Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 200211
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1011 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL PASS ACROSS THE REGION TONIGHT ALLOWING FOR A
DRIER AIR MASS TO BUILD IN. HIGH PRESSURE WILL CONTINUE TO BUILD
IN THROUGH WEDNESDAY NIGHT. LOW PRESSURE WILL PASS WELL TO OUR
SOUTH THURSDAY NIGHT INTO FRIDAY...WITH ANOTHER COLD FRONT
SWINGING ACROSS THE REGION DURING THE DAY ON FRIDAY. HIGHER
PRESSURE THEN BUILDS IN OVER THE WEEKEND. ANOTHER COLD FRONT LOOKS
TO PUSH INTO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
UPDATE 4...QUICK UPDATE TO TWEAK POPS BASED ON RADAR TRENDS.
ADJUST CLOUDS AND FOG AREAS. INPUT CURRENT TEMPS FROM
OBSERVATIONS. SHOWERS AND AN OCCASSIONAL RUMBLE OF THUNDER WINDING
DOWN. COLD FRONT IS THROUGH MOST OF VERMONT AT THIS TIME. FRONT
WILL SWING THROUGH WESTERN MAINE JUST AFTER MIDNIGHT AND TAKE THE
FOG AND STRATUS WITH IT. DEWPOINTS WILL DROP BY 20 DEGREES OR MORE
OVERNIGHT AS THE DRY AIR MOVES IN. WINDS WILL INCREASE WITH GUSTS
IN THE 25 TO 30 RANGE TOMORROW.

PREV DISC...SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS UPSTATE
NY AND VT WILL PUSH ACROSS OUR REGION LATE THIS AFTERNOON AND
EVENING...MAINLY BETWEEN 4 PM AND 9 PM. THE BEST INSTABILITY WILL
BE ACROSS WESTERN AND NORTHERN NH WHERE SOME SUNSHINE HAS ALLOWED
FOR SOME MODEST HEATING. THE RESULT SHOULD BE UP TO 1000 JOULES OF
CAPE JUXTAPOSED WITH AROUND 35 KT OF DEEP LAYER SHEAR. THIS SHOULD
BE SUFFICIENT FOR A COUPLE OF LOCALLY STRONG THUNDERSTORMS...WITH
AN ISOLATED SEVERE ONE OR TWO POSSIBLE. MORE STABLE AIR ON THE
COASTAL PLAIN WILL MITIGATE THE THREAT...BUT A FEW STORMS MAY EVEN
MAKE IT THERE EARLY THIS EVENING. STRONG SFC WIND GUSTS AND
MARGINALLY SEVERE HAIL WILL BE THE MAIN THREATS...ALONG WITH THE
USUAL ATTENDANT THREAT FOR LOCALLY HEAVY DOWNPOURS AND FREQUENT
LIGHTNING.

FOG MAY ONCE AGAIN DEVELOP ON THE COAST THIS EVENING PRIOR TO THE
COLD FRONTAL PASSAGE. THE FRONT WILL SWEEP THE SOUPIER AIR MASS
OFFSHORE AFTER MIDNIGHT...ALLOWING FOR MUCH DRIER AIR TO WORK IN.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A MUCH DRIER AIRMASS WILL MOVE IN ON WEDNESDAY ON GUSTY NW WINDS.
WINDS COULD POTENTIAL GUST UP TO 30 MPH. HIGHS WILL BE IN THE 60S
AND NO PRECIPITATION IS EXPECTED. HOWEVER...SUNSHINE WILL PROBABLY
BE REPLACED BY DEVELOPING STRATOCU LATE MORNING THRU AFTERNOON.

WINDS SHOULD DIMINISH AND SKIES SHOULD CLEAR WEDNESDAY EVENING. A
CHILLY NIGHT WILL BE IN STORE...WITH THE BETTER RADIATORS HEADING
DOWN INTO THE 30S. A FROST WILL BE POSSIBLE IN THESE AREAS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE MODELS ARE IN GENERAL AGREEMENT ON THE LONG WAVE PATTERN
THROUGH LATE NEXT WEEK OVER THE EASTERN HALF OF THE CONUS. WE
BEGIN THE PERIOD WITH AN UPPER TROUGH OVER THE GREAT LAKES AND NEW
ENGLAND. A SERIES OF SHORTWAVE IMPULSES WILL ROTATE AROUND THIS
TROUGH WITH SEVERAL MOISTURE STARVED TROUGHS OR WEAK COLD FRONTS
TO DROP SOUTH ACROSS THE AREA. ON SATURDAY...THE TROUGH LIFTS OUT
AND WE`RE LEFT WITH FLAT RIDGING AND SURFACE HIGH PRESSURE
BUILDING BY TO OUR SOUTH. THE NEXT SHORTWAVE PASSES TO OUR NORTH
LATE SUNDAY AND DRIVES A COLD FRONT SOUTHWARD INTO THE AREA TO END
THE WEEKEND ACCOMPANIED BY WIDELY SCATTERED CONVECTION. THE
SURFACE FRONT SHOULD STALL TO OUR SOUTH ON MONDAY...WITH SURFACE
RIDGE PROVIDING A DRY HOLIDAY FOR OUR AREA. HOWEVER...OVER THE
PAST 24 HOURS MODEL DIFFERENCES HAVE EMERGED WITH ECMWF SIMILAR TO
YESTERDAY`S SOLUTION...WHILE GFS RETURNS THE FRONT BACK NORTH WITH
INCREASING CLOUDS AND OVERRUNNING SHOWERS AND THUNDERSTORMS
ARRIVING BY MONDAY AFTERNOON.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...IFR OR LOWER CONDITIONS IN LOW STRATUS AND FOG THIS
EVENING...MAINLY AT THE COAST...WILL GIVE WAY TO RAPIDLY
DEVELOPING VFR CONDITIONS AFTER MIDNIGHT AS A COLD FRONT MOVES
THROUGH. VFR WITH GUSTY NWLY SFC WINDS LIKELY FOR WEDNESDAY. VFR
WITH DIMINISHED WINDS WEDNESDAY NIGHT. SCT THUNDERSTORMS POSSIBLE
20Z THRU 02Z THIS AFTERNOON/EVENING.

LONG TERM....

FRI AND SUN...SCT MVFR PSBL IN SHOWERS AND TSTMS.

&&

.MARINE...
SHORT TERM...SCA IN EFFECT FOR WEDNESDAY WITH NWLY WINDS GUSTING
AROUND 25 KT. THE MORE FREQUENT GUSTINESS SHOULD BE NEAR-SHORE
WHERE MIXING WILL BE BEST. SEAS SHOULD REMAIN A0B 5 FT HOWEVER.

LONG TERM...

THU NIGHT - SUN...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.

&&

.FIRE WEATHER...
MUCH DRIER CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY. FIRE
SPREAD POTENTIAL MAY BE HIGH ACROSS SRN NH WHERE MIN RH VALUES
DROP INTO THE 20S WEDNESDAY COUPLED WITH 25 KT WIND GUSTS. LIGHTER
WINDS AND EXPECTED THURSDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 7 PM EDT WEDNESDAY FOR
     ANZ150>154.

&&

$$
UPDATE...TFH



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