Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 022342 AFDBTV AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 742 PM EDT SUN AUG 2 2015 .SYNOPSIS... WEAK HIGH PRESSURE WILL EXIT THIS EVENING. CLOUDS WILL INCREASE TONIGHT IN ADVANCE OF A WARM FRONT...WHICH MAY PRODUCE A FEW SHOWERS OR STORMS ACROSS NORTHERN NEW YORK. AN UPPER LEVEL TROUGH AND SURFACE COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS TO THE REGION MONDAY AFTERNOON INTO MONDAY NIGHT. UNSETTLED WEATHER WITH THE CHANCE FOR A FEW SHOWERS OR THUNDERSTORMS WILL CONTINUE THROUGH MIDWEEK. && .NEAR TERM /UNTIL 8 AM MONDAY MORNING/... AS OF 736 PM EDT SUNDAY...MESOSCALE CONVECTIVE SYSTEM NORTH OF LAKE ONTARIO CONTINUES TO DECREASE IN INTENSITY PER WARMING IR CLOUD TOPS, DECREASE IN LIGHTNING ACTIVITY, AND GENERAL DECREASE IN COMPOSITE REFLECTIVTY PER U.S./CANADIAN RADAR MOSAICS. MCS IS ENCOUNTER MORE STABLE CONDITIONS...WITH CURRENT RAP-BASED SBCAPE VALUES LESS THAN 500 J/KG ACROSS ST. LAWRENCE AND FRANKLIN COUNTIES IN NY. DID INCREASE POPS IN THESE AREAS 01-03Z BASED ON EXTRAPOLATION...BUT KEPT THUNDER MENTION ISOLD. COULD SEE UP TO 0.25" RAINFALL...ESPECIALLY IN THE IMMEDIATE ST. LAWRENCE RIVER VALLEY DURING THE 01-03Z PERIOD. DRY AND PLEASANT ELSEWHERE THROUGH LATE EVENING WITH TEMPS IN THE 70S. ADDITIONAL SHOWERS/ISOLD THUNDERSTORMS POSSIBLE 06-12Z WITH UPSTREAM ACTIVITY ACROSS LWR MI/LAKE HURON MOVING EWD...AND MAY BE SUPPORTED BY A STRONG LOW-LEVEL JET AS IT MOVES INTO OUR REGION DURING THE PRE-DAWN HOURS. THERMODYNAMIC FIELDS ARE MARGINAL WITH DEWPOINTS IN THE 50S (AND UNFAVORABLE TIME OF DAY)...SO ANTICIPATE DECREASING INTENSITY TRENDS DESPITE DYNAMIC SUPPORT. MIN TEMPS WILL RANGE MOSTLY FROM THE UPPER 50S TO THE MID 60S ACROSS THE AREA...WITH THE COOLEST READINGS BEING EAST OF THE GREENS WHERE THERE MAY ALSO BE A LITTLE PATCHY FOG FOR A SHORT TIME AFTER MIDNIGHT. && .SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 339 PM EDT SUNDAY...ACTIVE WEATHER ANTICIPATED MONDAY THROUGH TUESDAY AS UPPER LEVEL TROUGH AND SERIES OF SHORTWAVES ROTATING THROUGH THIS FEATURE AND THE ASSOCIATED SURFACE FRONTAL BOUNDARIES/TROUGHS MOVE EASTWARD ACROSS THE AREA. SOME DIFFERENCES REMAIN REGARDING TIMING OF COLD FRONT AND HOW MUCH INSTABILITY WILL BE PRESENT HOWEVER. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE ON MONDAY ACROSS THE ENTIRE AREA. OUTFLOW BOUNDARY FROM CONVECTIVE COMPLEX MOVING UP THROUGH SOUTHERN ONTARIO INTO QUEBEC TONIGHT INTO MONDAY APPEARS AS IF IT WILL BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT DURING MONDAY. SBCAPE VALUES EXPECTED TO RANGE FROM 500-1500 J/KG ACROSS THE AREA DURING THE AFTERNOON...HAMPERED A BIT BY SURFACE DEWPOINTS WHICH ARE EXPECTED TO BE ONLY AROUND 60 DEGREES. PLENTY OF SHEAR HOWEVER WITH 0-6KM BULK SHEAR VALUES OF AROUND 50 KNOTS EXPECTED. SPC HAS ENTIRE FORECAST AREA IN SLIGHT RISK FOR MONDAY. HAVE INCLUDED SOME ENHANCED WORDING. EXPECT THUNDERSTORM DEVELOPMENT TO BEGIN EARLY TO MID AFTERNOON OVER ADIRONDACKS AND TRANSLATE EAST ACROSS CHAMPLAIN VALLEY AND REST OF VERMONT LATE MONDAY AFTERNOON INTO MONDAY EVENING WITH GREATEST CHANCE FOR STRONG/SEVERE STORMS IN THE 20Z TO 03Z TIMEFRAME WITH POTENTIAL FOR DAMAGING WINDS AND LARGE HAIL. WILL ALSO HAVE TO MONITOR THE POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL AND FLASH FLOODING...ESPECIALLY ACROSS CENTRAL AND NORTHERN VERMONT WITH PRECIPITABLE WATER VALUES PEAKING BETWEEN 1.5 AND 1.75 INCHES AND POSSIBLE TRAINING OF ECHOES IN SOUTHWEST FLOW REGIME. MAX TEMPS MONDAY EXPECTED TO RANGE FROM THE LOWER 80S WEST TO UPPER 80S TO NEAR 90 EASTERN VERMONT. SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH LATER MONDAY EVENING AND OVERNIGHT...BUT WITH UPPER TROUGH AXIS STILL WEST OF THE REGION AND POSITION OF ACTUAL SURFACE COLD FRONT DIFFICULT TO DETERMINE...THERE WILL BE A CHANCE FOR MORE SHOWERS AND THUNDERSTORMS TUESDAY. MORE INSTABILITY INDICATED FOR TUESDAY THAN ON MONDAY...BUT SHEAR LESS. EXPECT DECENT COVERAGE OF SHOWERS BY AFTERNOON ONCE AGAIN...AND CANNOT RULE OUT THE RISK FOR SOME LOCALLY STRONG STORMS DEPENDING ON POSITION OF COLD FRONT AND YET ANOTHER SHORTWAVE ROTATING AROUND UPPER TROUGH. TEMPS TUESDAY NEAR SEASONABLE LEVELS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. LINGERING SHOWERS TUESDAY NIGHT WITH THUNDERSTORM THREAT DIMINISHING DURING THE EVENING. LOW TEMPS MOSTLY IN THE 50S TO AROUND 60. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 252 PM EDT SUNDAY...THE PERIOD WILL START ACTIVE AS LARGE MID LEVEL TROUGH RESIDES OVER QUEBEC, BRINGING A FEW SHORTWAVES THROUGH THE REGION AND PRODUCING CLOUDS AND SHOWERS. OVERALL DRYING TREND EXPECTED LATE IN THE WORK WEEK AS THE MID LEVEL TROUGH SHIFTS EASTWARD. AS THE TROUGH MOVES EAST, 500MB HEIGHTS INCREASE AND SOME SLIGHT SURFACE RIDGING WILL MOVE OVER THE NORTH COUNTRY FOR MOSTLY DRY CONDITIONS ON THURSDAY AND FRIDAY. MODELS SHOW THIS RIDGING KEEPS A SURFACE LOW MOVING UP THE OHIO RIVER VALLEY TO OUR SOUTH TO CLOSE OUT THE WORK WEEK. ANOTHER MID LEVEL TROUGH MAY BRING WIDESPREAD CHANCES FOR SCATTERED SHOWERS ON SATURDAY. TEMPERATURES WILL BE ABOUT FIVE DEGREES BELOW NORMAL THROUGHOUT THE PERIOD. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... PLEASE SEE EQUIPMENT SECTION BELOW FOR KRUT DATA OUTAGE INFORMATION... THROUGH 18Z MONDAY...VFR CONDITIONS THROUGH MOST OF THE PERIOD WITH SOUTH TO SOUTHWESTERLY FLOW AT 5-10KTS, OCCASIONALLY GUSTY TO 15-20KTS THE REST OF THIS AFTERNOON. KPBG WILL EXPERIENCE SOME ONSHORE FLOW WITH WIND DIRECTION GENERALLY 150-170. PARTLY CLOUDY TO MOSTLY CLEAR VFR CIGS OVER THE REGION TODAY WILL PERSIST INTO THE EVENING. WINDS THIS EVENING WILL REMAIN 4-10KTS OUT OF THE SOUTH TO SW. REMNANTS OF CONVECTIVE SYSTEM CURRENTLY MOVING INTO GEORGIAN BAY MAY BRING SOME SHOWERS TO KMSS AROUND 06Z. APPROACHING FRONTAL BOUNDARY LATE IN THE FORECAST PERIOD MAY SPARK SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE ST LAWRENCE VALLEY AND ADIRONDACKS BETWEEN 15Z-18Z MONDAY. HAVE INCLUDED VCSH AND -SHRA AT KSLK AND KMSS RESPECTIVELY. A STRONG LOW LEVEL JET MOVING INTO THE ST LAWRENCE VALLEY, AHEAD OF THE FRONT, WILL BRING LLWS TO KMSS AND KSLK STARTING BETWEEN 05Z-09Z OUT OF THE SW AT 40-45KTS. THESE WINDS WILL BEGIN TO MIX TO THE SURFACE AFTER SUNRISE, RESULTING IN ALL TERMINALS EXPERIENCING SOUTH TO SW 10-20KTS GUSTS 20-30KTS. CLOUDS WILL LOWER AND INCREASE, BUT EXPECTED TO STAY VFR MONDAY MORNING. OUTLOOK 18Z MONDAY THROUGH FRIDAY... 18Z MONDAY - 12Z TUESDAY...SCATTERED/NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED WITH COLD FRONTAL PASSAGE. BRIEF MVFR CIGS AND IFR VISIBILITIES POSSIBLE BENEATH HEAVIER CONVECTIVE CORES. GUSTY WINDS/TURBULENCE ALSO POSSIBLE. 12Z TUESDAY - 12Z THURSDAY...MAINLY VFR...SCT AFTERNOON SHOWERS/THUNDERSTORMS WITH BRIEF MVFR/IFR POSSIBLE. PATCHY IFR IN BR/FG POSSIBLE 06-12Z EACH MORNING, MAINLY AT KMPV/KSLK TERMINALS. 12Z THURSDAY ONWARD...MAINLY VFR AS SURFACE HIGH PRESSURE TRIES TO BUILD IN OVER THE GREAT LAKES REGION. && .MARINE... A LAKE WIND ADVISORY HAS BEEN ISSUED FOR LATER TONIGHT THROUGH MONDAY MORNING. SOUTH WINDS FROM 5 TO 15 KNOTS THIS EVENING WILL INCREASE TO 15 TO 25 KNOTS TOWARDS AND AFTER MIDNIGHT TONIGHT. THE STRONG SOUTH WINDS WILL CONTINUE INTO MONDAY MORNING BEFORE TURNING SOUTHWEST AND SLIGHTLY DECREASING TO 10 TO 20 KNOTS MONDAY AFTERNOON. THE STRONGEST WINDS WILL BE FELT OVER THE BROAD LAKE AND ALONG SOUTHERN FACING SHORELINES WHERE GUSTS TO 30 KNOTS ARE LIKELY. WAVES 1 TO 2 FEET THIS EVENING WILL BUILD TO 2 TO 4 FEET LATE TONIGHT AND ON MONDAY MORNING. IN ADDITION...STRONG TO POSSIBLY SEVERE THUNDERSTORMS ARE FORECAST FOR MONDAY AFTERNOON AND EVENING. THESE STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN WITH SIGNIFICANTLY REDUCED VISIBILITIES...STRONG GUSTY WINDS...FREQUENT LIGHTNING...AND HAIL. PLEASE REMAIN WEATHER AWARE IF PLANNING TO BE OUT ON THE LAKE MONDAY. && .EQUIPMENT... AWOS OBSERVATIONAL DATA FROM THE RUTLAND/SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) REMAIN UNAVAILABLE AT THIS TIME. FOR AVIATION PARTNERS CURRENT OBSERVATIONS MAY BE ACCESSED VIA TELCO. PLEASE REFERENCE FAA KRUT NOTAM 07/007 FOR MORE INFORMATION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...RJS NEAR TERM...BANACOS SHORT TERM...RJS LONG TERM...KGM AVIATION...KGM MARINE...MUCCILLI EQUIPMENT...JMG

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