Area Forecast Discussion Issued by NWS Burlington, VT
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000
FXUS61 KBTV 230555
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
155 AM EDT THU MAY 23 2013
.SYNOPSIS...
FRONTAL BOUNDARY WILL CONTINUE TO LIFT NORTHWARD ACROSS THE REGION
OVERNIGHT...MORE SHOWERS AND STORMS ARE EXPECTED. A SLOW-MOVING
COLD FRONT WILL THEN APPROACH FROM THE EASTERN GREAT LAKES REGION
BRINGING ADDITIONAL WIDESPREAD RAINFALL AND EMBEDDED THUNDERSTORMS
DURING THURSDAY AND THURSDAY NIGHT. WHILE IT WILL NOT BE RAINING
CONTINUOUSLY...PERIODS OF BRIEFLY HEAVY RAIN ASSOCIATED WITH THE
SHOWERS AND THUNDERSTORMS WILL GENERALLY BRING AN ADDITIONAL 1 TO
2 INCHES OF RAIN ACROSS THE NORTH COUNTRY THROUGH THURSDAY NIGHT.
SOME MINOR FLOODING WILL BE POSSIBLE...MAINLY THURSDAY INTO
THURSDAY NIGHT WITH THE MOST WIDESPREAD RAINFALL.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT THURSDAY...OVERALL FORECAST IN REAL GOOD SHAPE
AND ONLY TWEAK WAS TO ADJUST WEATHER BASED ON RADAR. FOR THE NEXT
FEW HOURS...LOOKS LIKE GUSTY WINDS AND HEAVY DOWNPOURS WILL BE
MAIN THREAT ACROSS PARTS OF NORTHERN NEW YORK AND THE WESTERN HALF
OF VERMONT. HAVE HIGHLIGHTED THESE AREAS WITH THE ENHANCED WORDING
AND KEPT PROBABILITIES IN THE SCATTERED TO NUMEROUS CATEGORIES.
AGAIN REST OF FORECAST IN REAL GOOD SHAPE.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 350 PM EDT WEDNESDAY...THURSDAY WILL PRODUCE OUR MOST
WIDESPREAD RAINFALL AS COLD FRONT AND ASSOCIATED POSITIVE TILT
500MB TROUGH BEGINS TO SHIFT SLOWLY SEWD ACROSS THE FORECAST
AREA. MOIST AND MARGINALLY UNSTABLE AIR MASS WILL SUPPORT SEVERAL
BANDS OF SLOW MOVING CONVECTION ALONG/IN ADVANCE OF THE COLD
FRONT. GIVEN THE SETUP...MOST OF THE NWP QPF LOOKED ON THE LOW
SIDE GIVEN EVOLUTION AND MOIST AIR MASS IN PLACE. TRENDED CLOSER
TO HIGHER ECMWF QPF WITH WIDESPREAD 1+" RAINFALL AMTS ACROSS THE
CWA. SOME OF THIS HEAVY RAIN CONTINUES INTO THURSDAY
NIGHT...ESPECIALLY CENTRAL AND ERN VT. CAN/T RULE OUT LOCALIZED
2" RAINFALL AMTS BEFORE THINGS LIGHTEN UP EARLY FRIDAY. SOME
MINOR FLOODING IS POSSIBLE...REFER TO HYDRO SECTION BELOW. HIGHS
THURSDAY GENERALLY IN THE MID 70S. EPISODES OF SHOWERS/TSTMS
EXPECTED UNDER CLOUDY SKIES. FRIDAY...LIKELY POPS FOR RAIN
SHOWERS IN THE MORNING...THEN SLOW/GRADUAL DRYING FROM NW-SE
ACROSS THE REGION. SHOULD SEE SOME PARTIAL SUNSHINE LATE IN THE
DAY FROM THE CHAMPLAIN VALLEY WWD. COOLER TEMPS WITH HIGHS IN THE
LOW-MID 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 255 PM EDT WEDNESDAY...STILL NOT A VERY CLEAR CUT FORECAST
FOR THE HOLIDAY WEEKEND, BUT IT`S LOOKING INCREASINGLY LIKELY
THAT SATURDAY WILL FEATURE SOME RAIN -- AND PERHAPS EVEN INTO
SUNDAY FOR PARTS OF THE AREA THANKS TO A SLOW MOVING UPPER TROUGH
AND ASSOCIATED SURFACE LOW PRESSURE. MEMORIAL DAY AND AFTER DOES
LOOK DRY WITH WARMING TEMPERATURES. DAILY SPECIFICS BELOW:
SATURDAY: DECENT AMOUNT OF VARIABILITY IN THE MODELS. NAM PUSHES
THE TROUGH AND LOW PRESSURE OUT THE QUICKEST AND WOULD FEATURE A
PRETTY DRY DAY, WHILE 12Z GFS AND 00Z EURO ARE PRETTY SIMILAR
FEATURING A "BATTEN DOWN THE HATCHES" WET DAY AS THEY HOLD BACK
THE TROF AND LOW THE LONGEST. THIS SOLUTION WOULD FEATURE A SLUG
OF HEAVY RAIN, PROBABLY ACROSS VERMONT -- AND THIS COULD RESULT
IN FLOODING ISSUES. 00Z GFS ENSEMBLES ARE A BIT QUICKER, BUT
STILL FEATURE PRECIPITATION FOR THE DAY. GIVEN A BIG OMEGA BLOCK
EXPECTED TO FORM OVER THE ATLANTIC, THAT MEANS EVERYTHING WILL
SLOW DOWN. THUS FEEL THE FAST NAM NEEDS TO BE DISCARDED, BUT THE
GFS/EURO COMBO MIGHT BE A LITTLE SLOW. AT THE END OF MY THOUGHT
PROCESS THOUGH, FELT IT NECESSARY TO INCREASE POPS -- WITH THE
BEST CHANCE ACROSS VERMONT WHERE IT WILL BE CLOSER TO THE LOW OFF
THE COAST. ST LAWRENCE VALLEY SHOULD REMAIN DRY AND A LITTLE BIT
OF LIGHT RAIN COULD COME BACK TO THE `DACKS. WITH ALL THE CLOUDS
AND COLD AIR WITH THE ASSOCIATED TROUGH, TEMPERATURES WILL BE
WELL BELOW NORMAL, 50S IN THE VALLEYS AND 40S IN THE HIGHER
TERRAIN. GONNA BE A DAMP/DREARY DAY. ADDING TO THE MISERY WILL BE
SOME BREEZY CONDITIONS. NORTH/NORTHWEST WINDS SHOULD GUST UPWARDS
OF 25 MPH. COME SATURDAY NIGHT, COLDER AIR ALOFT COULD RESULT IN
A LITTLE BIT OF SNOW AT ELEVATIONS PRIMARILY ABOVE 2500FT.
SUNDAY: WILL BE A TRANSITION DAY. LOW PRESSURE WILL BE MOVING
TOWARD THE CANADIAN MARITIMES, BUT ENOUGH MOISTURE ROTATING BACK
SO THAT I EXPECT CLOUDS AND LIGHT PRECIPITATION TO CONTINUE,
ESPECIALLY ACROSS EASTERN SECTIONS. HAVE PLACED LOW CHANCE POPS
BACK TO THE CHAMPLAIN VALLEY WITH HIGHER IN EASTERN VERMONT. NEW
YORK SHOULD REMAIN DRY. BY LATE IN THE DAY, CLOUDS SHOULD BE
BREAKING UP FROM WEST TO EAST. WILL BE CHILLY AND CONTINUED
BREEZY. 850MB TEMPERATURES ALOFT WILL BE ON EITHER SIDE OF 0C.
EVEN IN PERFECTLY SUNNY/DRY CONDITIONS, THIS WOULD ONLY SUPPORT
VALLEY HIGHS ABOUT 60F. WITH CLOUDS AND CONTINUED NORTHERLY FLOW,
I SUSPECT LOW 50S WILL BE IT FOR LOWER ELEVATIONS AND 40S IN THE
HIGHER TERRAIN. AGAIN SUNDAY MORNING AT THE HIGHEST SUMMITS, I`M
EXPECTING A LITTLE BIT OF SNOW. MAYBE ACCUMULATING TO 1" OR SO ON
MANSFIELD BY MID-DAY.
MEMORIAL DAY: GETTING BETTER AND WILL BE THE BEST DAY FOR ALL
OUTDOOR ACTIVITIES. PERHAPS RESIDUAL CLOUDS EARLY ACROSS THE
EAST, BUT OTHERWISE MOSTLY SUNNY. STILL COOL ALOFT, BUT 850MB
TEMPERATURES UP TO ABOUT 4C, SUPPORTING SURFACE HIGHS ABOUT 10F
WARMER THAN SUNDAY. LOTS OF LOW-MID 60S AT LOWER ELEVATIONS AND
UPPER 50S AT HIGHER ELEVATIONS.
DO NEED TO NOTE THAT THE 12Z EURO IS JUST COMING IN, AND IT
SUGGESTS AN EVEN SLOWER MOVE OUT OF THE TROUGH AND UPPER LOW. IN
FACT, IF THAT MODEL FORECAST ENDS UP PERFECT, THEN EVEN MONDAY
WILL BE CLOUDY/COOL/SOME RAIN -- VERY MUCH LIKE SUNDAY.
TUESDAY/WEDNESDAY: RIDGING SLOWLY BUILDS IN, ALONG WITH WARMER
TEMPERATURES ALOFT. EACH DAY SHOULD FEATURE TEMPERATURES ABOUT 5
TO 7 WARMER THAN THE PREVIOUS ONE -- SO SHOULD BE SOME NICE DAYS
(AGAIN ASSUMING THINGS DONT COME TO A COMPLETE STANDSTILL AND
KEEP US SMACK IN THE MIDDLE OF THE TROUGH).
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
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THROUGH 06Z FRIDAY...HIGHLY VARIABLE CONDITIONS ACROSS FORECAST
AREA OVERNIGHT INTO THURSDAY MORNING. SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE REGION OVERNIGHT. CONDITIONS RANGING FROM
VFR TO IFR...WITH LOWEST CIGS EXPECTED AT MPV. LOWEST VSBYS
OCCURRING IN HEAVIER SHOWERS AND STORMS...WHICH WILL TAPER OFF A
BIT AFTER 09Z. POTENTIAL FOR SOME GUSTY WINDS 40 KTS IN TSRA AT
MPV. DURING THE DAY ON THURSDAY...SHOWER AND THUNDERSTORM ACTIVITY
WILL BECOME WIDESPREAD BY AFTERNOON WITH THE APPROACH OF A COLD
FRONT. FROPA IS EXPECTED AT MSS AROUND 21Z BUT NOT AT RUT/MPV TILL
NEAR 06Z FRIDAY. PREVAILING CONDITIONS MVFR THURSDAY PM/EVENING...
LOWERING TO IFR IN HEAVIER PCPN. WINDS SOUTH 10-20 KTS AHEAD OF
FRONT...SHIFTING TO NORTHWEST AFTER FROPA. GUSTS 40 KTS POSSIBLE
IN ANY THUNDERSTORMS AHEAD OF THE FRONT THURSDAY.
OUTLOOK 06Z FRIDAY THROUGH MONDAY...UNSETTLED WX WITH OCCASIONAL
RAIN WILL CONTINUE LATER THURSDAY NIGHT THROUGH FRIDAY. PREVAILING
MVFR LOWERING AT TIMES TO IFR. LATEST INDICATIONS ARE THAT MORE
WET WEATHER WITH MVFR CONDITIONS AND LOCAL IFR MAY CONTINUE
THROUGH SUNDAY WITH OCCASIONAL RAIN AND GUSTY NORTHWEST WINDS DUE
COASTAL LOW. IMPROVEMENT MONDAY AS LOW DEPARTS AND HIGH PRESSURE
BUILDS INTO THE REGION.-- End Changed Discussion --
&&
.HYDROLOGY...
350 PM WEDNESDAY...WIDESPREAD 1.0" TO 1.5" RAINFALL (WITH LOCALLY
HIGHER AMTS) HAS OCCURRED ACROSS THE NORTH COUNTRY DURING THE
PAST 24-30 HOURS ASSOCIATED WITH SEVERAL EPISODES OF HEAVY
SHOWERS AND TSTMS. AN ADDITIONAL 1-2" RAINFALL IS FORECAST
BETWEEN LATE AFTN/EVENING SHOWERS AND TSTMS AND THE MORE
WIDESPREAD RAIN AND EMBEDDED TSTMS ON THURSDAY. WHILE ANTECEDENT
SOIL CONDITIONS HAVE BEEN DRY...AND VEGETATION IS FULLY
ACTIVE...THE ADDITIONAL RAINFALL WILL EVENTUALLY BRING THE
POTENTIAL FOR STREET/POOR DRAINAGE FLOODING. ASSOCIATED MINOR
FLOODING WOULD MOST LIKELY OCCUR DURING THE DAY THURSDAY AND INTO
THURSDAY NIGHT. MAIN-STEM RIVER FLOODING IS NOT FORECAST...BUT
MAY NEED TO WATCH SOME OF THE SMALLER RIVERS AND STREAMS THAT
COULD LOCALLY EXCEED BANKFULL LATER THURSDAY AND THURSDAY NIGHT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS/NEILES
NEAR TERM...EVENSON
SHORT TERM...BANACOS/NEILES
LONG TERM...NASH
AVIATION...RJS
HYDROLOGY...