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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 212245
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
645 PM EDT TUE MAY 21 2013

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN ALONG THE SOUTHERN PART OF OUR
REGION THROUGH MID WEEK. SMALL WAVES OF LOW PRESSURE WILL TRACK
ALONG THIS BOUNDARY TODAY AND WEDNESDAY. A LARGER STORM SYSTEM
FROM THE MIDWEST WILL TRACK TO OUR WEST ON THURSDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
645 PM UPDATE: ADJUSTED THE POPS TO ADVERTISE RAIN COMING INTO THE
WRN AREAS EARLIER THAN PREVIOUSLY FCST USING THE LATEST RADAR AND
HRRR. RAFL AFTER MIDNIGHT IN THE WEST-CENTRAL AREAS COULD BE HEAVY
AT TIMES AS RUC SHOWS NICE 5OKT JETLET AT 700 MBS OVERRUNNING THE
WARM FRONT. DECENT LLVL CONVERGENCE IN PLACE AS WELL. THEREFORE,
QPF WAS ADJUSTED USING THE LATEST NERFC GRIDS WHICH SHOWS UP TO
.75" FROM 06-12Z WEDNESDAY IN THE AFOREMENTIONED AREAS. TWEAKED
TEMPERATURES USING THE LATEST LAMP WHICH POINTS TO TEMPERATURES
WARMER THAN PREVIOUSLY FCST.

THE FA WILL ENJOY A BRIEF BREAK IN THE ACTION ERLY THIS EVE
BEFORE CLDNSS FROM ANOTHER S/WV...OLD CNVCTV COMPLEX MOVE W TO E
INTO THE FA DURG THE OVRNGT HRS AS A SFC WARM FRONT REMAINS
STATIONARY OVR THE GULF OF ME. BLENDED 6 HRLY RNFL AMOUNTS LOOK TO
BE MORE SIG AND WIDESPREAD THAN THE AREA OF SHWRS THAT CROSSED THE
REGION EARLIER TDY. IN ADDITION...THERE MAY BE HEAVIER DOWNPOURS
AS MORE CNVCTV ELEMENTS MOVE INTO E CNTRL AND DOWNEAST PTNS OF THE
FA WITH A WEAK ELEVATED CAPE ENVIRONMENT. THIS IDEA IS SUPPORTED
BY CURRENT LGTNG STRIKES ON THE S SIDE OF THE COMPLEX AS IT MOVES
E THRU ERN ONT TOWARD SW QB...SO WE DID INCLUDE ISOLD TSTMS VERY
LATE TNGT OVR CNTRL AND DOWNEAST AREAS. WITH THIS IN MIND...SOME
LOCATIONS OVR THESE PTNS OF THE FA COULD RECEIVE ARND AN INCH OR
EVEN A LITTLE MORE OF TOTAL QPF...WITH ARND A HLF INCH OR SO OVR
THE N...ENOUGH TO JUSTIFY NEAR 100 PERCENT POPS FOR VIRTUALLY ALL
OF THE FA BY WED MORN. LASTLY...WITH LOW TO MID LVL WARM ADVCN
WHICH WILL INCLUDE A MARINE COMPONENT OF AIRFLOW WILL RESULT IN
PATCHY FOG ACROSS THE N VERY LATE TNGT AND AREAS OF FOG S WHICH
WILL LIKELY CARRY OVER WELL INTO THE MORN HRS.

MOST OF THE STEADY RN SHOULD TAPER OFF TO LIGHTER SHWRS WED AFTN
AS THE S/WV MOVES E OF THE FA. LOW TEMPS WILL BE MILD AGAIN AS
CLDNSS...RNFL AND FOG LATE TNGT KEEP TEMPS FROM FALLING MUCH.
HI TEMPS WED WILL BE MUCH SUPPRESSED DUE TO LLVL DAMMING OF RAIN
COOLED AIR HANGING IN ACROSS THE FA THRU THE DAY.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AN UPPER LEVEL TROF ACROSS THE WESTERN GREAT LAKES AT THE START OF
THE PERIOD WILL SLOWLY MIGRATE EAST WEDNESDAY NIGHT THROUGH
THURSDAY. MEANWHILE AT THE SURFACE...LOW PRESSURE WILL TRACK
NORTHEAST ACROSS THE GREAT LAKES AND THROUGH QUEBEC...PASSING TO
NORTH OF THE STATE LATE THURSDAY. A COLD FRONT ASSOCIATED WITH THIS
SYSTEM WILL SLOWLY APPROACH FROM THE WEST LATER THURSDAY. THE FRONT
WILL SLOW DOWN AS IT BECOMES PARALLEL TO THE UPPER FLOW WITH A BROAD
SOUTHWEST FLOW IN PLACE.

A CHANCE OF SHOWERS WILL EXIST WEDNESDAY NIGHT AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION. THE CHANCE OF SHOWERS WILL INCREASE DURING
THE DAY THURSDAY IN ADVANCE OF THE SLOW MOVING COLD FRONT
APPROACHING FROM THE WEST. THERE WILL ALSO BE THE CHANCE FOR
THUNDERSTORMS DURING THURSDAY AFTERNOON ESPECIALLY ACROSS WESTERN
AREAS WHERE SB CAPES INCREASE TO 500-1000 J/KG PER GFS. THERE IS
SOME 0-6KM SHEAR AS WELL SO POTENTIAL IS THERE FOR SOME ORGANIZED
THUNDERSTORMS TO DEVELOP. OF COURSE...THIS WILL BE DEPENDENT ON JUST
HOW MUCH INSTABILITY DEVELOPS IN ADVANCE OF THE FRONT. THINKING WE
WILL SOME BREAKS OF SUNSHINE ACROSS WESTERN AREAS AWAY FROM THE
COAST AS LOW LEVEL FLOW BECOMES SOMEWHAT MORE SOUTHWEST. FOR
NOW...HAVE CONFINED MENTION OF THUNDER TO WESTERN AND NORTHERN
AREAS THURSDAY WITH MARINE INFLUENCE KEEPING THINGS MORE STABLE
DOWNEAST. WITH THE POTENTIAL FOR BREAKS ON THURSDAY AND 925 MB
TEMPERATURES AROUND +17C HAVE HAVE LEANED WITH WARMER MAV NOS FOR
MAXS THURSDAY.

SHOWERY TYPE WEATHER AND PERHAPS SOME LINGERING THUNDER CAN BE
EXPECTED INTO THURSDAY EVENING BEFORE TRANSITIONING TO A MORE STEADY
RAIN THURSDAY NIGHT IN RESPONSE TO AN AREA OF LOW PRESSURE
DEVELOPING TO OUR SOUTH ALONG THE SLOW MOVING FRONTAL BOUNDARY. A
STEAD RAIN IS EXPECTED TO CONTINUE ON FRIDAY AS LOW PRESSURE MOVES
NORTHEAST ALONG THE NEARLY STATIONARY FRONTAL BOUNDARY ACROSS THE
AREA. LOOK LIKE MOST AREAS WILL SEE ANYWHERE FROM A QUARTER TO HALF
AN INCH OF RAINFALL ON FRIDAY. BLENDED SREF/GFS FOR RAINFALL
AMOUNTS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DAMP AND UNSETTLED WEATHER PTRN LOOKS TO CONT INTO THE LONGER
TERM... LONG RANGE GUIDANCE IN REASONABLE AGREEMENT W/ THE OPNL 12Z
GFS AND 00Z ECMWF SHOWING A NRLY STALLED FRONTAL BNDRY OVR EXTRA
SERN MAINE AT 00Z SAT. BOTH MODELS ADVERTISE BROAD AREA OF LOW
PRES FROM S OF SRN NEW ENGLAND UP INTO NB. BY 12Z SAT THE GFS HAS
DVLP A FAIRLY SIGNIFICANT CLOSED SFC LOW PRES SYSTEM NR CAPE COD
WHILE THE ECMWF IS FURTHER NEWRD W/ THIS LOW OVR WRN NS... BY 00Z
SUN...THE GFS HAS MOVD THIS DEEPENING SYSTEM NEWRD INTO SERN MAINE
WHILE THE ECMWF HAS THE SYSTEM OVR XTRM NERN NB. THEREAFTER THE
GFS WRAPS THIS LOW INTO NRN MAINE WHILE THE ECMWF LIFTS IT NEWRD
TO THE MOUTH OF THE ST LAWRENCE BY 12Z SUN. DESPITE THE 12
TIMING DIFFS...BOTH MODELS SUGGEST A POTENTIALLY SIGNIFICANT QPF
EVENT FOR THE PD LATER FRI NGT INTO SAT NGT W/ CHILLY AND
UNSETTLED CONDS PERSISTING THRU SUN.

STILL BRISK AND CHILLY INTO MON W/ A CONTG CHC OF SOME SHOWERS
SPCLY N AND W THEN APPEARS SOME DRIER AND MILDER AIR MAY FINALLY
WORK INTO THE FA BY TUE. ATTM...NOT THE BEST LOOKING MEMORIAL DAY
WEEKEND WX WISE FOR OUR REGION...

WILL CARRY LIKELY TO CAT POPS FRI NGT INTO SAT NGT W/ THE HIGHEST
POPS E AND SE. PLAYED TEMPS ON THE COOL SIDE USING A CONS ALL
BLEND...

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR NRN TAF SITES THIS EVENING WHILE DOWNEAST SITES
HOLD IFR OR IMPROVE TO MVFR. ALL SITES THEN LOWERING TO IFR TO
LIFR LATE TNGT INTO ERLY WED MORN WITH ANOTHER ROUND OF LOW CLDNSS
SHWRS AND PATCHY TO AREAS OF FOG. LIFR CONDITIONS WED MORN ONLY
IMPROVE TO IFR WED AFTN AS STEADY MORN RN AND FOG TAPERS TO AFTN
SHWRS.

SHORT TERM: MVFR/IFR CONDITIONS ARE EXPECTED WEDNESDAY NIGHT AND
INTO THURSDAY MORNING IN LOW CLOUDS AND SHOWERS. CONDITIONS
SHOULD IMPROVE TO MVFR/VFR LATER THURSDAY MORNING INTO THURSDAY
AFTERNOON. SHOWERS ARE EXPECTED TO INCREASE ACROSS THE REGION
LATER THURSDAY AFTERNOON AND COULD EVEN SEE SOME SCT TSRA NORTHERN
TERMINALS THURSDAY AFTERNOON. MVFR/IFR CAN BE EXPECTED ON FRIDAY
IN STEADY RAIN.

&&

.MARINE...
NEAR TERM: NO HDLNS XPCTD OVRNGT THRU WED. WV HTS WILL HAVE SOME
SWELL COMPONENT OVR THE OUTER WATERS...REACHING UP TO 4 FT AT TMS.
WE USED A BLEND OF WW3 AND SWAN GFS...SMOOTHED 10 TMS OVR IN THE
VCNTY OF THE COAST TO LOWER WV HTS FOR THE INNER BAY/HARBOR MZ.

SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
WEDNESDAY NIGHT. WINDS/SEAS WILL INCREASE THURSDAY AND CONTINUE
TO INCREASE TO SMALL CRAFT ADVISORY LEVELS THURSDAY NIGHT AND
FRIDAY. AREAS OF FOG WILL LIKELY REDUCE VISIBILITY TO 1 TO 3 NM
ESPECIALLY THURSDAY NIGHT AND ON FRIDAY.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...HEWITT/VJN
SHORT TERM...DUDA
LONG TERM...KHW
AVIATION...HEWITT/VJN/DUDA
MARINE...HEWITT/VJN/DUDA