Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 180202
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1002 PM EDT FRI APR 17 2015

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL DROP SOUTH AND EAST ACROSS THE
REGION TONIGHT AND TOMORROW BRINGING SCATTERED SHOWERS AND
POSSIBLY ISOLATED THUNDERSTORMS WITH IT. ANOTHER SYSTEM WILL
APPROACH THE REGION ON MONDAY AND TUESDAY. THIS SYSTEM LOOK MUCH
STRONG AND MAY BRING A SIGNIFICANT RAINFALL TO THE AREA. UNSETTLED
WEATHER LOOKS TO DOMINATE THROUGHOUT NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10PM...TEMPERATURES CONTINUE TO FALL RAPIDLY IN THE NORTHERN
MOUNTAINS. ALSO DEWPOINTS ARE A BIT HIGHER THAN ANTICIPATED, MADE
THESE ADJUSTMENTS AND DECREASED CLOUD COVER AS WAVE IS STILL
QUITE A WAYS TO OUR NORTH IN QUEBEC.

6PM... MINOR UPDATE FOR CURRENT TEMPERATURES. FORECAST IS ON TRACK
WITH CLEARING SKIES EXPECTED OVERNIGHT. MIDDAY DEWPOINTS WOULD
SUPPORT FOG FORMATION OVERNIGHT IN A FEW VALLEYS...SUCH AS BERLIN
AND KEENE... HOWEVER ADVECTION OF DRIER AIR FROM QUEBEC IS ONGOING
SO EXPECT AIR TO DRY BEFORE ANY FOG WOULD FORM.

PREV DISC BRIEF PERIOD OF QUIET WEATHER BETWEEN TODAYS SHOWERS
AND THE NEXT SHORT WAVE THAT MOVES THROUGH TOMORROW MORNING.
EXPECT TO SEE CLEARING SKIES ACROSS THE REGION. THIS WILL ALLOW
FOR RADIATIONAL COOLING. WITH DEW POINTS DOWN IN THE 40S
THOUGH...NOT SURE IF THERE WILL BE MUCH IN THE WAY OF FOG OR NOT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SHORT WAVE DROPS SOUTH AND EAST OUT OF CANADA TOMORROW MORNING.
MODELS HAVE SLIGHTLY DIFFERING SOLUTIONS WITH THIS FEATURE. THE
GFS KEEPS THE MAJORITY OF THE ENERGY OVER THE NORTHERN HALF OF THE
CWA. THE NAM HAS PRECIPITATION MORE WIDESPREAD WITH MOST OF THE
AREA SEEING PRECIPITATION. SYSTEM SHOULD BE FAST MOVING THOUGH AND
BY LATE TOMORROW AFTERNOON MOST OF THE THE AREA SHOULD BE DRY.
DYNAMICS LOOK PRETTY GOOD FOR THIS TIME OF YEAR ALSO AND WOULD NOT
BE SURPRISED TO SEE SOME ISOLATED THUNDER.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
AFTER TRANSITIONING HIGH PRESSURE MOVES THROUGH ON SUNDAY...
WINDS BECOME SOUTHERLY LATE SUNDAY NIGHT AS THE NEXT WAVE
APPROACHES. A WARM FRONT SURGES UP FROM THE SW AS A STOUT SHORT
WAVE ATTACHED TO THE MEAN CONUS TROUGH ROTATES INTO NEW ENGLAND BY
LATE MONDAY. WARM ADVECTION SHOWERS SHOULD BEGIN AS EARLY AS
MONDAY MORNING FROM WEST TO EAST. THE HEAVIER RAIN ARRIVES LATE
MONDAY THROUGH TUESDAY AFTERNOON AS IT SHIFTS EAST.

THIS COULD BE A HEAVY RAIN EVENT WITH A STRONG 50 KT LLJ CAUSING
TRAINING OF CELLS AND FEEDING INTO SECONDARY LOW PRESSURE THAT
WILL LIKELY FORM ALONG THE COAST TUESDAY. IN ADDITION FORECAST
SOUNDINGS FOR PORTLAND INDICATE WARM RAIN PROCESSES. THIS DOES NOT
EXCLUDE THE POSSIBILITY OF A COUPLE INCHES OF WET SNOW FOR THE
MOUNTAINS. DRIER SW AIR PUNCHES IN BY TUESDAY NIGHT ALLOWING FOR
PRECIPITATION EROSION FROM SW TO NE ACROSS NH AND CENTRAL ME
THROUGH WEDNESDAY MORNING.

HOWEVER ALMOST AS SOON AS THIS SYSTEM BEGINS TO EXIT INTO THE
CANADIAN MARITIMES ANOTHER ONE ARRIVES. THIS OCCURS BECAUSE THE
UPPER LEVEL LOW IS NOW NEARLY OVERHEAD AND A SERIES OF VORTICITY
MAXIMA ARE ROTATING AROUND THE CENTER... RESULTING IN A MESSY
WEEKEND IN THE NORTHEAST.

WRAP AROUND MOISTURE FROM THE TUESDAY SYSTEM HELPS TO KEEP SHOWERS
GOING THROUGH THE DAY WEDNESDAY. ANOTHER LOW PRESSURE SYSTEM
DEVELOPS AND CROSSES THE REGION IN THE THURSDAY/FRIDAY TIME FRAME
AND MAY FOCUS AN INVERTED TROF OVER THE REGION. THIS IS ANOTHER
HEAVY RAIN SIGNAL. SO AT THIS TIME DETAILS MAY CHANGE BUT IT LOOKS
LIKE A RAINY PERIOD IN THE EXTENDED.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...MVFR CONDITIONS SHOULD IMPROVE THIS AFTERNOON AND
EVENING. PATCHY FOG MAY AFFECT A COUPLE OF STATIONS TONIGHT...BUT
EXPECT MOSTLY VFR CONDITIONS. WEAK SYSTEM MOVES THOUGH TOMORROW
WITH MVFR CIGS AND VSBYS AGAIN IN RAIN SHOWERS AND FOG.

LONG TERM...VFR CONDITIONS SUNDAY INTO MONDAY MORNING. IFR
CONDITIONS IN RAIN ARE LIKELY STARTING MONDAY AFTERNOON AND
LASTING THROUGH WEDNESDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS EXPECTED.

LONG TERM...LOW PRESSURE AFFECTING THE WATERS MON NIGHT AND TUE
WILL LIKELY BRING ROUGH SEAS AND SCA CONDITIONS...IF NOT LOW END
GALES FOR A TIME.

&&

.FIRE WEATHER...
EXTREME SOUTHWESTERN PORTIONS OF THE CWA COULD SEE SOME RELATIVE
HUMIDITY VALUES TOMORROW IN THE LOWER 30S. HOWEVER... THE LACK OF
GUSTY WINDS AND POSSIBLE PRECIPITATION SHOULD KEEP CONDITIONS
ABOVE RED FLAG CRITERIA.

&&

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

&&

$$
SYNOPSIS...POHL
NEAR TERM...CURTIS
SHORT TERM...POHL
LONG TERM...HANES
AVIATION...HANES/POHL
MARINE...HANES/POHL
FIRE WEATHER...POHL



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