839
FXUS61 KCAR 191848
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
ISSUED BY NATIONAL WEATHER SERVICE BURLINGTON VT
248 PM EDT TUE MAY 19 2026
WHAT HAS CHANGED
- THE FORECAST TIMING OF THE COLD FRONT ON WEDNESDAY HAS SPED UP
SLIGHTLY, MAKING IT A MORE NOCTURNAL/EARLY MORNING PASSAGE,
REDUCING THE POTENTIAL FOR THUNDERSTORMS WEDNESDAY.
- STRONG TO SEVERE STORMS CONTINUE TO BE POSSIBLE THIS
AFTERNOON AND EVENING, WITH NO SIGNIFICANT CHANGES TO THIS.
KEY MESSAGES
1) STRONG TO SEVERE STORMS WITH GUSTY WIND GUSTS ARE POSSIBLE
THIS AFTERNOON AND EVENING AS TEMPERATURES WARM THROUGH THE MID
WEEK. PLEASE STAY WEATHER AWARE AS SHOWERS AND STORMS MOVE THROUGH
THE NEXT COUPLE OF DAYS.
2) BELOW AVERAGE TEMPERATURES ARE EXPECTED THURSDAY THROUGH
SATURDAY NIGHT. NEAR FREEZING TEMPERATURES ARE POSSIBLE EARLY FRIDAY
AND SATURDAY MORNINGS ACROSS THE NORTH, WHICH MAY REQUIRE ACTIONS TO
PROTECT VULNERABLE PLANTS.
DISCUSSION
KEY MESSAGE 1...STRONG TO SEVERE STORMS WITH GUSTY WIND GUSTS
ARE POSSIBLE THIS AFTERNOON AND EVENING AS TEMPERATURES WARM
THROUGH THE MID WEEK. PLEASE STAY WEATHER AWARE AS SHOWERS AND
STORMS MOVE THROUGH THE NEXT COUPLE OF DAYS.
KEY MESSAGE 1 DESCRIPTION...SURFACE LOW PRESSURE IS CROSSING
NORTHERN MAINE INTO CANADA THIS AFTERNOON, AND OBSERVED
TEMPERATURES RANGE IN THE 50S AND 60S ALONG THE COAST, ON THE
MOUNTAINS, AND ACROSS NORTHERN AROOSTOOK COUNTY, WITH 70S AND
80S ELSEWHERE. SEEING SOME SURFACE BASED CAPE ACROSS SOUTHERN
AND CENTRAL AREAS, BUT MUCH OF THE REGION REMAINS CAPPED. MODELS
HAVE SURFACE CAPE VALUES PEAKING AROUND 700- 900 J/KG THIS
AFTERNOON, HIGHEST IN PENOBSCOT AND HANCOCK COUNTIES. THE NAM3
IS EXTRA BULLISH WITH SBCAPE AS HIGH AS 1800-2000 J/KG, BUT THIS
SEEMS OVERDONE AS WE SEE PLENTY OF CLOUDS FROM THIS MORNING'S
RAIN SHOWERS HANGING AROUND.
EFFECTIVE BULK WIND DIFFERENCE SHEAR IS BEING MODELED AROUND 40-45
KNOTS AND PWATS ARE EXPECTED TO BE AROUND 1.75-2.00" IN SOUTHERN
PENOBSCOT, HANCOCK, AND WASHINGTON COUNTIES, WITH PWATS FARTHER
NORTH MUCH LOWER 1.30-1.50". LOW LEVEL LAPSE RATES 8.0-8.5 C/KM WILL
BE A CONTRIBUTOR IN HOW STRONG ANY DEVELOPING STORMS GET, AND
ANTICIPATED DCAPE VALUES CONTINUE TO RUN AROUND 500-700 J/KG. ALL OF
THIS TOGETHER INDICATES SOME POTENTIAL FOR GUSTY TO SEVERE WINDS IN
ANY THUNDERSTORMS THAT OCCUR THIS AFTERNOON SOUTH OF AROOSTOOK
COUNTY. SOME HAIL IS NOT OUT OF THE QUESTION, BUT NOT A MAJOR
THREAT. ALL THAT BEING SAID, THE CLOUDS WILL LIKELY LIMIT SUNSHINE,
SURFACE HEATING, AND INSTABILITY. FORCING ALSO LOOKS LESS THAN
IDEAL, THOUGH A WARM FRONT AND A WEAK UPPER SHORTWAVE COULD BE
TRIGGERS FOR CELLS TO POP UP HERE AND THERE.
AS A STRONGER COLD FRONT APPROACHES EARLY WEDNESDAY, THERE IS
ANOTHER CHANCE FOR SOME SHOWERS, THOUGH ITS TIMING LOOKS EARLY
ENOUGH IN THE MORNING TO KEEP SURFACE INSTABILITY VERY LOW, BUT
THERE COULD STILL BE A RUMBLE OF THUNDER FROM ELEVATED INSTABILITY.
LOWS TONIGHT WILL FALL INTO THE MID 50S TO MID 60S. AS COLD AIR
ALOFT ARRIVES, HOWEVER, EVEN SHOWERS COULD PRODUCE SLIGHTLY GUSTY
WINDS 25-35 MPH WEDNESDAY AFTERNOON. HIGHS WEDNESDAY SHOULD REACH
INTO THE MID 70S AND 80S, WITH WARMEST TEMPS IN EASTERN AREAS THAT
HAVE MORE TIME TO WARM UP AHEAD OF THE FRONT.
KEY MESSAGE 2 DESCRIPTION...
THE FROST/FREEZE PROGRAM WILL EXPAND ACROSS MUCH OF THE
REST OF NORTHERN AND EASTERN MAINE ON THURSDAY EXCEPT ACROSS THE
NORTH WOODS AND SAINT JOHN VALLEY, WHERE IT BEGINS ON JUNE 1.
STRONG COLD AIR ADVECTION IS EXPECTED THURSDAY BEHIND A COLD
FRONT, RESULTING IN HIGHS ONLY IN THE 50S AND LOWER 60S, WARMEST
ALONG THE COAST. THURSDAY NIGHT, A MODEST LOW LEVEL JET LOOKS
TO DEVELOP OVERHEAD, LIKELY KEEPING UNSHELTERED SPOTS FROM
DECOUPLING, AND CLOUDS SHOULD BE ON THE INCREASE THROUGHOUT THE
NIGHT AS WELL. DRIER AIR WITH DEW POINTS IN THE 20S AND LOWER
30S MAY ALSO PREVENT FROST FORMATION. EVEN WITHOUT FROST, SOME
DAMAGE TO PLANTS IS POSSIBLE IN THESE CONDITIONS WITH
TEMPERATURES FALLING INTO THE LOWER AND MID 30S IN NORTHERN
AREAS AS HIGH PRESSURE NOSES IN FROM THE GREAT LAKES.
BY FRIDAY NIGHT THE SURFACE RIDGE OF HIGH PRESSURE EXTENDS OVER THE
AREA FROM CENTRAL QUEBEC. THIS WILL LEAD TO LIGHTER WINDS AND A
BETTER CHANCE OF DECOUPLING OVER MORE AREAS, ESPECIALLY THE LOWER
ELEVATIONS OF NORTHERN MAINE. LOWS FRIDAY NIGHT AND SATURDAY MORNING
ARE FORECAST IN THE 30S TO MID 40S, BUT MAY END UP BEING LOWER IN
IDEAL RADIATIONAL COOLING CONDITIONS. DEW POINTS WILL ALSO BE HIGHER
IN THE UPPER 20S TO MID 30S, LEADING TO MORE FROST FORMATION
POTENTIAL ACROSS NORTHERN ZONES. BELOW AVERAGE TEMPERATURES WILL
CONTINUE FOR SATURDAY AND SATURDAY NIGHT, BUT A MODERATION IS
EXPECTED AS HIGH PRESSURE MOVES OVER AND EVENTUALLY EAST OF THE
AREA. OUR NEXT CHANCE OF PRECIPITATION WILL BE EARLY NEXT WEEK.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
THIS AFTERNOON: STRONG TO SEVERE STORMS WITH GUSTY WIND GUSTS ARE
POSSIBLE THIS AFTERNOON. ALL SITES EXCEPT KFVE ARE VFR, BUT MOST
SITES SHOULD SEE CEILINGS LOWERING TOWARDS MVFR AS SHOWERS ARRIVE
THIS AFTERNOON. WINDS WEST-SOUTHEAST AT KFVE, MORE NORTHEASTERLY AT
KCAR AND KPQI, WHILE WINDS ARE OUT OF THE SOUTHWEST AT KBGR. WIND
GUSTS 15-25 KNOTS POSSIBLE. BEST CHANCE FOR THUNDERSTORMS IS DURING
THE AFTERNOON INTO EVENING. MOVING THROUGH, THUNDERSTORMS COULD
PRODUCE ADDITIONAL GUSTY WINDS, LIGHTNING, AND SMALL HAIL.
TONIGHT: CEILINGS LOWERING TO MVFR AND IFR LEVELS FOR MOST SITES
WITH WINDS LIGHT AND VARIABLE, TERRAIN OR GEOGRAPHICALLY DRIVEN. ON
AND OFF SHOWERS ARE POSSIBLE THROUGHOUT THE NIGHT. LLWS BEGINNING
04Z-09Z WEDNESDAY AND CONTINUING INTO WEDNESDAY MORNING DAYLIGHT
HOURS.
WEDNESDAY: CEILINGS INCREASE AGAIN TO MVFR OR VFR LEVELS WITH SHOWER
CHANCES CONTINUING. WINDS INCREASING OUT OF THE SOUTHWEST WITH GUSTS
25-35 KNOTS.
WEDNESDAY NIGHT TO THURSDAY: VFR. NW WINDS 10-15 KTS WITH GUSTS TO
25 KTS.
THURSDAY NIGHT: VFR. WNW WINDS 5-10 KTS.
FRIDAY: VFR. NW WINDS NW WINDS 10-15 KTS WITH GUSTS TO 25 KTS.
FRIDAY NIGHT TO SATURDAY: VFR WITH LIGHT AND VARIABLE WINDS,
INCREASING TO AROUND 5-10 KTS DURING THE DAY.
MARINE
SMALL CRAFT ADVISORY FOR OUTER WATERS IN EFFECT FOR TONIGHT
INTO WEDNESDAY, WITH SEAS AROUND 5FT AND SOME WIND GUSTS TO
25KTS POSSIBLE. CHANCE FOR SOME MARINE FOG THIS MORNING. CHANCE
FOR PASSING RAIN TODAY, AND CHANCE FOR RAIN AND THUNDERSTORMS
ON WEDNESDAY. SW WINDS TODAY INTO WEDNESDAY.
WINDS AND SEAS ARE LIKELY TO REMAIN BELOW SCA CRITERIA WEDNESDAY
NIGHT THROUGH EARLY NEXT WEEK.
MARINE
SMALL CRAFT ADVISORY FOR OUTER WATERS IN EFFECT FOR TONIGHT
INTO WEDNESDAY, WITH SEAS AROUND 5FT AND SOME WIND GUSTS TO
25KTS POSSIBLE. CHANCE FOR PASSING RAIN THIS AFTERNOON, AND
CHANCE FOR RAIN ON WEDNESDAY. SW WINDS TODAY INTO WEDNESDAY.
WINDS AND SEAS ARE LIKELY TO REMAIN BELOW SCA CRITERIA WEDNESDAY
NIGHT THROUGH EARLY NEXT WEEK.
CAR WATCHES/WARNINGS/ADVISORIES
ME...AIR QUALITY ALERT UNTIL 10 PM EDT THIS EVENING FOR MEZ029-030.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT
WEDNESDAY FOR ANZ050-051.
DISCUSSION...JS
AVIATION...JS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page