Area Forecast Discussion
Issued by NWS Portland, ME

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940
FXUS61 KGYX 052148
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
548 PM EDT THU MAY 5 2016

.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE OVER THE EAST
COAST THROUGH THE END OF THE WEEK BRINGING GENERALLY COOL AND WET
CONDITIONS THROUGH THE START OF THE WEEKEND. LOW PRESSURE WILL
PASS OFFSHORE TONIGHT AND BRUSH COASTAL SECTIONS WITH SOME LIGHT
RAIN OR SHOWERS TONIGHT ALONG WITH AREAS OF DRIZZLE AND FOG. THERE
WILL BE A BRIEF BREAK ON FRIDAY AS SOME DRIER AIR FILTERS IN FROM
THE NORTH. ANOTHER LOW OVER THE MID ATLANTIC REGION AND AN ONSHORE
FLOW WILL BRING MORE COOL UNSETTLED WEATHER FRIDAY NIGHT AND SATURDAY.
A COLD FRONT WILL CROSS THE REGION ON SUNDAY FOLLOWED BY BRIEF HIGH
PRESSURE ON MONDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS AND LATEST SUITE OF
MESOSCALE MODELS. AREA OF RAIN CONTINUES TO EXPAND OFF THE COAST
INTO THE GULF OF MAINE AS CYCLONGENESIS OCCURS OFF THE EASTERN
SEABOARD. HAVE UPPED POPS FOR THE OVERNIGHT HOURS FOR SOUTHERN
AREAS. RAIN WILL CONTINUE DURING MUCH OF THE OVERNIGHT PERIOD.

OTHERWISE...JUST MINOR MODIFICATIONS TO KEEP IN LINE WITH THE
CURRENT OBSERVATIONAL TRENDS.

PREV DISC...
NWS DOPPLER RADAR MOSAIC SHOWED AN AREA OF RAIN
EXPANDING ALONG AND JUST OFFSHORE OF SOUTHEAST NEW ENGLAND AND
CAPE COD. THIS AREA WAS DRIFTING NORTHWARD AND WILL IMPACT EASTERN
NEW HAMPSHIRE AS WELL AS THE COASTAL PLAIN OF MAINE TONIGHT.
ONSHORE FLOW WILL ALSO GENERATE SOME AREAS OF DRIZZLE AND FOG
TONIGHT. LOWS TONIGHT WILL BE MAINLY IN THE 40S.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
BEHIND THE OFFSHORE LOW...SOME DRIER AIR WILL BE DRAWN SOUTHWARD
INTO THE AREA ON FRIDAY. WE`LL SEE SOME CLEARING OVER NORTHERN NEW
HAMPSHIRE THROUGH THE MAINE MOUNTAINS AND FOOTHILLS INTO CENTRAL
AND MID COAST MAINE. OVER SOUTHERN NEW HAMPSHIRE AND SOUTHWEST
COASTAL MAINE...WE MAY HAVE TO SETTLE FOR A FEW SUNNY BREAKS.
IT`LL BE A DRY DAY FOR A CHANGE...WITH THE EXCEPTION OF FAR
SOUTHWEST NEW HAMPSHIRE WHERE THERE COULD BE A BRIEF SHOWER. HIGHS
WILL RANGE FROM THE UPPER 50S TO LOWER 60S. LOW PRESSURE WILL
SLIDE NORTH INTO THE MID ATLANTIC REGION AND STALL FRIDAY NIGHT
WITH MOISTURE FROM THIS SYSTEM AND RETURNING ONSHORE FLOW
SPREADING CLOUDS AND A FEW SHOWERS NORTHWARD INTO THE FORECAST
AREA ONCE AGAIN.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH IMPACT WX: NONE EXPECTED.

MODELS INDICATING 500MB HEMISPHERIC PATTERN WILL DEAMPLIFY TO SOME
DEGREE BUT OVERALL TROUGHING OVERING ERN NOAM LOOK TO BE
PERSISTENT FEATURE INTO NEXT WEEK. STILL...WILL SOME PERIODS OF
RIDGING...WARMER 850 TEMPS OVERALL /BUT NO BIG WARM UP/ AND ALSO
LESS PROCLIVITY FOR ONSHORE FLOW AS WE MOVE INTO NEXT WEEK...WHICH
WILL HELP TEMPS HOVER CLOSER TO NORMAL.

HOWEVER...BEFORE ALL THIS HAPPENS...WE HAVE TO GET THROUGH THIS
WEEKEND...WHICH WILL NOT BE A GREAT ONE AS WE DEAL WITH CONTINUED
EAST-NORTHEAST FLOW ON SATURDAY AS 500MB LOW CROSSES JUST TO OUR
SOUTH. SATURDAY SHOULD BE MAINLY CLOUDY AND COOL WITH MAYBE A FEW
SHOWERS...AND SOME PATCHY DZ AS WELL. THE ONLY AREA THAT MIGHT
NOT BE TOO BAD WILL BE N AND OF THE MTNS WHERE DOWNSLOPE COULD
ALLOW FOR P/SUNNY SKIES AND HIGHS IN THE LOW 60S. OTHERWISE TEMPOS
WILL RANGE FROM AROUND 50 ALONG THE IMMEDIATE COAST TO MID TO
UPPER 50S AS YOU HEAD INLAND TOWARD THE FOOTHILLS.

THE UPPER LVL DRIFTS OFFSHORE SAT NIGHT...AND MAY SEE A BRIEF
PERIOD OF S-SW FLOW SUN MORNING...WHICH COULD ALLOW FOR A FEW
BREAKS OF SUN BEFORE THE COLD FRONT PUSHES MIDDAY AND
AFTERNOON...WHICH WILL BRING A ROUND SHOWERS. HIGHS WILL SHIFT A
LITTLE WITH WARMER TEMPS...NEAR 60 ON THE COAST.,..AND LOW TO MID
50S IN THE MTS AS COOLER AIR MOVES IN DURING THE AFTERNOON BEHIND
THE FRONT. SFC RIDGE THEN BUILDS BENEATH WNW ALOFT...WITH MONDAY
FEATURING SOME SUN...AND HIGHS A LITTLE CLOSER TO NORMAL...MID-
UPPER 50S N TO LOW-MID 60S S. ANOTHER 500 MB WAVE WAVE LOOKS TO
MOVE THRU TUE-WED...WITH ANOTHER THREAT OF SHRA. MODELS BEGIN TO
DIVERGE AT THIS POINT...WITH THE EURO SHOWING A RIDGE FOR
THU...AND THE GFS CLOSING OFF A LOW TO OUR WEST. LEANED MORE
TOWARD THE EURO FOR NOW AND KEPT THU DRY.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...MVFR WITH LCL IFR IN CLOUDS AND SHOWERS TONIGHT. NE
SFC WND COULD GUST UP TO 25 KT VCNTY OF KPSM AND KPWM. IMPROVING
TO VFR THROUGHOUT ON FRI WITH SCT MVFR PSB ALONG THE MA/NH BORDER.
AREAS OF MVFR DVLP S OF A KLEB TO KPWM LINE FRI NIGHT IN CEILINGS
AND -SHRA.


LONG TERM...FLIGHT RESTRICTIONS...PROBABLY VARYING BETWEEN MVFR-
IFR MOSTLY EXPECTED SAT INTO SAT NIGHT. SOME IMPROVEMENT POSSIBLE
SUN MORNING...THEN A ROUND OF SHOWERS EXPECTED SUN AFTERNOON WILL
BRING SEVERAL HOURS OF MORE RESTRICTIONS. MON AND TUE LOOK VFR.

&&

.MARINE...
SHORT TERM...LOW PRES CROSSING THE GULF OF ME TONIGHT WILL KEEP
WINDS AND SEAS ABOVE SCA THRESHOLDS. WINDS AND ESPECIALLY SEAS
WILL BE SLOW TO DIMINISH FRI WITH LINGERING SCA CONDITIONS LIKELY
OUTSIDE THE BAYS.

LONG TERM...PERSISTENT LIGHT E FLOW WILL PUSH SEAS UP TO AROUND 5
OR 6 FT THIS WEEK...MAINLY IN SWELL. A COLD FRONT PUSHES THRU ON
SUNDAY AND W-NW WINDS COULD APPROACH SCA LATE SUN NIGHT INTO MON.

&&

.FIRE WEATHER...
MORE RAIN WILL BRUSH THE AREA TONIGHT...ESPECIALLY COASTAL ZONES.
COOL AND MOIST WEATHER CONTINUES INTO THE WEEKEND...WITH MODERATE
TO HIGH RELATIVE HUMIDITY EXPECTED. PRECIPITATION IS EXPECTED TO
BECOME MORE SHOWERY OVER THE WEEKEND.

&&

.TIDES/COASTAL FLOODING...
PERSISTENT ONSHORE FLOW WILL STRENGTHEN INTO TONIGHT AS LOW
PRESSURE PASSES BY OFFSHORE. BUILDING SEAS AND A MARGINAL SURGE
WILL BRING THE LATE EVENING HIGH TIDE (AROUND 11 PM) TO THE FLOOD
STAGE BENCHMARK AT BOTH PORTLAND HARBOR AND FORT POINT...NH. IT`S
LIKELY WE`LL SEE SPLASH-OVER AND MINOR COASTAL FLOODING ALONG THE
COAST WITHIN AN HOUR OR TWO EITHER SIDE OF THIS HIGH TIDE AND A
COASTAL FLOOD ADVISORY HAS BEEN POSTED FOR PORTLAND AREA SOUTHWARD
TO THE NEW HAMPSHIRE SEACOAST.

THE NORTHEAST FLOW LINGERS FRIDAY...AND RESIDUAL SEAS WILL LINGER
AS WELL. HIGH TIDES WILL BE EVEN HIGHER FRIDAY NIGHT...AND IT WILL
NOT TAKE MUCH SURGE TO SURPASS FLOOD STAGE...ESPECIALLY FROM
PORTLAND AND POINTS SOUTH.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT
     FRIDAY FOR MEZ023-024.
NH...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT
     FRIDAY FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ150>154.

&&

$$



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