FXUS61 KGYX 181031
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
631 AM EDT SAT MAY 18 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE COAST AS A DEVELOPING WARM FRONT
APPROACHES FROM THE SOUTHWEST TODAY THROUGH SUNDAY. UNSETTLED
WEATHER CAN BE EXPECTED NEXT WEEK AS A SERIES OF DISTURBANCES
TRACK EASTWARD ACROSS NEW ENGLAND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL UPDATE TO INPUT LATEST OBSERVED DATA RESULTING IN NO
NOTICEABLE CHANGES TO THE PREVIOUS FCST OTHER THAN TO REMOVE FROST
FROM THE FCST THIS MORNING.
PREVIOUS DISCUSSION...
THE UPR LVL PATTERN SHOWS A CUTOFF LOW OVER THE MARITIMES WITH A
RIDGE TO OUR W CENTERED OVER THE GREAT LAKES. THIS WILL RESULT IN
A NW FLOW OVER NEW ENGLAND WHICH HAS AN EMBEDDED WEAK SHORT
WAVE/JET SEGMENT SLIDING SE IN THIS NW FLOW INTO NEW ENGLAND. AT
THE SFC WEAK HIGH PRES BETWEEN THE TWO UPR LVL SYSTEMS WILL SLOWLY
SHIFT OFFSHORE. THIS WILL ALLOW WINDS TO TURN ONSHORE DURING THE
DAY...BEING ENHANCED BY A DEVELOPING SEA BREEZE ALONG THE COAST.
THE UPR LVL SHORT WAVE/JET SEGMENT IS ACCOMPANIED BY AN AREA OF
HIGHER RH WHICH WILL TRANSLATE INTO VARYING AMOUNTS OF CLOUDINESS
ACROSS THE FCST AREA TDA. THIS FEATURE MAY EVEN TRIGGER AN
ISOLATED -SHRA OR TWO THIS AFTERNOON AS IT MOVES INTO THE REGION.
THE GFS MODEL IS OVERDOING THE CHC OF PRCP AND QPF FOR THIS EVENT.
WILL LOWER THE CHC OF PRCP DOWN TO SLGT CHC AND WILL USE RFC QPF
WHICH SHOWS MINIMAL AMOUNTS. HIGH TEMPS TDA WILL BE TEMPERED BY
ONSHORE FLOW...ESPECIALLY NEAR THE COAST. WILL USE A BLEND OF
MET/MAV MOS WHICH IS A COMPROMISE BETWEEN THE COOLER MET AND
WARMER MAV. EXPECT HIGHS IN THE 60S WITH AROUND 70 PSBL OVER SRN
INTERIOR NH AND COASTAL MAINE A LITTLE COOLER...ESPECIALLY THE
MID COAST WITH HIGHS TOPPING OUT IN THE 50S. ALSO USED A BLEND OF
MAV/MET MOS FOR DEW POINTS AND WINDS.
THERE WILL BE SOME PATCHY FROST IN SHELTERED INLAND AREAS EARLY
THIS MORNING WITH LOWS IN THE 30S...BUT WILL BE VERY LIMITED AND
IN AREAS WHERE THE GROWING SEASON HASN'T BEGUN SO NO FROST ADV
NEEDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
THE UPR LVL PATTERN DOESN'T CHANGE OVER THE SHORT TERM PERIOD AS
THE UPR LVL SHORT WAVE/JET SEGMENT IN THE NW FLOW PUSHES OFF THE
COAST TNGT. THIS BRINGS THE AREA OF HIGHER RH OFFSHORE AS WELL AS
ISOLD -SHRA. HOWEVER...A DEVELOPING WRM FNT, BETWEEN THE COOLER AIR
ASSOCIATED WITH THE UPR LVL CUTOFF TO OUR NE AND THE UPR LVL RIDGE
TO OUR W, WILL BE SPREADING MORE CLOUDS AND PSBL -SHRA NE INTO THE
FCST AREA ON SUNDAY /MAINLY IN THE AFTERNOON/. AGAIN THE GFS CHC
OF PRCP AND QPF APPEAR OVERDONE SO HAVE LOWER THE CHC OF PRCP
CONSIDERABLY AND USING RFC QPF WHICH KEEPS AMOUNTS VERY LOW. A
BLEND OF MAV/MET MOS WAS USED FOR TEMPS, DEW POINTS AND WINDS.
THE ONSHORE FLOW INCREASES ON SUNDAY AS THE PRES GRADIENT
INCREASES BETWEEN THE HIGH WHICH STRENGTHENS OFF THE COAST AND
THE WRM FNT THAT PUSHES IN FROM THE SW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE NUMERICALS ARE IN BASIC AGREEMENT ON LONGWAVE PATTERN THROUGH THE
MIDDLE OF NEXT WEEK. INITIALLY THE UPPER RIDGE BUILDS THROUGH THE
MIDWEST AND GREAT LAKES WHICH LEAVES THE FORECAST AREA IN WEST-NORTHWEST
FLOW INTO EARLY NEXT WEEK. THEREAFTER...FALLING HEIGHTS AS THE
RIDGE WEAKENS AND SOME DEGREE OF EASTERN TROUGH EMERGES. WITH MEAN
JET AXIS OVERHEAD OR NEARBY...THE AREA FOR MUCH OF THE PERIOD WILL
BE UNSETTLED AS A SERIES OF DISTURBANCES TRAVEL EASTWARD ALONG A
BOUNDARY SEPARATING SUMMER-LIKE WARMTH FROM EARLY SPRING CHILL.
IN THE DAILIES...UNSETTLED WEATHER CAN BE EXPECTED NEXT WEEK AS A
SERIES OF DISTURBANCES TRACK EASTWARD ACROSS NEW ENGLAND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SUNDAY/...VFR TDA...TNGT AND EARLY SUNDAY BUT
POSSIBLY LOWERING TO MVFR AT TIMES IN ANY ISOLD -SHRA. A SLIGHTLY
BETTER CHC OF MVFR CIG/VSBY IN ISOLD TO SCT -SHRA LATE SUNDAY.
WEAK WINDS BECOME ONSHORE TDA AND ENHANCED BY A SEA BREEZE ALONG
THE COAST. WINDS DROP OFF TNGT BUT ONSHORE FLOW PICKS UP AGAIN ON
SUNDAY. 
LONG TERM...
MON - WED...AREAS OF MVFR IN SHOWERS.
&&
.MARINE...
SHORT TERM /TODAY THROUGH SUNDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO NOTICEABLE CHANGES TO THE PREVIOUS
FCST. WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS. LGT AND
VARIABLE WINDS BECOME ONSHORE AS HIGH PRES MOVES OFF THE COAST TDA
. WINDS ENHANCED TDA FROM DAYTIME SEA BREEZES. SE ONSHORE FLOW
CONTINUES TNGT AND INCREASES ON SUNDAY AS THE PRES GRADIENT
INCREASES AS THE HIGH STRENGTHENS AND A WRM FNT APPROACHES FROM
THE SW.
LONG TERM...
SUN NIGHT - MON...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
&&
.FIRE WEATHER...
THE FIRE WEATHER DANGER WILL BE FAIRLY LOW FOR THE NEXT SEVERAL
DAYS AS GREEN UP CONTINUES ACROSS THE REGION. RH VALUES WILL BE
THE LOWEST TDA BUT WINDS WILL BE FAIRLY LGT EXCEPT FOR A
DEVELOPING SEA BREEZE ALONG THE COAST WHICH WILL ALSO FORCE RH
VALUES TO INCREASE THERE. WINDS INCREASE ON SUNDAY BUT OFF THE
OCEAN WHICH WILL RESULT IN HIGHER RH VALUES PUSHING INLAND. ISOLD
-SHRA OVER THE WEEKEND MAY INCREASE IN COVERAGE LATE SUNDAY. THERE
WILL BE A BETTER CHC OF -SHRA DURING THE WORK WEEK WHICH WILL BE
ACCOMPANIED BY FAIRLY HIGH RH VALUES.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$