Area Forecast Discussion Issued by NWS Portland, ME
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000
FXUS61 KGYX 190207
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1007 PM EDT SAT MAY 18 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.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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10 PM UPDATE...PATCH OF STRATUS HAS DEVELOPED OVER SW ME AND SE
NH. THE QUESTION IS HOW FAR THIS SPREADS OVERNIGHT. MESO MODELS
ALL IN AGREEMENT THAT THE STRATUS DOES SPREAD...BUT THEY COVER
DIFFERENT AREAS. FOR NOW...THINK THAT IT WILL LIKLY SPREAD N AND E
ALONG THE FIRST CUT OF UPSLOPE JUST INLAND FROM THE COAST...AND
HAVE BROUGHT BKN-OVC INTO THIS AREA OVERNIGHT. OTHERWISE...JUST A
FEW TWEAKS TO TEMPS AND POPS.
740 PM UPDATE...SHRA WILL MOSTLY DIMINISH WITH SUNSET... A FEW
SPKLS REMAIN [POSSIBLE THRU THE EVENING...ESPECIALLY OVER THE
TERRAIN OF FRANKLIN/SOMERSET COUNTIES AS WEAK SFC AND LOW LVL
BOUNDARY HANGS IN PLACE. ALSO...WILL HAVE TO WATCH FOR LOW STRATUS
AND FOG DEVELOPING ON THE COASTAL PLAIN TONIGHT. MODELS SUGGESTING
IT AND A PATCH HAS DEVELOPED OVER COASTAL YORK COUNTY S INTO
PORTSMOUTH. WITH TDS OVER THE WATER AROUND 50...AND ONLY IN THE
UPPER 30S TO LOW 40S NOT FAR INLAND...AND WEAK SE FLOW...COULD SEE
IT DEVELOPING LATER THIS EVE.
PREVIOUSLY...A DRY AND COOL NORTHWEST FLOW WILL CONTINUE INTO
TONIGHT. THE WDLY SCT AFTN INSBLTY CLDS AND SPRINKLES WILL COME TO
AN END AFTER SS FOLLOWED BY P/C CONDS. OVERNIGHT MINS WILL RANGE
FROM THE MID 30S IN THE MTNS TO MID 40S ALONG THE COASTAL PLAIN.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
THE FORECAST GETS SOMEWHAT INTERESTING SUNDAY AND SUNDAY NIGHT.
MODELS WIDELY DIFFER WITH POPS, TIMING, AND LOCATION OF MINOR
S/WVES 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.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
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.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...2340Z UPDATE...CONDS FOR LOW STRATUS AND SOME FOG ARE
COMING TOGETHER THIS EVE...AND HAVE ADDED TO MOST OF THE
TERMINALS. SOME HAS ALREADY DEVELOPED IN KPSM AND ALONG THE SW ME
COAST. WHERE THIS ST/FG DEVELOPS TONIGHT...THERE IS SOME QUESTION
AS TO WHETHER THE COASTAL TERMINALS CAN IMPROVE TO VFR ON
SUNDAY...GIVEN WEAK 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.
&&
.MARINE...
SHORT TERM...A LIGHT SE ONSHORE FLOW CONTINUES TNGT AND INCREASES
SOMEWHAT ON SUNDAY AND SUNDAY NIGHT AS THE PRES GRADIENT
SLOWLY INCREASES. THE ONSHORE FLOW WILL REMAIN BLO SCA CONDS
THROUGH SUNDAY NIGHT.
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.
&&
.FIRE WEATHER...
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.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...