FXUS61 KBTV 121750 AFDBTV AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1250 PM EST FRI MAR 12 2010 .SYNOPSIS... A RIDGE OF HIGH PRESSURE ACROSS THE GULF OF MAINE WILL RESULT IN VARIABLY CLOUDY BUT DRY CONDITIONS TODAY. A LARGE AND SLOW-MOVING AREA OF LOW PRESSURE ACROSS THE MISSISSIPPI VALLEY WILL GRADUALLY MOVE TO THE EASTERN SEABOARD...WITH INCREASING CHANCES FOR RAIN ACROSS OUR REGION SATURDAY NIGHT INTO SUNDAY. THIS SYSTEM ALSO HAS THE POTENTIAL TO BRING MODERATELY STRONG WINDS TO THE WESTERN SLOPES OF THE GREEN MOUNTAINS LATE SATURDAY THROUGH SUNDAY MORNING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1100 AM EST FRIDAY...UPDATED PRODUCTS SENT OUT WITH A FEW MINOR FIRST PERIOD ADJUSTMENTS TO SKY CONDITION AND TEMPS. LATEST STLT PICS INDICATE A MARKED LACK OF CLOUDS OVER ADRNDKS LATE THIS MORNING...WHILE REST OF FORECAST AREA IS STILL SHROUDED IN A GOOD DEAL OF CLOUDS...ESPECIALLY VERMONT. FOR THE REST OF TODAY...HAVE INDICATED MORE SUSNHINE FOR NRN NY...AND MORE CLOUDS IN VERMONT...ALTHO EXPECT SOME BRKS TO DEVELOP. WIDE RANGE IN MAX TEMPS EXPECTED...RANGING FROM LOWER 40S IN PORTIONS OF ERN VT TO 50S ACRS MUCH OF NRN NY. EXPECT DRY CONDITIONS THIS PM AS LATEST RADAR LOOPPS SHOW PCPN WELL SUPPRESSED OF OUR AREA. PREVIOUS DISCUSSION... SFC ANTICYCLONE EXTENDING FROM NRN QUEBEC INTO THE GULF OF MAINE IS DRAWING RELATIVELY COOL...MODIFIED MARINE AIR MASS INTO CENTRAL/ERN VT TODAY WITH VARIABLY CLOUDY CONDITIONS EXPECTED THROUGHOUT THE DAYLIGHT HRS ALONG AND EAST OF THE GREENS MTNS. FROM THE CHAMPLAIN VALLEY WWD...SOMEWHAT DIFFERENT STORY WITH SWLY LOW-LEVEL TRAJECTORIES LESS INFLUENCED BY ANTICYCLONIC FLOW. THIS IS INDUCING A PATTERN OF LOW-LEVEL ISENTROPIC ASCENT WITH ISOLD -RW ACTIVITY ACROSS SRN SECTIONS OF THE FCST AREA AS OF 08Z. THIS ACTIVITY WILL LIKELY DIMINISH BY 12Z. DIFFERENT AIR STREAMS IMPACTING THE FA TODAY SUGGEST HIGH TEMPERATURES SHOULD BE WARMER AS ONE PROGRESSES FURTHER WEST ACROSS THE CWA THIS AFTN. LOOKING FOR A RATHER LARGE DISPARITY IN AFTERNOON TEMPERATURES...RANGING FROM THE LOW 40S ALONG THE ERN SLOPES OF THE GREEN MTNS /CONTRIBUTED BY ADIABATIC/UPSLOPE COOLING/...TO THE LOW AND POSSIBLY MID 50S IN THE CHAMPLAIN VALLEY...AND NEAR 60F IN FAR WRN ST. LAWRENCE COUNTY NY. MEANWHILE...BUILDING 700-500MB RIDGE ORIENTED FROM SE-NW ACROSS THE FORECAST AREA WILL BE EFFECTIVE IN KEEPING PCPN SHIELD OVER WRN PA TO OUR SW. WHILE LOW CLOUDS WILL BE MOST PREVALENT IN THE ERN CWA...MID AND HIGH CLOUDS WILL BE MORE WIDESPREAD ACROSS SWRN SECTIONS ON EDGE OF RIDGE AXIS. WINDS ACROSS MOST SECTIONS WILL BE SELY AT 10-15 MPH TODAY...EXCEPT NELY THIS MORNING WITH P-GRADIENT ORIENTED ALONG THE ST. LAWRENCE RIVER VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... AS OF 256 AM EST FRIDAY...FAVORED BLEND OF 00Z NAM12 AND 00Z ECMWF DURING THE FORECAST PERIOD. LOOKING FOR 700-500MB RIDGE AXIS TO GRADUALLY SHIFT NEWD ALLOWING FOR DEFORMATION BAND RAINFALL TO SLOWLY WORK TOWARD SRN EDGE OF THE CWA TONIGHT. DEFORMATION RAIN BAND WILL BE EXTREMELY CLOSE TO OUR CWA BORDER...AND HAVE INDICATED 30-40 POPS ALONG THE CWA EDGE AFTER 06Z TONIGHT. ACROSS CENTRAL AND NRN SECTIONS...SHOULD REMAIN DRY. IF IT CAN PRECIPITATE ACROSS THE NRN ADIRONDACKS AND RUTLAND AND WINDSOR COUNTIES LATE TONIGHT...VERTICAL TEMPERATURE PROFILES MARGINALLY SUPPORT A IP/ZR MIX...ESPECIALLY IN THE 1000-2000 FT ELEVATIONAL BAND. HAVE CONTINUED THIS IN THE FORECAST...BUT WITH LOW POPS FORECAST...NOT ENOUGH TO INCLUDE IN THE HWO AT THIS POINT. WILL CONTINUE TO MONITOR TRENDS. LOWS OVERNIGHT WILL MAINLY BE IN THE LOW TO MID 30S...EXCEPT MID-UPR 20S POSSIBLE FAR NERN VT WITH BINOVC POSSIBLE CLOSER TO MID-LEVEL RIDGE AXIS. ON SATURDAY...A DEEPER-LAYER SELY FLOW DEVELOPS ACROSS THE SRN FCST AREA...ESPECIALLY BY AFTERNOON...AS SFC LOW TRACKS INTO THE MID-ATLANTIC REGION. AGAIN...CWA IS ON NRN FRINGE OF POTL PCPN AREA AND KEPT POPS IN CHANCE CATEGORY /30-40 PERCENT ACROSS RUTLAND AND WINDSOR COUNTIES...AND LOWER TO THE NORTH /AROUND 10 PERCENT FROM BTV NWD/. WINDS WILL INCREASE ALONG THE WRN SLOPES OF THE GREEN MTNS WITH STRENGTHENING GRADIENT FLOW...SELY AT 15-25 MPH NEAR KRUT WITH GUSTS TO 35 MPH LATE IN THE DAY. AFTN HIGHS WILL MOSTLY BE IN THE MID TO UPR 40S...EXCEPT LWR 50S ACROSS THE ST. LAWRENCE VALLEY OF NY FURTHER REMOVED FROM THE LOW-LEVEL CYCLONIC CIRCULATION. SATURDAY NIGHT EXPECT POPS TO INCREASE MORE SIGNIFICANTLY WITH NWD PIVOT OF WARM CONVEYOR BELT FROM THE ATLANTIC OCEAN ACROSS CENTRAL NEW ENGLAND INTO OUR SRN FCST AREA. WILL CONTINUE WITH MODERATELY STG SELY WINDS 20-30 MPH...WITH GUSTS 30-40 MPH ACROSS S-CENTRAL VT AND THE WRN SLOPES OF THE GREEN MTNS IN PARTICULAR. QPF AMTS WILL BE HIGHEST ALONG THE ERN SLOPES OF THE GREEN MTNS AIDED BY OROGRAPHIC ASCENT. TAKEN BLEND OF SREF/ECMWF/NAM...LOOKING FOR A QUARTER TO THIRD OF AN INCH OVERNIGHT ALONG THE EAST FACING SLOPES OF THE GREEN MTNS...AND POSSIBLY ACROSS THE EAST FACING SLOPES OF THE NRN ADIRONDACKS AS WELL. AGAIN PRESENTED WITH THERMODYNAMIC SOUNDINGS MARGINAL FOR IP/ZR MIX AT 1000-2000 FT ELEVATIONS IN CENTRAL/ERN VT AND THE DACKS. HAVE MENTIONED RAIN LIKELY WITH A CHANCE OF FREEZING RAIN AND SLEET IN THESE LOCATIONS DURING SATURDAY NIGHT. WITH RELATIVELY WARM GROUND...LIKELY NOT A SIGNIFICANT TRAVEL CONCERN BUT SOME MIXED P-TYPE IS WORTH NOTING. ON SUNDAY...MAINLY CLOUDY WITH CONTINUED RAINFALL AS WARM CONVEYOR BELT PIVOTS NWD INTO NRN VT AND GRADUALLY WEAKENS PER 00Z ECMWF. TOTAL RAINFALL COULD APPROACH 1 INCH ACROSS SERN VT...WITH GENERALLY 0.30 TO 0.70" ELSEWHERE ACROSS THE FA. SELY WINDS SHOULD GRADUALLY DIMINISH ACROSS THE WRN SLOPES OF THE GREEN MTNS DURING THE AFTN HRS. HIGHS WILL MAINLY BE IN THE 40S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 400 AM EST FRIDAY...THE LONG TERM WX CHALLENGE WL BE CHC FOR POPS SUNDAY NIGHT INTO MONDAY ASSOCIATED WITH DEPARTING MID/UPPER LVL SYSTEM...FOLLOWED BY TEMPS FOR NEXT WEEK. WL TREND TWD ECMWF FOR THIS PACKAGE...BASED ON BETTER RESULTS WITH DEEP CLOSED CYCLONIC CIRCULATIONS AND PREVIOUS PERFORMANCES THIS WINTER. GIVEN POSITION OF DEEP CIRCULATION AND WEAK EMBEDDED 5H VORTS INTERACTING WITH WELL ESTABLISHED EASTERLY FLW...WL CONT TO MENTION CHC POPS SUNDAY NIGHT INTO MONDAY ACRS OUR EASTERN/SOUTHERN ZNS. LLVL THERMAL PROFILES SUGGEST MAINLY RAIN...WITH SOME VERY HIGH MTN SNOW/SLEET POSSIBLE LATE SUNDAY NIGHT. OVERALL...DYNAMICS AND MOISTURE WL BE DECREASING...THEREFORE QPF AMOUNTS WL BE LIGHT. BY MONDAY AFTN...850 TO 500MB MOISTURE DECREASES FROM NW TO SE ACRS OUR CWA...WITH INCREASING AMOUNTS OF SUN EXPECTED. THIS COMBINED WITH PROGGED 85H TEMPS NEAR 0C...SUPPORT HIGHS NEAR 50F MOST LOCATIONS. WEAK BACKDOOR FRNT WL PUSH ACRS CWA ON TUES...WITH BEST 850 TO 700MB MOISTURE/UVVS STAYING NORTH OF CWA...WL CONT TO MENTION SCHC POPS AND SLIGHTLY COOLER TEMPS ON WEDS. OVERALL...BEST 85H CAA AND LARGEST DROP IN 1000 TO 500 MB THICKNESS VALUES WL STAY NORTH OF CWA. PROGGED 85H TEMPS BTWN -1C AND -3C ON WEDS SUPPORT HIGHS BACK IN THE 40S...BUT TEMPS ARE EXPECTED TO REBOUND BACK INTO THE L50S BY THURS. OVERNIGHT LOWS WL RANGE FROM THE 20S TO L30S MOST LOCATIONS...WHICH IS 5 TO 8 DEGREES ABOVE NORMAL. BOTH ECMWF/GFS SHOW DEVELOPMENT OF A DEEPER MID/UPPER LVL TROF LATE THURS INTO FRIDAY...WHICH MAY PRODUCE SOME LIGHT PRECIP AND COOLER TEMPS BY WEEKS END. HOWEVER...STILL PLENTY OF UNCERTAINTY WITH REGARDS TO DEVELOPMENT OF TROF AND AMOUNT OF LLVL CAA...WL TREND WARMER FOR NOW. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THROUGH 18Z SATURDAY...VFR CONDITIONS CONTINUE AT MOST TAF SITES TODAY. EXCEPTIONS ARE KRUT AND KMPV...WITH LOWER LEVEL MOISTURE ASSOCIATED WITH ESE FLOW MAINTAINING MVFR CEILINGS AT LEAST THROUGH THE AFTERNOON. CEILINGS WILL LIFT THIS EVENING DUE TO DEVELOPING RIDGE AND INCREASE SUBSIDENCE. GENERALLY LOOKING FOR JUST SOME HIGH CIRRUS TONIGHT IN ADVANCE OF AN APPROACHING SYSTEM. WINDS ARE GENERALLY LESS THAN 10 KT OUT OF THE ESE...EXCEPT AT KRUT WITH SUSTAINED TO 12 AND GUSTS TO 20KT. WINDS WILL DIMINISH A BIT TONIGHT....THEN INCREASE AGAIN AROUND DAYBREAK...ONLY TO INCREASE FURTHER MIDDAY TOMORROW. GUSTS TO 15KT WILL BE WIDESPREAD AT MOST TAF SITES BY 16Z...AND TO NEAR 30KT AT KRUT. OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY... 18Z SATURDAY THROUGH 06Z SUNDAY...VFR CONDITIONS 12Z SAT THRU 06Z SUN WITH SFC RIDGE IN PLACE. GUSTY WINDS ESPECIALLY AT KRUT. 06Z SAT THROUGH 06Z MON...MVFR CONDITIONS DEVELOPING WITH IFR POSSIBLE AT KRUT BY 12Z SUNDAY. BAND OF RAIN SHOWERS AND GUSTY SE WINDS. 06Z MON THROUGH WED...IMPROVING CONDITIONS. VFR PREVAILING. && .CLIMATE... QUITE A REMARKABLE STRETCH OF MILD WEATHER ACROSS THE NORTH COUNTRY DURING THE PAST MONTH PLUS. AT BURLINGTON...THE DAILY AVERAGE TEMPERATURE HAS BEEN AT OR ABOVE THE 30-YEAR CLIMATOLOGICAL MEAN FOR 32 CONSECUTIVE DAYS...DATING BACK TO FEBRUARY 7TH. THE AVERAGE TEMPERATURE FOR MARCH THUS FAR IS 35.0F...OR 8.4F ABOVE NORMAL. THE AVERAGE TEMPERATURE FOR FEBRUARY FINISHED AT 26.0F OR 6.1F ABOVE NORMAL. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/RJS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...AMF/TABER CLIMATE...