790
FXUS61 KCAR 201819
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
219 PM EDT SAT JUN 20 2026
WHAT HAS CHANGED
-DECREASED THUNDER CHANCES ON TUESDAY TO SLIGHT CHANCE.
-DROPPED DAYTIME TEMPERATURES EARLY NEXT WEEK.
KEY MESSAGES
1) SLOW MOVING SHOWERS AND THUNDERSTORMS ON SUNDAY COULD LEAD TO
LOCALIZED SIGNIFICANT RAINFALL.
2) A LOW PRESSURE SYSTEM PASSES THROUGH THE REGION
MONDAY NIGHT INTO TUESDAY, WHILE TRACK AND TIMING REMAINS
UNCERTAIN.
3) PROLONGED TROUGHING IN THE NORTHEAST WILL LEAD TO MULTIPLE
ROUNDS OF SHOWERS AND STORMS THIS WEEK.
DISCUSSION
KEY MESSAGE 1...SLOW MOVING SHOWERS AND THUNDERSTORMS ON SUNDAY
COULD LEAD TO LOCALIZED SIGNIFICANT RAINFALL.
KEY MESSAGE 1 DESCRIPTION...
AN UNSETTLED PATTERN CONTINUES TOMORROW WITH A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. BETTER
INSTABILITY WILL BE CONFINED TO WRN AREAS WITH CAPES FROM
500-800 J/KG. ALTHOUGH PW VALUES WILL BE RIGHT AROUND, IF NOT
SLIGHTLY BETTER THAN NORMAL, LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE WITH ANY STORMS THAT CAN DEVELOP. THIS IS BECAUSE
CORFIDI VECTORS ARE VERY LIGHT, PRETTY MUCH LESS THAN 5KTS MOST
PLACES IN THE AFTERNOON. FLOW IS VERY WEAK UP THROUGH THE
TROPOPAUSE WITH SIGNIFICANT RAINFALL POSSIBLE IN ONE AREA AND
NOT IN THE ONE NEXT TO IT. ONE-HOUR FFG VALUES ARE AROUND 1
INCH/HOUR ACROSS THE NORTH AND 1.25-1.50 INCHES IN CENTRAL
AREAS.
KEY MESSAGE 2...A LOW PRESSURE SYSTEM PASSES THROUGH THE REGION
MONDAY NIGHT INTO TUESDAY, WHILE TRACK AND TIMING REMAINS
UNCERTAIN.
KEY MESSAGE 2 DESCRIPTION...
SHORTWAVE MOVES THROUGH REGION MONDAY AFTERNOON INTO TUESDAY
EVENING. WITH THIS SYSTEM, MOISTURE QUICKLY INCREASES THROUGHOUT
MAINE, AND RAIN SHOWERS, WITH AN ISOLATED THUNDERSTORM, ARE
POSSIBLE. MODELS SEEM TO FAVOR THE GENERAL PATH OF THE LOW
PRESSURE STAYING SOUTH OF MAINE, BUT THERE IS UNCERTAINTY IN
THE TIMING AND EXACT TRACK. MODELS THAT SEEM TO HAVE A MORE
SOUTHERN LOW PRESSURE SYSTEM, BRING LESS PRECIPITATION TO THE
DOWNEAST REGION, WHILE MODELS FAVORING A FARTHER NORTH LOW
PRESSURE SYSTEM, BRING MORE PRECIPITATION TO THE DOWNEAST
REGION. GLOBAL MODELS SEEM TO BE TRENDING NORTHEAST WITH THE
LOW, BRINGING MORE RAIN TO THE COASTLINE. STUCK WITH THE NBM FOR
THIS UPDATE, SINCE IT SHOWS THE GENERAL TREND WELL BETWEEN
MODELS. THE BEST CHANCE FOR PRECIPITATION IS GOING TO BE
INTERIOR AND COASTAL DOWNEAST, WITH GRADUALLY LIGHTER SHOWERS
EXPANDING FARTHER INLAND. HOW FAR INLAND THE PRECIPITATION
REACHES, IS GOING TO DEPEND ON THE TRACK. LOOKING AT BETWEEN 1
TO 1.5 INCHES OF RAIN POSSIBLE DOWNEAST.
MINIMAL INSTABILITY COULD LEAD TO SOME ISOLATED THUNDERSTORMS IN
THE CENTRAL HIGHLANDS AND NORTHERN REGIONS. SOUTHERLY FLOW
SHOULD KEEP DOWNEAST STABLE ENOUGH TO AVOID CONVECTION. AROUND
500 J/KG OF CAPE, AND SOME DECENT LOW-LEVEL LAPSE RATES COULD
GET SOME THUNDER RUMBLES OVER THE REGION IN THE AFTERNOON.
DECREASED THUNDER CHANCES HOWEVER, SINCE SHEAR AND HELICITY
LOOK WEAK, AND SOME CIN IS PRESENT. WILL HAVE TO CONTINUE TO
MONITOR TO SEE HOW TRENDS PROGRESS.
KEY MESSAGE 3...PROLONGED TROUGHING IN THE NORTHEAST WILL LEAD
TO MULTIPLE ROUNDS OF SHOWERS AND STORMS THIS WEEK.
KEY MESSAGE 3 DESCRIPTION...
POSITIVE PNA PATTERN OVER THE ATLANTIC PARKS A HIGH PRESSURE
SYSTEM OVER THE WEST, RESULTING IN PROLONGED TROUGHING OVER THE
REGION, WITH MULTIPLE ROUNDS OF RAIN SHOWERS MOVING THROUGH.
COOL TEMPERATURES GENERALLY IN THE 70S. OVERNIGHT LOWS GENERALLY
IN THE 50S. PROLONGED TROUGH RESULTS IN MULTIPLE ROUNDS OF
SHOWERS, WITH CHANCES FOR THUNDERSTORMS EACH AFTERNOON.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
MAINLY VFR AT ALL TERMINALS TONIGHT, THOUGH A VERY BRIEF MVFR CIG
MAY BE PRESENT OVER THE NEXT HOUR OR TWO THIS AFTERNOON. AFTER 00Z
LOW CIGS SHOULD BEGIN TO IMPROVE TO VFR. FVE, CAR AND PQI MAY SEE
LIGHT SHOWERS BETWEEN 00 AND 04Z TONIGHT BUT NO RESTRICTIONS ARE
EXPECTED. NW WINDS 5-10KTS TONIGHT.
SUNDAY...MAINLY VFR WITH SHOWERS AND TSTMS DEVELOPING IN THE
AFTERNOON. CONFIDENCE IS LOW WITH -TSRA IMPACTING ANY ONE TERMINALS
AND WILL NEED TO WAIT UNTIL NEXT SET OF TAFS. LIGHT WINDS EXPECTED.
SUNDAY NIGHT...VFR AND SHOWERS EARLY WITH MVFR/IFR POSSIBLE LATE.
CANNOT RULE OUT FOG DEVELOPING IN AREAS THAT RECEIVED RAINFALL ON
SUNDAY. CALM WINDS.
MONDAY - MONDAY NIGHT...MVFR/IFR IN RAIN SHOWERS AT ALL
TERMINALS, AND WITH A CHANCE OF THUNDERSTORMS AT
KFVE/KCAR/KPQI/KHUL. S WINDS AT 5 TO 10 KTS, BECOMING E AT 5 TO
10 KTS OVERNIGHT. UNCERTAINTY IN TRACK OF LOW PRESSURE SYSTEM,
WHICH COULD SHIFT PRECIP MORE OFFSHORE AND SHIFT FORECASTED WIND
DIRECTION.
TUESDAY - TUESDAY NIGHT... MVFR/IFR IN RAIN SHOWERS AT ALL
TERMINALS, AND WITH A CHANCE OF THUNDERSTORMS AT
KFVE/KCAR/KPQI/KHUL. IMPROVING TO VFR LATE AFTERNOON. E/SE WINDS
AT 5 TO 10 KTS, GUSTING TO 20 KTS, SHIFTING TO NW 5 TO 10 KTS.
WEDNESDAY - WEDNESDAY NIGHT...MAINLY VFR. POSSIBLE MVFR AT
KFVE/KCAR/KPQI/KHUL IN THE AFTERNOON WITH SHOWERS AND CHANCE OF
THUNDERSTORMS. NW WINDS AT 5 TO 10 KTS. BECOME LIGHT AND
VARIABLE OVERNIGHT.
THURSDAY...POSSIBLE MVFR AT KFVE/KCAR/KPQI/KHUL, IN THE
AFTERNOON WITH SHOWERS AND CHANCE OF THUNDERSTORMS. S/SE WINDS
AT 5 - 10 KTS.
MARINE
SEAS AROUND 4FT WILL CONTINUE THIS AFTERNOON BEFORE DROPPING
SUNDAY MORNING AND CONTINUING BETWEEN 1-2 FEET INTO MONDAY
MORNING. ALL WATERS WILL SEE WINDS BELOW 20KTS THROUGHOUT THE
NEAR TERM PERIOD. PATCHY FOG WILL REDUCE VISIBILITIES OVER THE
WATERS ON SUNDAY NIGHT.
BELOW SCA CONDITIONS MONDAY. SEAS CREEP UP TO 5 FT ON TUESDAY
INTO WEDNESDAY. RAIN AND PATCHY FOG MONDAY NIGHT INTO TUESDAY.
CHANCE FOR THUNDERSTORMS TUESDAY. S WINDS ON MONDAY, SHIFT TO
THE NW ON TUESDAY NIGHT.
CAR WATCHES/WARNINGS/ADVISORIES
ME...NONE.
MARINE...NONE.
DISCUSSION...ASB/21
AVIATION...ASB/21
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