470
FXUS61 KCAR 211121
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
721 AM EDT THU AUG 21 2025
SYNOPSIS
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY THROUGH FRIDAY,
THEN SLIDES OFFSHORE FRIDAY NIGHT AS HURRICANE ERIN PASSES WELL
SOUTH AND THEN EAST OF THE GULF OF MAINE. A WARM FRONT WILL
LIFT NORTH OF THE AREA SATURDAY. A COLD FRONT THEN SLOWLY
APPROACHES FROM THE WEST THROUGH SUNDAY NIGHT, THEN BEGINS TO
CROSS MAINE ON MONDAY.
NEAR TERM /THROUGH FRIDAY/
7:20 AM UPDATE...UPDATED AVIATION SECTION TO REFLECT THE 12Z
TAFS. OTHERWISE, FORECAST REMAINS ON TRACK AT THIS TIME.
PREVIOUS DISCUSSION...
HIGH PRESSURE OVER THE AREA TODAY WILL BRING A TRANQUIL DAY WITH
SEASONABLE HIGHS IN THE MID TO UPPER 70S. A BIT OF MOISTURE
STREAMING SOUTHEAST THROUGH THE SOUTHERN EDGE OF AN UPPER TROUGH TO
OUR NORTHEAST WILL BRING PATCHY CLOUDS TO NORTHERN AREAS WHILE
DOWNEAST REMAINS SUNNY. MEANWHILE, SEAS PUSHING NORTH FROM HURRICANE
ERIN WILL GRADUALLY BUILD TODAY FROM AROUND 4 TO 5 FT THIS MORNING
UP TO 5 TO 6 FT ALONG OUR COAST BY LATE TODAY.
HIGH PRESSURE REMAINING OVER THE AREA TONIGHT WILL BRING A MOSTLY
CLEAR AND TRANQUIL NIGHT WITH COOL OVERNIGHT LOWS ONCE AGAIN IN THE
UPPER 40S TO NEAR 50 ACROSS THE REGION. THE NORTHERN FRINGE OF
HURRICANE ERIN WILL BRING A LIGHT NORTHEASTERLY BREEZE ALONG THE
COAST. SEAS ALONG THE COAST WILL BUILD SIGNIFICANTLY OVERNIGHT FROM
5 TO 6 FT IN THE EVENING TO AROUND 9 TO 10 FT BY FRIDAY MORNING.
FRIDAY WILL AGAIN BE MOSTLY SUNNY AND SEASONABLY WARM AS HIGH
PRESSURE REMAINS ACROSS THE AREA. NORTHERN AREAS WILL BE TRANQUIL
WHILE DOWNEAST HAS A LIGHT NORTHEASTERLY BREEZE NORTH OF ERIN. LONG
PERIOD 17 SECOND SEAS FROM THE HURRICANE WILL BUILD UP TO 10 TO 12
FT ALONG OUR SHORE ON FRIDAY.
REFER TO THE LATEST PRODUCTS FROM THE NATIONAL HURRICANE CENTER
FOR THE LATEST INFORMATION ON HURRICANE ERIN.
SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
DANGEROUS HIGH SURF DUE TO LONG PERIOD SWELLS FROM HURRICANE
ERIN WILL CONTINUE INTO SATURDAY. HOW LONG INTO SATURDAY WILL BE
DETERMINED BY EXACTLY HOW FAST ERIN EXITS TO THE ENE. SO NO
CHANGE TO THE END TIME OF THE HIGH SURF ADVISORY AT THIS TIME.
IN ADDITION TO THE POUNDING SURF PRODUCING LARGE WAVES, THERE IS
THE POTENTIAL FOR MINOR BEACH EROSION, AND POSSIBLY SOME MINOR
COASTAL FLOODING WITH OVERWASH FROM THE WAVES DURING THE HIGH
TIDE FRIDAY EVENING. WINDS SHOULD RAPIDLY DIMINISH FRIDAY
EVENING WITH ERIN PASSING WELL S OF NOVA SCOTIA AND A RELAXED
PRESSURE GRADIENT OVER THE REGION, SO THE TIDE MIGHT BE ABLE TO
PUSH IN FURTHER THAN DURING THE HIGH TIDE DURING THE DAY ON
FRIDAY. ONCE CONFIDENCE INCREASES IN THE TIMING OF ERINS EXTRA-
TROPICAL TRANSITION AND RESULTING EXPANSION OF ITS WIND FIELD,
THEN THERE SHOULD BE A BETTER AN IDEA OF IF ANY MINOR COASTAL
FLOODING WILL OCCUR.
NORTHERN STREAM RIDGING BUILDS OVER THE AREA FRIDAY NIGHT, THEN
ITS AXIS SLIDES TO THE EAST ON SATURDAY, ALLOWING A SURFACE TO
850 MB WARM FRONT TO LIFT THROUGH THE REGION FROM SW TO NE.
FRIDAY NIGHT SHOULD BE DRY, THEN ON SATURDAY THERE IS A SLIGHT
CHANCE OF SHOWERS, MAINLY ACROSS NORTHERN AROOSTOOK WHERE THE
BEST FORCING IS. LOWS FRIDAY NIGHT SHOULD BE FROM A FEW TO
AROUND 5 DEGREES ABOVE NORMAL, WITH HIGHS ON SATURDAY AROUND 5
DEGREES ABOVE NORMAL ACROSS THE NORTH AND NEAR NORMAL ELSEWHERE.
THE REGION IS UNDER SOUTHWEST FLOW ALOFT SATURDAY NIGHT, WITH A
WEAK SHORTWAVE PASSING TO THE NORTH. AS A RESULT, DO HAVE
SLIGHT CHANCE POPS, MAINLY ACROSS N AROOSTOOK, CLOSEST TO THE
BEST FORCING. LOWS SATURDAY NIGHT SHOULD BE AROUND 5 DEGREES
ABOVE NORMAL.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
THE REGION REMAINS UNDER SOUTHWEST FLOW ALOFT SUNDAY THROUGH
MONDAY, AS A CUTOFF LOW SLOWLY TRACKS FROM SOUTHWEST TO
SOUTHEAST OF JAMES BAY. THE RESULT WILL BE A SERIES OF
SHORTWAVES ROTATING AROUND THE BASE OF LOW, AND BRINGING A
THREAT OF SHOWERS, WITH POSSIBLY SOME EMBEDDED THUNDER DURING
PEAK HEATING IN THE AFTERNOON. NOTING THE HIGHLY AMPLIFIED
PATTERN, LEANED TOWARDS SLOWER ECMWF/CMC FOR ONSET TIMING,
SOMETHING THE GFS TRENDED TOWARDS FROM ITS 18Z TO ITS 00Z RUN.
AS A RESULT, SIGNIFICANTLY UNDERCUT NBM POPS ON SUNDAY, THEN
GRADUALLY WORKED TOWARDS THEM BY MONDAY. LIMIT POPS ON SUNDAY TO
SLIGHT CHANCE OVER FAR NW PORTIONS OF THE CWA, THEN LIKELY POPS
MAINLY ACROSS THE NORTH SUNDAY NIGHT, THEN LIKELY TO CATEGORICAL
POPS MONDAY FOR ALL BUT MOST OF DOWNEAST MAINE, WHERE POPS ARE
IN THE CHANCE RANGE (DUE TO THE SLOW PROGRESSION OF THE SYSTEM
AND DOWNEAST MAINE BEING FARTHEST FROM THE BEST DYNAMICS).
NORTHERN STREAM TROUGH BUILDS IN MONDAY NIGHT-TUESDAY WITH A
COUPLE OF SHORTWAVE TROUGHS MOVING THOUGH AS IT DOES SO. EXPECT
THE BULK OF THE PRECIPITATION MONDAY NIGHT, WITH SOME REDUCTION
IN COVERAGE/INTENSITY ON TUESDAY AS THE LOW LEVELS BEGIN TO DRY
SO TAKE POPS FROM LIKELY ON MONDAY NIGHT DOWN TO CHANCE ON
TUESDAY.
NOTE THERE IS THE POTENTIAL FOR AROUND AN INCH OF PRECIPITATION
BASIN AVERAGE OVER THE NORTH WOODS FROM LATE SUNDAY INTO
TUESDAY, HOWEVER GIVEN THE CONVECTIVE NATURE OF THE
PRECIPITATION, AND THE POTENTIAL FOR TRAINING, LOCALLY HIGHER
AMOUNTS ARE POSSIBLE, ESPECIALLY IN AREAS THAT EXPERIENCE
TRAINING, THERE IS THE POTENTIAL FOR SOME HYDROLOGIC ISSUES
THERE. HOWEVER, AT THIS TIME THE CONFIDENCE IN THIS IS NOT HIGH
ENOUGH TO REFLECT IN THE HWO.
FULL LATITUDE TROUGHING OVER THE EASTERN US IS REINFORCED BY A
COUPLE OF NORTHERN STREAM SHORTWAVE TROUGHS PUSHING THROUGH
TUESDAY NIGHT AND WEDNESDAY. THE BEST FORCING SHOULD BE MAINLY
ACROSS THE NORTH SO HIGHEST POPS ARE THERE BOTH PERIODS FOR SOME
SHOWERS.
TEMPERATURES SHOULD BE WITHIN A FEW DEGREES OF EITHER SIDE OF
NORMAL SUNDAY NIGHT-MONDAY NIGHT, THEN BELOW NORMAL TUESDAY-
WEDNESDAY.
AVIATION /11Z THURSDAY THROUGH MONDAY/
NEAR TERM:
MAINLY VFR CONDITIONS ARE EXPECTED TODAY, TONIGHT, AND FRIDAY.
BRIEF BCFG POSSIBLE AT KBGR AND KBHB THROUGH 12-13Z. LOCALIZED
BCFG POSSIBLE LATE TONIGHT, BUT CONFIDENCE IS TOO LOW TO INCLUDE
IN 12Z TAFS. WINDS WILL BE LIGHT AND VARIABLE TODAY THEN LIGHT
AND VARIABLE NORTH AND LIGHT NE SOUTH TONIGHT.
SHORT TERM:
FRIDAY NIGHT...VFR.
SATURDAY...VFR, WITH THE EXCEPTION OF POSSIBLY A BRIEF PERIOD OF
MVFR AT NORTHERN TERMINALS IN ANY PASSING SHOWER.
SATURDAY NIGHT-SUNDAY...VFR, WITH POSSIBLY EXCEPTION OF A BRIEF
PERIOD OF MVFR IN ANY SHOWERS ALONG THE WESTERN BOARDER WITH
QUEBEC. LLWS POSSIBLE SATURDAY NIGHT AT SOUTHERN TERMINALS. S-SW
WINDS G15-25KT POSSIBLE SUNDAY.
SUNDAY NIGHT-MONDAY...MVFR OR LOWER PROBABLE AT NORTHERN
TERMINALS AND POSSIBLE AT SOUTHERN TERMINALS. LLWS POSSIBLE
SUNDAY NIGHT. S-SE WINDS G15-20KT POSSIBLE MONDAY.
MARINE
NEAR TERM:
LONG PERIOD SWELL OF AROUND 17 SECOND INTERVALS PUSHING NORTH
FROM HURRICANE ERIN WILL BUILD TO 5 TO 6 FT TODAY, 9 TO 10 FT
TONIGHT, THEN 10 TO 12 FT ON FRIDAY. WINDS WILL BE LIGHT AND
VARIABLE TODAY THEN LIGHT NE TONIGHT AND FRIDAY.
SHORT TERM: LONG PERIOD SWELLS WILL KEEP SEAS AT SCA LEVELS
THROUGH SATURDAY ON ALL WATERS (THOUGH THERE IS SOME DOUBT
ABOUT EXACTLY HOW LONG ON SATURDAY IN THE INTRA-COASTAL WATERS),
AND POSSIBLY INTO SUNDAY ON THE COASTAL OCEAN WATERS. SO NO
CHANGE TO THE EXISTING SCA INTO SATURDAY AFTERNOON ON ALL
WATERS FOR NOW. ALL WATERS SHOULD SEE SUB-SCA CONDITIONS SUNDAY
NIGHT AND MONDAY.
CAR WATCHES/WARNINGS/ADVISORIES
ME...HIGH SURF ADVISORY FROM 6 PM THIS EVENING TO 2 PM EDT SATURDAY
FOR MEZ029-030.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR ANZ050>052.
NEAR TERM...BLOOMER/CLARK
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...BLOOMER/CLARK/MALOIT
MARINE...BLOOMER/CLARK/MALOIT
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