FXUS61 KGYX 120810
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
310 AM EST SAT DEC 12 2009
.SYNOPSIS...
HIGH PRES WILL BEGIN TO BUILD IN FROM S TODAY...AND GRADUALLY
ALLOW WINDS TO FINALLY DIMINISH TONIGHT. THE HIGH WILL SLOWLY
DRIFT EAST TONIGHT AND SUNDAY AND ALLOW WEAK LOW PRES TO TRACK TO
OUR SOUTH. THIS WILL PROVIDE INCREASING CLOUDS SUNDAY...WITH LIGHT
RAIN OR SNOW DEVELOPING LATER IN THE DAY. THIS PRECIPITATION WILL
CONTINUE SUNDAY EVENING. WEAK HIGH PRESSURE BUILDS IN AGAIN ON
MONDAY. LOW PRESSURE WILL APPROACH FROM THE WEST MONDAY NIGHT AND
WILL MOVE INTO QUEBEC ON TUESDAY WITH A TRAILING COLD FRONT
CROSSING THE REGION. A STRONG NORTHWEST FLOW WILL DEVELOP BEHIND
THE LOW AS IT STALL AND INTENSIFIES IN THE MARITIMES WEDNESDAY
THROUGH FRIDAY...PRODUCING ANOTHER STRETCH OF COLD AND WINDY
WEATHER.
&&
.NEAR TERM /THROUGH TODAY/...
STRONG WESTERLY FLOW WILL CONTINUE TODAY AS PRESSURE GRADIENT
REMAINS FAIRLY TIGHT AND MIXING CONTINUES TO KEEP WINDS GUSTY
THROUGH THE AFTERNOON. ALTHOUGH THERE WILL BE SOME CUMULUS
DEVELOPMENT TODAY...SKIES SHOULD BE MOSTLY SUNNY ACROSS MUCH OF
THE AREA. THE EXCEPTION WILL BE IN THE UPSLOPE AREAS OF THE
MOUNTAINS WHERE SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY AND
WIDELY SCATTERED SNOW SHOWERS ARE POSSIBLE.
TEMPS WILL REMAIN COOL WITH HIGHS RANGING FROM THE TEENS IN THE
MAINE MOUNTAINS TO NEAR 30 IN SOUTHEASTERN NH AND ALONG THE COAST.
&&
.SHORT TERM /TONIGHT/...
AS RIDGE OF HIGH PRESSURE CROSSES AREA...LOW LEVEL AIR SHOULD
DECOUPLE FROM WINDS ALOFT ALLOWING TEMPS TO DROP QUICKLY THIS
EVENING. SKIES WILL START OUT MOSTLY CLEAR EARLY BUT HIGH CLOUDS
WILL BE ON THE INCREASE LATER AS WARMER AIR STARTS MOVING IN ALOFT.
TEMPS WILL DROP TO ZERO IN THE COLDER LOCATIONS IN THE MOUNTAINS
AND SINGLE DIGITS TO TEENS ELSEWHERE.&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY MORNING LOOKS TO BE DECENT...BUT THINGS WILL BEGIN TO
DETERIORATE AROUND MIDDAY...AS 500MB RIDGING GETS BROKEN DOWN BY A
COMPACT...AND FAST MOVING SHORT WAVE. MAIN SFC LOW WITH THIS WAVE
STAYS TO OUR S...BUT GFS SHOWS SOME SFC TROUGHINESS EXTENDING NWD
TO SFC LOW ASSOCIATED WITH LARGER SCALE 500MB TROUGH WELL TO THE
N. PRECIP LOOKS TO WORK IN FROM SW TO NE SUN AFTERNOON...BUT COULD
HOLD OFF UNTIL SUNSET N AND E OF PWM. P-TYPE AND QPF ARE UNCERTAIN
ATTM. GFS RANGES FROM ABOUT TWO TO FOUR TENTHS OF AN INCH...WITH
THE HIGHER AMOUNTS NEAR THE COAST...WHILE THE NAM DOUBLES ROUGHLY
DOUBLES THESE AMTS. THE NAM IS VERY BULLISH ON WAA AND SHOWS
POCKETS OF VERY STRONG ISENTROPIC UPGLIDE BETWEEN 850 AND
700MB. NOT TOO CERTAIN ABOUT THIS...AND HAVE GONE WITH HPC QPF
WHICH EVEN UNDERCUTS THE GFS...THOUGH IS CLOSE. THE OTHER ISSUE IS
P-TYPE...ALTHOUGH THINK THAT THE FOOTHILLS AND MOUNTAINS WILL SEE
MAINLY SNOW...WITH POINTS S BEING THE ISSUE. THE GFS SHOWS WARM
AIR WORKING IN ON DECENT S-SW LOW-MID LVL FLOW...AS DOES THE NAM.
BUT THE NAM HAS A VERY SHALLOW WARM LYR NR THE SFC...AND GIVEN ITS
STRONG PERIODS OF UPWARD MOTION...IT MAY BE ENOUGH TO TURN THINGS
TO SNOW...BUT ACCUMS LOOK TO BE LIGHT...GIVEN IN THE MID-UPPER
30S SUN EVE...WHEN THE BULK OFF THE PRECIP FALLS. SO ALL IN
ALL...LOOKS LIKE AN INCH OR TWO IN THE NORTH...AND PERHAPS AS MUCH
AS 2 INCHES ON THE COASTAL PLAIN. PRECIP WINDS DOWN AFTER
MIDNIGHT...AND SHOULD BE DONE BEFORE OR RIGHT AROUND SUNRISE
MONDAY.
STRONG RIDGING BEHIND THIS SYSTEM WILL CUT US OFF FROM ANY COLD
AIR...AND WE/LL SEE ABOVE NORMAL TEMPS MON INTO TUES...WHEN THE
NEXT SYSTEM WILL BEGIN TO AFFECT US. FOR NOW IT LOOKS LIKE
DEEPENING 500 MB LOW TO OUR N...AND WEAK WAVE TRAVERSING THE SERN
US WILL NOT PHASE...AND WE WILL BE LEFT WITH MAINLY A COLD FROPA
LATE TUE OR TUE NIGHT. SOME WAA WILL DEVELOP OVER NRN ZONES MON
NIGHT...AND THEN A CHANCE OF OF SHOWERS TUE AND TUE NIGHT...RAIN
NEAR THE COAST AND SNOW IN THE N.
THAT LOW TO THE NORTH WILL STALL AND INTENSIFY OVER THE
MARITIMES...AND THIS WILL PROVIDE A STRONG N-NW FLOW...AND A
STEADY STREAM OF COLD AIR AND WINDS WED THRU FRI. OTHER THAN
UPSLOPE SHSN...SOME OF WHICH COULD PRODUCE SOME DECENT SNOW
ACCUMS...IT WILL BE MAINLY DRY...BUT COLD AND WINDY AGAIN.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED THROUGH TONIGHT. SOME MVFR
CONDITIONS ARE POSSIBLE IN THE MOUNTAINS TODAY IN WIDELY SCATTERED
SNOW SHOWERS.
LONG TERM...WEAK LOW PRES WILL BRING A RA/SN MIX TO THE TERMINALS
SUN AFTERNOON AND SUN NIGHT. MVFR LIKELY...BUT IFR OR LOWER
POSSIBLE WHERE PRECIP PERSISTS AS SNOW. VFR RETURNS FOR MON AND
MON NIGHT...WITH COLD FRONT PASSAGE ON TUE POSSIBLY LOWERING CONDS
TO MVFR LATE TUE AND TUE NIGHT. STRONG N-NW WINDS RETURN FOR WED.
&&
.MARINE...
SHORT TERM...GALE WARNINGS CONTINUE TODAY. WINDS WILL GUST UP TO
35 TO 40 KNOTS ACROSS THE AREA. SCATTERED SNOW SHOWERS ARE
POSSIBLE WELL OFFSHORE. WINDS SHOULD BEGIN TO DIMINISH THIS
EVENING.
LONG TERM...SW FLOW INCREASES AND SEAS BUILD TO SCA LEVELS AHEAD
OF SFC TROF LATE SUNDAY AND SUNDAY NGT. WINDS AND SEAS BUILD TO
SCA LEVELS AGAIN AHEAD OF A STRONGER FRONTAL SYSTEM LATE TUESDAY
INTO TUESDAY NGT. STRONG AND GUSTY NW WINDS DEVELOP BEHIND THIS
FNT LATE TUESDAY NGT AND CONT THRU WEDNESDAY WITH GALE FORCE WINDS
PSBL.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ150>154.
&&
$$
NEAR TERM...JENSENIUS
SHORT TERM...JENSENIUS
LONG TERM...CEMPA
