000
FXUS61 KGYX 061204
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
704 AM EST TUE JAN 6 2009
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL CREST OVER THE AREA TODAY AND
BEGIN TO MOVE OFFSHORE TONIGHT. LOW PRESSURE OVER THE GREAT LAKES WILL
PUSH A WARM FRONT NORTH TOWARD THE AREA BY WEDNESDAY MORNING AND
THEN SPAWN A COASTAL LOW OFF THE NEW ENGLAND COAST DURING WEDNESDAY
AFTERNOON AND EVENING. THE SYSTEM WILL EXIT INTO THE MARITIMES WEDNESDAY
NIGHT FOLLOWED BY COLDER HIGH PRESSURE FOR LATER IN THE WEEK. THE
NEXT IN A SERIES OF TROFS OF LOW PRESSURE WILL MOVE ACROSS THE
REGION ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRES WILL CREST OVER THE FORECAST AREA TODAY WITH DOWNSLOPING
WINDS CONTINUING BUT DIMINISHING. PARTLY TO MOSTLY SUNNY SKIES
EXPECTED EXCEPT IN THE MTNS WHERE SOME MORNING CLOUDS WILL PERSIST
BUT SHOULD DISSIPATE BY AFTN. GFS TEMPS LOOKED GOOD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
HIGH PRES WILL BEGIN MOVING OFF THE COAST AND THE OVERSPREADING OF
MID/HI CLOUDS DUE TO THE ONSET OF WAA ALOFT WILL BE NOTED. WITH A
VERY COLD ARCTIC AMS IN PLACE AND VERY DRY AIR IN THE LOWER LEVELS
THINKING IS TO SLOW THE ONSET OF SNOW TIL WED MRNG BUT WILL
MENTION A CHC OF SNOW AFT 06Z OVER SOUTHERN AREAS. A BLEND OF
NAM/GFS TEMPS WERE USED.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
WILL BE HOISTING A WINTER STORM WATCH THIS MORNING FOR THE ENTIRE
CWA FOR WEDNESDAY AND WEDNESDAY NIGHT.
SURFACE LOW PRESSURE OVER THE GREAT LAKES WILL BEGIN TO DEEPEN
WEDNESDAY MORNING...WITH THE ATTENDANT WARM FRONTAL BOUNDARY
EXTENDING ACROSS SOUTHERN NEW ENGLAND. STRONG SOUTHWESTERLY FLOW
ALOFT AHEAD OF THE SYSTEM WILL PROVIDE GOOD LIFT IN AN OVERRUNNING
SITUATION. EXPECT SNOW TO OVERSPREAD THE REGION DURING THE MORNING
ON WEDNESDAY. BEST DYNAMICS WITH THIS SYSTEM OCCUR BETWEEN 15Z
WEDNESDAY AND 03Z THURSDAY. SNOW SHOULD BEGIN OVER SOUTHERN NH BY
ABOUT 12Z...THEN DEVELOP STEADILY NORTHWARD...EVENTUALLY COVERING
THE ENTIRE CWA BY 18Z. MODELS HAVE CONTINUED A COLD TREND WITH
THIS SYSTEM. EVEN THE GFS IS NOW PRODUCING MOSTLY SNOW AT NEARLY
ALL LOCATIONS. ONLY EXCEPTION IS OVER COASTAL NEW HAMPSHIRE WHERE
SNOW SHOULD CHANGE OVER TO RAIN IN THE EARLY AFTERNOON HOURS.
FURTHER NORTH ALONG THE MAINE COAST...PRECIPITATION SHOULD BE
PRIMARILY SNOW. LATE IN THE AFTERNOON THE SNOW MAY MIX WITH ICE
PELLETS AND FREEZING RAIN. THE FOOTHILLS AND MOUNTAINS SHOULD SEE
ALL SNOW. SNOW AMOUNTS FOR THIS SYSTEM ARE SOMEWHAT ON THE BUBBLE
FOR A WARNING. HAVE OPTED TO ISSUE THE WATCH AND LET THE DAY SHIFT
TAKE ONE MORE LOOK AT NEW MODEL DATA BEFORE PULLING THE TRIGGER ON
ADVISORIES AND WARNINGS.
AS THE PRIMARY LOW PRESSURE SYSTEM MOVES INTO THE SAINT LAWRENCE
VALLEY...A SECONDARY CIRCULATION WILL BEGIN TO DEVELOP ON THE
TRIPLE POINT OVER THE GULF OF MAINE. WHILE MOST OF THE ENERGY GETS
TRANSFERRED...THERE WILL REMAIN A SURFACE TROUGH EXTENDING BETWEEN
THE TWO LOW PRESSURE SYSTEMS ACROSS CENTRAL AND NORTHERN MAINE
THROUGH 12Z THURSDAY. THIS WILL PROVIDE A FOCUS FOR SNOW TO
CONTINUE OVERNIGHT WEDNESDAY.
ONCE THIS SYSTEM MOVES THROUGH...WEAK HIGH PRESSURE TRIES TO BUILD
IN FOR LATE THURSDAY AND FRIDAY.
ANOTHER LOW PRESSURE SYSTEM...ALTHOUGH MUCH WEAKER...WILL MOVE
THROUGH THE REGION LATE SATURDAY AND EARLY SUNDAY PRODUCING A
SMALL AMOUNT OF PRECIPITATION. HIGH PRESSURE THEN BUILDS IN AGAIN
FOR MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TONIGHT...VFR CONDS THRU TONIGHT.
LONG TERM...LOW PRESSURE SYSTEM MOVING THROUGH THE REGION ON
WEDNESDAY AND WEDNESDAY NIGHT WILL BRING WIDESPREAD IFR/LIFR
CONDITIONS TO THE AREA.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...WINDS CONTINUE RATHER STRONG OVER
THE WATERS BUT SHOULD DIMINISH BY MID MORNING...THUS WILL CONTINUE
THE SCA THRU 10 AM. WINDS THIS AFTN AND TONIGHT WILL CONTINUE TO
DIMINISH AS A WEAK RIDGE OF HIGH PRES SETTLES OVER THE AREA.
LONG TERM...STRONG LOW PRESSURE WILL DEVELOP OVER THE GULF OF
MAINE WEDNESDAY AND WEDNESDAY NIGHT. WINDS MAY APPROACH GALE FORCE
SO HAVE ISSUED A GALE WATCH FOR THE WATERS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE
WEDNESDAY NIGHT FOR MEZ012-018>020-023>025.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR MEZ007>009-013-014-021-022-026>028.
NH...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE
WEDNESDAY NIGHT FOR NHZ002>010-013-014.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR NHZ001.
MARINE...GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR
ANZ150>154.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
ANZ150>154.
&&
$$
