Area Forecast Discussion Issued by NWS Portland, ME
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000
FXUS61 KGYX 252305
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
705 PM EDT SAT MAY 25 2013
.SYNOPSIS...
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LOW PRESSURE WILL MOVE SLOWLY THROUGH THE GULF OF MAINE OVERNIGHT
AND SUNDAY, THEN INTO THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL
BUILD IN FROM THE WEST MONDAY THEN SHIFT OFFSHORE ON TUESDAY. A WARM
FRONT WILL MOVE ACROSS THE REGION WEDNESDAY AND WEDNESDAY NIGHT
FOLLOWED BY A LARGE BUILDING RIDGE OF HIGH PRESSURE WITH VERY WARM
TEMPERATURES FOR LATE IN THE WEEK.-- End Changed Discussion --
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.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
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655 PM...ADJUSTED 1ST PERIOD GRIDS BASED LARGELY ON MESONET FOR
THIS ESTF UPDATE. THE SNOW LEVELS WERE LOWERED TO NEAR 2000 THSD FEET
ACROSS THE NORTHERN WHITE MOUNTAINS FOR THIS UPDATE. TIDE AT
PORTLAND HARBOR CONTINUES TO RUN NEAR 0.4 FT ABOVE PROJECTED.
REGARDING RIVER FLOODING...
ANDROSCOGGIN AT GORHAM NH
CONNECTICUT AT DALTON
KENNEBEC AT SKOWHEGAN
ARE NOW EXPECTED TO EXCEED FLOOD STAGE. ADDITIONAL FORECAST POINTS ARE
BEING MONITORED AS WELL FOR FLOODING POTENTIAL.
PREV DISC... SLOW MOVING LOW MOVING
NE THRU THE GULF OF ME TNGT WILL CONT RA ACROSS THE FCST AREA.
HOWEVER...AS COLDER AIR MOVES IN AND THE FREEZING LVL DROPS WITH
THE CUTOFF STRENGTHENING AND DRIFTING OVERHEAD THE RA WILL MIX
WITH OR CHANGE TO SN WITH SOME IP/ZR PSBL AS WELL ACROSS THE
HIGHER ELEVATIONS...MAINLY ABOVE 2000 FT. SOME LGT SN ACCUMULATION
PSBL WITH 1 TO 4 INCHES PSBL ABOVE 4000 FT.
GUSTY NORTHERLY WINDS WILL EASE UP ONLY A LITTLE OVERNIGHT AS
TEMPS ONLY DROP A FEW DEGREES WITH CLOUD COVER AND PRCP. LOOK FOR
LOWS IN THE 30S N AND UPPER 30S TO LOWER/MIDDLE 40S S.
GENERALLY USED A BLEND OF NAM/GFS AND MET/MAV GUIDANCE FOR THE
NEAR TERM FCST.
FLOOD WATCH NOW FOR ALL OF THE WRN ME MT AND FOOTHILL ZONES AND
NRN NH. SEE THE HYDROLOGY DISCUSSION BELOW FOR MORE DETAILS.-- End Changed Discussion --
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.SHORT TERM /7 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
THE SFC LOW CONTINUES TO MOVE SLOWLY NE SUNDAY THEN ACCELERATES
INTO THE MARITIMES SUNDAY NGT. THUS EXPECT THE RAIN /OR MIXED PRCP
AT HIGHER ELEVATIONS ABOVE 2000 FT/ TO GRADUALLY END OR AT LEAST
TAPER OFF ON SUNDAY THEN COME TO AN END SUNDAY NGT FROM SW TO NE.
SOME CLEARING LIKELY LATE SUNDAY NGT ESPECIALLY SW ZONES.
GENERALLY USED A BLEND OF GFS/NAM, MET/MAV AND HPC/RFC QPF FOR THE
SHORT TERM FCST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRES BUILDS ACROSS THE REGION FOR MON AND TUES BEFORE MOVING
OFFSHORE TUES NIGHT. A WARM FRONT WILL APPROACH FROM THE WEST WED
AND MOVE THROUGH THE AREA BY LATER WED NIGHT PRODUCING SHOWERS
AHEAD AND ALONG THE WARM FRONT. ON THURSDAY A LARGE RIDGE OF HIGH
PRES THAT WILL BUILD OVER THE ERN THIRD OF THE US WILL ALSO BUILD
NORTH ACROSS NEW ENGLAND FOR BOTH THURS AND FRI BRINGING VERY
WARM AND HUMID CONDITIONS TO THE AREA.
USED A BLEND OF THE MAV/MET TEMPS FOR 4TH/5TH PDS. USED GMOS FOR
MAX TEMPS BUT HAD TO RAISE TEMPS SOME FOR THU/FRI/SAT. FOR MINS
USE THE BIAS ADJ MEX GUID.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY NIGHT/...MAINLY IFR/LIFR TNGT WITH
CONDITIONS IMPROVING SUNDAY AND SUNDAY NGT TO VFR. MIXED PRCP AT
HIGHER ELEVATIONS DEVELOPING TNGT THEN ENDING SUNDAY/SUNDAY EVE.
LONG TERM...
VFR CONDS XCPT MVFR CONDS WED/WED NIGHT IN ANY SHWRS.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...WILL EXTEND THE SCA
THRU 11 PM THIS EVE FOR WIND GUSTS AND SEAS BASED ON LATEST BUOY
REPORTS AND SLOW TRACK OF SFC LOW. WINDS LET UP OVERNIGHT BUT SEAS
WILL BE SLOW TO SUBSIDE OVER THE OPEN WATERS. MAY NEED TO EXTEND
THE SCA AT LEAST FOR HAZARDOUS SEAS OVER THE OPEN WATERS FOR LATE
TNGT AND POSSIBLY INTO SUNDAY AS WELL.
LONG TERM...NO FLAGS MON OR TUE...BY WED AN INCREASING SLY FLOW
MAY ALLOW SCA CONDS TO DEVELOP.
&&
.FIRE WEATHER...
FIRE WX DANGER VERY LOW. EXCESSIVE RAINFALL PAST SEVERAL DAYS AND
MORE RAIN OR EVEN MIXED PRCP OVER THE HIGHER TERRAIN THRU TNGT AND
ONLY SLOWLY LETTING UP SUNDAY ALONG WITH GREEN UP OVER MUCH IF NOT
ALL OF THE FCST AREA.
&&
.HYDROLOGY...
GENERALLY USED A BLEND OF GFS/HPC/RFC QPF. 24 HOUR QPF AMOUNTS
TNGT THRU SUNDAY AROUND 1/2 INCH WITH SOME AMOUNTS TOPPING 1 INCH
PSBL ACROSS N/MT FOOTHILL ZONES DUE TO UPSLOPE ENHANCEMENT WITH
LOW/MID LVL WINDS ADVECTING MOISTURE IN OFF THE ATLANTIC. WILL
EXPAND THE FLOOD WATCH TO INCLUDE SOMERSET COUNTY /THRU 8 AM
SUNDAY/ WHERE A RIVER FLOOD WARNING IS CURRENTLY IN EFFECT FOR
THE KENNEBEC AT SKOWHEGAN.
&&
.TIDES/COASTAL FLOODING...
THE PREDICTED HIGH TIDE IS 11.8 FT AT 1158 PM TNGT AT PWM. TIDAL
FLOOD STAGE IS 12.0 FT. THERE HAS BEEN A SURGE OF 1/4 TO JUST
UNDER 1/2 FT OVER THE PAST COUPLE DAYS. NOW THAT WINDS ARE FROM
THE N THAT MAY BE LOWERED A BIT...BUT STILL COULD SEE THE TIDE
REACH THE 12 FT BENCHMARK FOR MINIMAL COASTAL FLOODING. MORE
SIGNIFICANT ARE THE WAVE OVER THE COASTAL WATERS...RUNNING 5 FT AT
THE PWM BUOY. WAVE ACTION WILL CREATE SOME SPLASHOVER AND BEACH
EROSION. WILL ISSUE A COASTAL FLOOD ADVISORY FOR THE HIGH TIDE
AROUND MIDNIGHT TNGT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH SUNDAY MORNING FOR MEZ007>009-012>014.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SUNDAY FOR MEZ023>028.
NH...FLOOD WATCH THROUGH SUNDAY MORNING FOR NHZ001>005.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SUNDAY FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
ES