Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 172350 AFDBTV AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 750 PM EDT FRI APR 17 2015 .SYNOPSIS... A WEAK TROUGH OF LOW PRESSURE WILL MOVE THROUGH THE REGION OVERNIGHT WITH JUST SOME PARTLY CLOUDY SKIES EXPECTED OVERNIGHT. A LOW PRESSURE AREA WILL MOVE SOUTHEAST FROM CANADA ON SATURDAY AND BRING A CHANCE OF LIGHT RAIN SHOWERS TO THE NORTH COUNTRY. A STRONG RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT AND WILL REMAIN OVER THE NORTH COUNTRY ON SUNDAY. RATHER UNSETTLED WEATHER IS EXPECTED MONDAY AND TUESDAY WITH RAIN LIKELY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 750 PM EDT FRIDAY...QUIET UNEVENTFUL NIGHT ON TAP TONIGHT UNDER CLR/PC SKIES AND SEASONABLY COOL TEMPERATURES IN THE 30S TO AROUND 40. ONLY FEATURE OF NOTE WILL BE A WEAK SURFACE TROUGH/WIND SHIFT LINE SLIDING SOUTH THROUGH THE AREA IN THE 8-10 PM TIME FRAME. LITTLE FANFARE WITH THIS FEATURE OTHER THAN SOME MID LEVEL CLOUD COVER AND A LIGHT WIND SHIFT TO THE NORTH AFTER MIDNIGHT. BTV/HRRR OUTPUT SEEMINGLY BULLISH ON SHOWING DEVELOPMENT OF A BROKEN LINE OF LIGHT SHOWERS WITH THIS FEATURE ACROSS NORTHERN COUNTIES THIS EVENING BUT FEEL THIS IS OVERDONE. KCXX RADAR DOES APPEAR TO BE SHOWING SOME LIGHT SPRINKLES/SHOWERS DEVELOPING NORTH OF THE INTL BORDER FROM MONTREAL EAST, BUT CANADIAN OBSERVATIONS REMAIN PCPN-FREE AND WITH SUCH DRY LOWER LEVELS FEEL THAT ANYTHING THAT WOULD FALL OUT OF THE SKY WOULD BE MINIMAL AT BEST. BEST SHOT AT A SPRINKLE WOULD BE THROUGH 10 PM ACROSS THE FAR NRN VT MTNS OTHERWISE DRY WX EXPECTED. HAVE A GREAT EVENING. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 427 PM EDT FRIDAY...MODELS SHOWING A STRONG UPPER SHORTWAVE WILL MOVE SOUTHEAST FROM CANADA ON SATURDAY. HAVE PUT IN A CHANCE OF LIGHT RAIN SHOWERS ON SATURDAY...EXCEPT HAVE GONE WITH LIKELY POPS FOR NORTH CENTRAL AND NORTHEAST VERMONT ON SATURDAY. GUSTY WEST TO NORTHWEST WINDS WILL DEVELOP ACROSS THE REGION BY SATURDAY AFTERNOON AS A SURFACE LOW PRESSURE AREA OVER NORTHEAST VERMONT MOVES SOUTHEAST INTO THE GULF OF MAINE BY LATE SATURDAY AFTERNOON. A STRONG RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT WILL BUILD INTO THE REGION SATURDAY NIGHT AND WILL REMAIN OVER THE REGION ON SUNDAY. MOS GUIDANCE LOOKS TOO COOL FOR MAX TEMPERATURES ON SUNDAY GIVEN FULL SUN...SO HAVE LEANED TOWARD THE WARMER END OF THE ENSEMBLE MOS GUIDANCE FOR MAX TEMPERATURES ON SUNDAY...WITH HIGHS MAINLY IN THE 60S. GFS MOS GUIDANCE LOOKS A BIT TOO COLD FOR MIN TEMPERATURES SATURDAY NIGHT...SO HAVE ALSO LEANED TOWARD THE WARMER END OF THE ENSEMBLE MOS MIN GUIDANCE. ECMWF...GFS AND NAM MODELS IN GOOD AGREEMENT IN SLOWING DOWN THE ARRIVAL OF SHOWERS INTO THE REGION TOWARD DAYBREAK ON MONDAY. HAVE JUST SLIGHT OR LOW CHANCE POPS FOR LATE SUNDAY NIGHT ACROSS THE ADIRONDACKS AND THE SAINT LAWRENCE VALLEY. HAVE ALSO GONE WARMER THAN MOS GUIDANCE FOR MIN TEMPERATURES SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 315 PM EDT FRIDAY...OVERALL THOUGHTS FOR THE UPCOMING WEEK HAVE NOT CHANGED WITH THIS REFRESH OF THE LONG-TERM FORECAST. 12Z GUIDANCE STILL SIMILAR WITH ONE ANOTHER AND RESPECTIVE PREVIOUS RUNS AND INDICATING A RATHER UNSETTLED AND COOLISH WEEK COMING UP. MOST SIGNIFICANT SYSTEM WILL BE COMING THROUGH MONDAY INTO EARLY TUESDAY, AND WILL BRING THE POTENTIAL OF SOME SIGNIFICANT RAINFALL (PERHAPS 1" IN PREFERRED UPSLOPE REGIONS) AND GUSTY/STRONG WINDS (ESPECIALLY ALONG THE WESTERN SLOPES OF THE GREEN MOUNTAINS). DAILY DETAILS ARE BELOW... MONDAY: GUIDANCE ALL SHOWING A DEEPENING LONGWAVE TROUGH ACROSS THE MIDDLE OF THE COUNTRY WITH ASSOCIATED SURFACE LOW PUSHING FAIRLY QUICKLY NORTHWARD INTO THE GREAT LAKES REGION. AS THIS LOW REACHES OUR LATITUDE, A SOUTH/SOUTHEAST LOW-MID LEVEL JET DEVELOPS AND HELPS TO TRANSPORT A PRETTY DEEP RIVER OF MOISTURE INTO THE REGION DURING THE DAY. THIS MOISTURE HAS BOTH GULF OF MEXICO AND ATLANTIC ORIGINS, AND AS A RESULT PRECIPITABLE WATER VALUES WILL BE APPROACHING 1" (WHICH IS ABOVE NORMAL FOR THIS TIME OF YEAR). AT THE SAME TIME, THE 0.5 TO 1KM WINDS STRENGTHEN INTO THE 45-55KT RANGE. GIVEN THE SOUTHEASTERLY COMPONENT AND INDICATIONS OF AN INVERSION AROUND MOUNTAIN SUMMIT LEVEL, THIS INDICATES TO ME THE POTENTIAL FOR A SOME OF THOSE STRONG WINDS TO GET FUNNELED BETWEEN THOSE SUMMITS AND INVERSION AND RESULT IN SOME STRONG DOWNSLOPE WINDS ALONG THE WESTERN SLOPES OF THE GREENS. TRIED TO BEEF UP THE WIND GUSTS TO SHOW SOME GUSTS OF 40-50MPH. ON THE RAINFALL ASPECT, THE DEEP MOISTURE AND STRONG JET SHOULD RESULT IN A PERIOD OF MODERATE RAINFALL DURING THE DAY AND INTO MONDAY NIGHT. OROGRAPHIC EFFECTS COULD BE PRETTY STRONG - PERHAPS AN 1" OR SO ON THE EASTERN SLOPES OF THE CENTRAL/SOUTHERN GREENS AND PERHAPS THE EASTERN SIDE OF THE `DACKS, HOWEVER SHADOWING FROM THE WHITE MOUNTAINS SHOULD KEEP QPF LOWER IN THE NORTHEAST KINGDOM AND SHADOWING FROM THE GREENS WILL KEEP THE CHAMPLAIN VALLEY REGION A BIT DRIER. THIS SHOULD LEAD TO SOME SHARP RISES ON SOME RIVERS. WILL HAVE TO EVALUATE LATER GUIDANCE TO SEE IF THERE WILL BE ANY SORT OF FLOOD THREAT. ON THE TEMPERATURE FRONT, STUCK CLOSE TO A GUIDANCE MIX. CLOUDS AND RAIN WILL KEEP IT ON THE COOL SIDE (50S) WITH 40S AT NIGHT. IN SUMMARY -- ONE OF THOSE RAW/WET DAYS. TUESDAY: LOOKS LIKE A SMALL SECONDARY LOW WILL PASS JUST TO OUR SOUTH ON TUESDAY. AS IT DOES SO, RAIN SHOULD START COMING TO AN END. MAY SEE SOME SUNSHINE IN THE AFTERNOON - ESPECIALLY THE ST LAWRENCE VALLEY, BUT OTHERWISE LOTS OF CLOUDS. TEMPERATURES AGAIN ON THE COOLER SIDE COMPARED TO NORMAL - MORE 50S. WEDNESDAY, THURSDAY & FRIDAY: NOT MUCH DIFFERENCE FROM DAY TO DAY. LOOKS LIKE WE`LL SEE A BIG BOWLING BALL CUT-OFF LOW SET UP SOMEWHERE OVER EASTERN CANADA. GFS AND EURO ARE A LITTLE DIFFERENT IN EXACT LOCATION (EURO A BIT MORE SOUTH), BUT THE NET RESULT IS THE SAME. LOTS OF CLOUDS, SCATTERED SHOWERS AND BELOW NORMAL TEMPERATURES. 850MB TEMPERATURES WILL BE IN THE -1 TO -4C RANGE, THUS IT WILL BE COLD ENOUGH FOR THE HIGHER SUMMITS (ABOVE 2000FT) TO SEE SOME WET SNOW SHOWERS. COULD BE SEVERAL INCHES OF ACCUMULATION OVER THE 2 TO 3 DAY PERIOD AT THOSE HIGH ELEVATIONS. NOTHING TO REALLY LATCH ONTO WITH REGARD TO IF THERE WILL BE A PREFERRED TIME FOR SHOWERS VS PREFERRED TIME OF BRIEF DRY PERIODS. AS SUCH, JUST PAINTED IN A LOT OF 30-50% POPS THE ENTIRE PERIOD. TEMPERATURES WILL RUN ABOUT 5 DEGREES BELOW NORMAL THROUGH THE PERIOD. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...VFR THOUGH THE NEXT 12 HOURS OR SO, WITH POSSIBLE MVFR OR BRIEF IFR VISIBILITY IN CONVECTIVE SHOWERS SATURDAY AFTERNOON, TRENDING BACK TO VFR LATE IN THE TAF PERIOD. A WEAK COLD FRONT PRODUCING THIN LINE OF SCT-BKN MID CLOUDS WILL MOVE SOUTH FROM THE INTERNATIONAL BORDER NEXT 2 HOURS. WHILE A DRY PASSAGE IS EXPECTED, ITS MOST NOTABLE EFFECT WILL BE A SHIFT TO WEST- NORTHWEST/NORTHWEST WINDS UP TO AROUND 10 KTS BEFORE MIDNIGHT. LIGHT/VARIABLE WINDS BEHIND IT AS BRIEF SUBSIDENCE BUILDS IN FROM THE NORTHWEST. A MORE POTENT UPPER DISTURBANCE AND ASSOCIATED FRONTAL SYSTEM MOVES IN INTO SATURDAY AFTERNOON. EXPECT SHOWERS TO DEVELOP IN DIURNAL HEATING, SOME OF WHICH COULD PRODUCE BRIEF LOWERED VISIBILITY. SMALL HAIL/GRAUPEL MAY ACCOMPANY THE STRONGEST CELLS GIVEN LOW WET-BULB ZERO HEIGHTS (AROUND 4 KFT AGL) AND RATHER STEEP MID- LEVEL LAPSE RATES. SHOWERS TO END WITH LOSS OF HEATING LATE IN THE TAF PERIOD. WINDS BECOME SOUTH UNDER 10 KTS IN THE MORNING, BUT THEN BECOME NORTHWEST AND GUSTY (UP TO 25-28 KTS) IN STRONG AFTERNOON MIXING. OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY... 00Z - 06Z SUNDAY...GENERALLY VFR. ANY LEFTOVER AFTERNOON SHOWERS DISSIPATE EARLY. GUSTY NORTHWEST SURFACE WINDS. 00Z SUNDAY - 06Z MONDAY...VFR UNDER HIGH PRESSURE. 06Z MONDAY - 00Z WEDNESDAY...FRONTAL SYSTEM BRINGS POTENTIAL MVFR/IFR RAINFALL. MODERATELY STRONG PRESSURE GRADIENT MAY ALSO RESULT IN GUSTY WINDS POTENTIALLY IN EXCESS OF 25 KTS AND LLWS DURING MONDAY AND MONDAY NIGHT. 00Z WEDNESDAY - 00Z THURSDAY...MVFR POSSIBLE IN SCATTERED SHOWERS. && .FIRE WEATHER... AS OF 427 PM EDT FRIDAY...HAVE PUT UP A FIRE WEATHER WATCH FROM NOON THROUGH 6 PM EDT SATURDAY FOR WESTERN RUTLAND AND WINDSOR COUNTIES IN SOUTH CENTRAL VERMONT. HAVE NOT PUT UP A FIRE WEATHER WATCH FOR EASTERN RUTLAND COUNTY DUE TO SNOW OVER THE HIGHER ELEVATIONS OF THE GREEN MOUNTAINS. EXPECTING MINIMUM RELATIVE HUMIDITIES AROUND 30 PERCENT SATURDAY AFTERNOON WITH WEST WINDS OF 15 TO 25 MPH WITH GUSTS UP TO 35 MPH POSSIBLE. FUELS ARE DRY ACROSS SOUTH CENTRAL VERMONT. THE CONDITIONS ARE RATHER MARGINAL THAT RED FLAG WARNING CRITERIA WILL BE REACHED ON SATURDAY...SO WILL LET THE MIDNIGHT SHIFT MAKE THE FINAL CALL ON THIS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR VTZ011-012. NY...NONE. && $$ SYNOPSIS...WGH NEAR TERM...JMG SHORT TERM...WGH LONG TERM...NASH AVIATION...LOCONTO/NASH FIRE WEATHER...WGH

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