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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 260014
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
814 PM EDT SAT MAY 25 2013

.SYNOPSIS...
-- Changed Discussion --
A DEEP TROUGH AND ASSOCIATED COASTAL LOW PRESSURE SYSTEM WILL
PRODUCE A WIDESPREAD 1 TO 2 INCHES OF ADDITIONAL RAINFALL ACROSS
THE NORTH COUNTRY THIS WEEKEND. FURTHERMORE...SOME ACCUMULATING
SNOWFALL WILL BE POSSIBLE ACROSS THE HIGHER SUMMITS OF THE
ADIRONDACK AND GREEN MOUNTAINS. THE RAINFALL WILL CAUSE
SIGNIFICANT RISES ON LOCAL WATERWAYS...WITH SOME RIVER FLOODING
POSSIBLE. TEMPERATURES WILL BE MUCH BELOW NORMAL THROUGH
SUNDAY...WITH A WARMING TREND EXPECTED BY EARLY NEXT WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
-- Changed Discussion --
AS OF 800 PM EDT SATURDAY...GOING FORECAST IN GOOD SHAPE. ONLY
SOME MINOR ADJUSTMENTS MADE TO HOURLY PARAMETERS FOR EARLY THIS
EVENING TO REFLECT LATEST CONDITIONS. WILL HAVE TO CONTINUE TO
MONITOR FLOOD THREAT DUE THE ONGOING RAIN. WILL ALSO NEED TO
MONITOR ELEVATION SNOW POTENTIAL AND IMPACTS RESULTING FROM ANY
WET SNOW ACCUMULATION. GETTING SOME REPORTS OF SNOW AT ELEVATIONS
ABOVE 1000 FEET IN NORTHEAST VERMONT AT THIS TIME AS A BAND OF
HEAVIER PCPN MOVES WEST ACROSS THE AREA. SOME LIGHT ACCUMULATIONS
BEING REPORTED ON GRASSY SURFACES.


PREVIOUS DISCUSSION...
LOW PRESSURE SYSTEM HAS BECOME VERTICALLY STACKED OVER THE GULF OF
MAINE. REGION IS CURRENTLY BEING IMPACTED BY DRY SLOT MOVING INTO
VERMONT AND CUTTING OFF PRECIPITATION AT THIS TIME. WINDS HAVE
BEEN STRONG OUT OF THE NORTH...GUSTING TO ALMOST 30 KTS. LOW WILL
VERY SLOWLY DRIFT NORTH OVERNIGHT. SYSTEM TRANSITIONS FROM LARGE
SCALE SYNOPTIC LIFT TO MESOSCALE FEATURES DRIVEN BY THE TERRAIN.
GFS/NAM SHOWS VERY FAVORABLE 850 TO 700MB RH AND LLVL WINDS LATE
TONIGHT INTO THE MORNING FOR ENHANCED PRECIP ACROSS THE
CPV...WESTERN SLOPES...AND NORTH/CENTRAL MTNS OF VT. THIS
FAVORABLE MOISTURE/LIFT IS PRESENT THRU 18Z SUNDAY...BEFORE
FINALLY WEAKENING BY EVENING. GENERALLY ANOTHER HALF AN INCH TO
INCH AND A QUARTER OF QPF EXPECTED...WITH HARDLY ANY PRECIP IN OUR
FAR WESTERN ZONES. THINKING CPV CONVERGENCE AND UPSLOPE FLW WL
HELP TO ENHANCE QPF AMOUNTS ACRS THE WESTERN SLOPES AND CPV. THIS
WILL CAUSE SIGNIFICANT RISES ON LOCAL WATERWAYS...WITH SOME MAIN
STEM FLOODING POSSIBLE. SEE HYDRO SECTION BELOW FOR MORE INFO.

THE TOUGHEST PART OF THE FORECAST CONTINUES TO BE SNOW LEVELS AND
POTENTIAL IMPACTS. WE HAD SOME SNOW REPORTS TODAY AS LOW AS 1000
FEET...THOUGH NOT REALLY STICKING. THIS IS EXTREMELY TRICKY TO
DETERMINE...ESPECIALLY IN LATE MAY...WITH A VERY HIGH SUN ANGLE.
ABOVE 2000 FEET THERE WAS SOME DECENT ACCUMULATION...AND SPOTTY
DOWN TO 1000 FEET. THE SNOW SEEMS TO HAVE BEEN VERY INTENSITY
DRIVEN. EXPECT A DUSTING TO 3 INCHES FROM 1000-1500 FEET. ABOVE
2000 FEET...3 TO 8 INCHES WITH THE HIGHEST POINTS HAVING UP TO A
FOOT OF SNOW.

TEMPS WL ONLY FALL SLIGHTLY TONIGHT...AS WINDS/PRECIP AND CLOUDS
PREVAIL...THINKING L/M 30S MTNS TO U30S TO L40S.

MOST OF THE MARATHON WL EXPERIENCE LIGHT RAIN WITH COOL TEMPS AND
BREEZY NORTH WINDS...ESPECIALLY NEAR THE LAKE ON SUNDAY MORNING.
CONDITIONS WL IMPROVE BY SUNDAY AFTN WITH SCATTERED SHOWERS AND
TEMPS SLOWLY WARMING TO NEAR 50F...AND LIGHTER WINDS.
-- End Changed Discussion --

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 451 PM EDT SATURDAY...SURFACE AND UPPER LEVEL LOW PRESSURE
SYSTEM WILL LIFT NORTH AND AWAY FROM THE REGION SUNDAY. RAIN
SHOWERS...WITH MOUNTAIN SNOW SHOWERS WILL END DURING THE
AFTERNOON. SURFACE AND UPPER LEVEL RIDGE WILL THEN BUILD INTO THE
NORTH COUNTRY FROM SUNDAY NIGHT THROUGH MONDAY NIGHT.

THERE WILL BE A RANGE OF MAX TEMPS ON SUNDAY AS COLD LOW PRESSURE
SYSTEM WITH SHOWERS ACROSS OUR EASTERN ZONES KEEPS MAX TEMPS IN
THE UPPER 40S. MAX TEMPS WILL BE IN THE LOWER TO MID 50S IN THE
SAINT LAWRENCE VALLEY. SUNDAY NIGHT WILL BE THE COLDEST OF THE
PERIOD WITH LOWS DIPPING INTO THE 30S. AFTER ABUNDANT RAIN THE
LAST WEEK WILL LIKELY HAVE A LOT OF FOG WITH RIDGE BUILDING AND
LIGHT WINDS. TEMPERATURES MONDAY WILL RETURN TO THE 60S WITH
BUILDING RIDGE...BUILDING HEIGHTS AND WAA. BELOW NORMAL MIN TEMPS
ARE AGAIN EXPECTED MONDAY NIGHT WITH TEMPS IN THE MID TO UPPER
30S.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 439 PM EDT SATURDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION TUESDAY AND TUESDAY NIGHT. A WARM FRONT WILL MOVE
THROUGH THE REGION ON WEDNESDAY...SO HAVE INDICATED A CHANCE FOR
SOME SHOWERS AND THUNDERSTORMS WEDNESDAY AND WEDNESDAY NIGHT.
ECMWF AND GFS MODELS DIFFER ON THE FORECAST FROM THURSDAY THROUGH
SATURDAY...WITH THE ECMWF MODEL SHOWING A CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS THROUGH THE PERIOD...WHILE THE GFS TENDS TO HAVE
A DRIER FORECAST. GIVEN THAT TEMPERATURES THURSDAY AND FRIDAY WILL
BE IN THE 80S...CAN NOT RULE OUT SOME SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE PERIOD...SO HAVE LEANED TOWARD THE ECMWF
MODEL...BUT THIS LOOKS LIKE THIS MODEL COULD BE A BIT OVERDONE
WITH THE CONVECTION.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
THROUGH 00Z MONDAY...MAINLY MVFR/IFR CEILINGS IN RAIN THROUGH MUCH
OF THE PERIOD AS A LOW PRESSURE AREA REMAINS OFF THE NEW ENGLAND
COAST. NORTHERLY SURFACE WIND GUSTS AT OR ABOVE 20 KNOTS THROUGH
THE PERIOD. COLDER AIR ALOFT WILL PRODUCE LIGHT SNOW OVER THE
HIGHER ELEVATIONS OF THE ADIRONDACKS AND GREEN MOUNTAINS...WHICH
MAY AFFECT SLK/MPV AT TIMES TONIGHT WITH IFR VSBYS POSSIBLE.

OUTLOOK 00Z MONDAY THROUGH THURSDAY...

00Z MONDAY THROUGH 00Z FRIDAY...MAINLY VFR CONDITIONS EXPECTED AS
A RIDGE OF HIGH PRESSURE BUILDS EAST FROM THE GREAT LAKES AND
REMAINS OVER THE REGION THROUGH TUESDAY. AN APPROACHING WARM FRONT
WILL BRING A CHANCE OF SCATTERED THUNDERSTORMS ON WEDNESDAY WITH A
PERIOD OF MVFR POSSIBLE.
-- End Changed Discussion --

&&

.HYDROLOGY...
-- Changed Discussion --
AS OF 800 PM SATURDAY...A WIDESPREAD RAIN EVENT WILL CONTINUE
INTO SUNDAY...WITH STORM TOTAL PRECIP VALUES OF 1 TO 2 INCHES WITH
LOCALIZED 3 INCH AMOUNTS POSSIBLE ACRS THE WESTERN SLOPES...PARTS
OF THE CPV...AND MTNS OF NORTH-CENTRAL VT BY SUNDAY AFTN. LOCALLY
RUN SSHP MODEL HYDROGRAPHS SUGGEST THESE TOTALS WILL LIKELY BRING
NUMEROUS SMALL STREAMS TO BANKFULL...AND SEVERAL MAINSTEM RIVERS
INTO FLOOD BY THIS AFTN INTO SUNDAY. THUS A FLOOD WATCH REMAINS IN
EFFECT. RIVER FLOOD WARNINGS FOR MINOR FLOODING ALREADY IN EFFECT
FOR PARTS OF THE AUSABLE...MISSISQUOI AND BARTON RIVERS. OTHER RIVERS
OF CONCERN WOULD BE THE LAMOILLE AND OTTER. IN ADDITION...A COUPLE
OF AREAL FLOOD WARNINGS ARE ALSO IN EFFECT FOR PARTS OF NORTHERN
VERMONT. GIVEN THE CURRENT TRENDS IN RAINFALL TIMING AND AMOUNTS...
MOST RIVER CRESTS ARE EXPECTED TO OCCUR LATE TONIGHT OR SUNDAY
MORNING.
-- End Changed Discussion --

&&

.MARINE...
AS OF 420 PM SATURDAY...A LAKE WIND ADVISORY WILL REMAIN IN EFFECT
THROUGH THE DAY ON SUNDAY WITH NORTH WINDS FROM 25 TO 35 KNOTS
TONIGHT...GRADUALLY DECREASING TO 15 TO 25 KNOTS ON SUNDAY...BEFORE
LESSENING CONSIDERABLY SUNDAY NIGHT.

THESE WINDS WILL MAKE FOR VERY ROUGH CONDITIONS, WITH
WAVES ACROSS THE OPEN LAKE ULTIMATELY BUILDING UPWARDS OF 3 TO 5
FEET.

CONDITIONS WILL IMPROVE BY MONDAY WITH NORTHWEST WINDS FROM 5 TO
15 KNOTS WITH MOSTLY SUNNY SKIES AND MILDER TEMPERATURES.

&&

.CLIMATE...
WITH THE UNSEASONABLY CHILLY WEATHER EXPECTED FOR TODAY...SOME
RECORD LOW MAXIMUMS MAY BE APPROACHED OR BROKEN. THEY ARE LISTED
BELOW.

BURLINGTON:   51F (1921,1925)
MONTPELIER:   48F (1967)
MASSENA:      55F (1969,1979)
ST JOHNSBURY: 52F (1931,1925)

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR VTZ002>012-016>019.
NY...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NYZ028-031-034-035.

&&

$$
SYNOPSIS...NEILES/TABER
NEAR TERM...RJS/NEILES
SHORT TERM...NEILES/TABER
LONG TERM...WGH
AVIATION...WGH/RJS
HYDROLOGY...
MARINE...
CLIMATE...