320
FXUS61 KGYX 012319
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
719 PM EDT SAT AUG 1 2026
WHAT HAS CHANGED
NO MAJOR CHANGES WERE NEEDED FOR THIS FORECAST PACKAGE.
KEY MESSAGES
1.SHOWERS AND THUNDERSTORMS DEVELOP SUNDAY NIGHT THROUGH MONDAY,
WITH LOCALLY HEAVY RAINFALL POSSIBLE. AN ISOLATED STRONG TO
SEVERE STORM IS POSSIBLE OVER SOUTHERN NEW HAMPSHIRE ON MONDAY.
2.HUMID CONDITIONS PERSIST THROUGH THE REMAINDER OF THE WEEK
WITH LATE WEEK CHANCES FOR SCATTERED THUNDERSTORMS
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
SHOWERS AND THUNDERSTORMS WITH LOCALIZED DOWNPOURS ARRIVE
SUNDAY AFTERNOON INTO MONDAY, BUT ANTECEDENT DROUGHT CONDITIONS
WILL SIGNIFICANTLY LIMIT THE OVERALL FLOOD THREAT. A SLOW-
MOVING COLD FRONT APPROACHING FROM SOUTHERN ONTARIO WILL
INTERACT WITH A CLOSING UPPER-LEVEL LOW TO PULL A PLUME OF
MOISTURE RICH AIR INTO THE REGION. PWATS WILL CLIMB TO NEAR 2
INCHES BY MONDAY. STRONG LOW LEVEL MOISTURE CONVERGENCE WILL
SUPPORT DEVELOPING SHOWERS AND THUNDERSTORMS, THOUGH THE LACK OF
STRONGER INSTABILITY WILL LARGELY LIMIT ANY ORGANIZED STORMS
WITH POTENTIAL TO REACH SEVERE THRESHOLDS. SHOWERS AND A FEW
THUNDERSTORMS COULD LINGERING MONDAY NIGHT DEPENDING ON THE
SPEED OF THE COLD FRONTAL PASSAGE.
THERE IS A POTENTIAL FOR STORMS TO MOVE PARALLEL TO THE SLOW-MOVING
FRONT, LEADING TO LOCALIZED TRAINING, SUPPORTING LOCALLY HIGH
RAINFALL TOTALS. THE PROBABILISTIC MODELS SHOW THE HIGHEST
RAINFALL IN THE MOUNTAINS, WITH <15% CHANCE OF 2 OR MORE ACROSS
THE AREA. THIS SEEMS OPTIMISTIC SINCE RAINFALL RATES AND
TRAINING COULD EASILY PRODUCE AMOUNTS 2-3. HOWEVER, THE
MAJORITY OF THE AREA CAN EXPECT LESS THAN 0.5. THE ANTECEDENT
DRY CONDITIONS WILL BE A SIGNIFICANT BUFFER AGAINST HIGH IMPACT
FLOODING. ENSEMBLE GUIDANCE SHOWS A NOTABLE ABSENCE OF SMALL
STREAM AND RIVER RESPONSES. OUTSIDE OF SENSITIVE URBAN CENTERS,
REGIONAL RIVER BASINS WILL BENEFIT FROM THE RAINFALL.
REGARDING THUNDERSTORM POTENTIAL, THERE DOES SEEM TO BE AT LEAST
SOME ISOLATED SEVERE STORM POTENTIAL ALONG AND AHEAD OF THE
FRONT ON MONDAY. 12Z NAM NEST SOUNDINGS SUGGEST THAT WE COULD
SEE DEWPOINTS IN THE UPPER 60S AND LOWER 70S ACROSS SOUTHERN NEW
HAMPSHIRE, YIELDING 1000 TO 1500 J/KG OF MLCAPE. THIS
INSTABILITY WILL BE COLLOCATED WITH EFFECTIVE SHEAR AROUND 40
KNOTS AND STRONG LOW LEVEL SHEAR AS WELL. THE NAM NEST IS
CURRENTLY THE MOST BULLISH WITH IT'S PARAMETER SPACE BUT OTHER
LONGER RANGE CAMS DO SUGGEST THE POTENTIAL FOR AT LEAST A FEW
STRONG STORMS. MUCH WILL DEPEND ON HOW EARLY DAY CONVECTION
EVOLVES AND WHETHER WE GET WARM ENOUGH AHEAD OF THE FRONT FOR
UPDRAFTS TO BECOME ESTABLISHED.
KEY MESSAGE 2 DESCRIPTION...
BEYOND MONDAY, A CLASSIC SUMMER BERMUDA HIGH SETUP WILL TAKE
HOLD OFFSHORE FOR THE REMAINDER OF THE WEEK. PERSISTENT
SOUTHWESTERLY FLOW WILL KEEP HUMID AIR LOCKED IN, WITH DEW
POINTS HANGING IN THE 60S TO LOW 70S AND HIGH TEMPERATURES IN
THE 80S. THIS PATTERN WILL FAVOR DIURNALLY DRIVEN CHANCES FOR
SCATTERED DOWNPOURS AND WEAK AFTERNOON THUNDERSTORMS
PARTICULARLY LATER IN THE WEEK. HOWEVER MOST DAYS WILL STILL
FEATURE EXTENDED STRETCHES OF DRY & HUMID CONDITIONS. COASTAL
AREAS CAN EXPECT REPRIEVES FROM THE HEAT AS ONSHORE FLOW AND/OR
SEA BREEZES ARE LIKELY MOST DAYS, THOUGH IT MAY BE WEAK IN
NATURE.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
THROUGH SUNDAY: LOSS OF DAYTIME HEATING WILL ALLOW ANY REMAINING
SHOWERS TO GRADUALLY DISSIPATE THIS EVENING. THEN VFR CONDITIONS
WIDESPREAD TONIGHT. PATCHY VALLEY FOG WILL BE POSSIBLE ONCE
AGAIN, ESPECIALLY AT LEB AND HIE. HOWEVER HIGH CLOUD COVER MAY
DELAY THE ONSET OF FOG. ALONG THE MIDCOAST SOME MARINE
FOG/STRATUS WILL BE POSSIBLE AFTER MIDNIGHT. AUG AND RKD I HAVE
BOTH GOING DOWN TO IFR AND LIFR RESPECTIVELY. SOME LINGERING LOW
CLOUD IS POSSIBLE AROUND PENOBSCOT BAY SUN, BUT A RETURN TO VFR
IS EXPECTED FOR ALL TERMINALS.
OUTLOOK:
SUNDAY AND SUNDAY NIGHT: INCREASING CLOUDS. MVFR TO IFR CIGS
POSSIBLE SUN NIGHT. SHOWERS OR THUNDERSTORMS POSSIBLE ACROSS NH
LATE IN THE PERIOD.
MONDAY AND MONDAY NIGHT: SHOWERS AND THUNDERSTORMS BECOME MORE
WIDESPREAD. MVFR AND IFR LIKELY, ESPECIALLY NEAR THE COAST,
UNTIL FRONT CROSSES THE AREA.
TUESDAY - WEDNESDAY: VFR CONDITIONS EXPECTED. SOME SHOWERS
POSSIBLE IN THE AFTERNOON WITH LOCAL MVFR OR LOWER.
THURSDAY: MVFR OR LOWER RESTRICTIONS POSSIBLE UNDER SHOWERS AND
THUNDERSTORMS.
MARINE
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW SCA
THRESHOLDS THRU THE EXTENDED. AS A FRONT APPROACHES SUN,
SOUTHERLY WINDS WILL INCREASE AND A FEW GUSTS NEAR 25 KT ARE
POSSIBLE WELL OUTSIDE OF THE BAYS. GUIDANCE DOES NOT POINT
TOWARDS A HIGH CHANCE OF SCA CONDITIONS HOWEVER. IT IS ALSO
POSSIBLE THAT INCREASING MOISTURE AHEAD OF THE FRONT MAY LEAD TO
AREAS OF FOG DEVELOPING SUN NIGHT. WAVES MAY BRIEFLY APPROACH
SCA CRITERIA MONDAY NIGHT OUTSIDE OF THE BAYS.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...HARGROVE/JAMISON
AVIATION...LEGRO
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