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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KGYX 240418
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1218 AM EDT FRI MAY 24 2013

.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE REGION TONIGHT WILL STALL OFF
THE COAST ON FRIDAY. LOW PRESSURE WILL DEVELOP ON THE FRONT SOUTH
OF CAPE COD FRIDAY NIGHT AND SLOWLY MOVE NORTH THROUGH THE GULF OF
MAINE THROUGH SUNDAY MORNING. LOW PRESSURE WILL CONTINUE NORTH
THROUGH THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE WEST MONDAY AND WILL SHIFT OFFSHORE ON TUESDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON WEDNESDAY.

&&

.NEAR TERM /UNTIL 9 AM THIS MORNING/...
-- Changed Discussion --
1205 AM...JUST A QUICK UPDATE TO ADJUST POPS AND TEMPS A BIT
OVERNIGHT...AND TO FOCUS ON BEST CH OF HEAVIER DOWNPOURS IN THE
06-13Z TIME FRAME AS 500 MB SH COMBINES WITH MID-LVL JET AND HIGH
PWATS...APPROACHING 200% OF NORMAL COM TO TOGETHER TO PRODUCE A
SURGE OF HEAVY RAINFALL...WHICH WILL DEVELOP AFTER MIDNIGHT AND LKLY
AFFECT MORNING COMMUTE. 00Z NAM12 AND LATEST HRRR FOCUS THE BULK
OF THE PRECIP CLOSER TO THE COAST...WHERE THE GROUND CAN HANDLE IT
BETTER. HOWEVER...COULD CAUSE SOME LOCALIZED PROBLEMS...PONDING ON
THE ROADS AND IN URBAN AREAS.

UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. RADAR CONTS TO
SHOW AREAS OF SHOWERS AND ISOLD TSTMS OVER THE NRN MTNS WHERE WE
HAVE ISSUED AN AREAL FLOOD ADVISORY. OVER SRN NH...THE ECHOES CONT TO
WEAKEN AS THEY HEAD NORTH...DESPITE A PRECIPITABLE WATER LEVEL
AXIS OF 1.6" OVER THE REGION.

LATEST HRRR RUN CONTS TO SHOW PCPN STREAMING IN FROM THE SOUTH
OVERNIGHT...ALONG AND AHEAD OF APPROACHING COLD FRONT. CATEGORICAL
POPS WILL REMAIN IN THE GRIDS OVERNIGHT WITH PATCHY/AREAS OF FOG.
EXPECT AROUND AN INCH OR SO OF RAINFALL OVER THE COASTAL AREAS
WHICH REMAINS WELL BELOW FLASH FLOOD GUIDANCE.

PREV DISC...
COLD FRONT APPROACHING FROM THE WEST WILL MAKE FOR A WET AND
BREEZY NIGHT ACROSS THE REGION. SCATTERED SHOWERS AND SOME
THUNDERSTORMS WILL GRADUALLY CHANGE TO A WIDESPREAD RAIN OVERNIGHT
AS THE FRONT SLOWLY CROSSES THE AREA. EXPECT THUNDERSTORM ACTIVITY
TO BE MAINLY CONFINED TO NEW HAMPSHIRE LATE THIS AFTERNOON AND
THIS EVENING AS MARINE LAYER PERSISTS ACROSS MOST OF MAINE. CAN`T
RULE OUT A RUMBLE OF THUNDER OVERNIGHT BUT SHOULD BE ISOLATED AND
HAVE NOT INCLUDED THIS IN THE FORECAST AFTER THIS EVENING. EXPECT
OVERNIGHT LOWS TO BE UNIFORM ACROSS THE REGION WITH MOST AREAS
DIPPING INTO THE MID 50S TO NEAR 60.
-- End Changed Discussion --

&&

.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FRONT WILL STALL JUST OFF THE COAST ON FRIDAY WITH RAIN CONTINUING
THROUGH THE DAY ACROSS THE FORECAST AREA. NOT EXPECTING
TEMPERATURES TO MOVE MUCH FROM OVERNIGHT LOWS WITH MOST LOCATIONS
ONLY REACHING THE UPPER 50S TO LOWER 60S. RAIN CONTINUES FRIDAY
NIGHT AS LOW PRESSURE TRACKS NORTH ALONG THE FRONT. FOCUS WILL
TURN TO AREA RIVERS IN NORTHERN ZONES WHERE STORM TOTALS COULD
WILL FALL IN THE THE 2 TO 4 INCH RANGE BY LATE ON SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
CUTOFF AND SFC LOW WILL DRIFT SLOWLY NE THRU THE WEEKEND
CONTINUING PRCP ACROSS THE FCST AREA WITH THE POTENTIAL FOR HEAVY
RAINFALL. MODELS SHOWING MAX QPF ACROSS THE N/MT ZONES TO WRN NH
ZONES. GFS MUCH HIGHER ON QPF...WITH OTHER MODELS PREFERRED. USED
HPC QPF FOR A COMPROMISE. CUTOFF AND SFC LOWS MOVE NE OF THE AREA
MONDAY WITH IMPROVING WX...BUT STILL COOL AIR AND CYCLONIC FLOW
ALOFT ALONG WITH FAIRLY AMPLE RH COULD PRODUCE SOME CLOUDS AND
PSBL -SHRA EVEN ON MONDAY. FOR NOW WILL GO WITH SLGT CHC.

AN UPR LVL AND SFC RIDGE BUILD IN TUESDAY FINALLY BRINGING DRY WX
WITH WARMING TEMPS. AN UPR LVL SHORT WAVE TROF SLIDES E THRU THE
UPR LVL RIDGE LATE WEDNESDAY AND WEDNESDAY NGT...BRINGING ISOLD TO
SCT SHRA TO THE REGION WEDNESDAY NGT AND THURSDAY.

GENERALLY USED BLEND OF GFS40/NAM, MET/MAV & HPC QPF FOR DAYS 4
AND 5 THEN A BLEND OF GFS40, GMOS, MEX/ECE FOR THE REST OF THE
LONG TERM FCST.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY TONIGHT THROUGH FRIDAY.

LONG TERM /SATURDAY THROUGH TUESDAY/...IFR/LIFR SATURDAY THRU MUCH
OF SUNDAY...IMPROVING TO VFR WITH PSBL MVFR ON MONDAY THEN VFR
TUESDAY.

&&

.MARINE...
SHORT TERM...SCA IN EFFECT THROUGH FRIDAY TONIGHT.

LONG TERM /SATURDAY THROUGH TUESDAY/...NE WINDS AHEAD OF
APPROACHING LOW AND SEAS LIKELY AT SCA LEVELS SATURDAY AND MAY
NEED TO EXTEND THE SCA THRU THE DAY. WINDS LET UP AND BACK TO THE
NW SLOWLY SATURDAY NGT THRU MONDAY...LIKELY DROPPING BELOW SCA
LEVELS BY LATE SATURDAY NGT OR EARLY SUNDAY. SEAS WILL BE SLOWER
TO DROP OFF. HIGH PRES PROVIDES RELATIVELY CALMER WINDS AND SEAS
ON TUESDAY.

&&

.FIRE WEATHER...
NO PROBLEMS NOTED.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ150>154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...
HYDROLOGY...