Area Forecast Discussion
Issued by NWS Portland, ME

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000
FXUS61 KGYX 301546
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1146 AM EDT THU OCT 30 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD EAST INTO THE REGION TODAY INTO FRIDAY.
POWERFUL LOW PRESSURE WILL BEGIN TO IMPACT THE REGION OVER THE
WEEKEND...BRINGING EVEN COLDER AIR AND THE CHANCE OF RAIN AND SOME
SNOW. HIGH PRESSURE BUILDS IN FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1145 AM...FORECAST UPDATED TO LINGER THE SPRINKLES A LITTLE LONGER AROUND
THE UPSLOPE AREAS...AND MODIFY MAXES A BIT...MAINLY IN THE MTNS
WHERE CURRENT OBS ARE NEAR FORECAST HIGHS. STARTING TO SEE BACK
EDGE OF THE MID-HIGH CLOUDS SHIFTING EAST...AND EXPECTING MORE
SUN ON THE COASTAL PLAIN THIS AFTERNOON.

10 AM...SOME QUICK TWEAKS TO THE FORECAST TO COVER THE SWATH OF
MID-HIGH CLOUDS MOVING ACROSS THE CWA...AND A FEW SPRINKLES IN
THE MTNS...THIS MORNING...AS WEAK 500MB WAVE MOVES THRU. SHOULD
SEE MORE SUN THIS AFTERNOON...ESPECIALLY IN THE DOWNSLOPE AREAS
OUTSIDE THE MTNS.

645 AM UPDATE: ONLY CHANGES WERE TO TAKE OUT THE MENTION OF EARLY
MORNING PATCHY FOG IN THE NORTHERN VALLEYS. NO OTHER CHANGES
NEEDED ATTM.

PREV DISC:
HIGH PRES BUILDS ACROSS THE REGION TODAY WITH A NICE
DRY SLOT OF AIR MOVING ACROSS THE AREA ON WNW WINDS. MOSTLY SUNNY
CONDS ARE EXPECTED IN THE DOWNSLOPE AREAS WHILE IN THE MOUNTAINS
SOME CLOUDS WILL LINGER. MODELS IN GENERAL AGREEMENT ON MAX TEMPS
RANGING FROM THE MID 40S IN THE MOUNTAINS TO THE MID 50S IN THE S
AND ALONG THE COAST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
HIGH PRES CONTINUES OVER THE
AREA TONIGHT AND INTO FRI. CLOUDS AHEAD OF THE NEXT DEVELOPING
SYSTEM WILL BEGIN TO SPREAD INTO THE AREA ON FRIDAY ALTHOUGH NO
PCPN IS EXPECTED THROUGH FRIDAY. USED A BLEND OF MODELS FOR TEMP
AND CLOUD FORECAST FOR TONIGHT AND FRI. GENERALLY MODELS WERE IN
CLOSE AGREEMENT THROUGH FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A SOUTHERN STREAM SHORT WAVE WILL ROUND THE BASE OF THE MEAN
TROUGH LATE FRIDAY IN THE DEEP SOUTH BEFORE EJECTING OFF THE
COAST OF THE CAROLINAS. THIS STRONG SHORT WAVE FINALLY PHASES
WITH THE MAIN TROUGH SOMETIME LATE SATURDAY NEAR NEW ENGLAND AS
THE WHOLE THING BECOMES NEGATIVELY TILTED.

AT THE SURFACE A COASTAL STORM DEEPENS RAPIDLY AND MOVES NORTH
AS WELL. THE GFS MSLP ENSEMBLE MEAN KEEPS IT EAST OF THE 40N/70W
BENCHMARK AS DO THE OPERATIONAL RUNS OF THE GFS AND THE EUROPEAN.
HOWEVER...COLD TEMPERATURES WILL ALREADY BE IN PLACE OVER THE AREA
AND WRAP AROUND MOISTURE COMBINED WITH UPSLOPE FLOW WILL BE ENOUGH
FOR SOME LIGHT SNOW IN THE MOUNTAINS AND FOOTHILLS. FARTHER EAST
LOCATIONS SUCH AS THE MIDCOAST WILL HAVE A HIGHER CHANCE FOR A
GLANCING BLOW. DECREASED THE QPF OVER THE REGION A BIT AS THE
STORM CONTINUES TO MOVE EAST WITH EACH NEW MODEL RUN... HOWEVER
THE KENNEBEC VALLEY AND MIDCOAST REGIONS STILL SHOULD SEE 1-2" OF
SNOW. LOCATIONS IN BETWEEN WILL LIKELY SEE A FEW TENTHS OF AN
INCH. THE SNOW WILL MELT OFF QUICKLY AS HIGHS REACH THE 40S ON
SUNDAY.

WINDS ON THE BACKSIDE OF THE STORM ARE ANOMALOUSLY STRONG...BOTH
THE U AND THE V COMPONENTS AT 925MB AND 850MB. THIS WILL PROBABLY
RESULT IN GALES OVER THE BAYS TO STRONG GALES OR EVEN STORM FORCE
WINDS OVER THE OUTER GULF OF MAINE ON SUNDAY. IN ADDITION A WIND
ADVISORY MAY BE NEEDED FOR THE COAST.

SATURDAY NIGHT THROUGH MONDAY NIGHT LOOK ESPECIALLY CHILLY FOR
OVERNIGHT LOWS AS MUCH COLDER AIR FILTERS IN ON THE BACKSIDE OF
THE COASTAL SYSTEM. IN ADDITION...PWATS TAKE A NOSEDIVE SUNDAY
NIGHT TO NEAR 0.10" OR VERY CLOSE TO THE KNOWN MINIMUM FOR THIS
STATION FOR THIS TIME OF YEAR...HELPING RADIATIONAL COOLING OUT
TREMENDOUSLY. HAVE GONE BELOW GUIDANCE SUNDAY NIGHT FOR THIS
REASON.

ANOTHER LOW PRESSURE SYSTEM PASSES NORTH OF THE REGION TUESDAY AND
WEDNESDAY BRINGING ANOTHER CHANCE OF PRECIPITATION.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM...SOME EARLY MORNING VLY FOG WILL ALLOW IFR CONDS INTO
THE MORNING OTRW MOST AREAS WILL BE VFR TODAY INTO FRI. BY LATE
FRI SOME MVFR CIGS MAY DEVELOP AS THE NEXT SYSTEM APPROACHES.

LONG TERM...COASTAL LOW PRESSURE MOVES NORTH ON SATURDAY BRINGING
CEILINGS DOWN BELOW VFR. MVFR AND EVENTUALLY IFR CIGS/VSBYS MOVE
INTO THE AREA AS RAIN AND SNOW SHOWERS SPREAD NORTH. IFR VSBYS
WILL BE POSSIBLE WITH ANY SNOW. GRADUAL IMPROVEMENT BACK TO VFR
CONDITIONS ARE EXPECTED LATE SUN THROUGH MONDAY.

&&

.MARINE...
SHORT TERM...WINDS/SEAS WILL REMAIN BLO SCA LVLS THRU FRI.

LONG TERM...A DEVELOPING COASTAL STORM WILL AFFECT THE WATERS OVER
THE WEEKEND. THERE REMAINS SOME UNCERTAINTY...BUT CONSECUTIVE
MODEL RUNS HAVE BEEN MOVING THE STORM OUT FARTHER. CURRENTLY THE
STORM PASSES OUTSIDE THE 40N/70W BENCHMARK. HOWEVER GALES APPEAR
LIKELY OVER THE BAYS WITH STORM FORCE GUSTS POSSIBLE OVER THE
OUTER WATERS. SEAS WILL ALSO CLIMB TO 8-12 FT IN THE OUTER WATERS.
WINDS AND SEAS DIMINISH BELOW SMALL CRAFT CRITERIA BY MONDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



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