Area Forecast Discussion Issued by NWS Caribou, ME
000
FXUS61 KCAR 181601
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1201 PM EDT TUE JUN 18 2013
.SYNOPSIS...
A SECOND COLD FRONT IS EXPECTED TO CROSS THE REGION TODAY WITH
COOLER AIR TONIGHT INTO WEDNESDAY AS HIGH PRESSURE ACROSS THE
GREAT LAKES BUILDS TOWARD THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
1200 PM UPDATE...WILL UPDATE TO INCREASE THE POPS ALONG THE COAST
FOR THIS AFTERNOON. RETURNS ON THE KGYX RADAR ARE SEEN SPREADING
TO THE NORTHEAST TOWARD COASTAL HANCOCK COUNTY AT MIDDAY WITH
SHOWERS OBSERVED AT A FEW OBSERVATIONS SITES UPSTREAM. THE
SHOWERS ARE ASSOCIATED WITH A SFC FRONT THAT IS VERY CLOSE TO THE
COAST AND SOME UPPER LEVEL ENERGY THAT IS MOVING ACROSS THE AREA
JUST TO THE NORTH OF THE FRONT. THE THREAT OF T-STORMS LOOKS TO
BE LOW AS THE AIR MASS IS DRIER AND MUCH MORE STABLE THAN
YESTERDAY AFTERNOON.
915 AM UPDATE...AN UPPER LOW IS SEEN ON VISIBLE SATELLITE
SPINNING ABOUT 150 MILES SE OF JAMES BAY. THE LOW AND ITS
ASSOCIATED COLD POOL ALOFT WILL MOVE EAST TODAY AND INTO THE ST
LAWRENCE RIVER VALLEY BY THIS EVENING. STRATOCU COVERS MOST OF FAR
NORTHERN MAINE THIS MORNING AND CU IS RAPIDLY DEVELOPING ACROSS
CENTRAL MAINE. CLOUDS WILL ALSO STREAM ACROSS DOWNEAST AREAS TODAY
ASSOCIATED WITH A STALLED OUT FRONTAL BOUNDARY IN THE AREA WITH
LOW PRES EXPECTED TO DEVELOP OFF THE MIDDLE ATLANTIC COAST BY THIS
EVENING.
MADE SOME ADJUSTMENTS TO THE SKY GRIDS FOR TODAY...MAINLY TO
INCREASE THE CLOUD COVER. THE POP GRIDS LOOKED REAL GOOD WITH
ISOLATED SHOWERS POSSIBLE THIS AFTERNOON ACROSS THE WESTERN
MOUNTAINS AND FAR NORTHERN MAINE...DID HOWEVER EXTEND THE
ISOLATED POPS JUST A BIT FURTHER TO THE SOUTH AND EAST INTO PARTS
OF CENTRAL MAINE. THE SHOWERS ARE LIKELY NOT GOING TO HAVE MUCH
VERTICAL EXTENT AS THE 12Z KCAR SOUNDING HAS A GOOD CAP AT AROUND
800 MILLIBARS.
TEMPS WERE LOWERED A COUPLE OF DEGREES IN THE FAR NORTH WHERE IT IS
ALREADY M/CLOUDY AND WILL LIKELY REMAIN MAINLY CLOUDY ALL DAY.
UPDATE 0715 EDT: HAVE ADJUSTED SKY COVER BASED ON LATEST SATELLITE
POPS AND TEMPERATURE GRIDS BASED ON LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY. AN UPPER TROUGH
WILL APPROACH FROM THE WEST TONIGHT AS LOW PRESSURE PASSES TO THE
SOUTHEAST OF NEW ENGLAND. WILL BLEND THE GFS...SREF AND ECMWF FOR
POPS AND QPF. CLOUDS WILL INCREASE TODAY AS UPPER TROUGH
APPROACHES. FOR WIND GRIDS HAVE USED A 50/50 BLEND OF THE NAM12
AND GMOS. TEMPERATURE GRIDS INITIALIZED WITH THE GMOS AND WILL
ADJUST MINIMUM TEMPERATURE TWO DEGREES HIGHER AND MAXIMUM TWO
DEGREES LOWER. FOR DEW POINT WILL USE THE GEMREG.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
DRIER WX IS IN STORE FOR THE REGION THROUGH THIS TERM.
HIGH PRES AT THE SFC WILL BUILD INTO THE REGION ON WEDNESDAY WITH
A TROUGH PASSING TROF IN THE UPPER LEVELS. THIS WILL MEAN COOLER
TEMPERATURES AND SOME CUMULUS DEVELOPMENT DURING THE DAY, BUT DRY.
DECIDED ON A BLEND OF THE NAM12/GMOS AND ECMWFMOS FOR THE HIGH
TEMPERATURES WHICH SHOWS UPPER 60S TO LOWER 70S ACROSS THE
NORTHERN 1/2 OF THE CWA AND MID 70S FOR THE CENTRAL AND DOWNEAST
AREAS. HIGH PRES IS SHOWN TO RIDGE ACROSS THE REGION ON WEDNESDAY
NIGHT AND UPPER TROF MOVING E OF THE REGION. ATTM, OPTED TO STAY
CLOSE TO THE DAYCREW`S TEMPERATURES OF MID TO UPPER 40S NORTH AND
WEST AND UPPER 40S TO LOWER 50S CENTRAL AND DOWNEAST. THE DAYCREW
WILL NEED TO LOOK AT THIS AS THE 12Z ECMWF HAD 925MBS TEMPERATURES
IN THE 10-12C RANGE WHICH WOULD LEAD TO WARMER READINGS.
HIGH PRES SLIDES OFF THE COAST ON THURSDAY W/A RETURN FLOW OF WARMER
AIR BEING PULLED INTO THE REGION W/DAYTIME HIGHS ABOUT 5 DEGREES
WARMER THAN WEDNESDAY. A BLEND OF THE ECMWFMOS AND GMOS WAS USED
FOR THE DAYTIME HIGHS OF LOW TO MID 70S ACROSS THE CWA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
TEMPERATURES LOOK TO BE ON THE REBOUND BY LATE IN THE WEEKEND.
IN THE MEANTIME, A WARM FRONT IS PROJECTED TO LIFT ACROSS THE
REGION THURSDAY NIGHT W/A THREAT FOR A FEW SHOWERS MAINE ACROSS
THE NORTHERN TIER OF THE CWA. THE CWA THEN GETS INTO A WARM SECTOR
ON FRIDAY AHEAD OF THE COLD FRONT. THIS WILL ALLOW FOR TEMPERATURES
TO WARM INTO THE MID AND POSSIBLY UPPER 70S. THE LATEST RUNS OF
THE ECMWF AND GFS POINT TO THE POTENTIAL FOR SOME TSTMS W/SOME
INSTABILITY AS SB CAPES ARE FCST TO HIT 800-1000 J/KG BY EARLY
FRIDAY AFTERNOON. 0-6KM SHEAR OF 25-30 KTS WILL BE ENOUGH TO GET
THE STORMS GOING. THERE ALSO APPEARS TO BE ENOUGH MID LEVEL
FORCING TO AID IN PRECIP CHANCES. THEREFORE, DECIDED TO SHOOT FOR
40% POPS FOR SHOWERS/TSTMS FRIDAY AFTERNOON INTO THE EVENING W/THE
HIGHEST CHANCES ACROSS THE NORTHERN AND WESTERN PORTION OF THE
CWA. THE COLD FRONT WILL HAVE ENOUGH SUPPORT ALOFT TO MOVE ALONG
PRETTY QUICKLY AND BE OFF THE COAST FRIDAY NIGHT. THERE IS A
SLIGHT COOLDOWN BEHIND THE FRONT FRIDAY INTO SATURDAY, BUT THE
TEMPERATURES WILL BE NEAR NORMAL FOR MID JUNE(MID 70S).
THE LATEST ECMWF/CANADIAN GLOBAL AND GFS SUPPORT TEMPERATURES
WARMING SIGNIFICANTLY BY SUNDAY AND CONTINUE INTO MONDAY AS HIGH
PRES OVER THE TN VALLEY RIDGES ACROSS THE NERN US. USING A BLEND
OF THE ECMWFMOS AND GMOS YIELDS DAYTIME HIGHS HITTING MID TO UPPER
70S W/THE POTENTIAL FOR 80S ON MONDAY. THE ONLY CAVEAT TO THIS IS
THAT BOTH THE GFS AND THE 00Z ECMWF SHOW ANOTHER SHOT FOR SHOWERS
AND POSSIBLE TSTMS BY MONDAY AND POSSIBLY CONTINUING INTO MIDWEEK.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: MVFR/IFR POSSIBLE THIS MORNING...OTHERWISE VFR CONDITIONS.
SHORT TERM: LOOKING FOR VFR INTO THURSDAY. A BRIEF PERIOD OF MVFR
CONDITIONS IS POSSIBLE BY FRIDAY FOR THE NORTHERN TERMINALS W/THE
COLD FRONT MOVING ACROSS THE REGION AND POSSIBLE TSTMS.
&&
.MARINE...
NEAR TERM: FOR WIND HAVE USED A BLEND OF THE NAM12 AND GFS40. FOR
WAVES: LONG PERIOD SOUTH TO SOUTHEASTERLY WAVE SYSTEM RESULTING
FROM SOUTHERLY FLOW SOUTH AND EAST OF THE GULF OF MAINE LAST
SEVERAL DAYS CONTINUES TO DOMINATE. THIS IS COMPOSED OF 3-4 FOOT/8
SECOND GROUP FROM SOUTH AND SECONDARY SOUTHEASTERLY GROUP 1
FOOT/9-10 SECONDS. LOCAL WIND WAVE WILL CONTINUE TO BE NEGLIGIBLE.
WILL USE THE SWAN/NAM FOR GRIDS.
SHORT TERM: NO HEADLINES ANTICIPATED FOR THIS TERM. A BLEND OF
THE GEM/NAM12 AND GFS40 WAS USED FOR THE SUSTAINED WINDS SHOWING
10 KTS AT BEST INTO THURSDAY. SW WINDS BECMG NW LATER FRIDAY W/AN
INCREASE IN SPEEDS BEHIND THE FRONT CAN BE EXPECTED BUT WELL BELOW
SCA LEVELS OF 25 KT. WAVE HEIGHTS FOR FCST TO REMAIN WELL BELOW
5 FT.
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...CB/MIGNONE/HEWITT
MARINE...CB/MIGNONE/HEWITT