-LEVEL WLY FLOW TOPPING THE SRN PLAINS RIDGE...AND LARGE HEIGHT FALLS /AROUND 180M/ OVER THE NORTHEAST. ...UPPER OH VALLEY/ERN GREAT LAKES... A SEVERE THUNDERSTORM OUTBREAK APPEARS IN STORE FOR MUCH OF UPSTATE NY AND THE UPPER OH VALLEY. SURFACE BOUNDARY NOW STALLED OVER CENTRAL PA EXPECTED TO SURGE NWD INTO NY SUNDAY MORNING IN RESPONSE TO CONTINUED STRONG PRESSURE FALLS OVER THE ERN GREAT LAKES. THIS WILL ALLOW VERY MOIST /DEWPOINTS IN THE MID 60S/ BOUNDARY LAYER TO SPREAD NWD BENEATH INCREASING WLY FLOW ALOFT. MID-LEVEL LAPSE RATES SHOULD BE FAIRLY STEEP...ON THE ORDER OF 7.5 DEG C PER KM. WITH 500 MB WLY FLOW LIKELY TO BE IN EXCESS OF 60 KTS /EXTRAPOLATING CURRENT CONDITIONS OVER WI AND LK MI/...AND SWLY LOW LEVEL JET SPEEDS LIKELY TO INCREASE TO ABOVE 50 KTS /AS GREAT LAKES SURFACE LOW CONTINUES TO DEEPEN/...CONDITIONS WILL BE FAVORABLE FOR BOW ECHOES AND SUPERCELLS...ESPECIALLY IN VICINITY OF WARM FRONT. EXPECT SOME SEVERE WEATHER /LIKELY IN THE FORM OF A DERECHO OR BOW ECHO/ TO BE ON-GOING AT THE START OF THE PERIOD OVER SRN LWR MI/NRN OH/SE ONTARIO. THIS ACTIVITY...AND NEW DEVELOPMENT...WILL LIKELY SWEEP E ACROSS NY/NRN PA DURING MAX HEATING TIME...WITH THE THREAT FOR DAMAGING WINDS/LARGE HAIL AND TORNADOES. GIVEN WLY FLOW ALOFT...SUPERCELL POTENTIAL AND LOW-LEVEL ROTATION WILL ALSO BE ENHANCED WHERE CHANNELING FORCES THE BOUNDARY LAYER FLOW TO REMAIN SLY ALONG THE HUDSON AND CT RIVER VALLEYS. ...LOWER OH AND TN VALLEYS... DAYTIME HEATING AND CONVERGENCE ALONG TRAILING COLD FRONT/PRE- FRONTAL WINDSHIFT LINE LIKELY TO RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT OVER PARTS OF IND AND KY SUNDAY AFTERNOON. DEEPENING OF LARGE SCALE TROF OVER THE NORTHEASTERN STATES EXPECTED TO RESULT IN INCREASED WNW UPPER FLOW OVER THE LOWER OH VALLEY. WITH STEEP MID-LEVEL LAPSE RATES /AROUND 8 DEG C PER KM/...AMPLE BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE LOW 70S/...AND INCREASING HIGH LEVEL DIVERGENCE IN PLACE...THE STORMS SHOULD EVOLVE INTO A STRONG TO SEVERE MCS. THIS SYSTEM SHOULD TRACK ESE INTO TN WITH DAMAGING WINDS AND PERHAPS SOME LARGE HAIL LATER SUNDAY AND SUNDAY NIGHT. ...A PUBLIC SEVERE WEATHER OUTLOOK /AFOS MESSAGE I.D. MKCPWOMKC/ WILL BE ISSUED AT 11Z... ..CORFIDI.. 05/31/98 NNNN