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Area Forecast Discussion
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000
FXUS61 KGYX 181628
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1228 PM EDT FRI APR 18 2014

.SYNOPSIS...
HIGH PRESSURE TO OUR EAST WILL PROVIDE A COOL ONSHORE FLOW TODAY.
WEAK LOW PRESSURE PASSES NORTH OF THE AREA LATE TONIGHT INTO
SATURDAY MORNING ACCOMPANIED BY SCATTERED SHOWERS. MILDER HIGH
PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT THROUGH MONDAY.
A WEAK COLD FRONT WILL CROSS THE REGION TUESDAY.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...

1225 PM...MINOR ESTF UPDATE TO REFLECT THE PRESENT MESONET.

1015 AM...METARS AND GOES IMAGERY SHOW THE LOW CLOUD SPREADING 
INLAND ON THE ONSHORE FLOW. FOR THIS ESTF UPDATE...I MADE
ADJUSTMENTS TO SKY GRIDS AS WELL AS OTHER 1ST PERIOD GRIDS TO
REFLECT THE MESONET. I ADJUSTED WINDS AND RELATIVE HUMIDITY VALUES
ON SATURDAY TO REFLECT NEAR RED FLAG CONDITIONS FOR SOUTHEAST NEW
HAMPSHIRE AND SOUTHWEST MAINE AND ISSUED AN UPDATED FIRE WEATHER FORECAST.

PREV DISC...
635 AM...JUST A FEW MINOR UPDATES OT THE FORECASTS...MAINLY TEMPS
AND SKY. SKY WAS ADJUSTED BASED ON PROGRESS OF SCT-BKN STRATUS NWD
ACROSS THE GULF OF ME. MOST OF THE MODELS SUGGEST THIS DOES MAKE
IT INTO COASTAL AREAS LATER THIS MORNING...BUT MOSTLY AS SCT
CLOUDS...AND HAVE ADJ THE GRIDS TO REFLECT 40-50 PERCENT SKY
COVER.  OTHERWISE NO CHANGES. 

SFC HIGH PRES SHIFTS OFF THE NE TODAY AND WILL SEE AN EASTERLY
FLOW DEVELOP...ALTHOUGH THE SFC HIGH DOES NOSE BACK TO THE WEST A
BIT. THIS...COMBINED WITH A VERY DRY COLUMN OF AIR WHICH CONTINUE
TO BE ADVECTED FROM THE NE...HAS PREVENTED COASTAL STRATUS FROM
DEVELOPING...AND THIS WILL LKLY PERSIST THROUGH A GOOD CHUNK OF
TODAY. AS THE HIGH PULLS FURTHER E LATE TODAY AND THIS
EVENING...WILL SEE FLOW WEAKEN AND SHIFT MORE SE...WHICH COULD
BRING SOME STRATUS IN TO COASTAL AREAS LATE TODAY INTO THIS
EVENING. THE ONSHORE FLOW WILL MAKE FOR ANOTHER COOL DAY...WITH
HIGHS LOW TO MID 40S ON THE COAST AND WARNING TO AROUND 50 INLAND.
OTHERWISE LOOK FOR MAINLY SUNNY SKIES WITH THICKENING CIRRUS THIS
AFTERNOON.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
WEAK LOW PRES WILL PASS N OF THE CWA LATE TONIGHT INTO SAT
MORNING...AND WILL DRAG A COLD FRONT...OF SORTS...ACROSS THE AREA.
SHRASN WILL MOVE INTO THE MOUNTAINS OF NH LATE THIS EVENING...AND
WORK ACROSS THE INTERIOR ME ZONES AFTER MIDNIGHT. THE 500MB
ASSOCIATED WITH THIS SYSTEM MOVES QUICKLY...AND THERE IS A BRIEF
SHOT OF DYNAMIC SUPPORT...BUT AIR MASS...ESPECIALLY IN THE MID LVLS
REMAINS QUITE DRY...SO QPF ASSOCIATED WITH THE WAVE LATE TONIGHT
INTO EARLY SATURDAY ON THE ORDER OF A TENTH OF AN INCH IN THE NRN
ZONES. CLOSER TO THE COAST...NOT REALLY EXPECTING ANY
PRECIP...ALTHOUGH WONT RULE OUT A SPKL OR FLURRY AROUND 12Z SAT.
MINS TONIGHT WILL LKLY OCCUR AROUND MIDNIGHT...WITH TEMPS STEADY
OR RISING A BIT DURING THE PRE-DAWN.  

THE FRONT CLEARS THE CWA BY LATE SAT MORNING...AND SHOULD SEE SOME
BREEZY NW WINDS DURING THE AFTERNOON...GUSTS TO 25 MPH OR SO. THIS
WILL CLEAR OUT THE DOWNSLOPE AREAS QUICKLY...BUT WILL SLO KEEP THE
THREAT OF SOME UPSLOPE SHRASN IN THE MTNS INTO THE AFTERNOON.
DECENT LOW TO MID LVL LAPSE RATES DEVELOP RIGHT BEHIND THE FRONT
IN THE NW FLOW...AND WOULD NOT BE SURPRISED TO SEE SOME SHOWERS
PRODUCE SOME GRAUPEL IN THE MTNS OR FOOTHILLS. MAXES SAT LOOK TO
CLIMB INTO THE MID-UPPER 50S OUTSIDE OF THE MTNS...WHERE 50ISH
LOOKS LIKE THE LIMIT.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRES WILL BE IN CONTROL TO START THE PERIOD. AS THIS HIGH
SHIFTS EWD INTO EARLY NEXT WEEK...TEMPS SHOULD GRADUALLY MODERATE
TO ABOVE NORMAL. ATTM WEAK SFC FLOW MOVING OFF THE CAROLINAS
SHOULD PREVENT DEEPER RETURN OF MOISTURE NWD. THIS SHOULD LIMIT
LOW CLOUDS/FOG UNTIL TUE...WHEN APPROACHING FNT FROM THE W
INCREASES SLY FLOW. ALONG WITH THE INCREASE IN CLOUDS WILL BE AN
INCREASE IN SHRA COVERAGE...FIRST FOR NH THEN ME AS TUE PROGRESSES
INTO WED. 

THEREAFTER MODEL GUIDANCE SUGGEST A COMPLEX INTERACTION BETWEEN
GREAT LAKES TROF AND WEAK LOW PRES OFFSHORE. TO SOME EXTENT ALL
MODELS CONSOLIDATE THE TWO AREAS OF LOW PRES AND TRY AND CUT IT
OFF FROM THE MAIN STEERING WINDS. THE 18/00Z CMC IS THE WEAKEST
WITH PHASING...WHILE THE 18/00Z ECMWF IS THE NEXT QUICKEST TO LIFT
THE SYSTEM OUT. THE GFS HOWEVER WOULD HAVE THE SYSTEM CUT OFF NEAR
THE GULF OF ME...KEEPING UNSETTLED WX LINGERING OVER THE AREA INTO
THE LATTER HALF OF THE WEEK. GIVEN NWP IS NOTORIOUSLY POOR WITH
HANDLING THESE TYPES OF FEATURES I SEE NO REASON TO DIVERGE FROM A
MULTI MODEL CONSENSUS. AT THE VERY LEAST SHRA CHANCES ARE
INCREASING TUE INTO WED...WITH THE QUESTION REVOLVING AROUND HOW
QUICKLY THEY COME TO AN END.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR THROUGH MOST OF TODAY...ALTHOUGH THERE IS A CHC
THAT COASTAL TERMINALS SEE MVFR CIGS IN COASTAL STRATUS AFTER
20Z...WITH A BETTER CHC THIS EVENING AND OVERNIGHT. ALL TERMINALS
IMPROVE TO VFR SAT MORNING...ALTHOUGH KHIE COULD SEE SOME TEMPO
MVFR IN SHRASN ON SAT. 

LONG TERM...VFR CONDITIONS EXPECTED TO PREVAIL IN THE EXTENDED. A
PERIOD OF MVFR TO IFR CONDITIONS WILL BE POSSIBLE TUE INTO WED AS
A FRONTAL BOUNDARY/LOW PRES SLOWLY CROSSES THE AREA.

&&

.MARINE...
SHORT TERM /THROUGH FRIDAY NIGHT/...
PERSISTENT ERLY FLOW WILL BRING SWELL UP TO 5 OR 6 FT TODAY
OUTSIDE THE BAYS...AND THIS WILL PERSIST THROUGH TONIGHT. A COLD
FRONT CROSSES THE WATERS SAT MORNING...AND FLOW SWITCHES TO
NW...WHICH SHOULD KNOCK BACK THE SWELL.


LONG TERM..WINDS AND SEAS LOOK TO GENERALLY REMAIN BELOW SCA
THRESHOLDS UNTIL EARLY NEXT WEEK. DEVELOPING LOW PRES INVOF THE
GULF OF ME MAY AT LEAST BRING A PERIOD OF HIGH SEAS TO THE WATERS
AT THAT TIME.

&&

.FIRE WEATHER...
I LOWERED THE MINIMUM RELATIVE HUMIDITY VALUES AND ADJUSTED THE
WINDS TO REFLECT NEAR METEOROLOGICAL RED FLAG CONDITIONS.

&&

.HYDROLOGY...
WE CONTINUE TO SEE RIVER LEVELS SLOWLY RECEDING ATTM. PLEASE
CONSULT THE LATEST PWMFLSGYX AND PWMFLWGYX FOR DETAILS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT 
     SATURDAY FOR ANZ150-152-154.

&&

$$
ES






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