Area Forecast Discussion Issued by NWS Portland, ME
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000
FXUS61 KGYX 190441
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1241 AM EDT SUN MAY 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE COAST TONIGHT. A WARM FRONT
APPROACHES FROM THE SOUTHWEST LATE SUNDAY AND SUNDAY
NIGHT...BRINGING A ROUND OF SHOWERS WITH IT. ON AND OFF AGAIN
SHOWERS CAN BE EXPECTED EARLY TO MID NEXT WEEK AS A SERIES OF
DISTURBANCES TRACK EASTWARD ACROSS NEW ENGLAND.
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.NEAR TERM /UNTIL 6 AM THIS MORNING/...
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UPDATED TO INCREASE SKY COVER OVER SE NH AND EXTREME SW ME PER
LATEST SATELLITE AND MTR REPORTS SHOWING MARINE STRATUS DECK
CONTINUING TO SLOWLY SPREAD INLAND. CLOUD DECK HAS PUSHED INTO
CON, PSM, DAW AND SFM...BUT NOT INTO PWM OR IZG YET. A BATCH OF
-SHRA MOVED THRU THE PWM AREA AN HOUR OR TWO AGO BUT IS NOW
OFFSHORE AND CONTINUING TO MOVE TO THE SE...SO EXPECT MAINLY DRY
WX THOUGH PATCHY F LIKELY TO FORM ALONG THE NH AND EXTREME SW ME
COAST OVERNIGHT AND MAY PUSH INLAND AS THE MARINE AIR CONTINUES TO
SURGE INLAND. ELSEWHERE SOME CLOUDS AROUND BUT NO STRATUS OR F
EXPECTED. HAVE TWEAKED OVERNIGHT LOWS A DEGREE OR TWO BASED ON
LATEST TEMP/DEW POINT/SKY COVER CONDITIONS.-- End Changed Discussion --
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.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM MONDAY/...
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THE FORECAST GETS SOMEWHAT INTERESTING SUNDAY AND SUNDAY NIGHT.
MODELS WIDELY DIFFER WITH POPS, TIMING, AND LOCATION OF MINOR
S/WAVES AND ALSO QPF. WILL ASSUME THE GFS IS OVERPLAYING CONVECTION
MOVING THRU THE DIRTY RIDGE AND ALSO THE AREAL COVERAGE OF SHWRS
SUNDAY AND SUNDAY NIGHT. WILL PREFER THE SOLUTION CLOSER TO THE
DRIER NAM AND ALSO LOWER POPS SO MADE ADJUSTMENTS ACCORDINGLY.
USED A BLEND OF THE MAV/MET MOS GUID FOR TEMPS.-- End Changed Discussion --
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.LONG TERM /MONDAY THROUGH SUNDAY/...
GLOBAL MODELS AGREE THAT A FRONT WILL STALL OVER OR JUST NORTH OF
THE AREA THROUGH THURSDAY. MODELS DO DIFFER ON THE EXACT LOCATION
AND TIMING OF WEAK SHORT WAVES MOVING ALONG THE FRONT. THIS WILL
AFFECT TIMING OF PRECIP AS WELL AS WIND DIRECTION. FOR NOW HAVE
USED THE ECMWF. THIS RESULTS IN THE THREAT OF SHOWERS AND EMBEDDED
THUNDERSTORMS THROUGH THE PERIOD. LOOKS LIKE THE HIGHEST POPS WILL
BE OVER THE MOUNTAINS MONDAY INTO TUESDAY WITH A BETTER THREAT OF
SHOWERS OVER THE SOUTH TUESDAY INTO TUESDAY NIGHT. THE ONSHORE
FLOW MAY PRODUCE AREAS OF FOG AND DRIZZLE ALONG THE COAST. A MORE
ORGANIZED LOW WILL MOVE ALONG THE FRONT ON THURSDAY INTO THURSDAY
NIGHT. ONCE THIS LOW MOVES PAST THE AREA EXPECT DRY AND COOL
CONDITIONS FOR NEXT WEEKEND.
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.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
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SHORT TERM /THROUGH SUNDAY NIGHT/...STRATUS DECK BETWEEN 500 AND
1500 FEET CONTINUES TO SLOWLY WORK INLAND ACROSS SE NH AND EXTREME
SW ME AT THIS TIME...HAVING REACHED PSM, DAW, CON AND SFM...BUT
NOT YET INTO PWM, AUG OR IZG. THE LOW CLOUDS WILL CONT TO SLOWLY
SPREAD INLAND THRU THE NGT. SOME F MAY FORM TO ALSO LOWER VSBY
BUT MAIN CONCERN IS THE LOW CIG. LEB AND HIE TAF SITES ON OTHER
SIDE OF HIGH TERRAIN MAY NOT SEE THE LOW CLOUDS OVERNIGHT AND HAVE
A BETTER CHC OF STAYING VFR.
WHERE THE STRATUS AND F DEVELOPS TONIGHT...THERE IS SOME QUESTION
AS TO WHETHER THESE TAF SITES CAN IMPROVE TO VFR ON SUNDAY...GIVEN
WEAK ONSHORE SE FLOW PERSISTING THROUGH THE DAY. CURRENT THINKING
IS THERE WILL BE SOME IMPROVEMENT...BUT WHETHER CIGS GET TO VFR IS
UNCERTAIN. ALL TERMINALS WILL SEE A CHC OF IFR CIG/VSBY IN ISOLD
TO SCT -SHRA LATE SUNDAY AFTN AND SUNDAY NIGHT.
LONG TERM...
MVFR TO IFR CONDITIONS WILL BE WIDE SPREAD DUE TO A STALLED FRONT
AND AREAS OF LOW PRESSURE MOVING ALONG THE FRONT. AN ONSHORE FLOW
COULD PROMOTE FOG ALONG COASTAL AREAS.-- End Changed Discussion --
&&
.MARINE...
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SHORT TERM /OVERNIGHT THROUGH SUNDAY NIGHT/...WILL UPDATE TO
INCREASE ONSHORE WINDS A BIT OVERNIGHT AND SUNDAY...BUT CONT KEEP
CONDITIONS BELOW SCA LEVELS THRU THE SHORT TERM. STILL EXPECT
SOME PATCHY F OVER WRN WATERS OVERNIGHT.
LONG TERM...
WIND DIRECTIONS WILL BE VARIABLE DUE TO THE LOCATION OF A STALLED
FRONT. EXPECT THEM TO TURN ONSHORE BY MID WEEK. AREAS OF FOG MAY
FORM. WINDS AND SEAS TO REMAIN BLO SCA LEVELS THROUGH
WEDNESDAY...THEY WILL APPROACH SCA LEVELS THURSDAY AND THURSDAY
NIGHT AS LOW PRESSURE APPROACHES.-- End Changed Discussion --
&&
.FIRE WEATHER...
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THE FIRE WEATHER DANGER WILL BE FAIRLY LOW FOR THE NEXT SEVERAL
DAYS AS GREEN UP CONTINUES ACROSS THE REGION. WINDS WILL BE LIGHT
INTO SUNDAY MORNING...THEN WINDS INCREASE ON SUNDAY BUT OFF THE
OCEAN WHICH WILL RESULT IN HIGHER RH VALUES PUSHING INLAND.
ISOLATED SHOWERS WILL INCREASE IN COVERAGE LATE SUNDAY. THERE WILL
BE A BETTER CHC OF SHOWERS DURING THE WORK WEEK WHICH WILL BE
ACCOMPANIED BY FAIRLY HIGH RH VALUES.-- End Changed Discussion --
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$