Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 041253
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
853 AM EDT WED MAY 4 2016

.SYNOPSIS...
AFTER A BRIEF BREAK...THE COOL AND WET WEATHER WILL RETURN AGAIN
LATER TODAY AND TONIGHT. A DEEP TROUGH OF LOW PRESSURE WILL EVOLVE
OVER THE EASTERN THIRD OF THE COUNTRY AND REMAIN IN PLACE THROUGH
THE END OF THE WEEK. A SERIES OF WAVES WILL MOVE NORTH ALONG THE
EAST COAST AND BRING PERIODS OF RAIN TO NEW ENGLAND...ALONG WITH
COOL...ONSHORE WINDS. ONE PERIOD COMES TONIGHT...WITH ANOTHER SET
TO ARRIVE THURSDAY NIGHT. TEMPERATURES WILL MAINLY BE STUCK IN THE
40S TO LOWER 50S.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDITIONS AND LATEST
MESOSCALE MODEL RUNS. SHOWERS WILL CONTINUE TO MOVE NORTHWARD THIS
MORNING PER LATEST COMPOSITE RADAR LOOPS FROM SOUTHERN NEW
ENGLAND. THIS PRECIPITATION IS EXPECTED TO CONTINUE ON AND OFF
THROUGH TONIGHT...DROPPING ABOUT A HALF INCH OF RAIN ACROSS THE
REGION.

LOW CLOUDS AND PRECIPITATION WILL KEEP TEMPERATURES ON THE COOL
SIDE TODAY...STRUGGLING TO REACH THE LOWER 50S IN MANY LOCATIONS.

PREV DISC...
6AM UPDATE... JUST A MINOR ADJUSTMENT TO TEMPERATURES. A FEW
PATCHY AREAS OF FOG HAVE FORMED IN THE CONNECTICUT RIVER VALLEY
AND NORTHEAST KINGDOM OF VT.

UPPER LEVEL LOW WILL DIG SOUTHWARD OVER THE EASTERN
UNITED STATES ALLOWING FOR LOW PRESSURE TO STRENGTHEN OVER THE
DELMARVA AREA THROUGH THE DAY TODAY. THE STRENGTHENING LOW TO THE
SOUTH ALONG WITH THE DEPARTING HIGH PRESSURE WILL KEEP WINDS OUT
OF THE EAST KEEPING COOL DAMP AIR IN THE AREA. HAVE KEPT
TEMPERATURES SLIGHTLY BELOW GUIDANCE AS THE OCEAN TEMPERATURE
REMAINS AROUND 45 DEGREES WHICH, COMBINED WITH THE CLOUD COVER
WILL LIMIT TEMPERATURES. EVEN INLAND WHERE THE WATER IS NOT ALWAYS
A FACTOR THE OVERCAST SKIES WILL PERSIST AND LIMIT TEMPERATURES TO
THE LOW 50S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
RAIN WILL BEING TO OVERSPREAD THE REGION FROM THE SOUTH THIS
EVENING AS THE LOW PRESSURE STRENGTHENS. LIFT AHEAD OF THE LOW
PRESSURE WILL PROVIDE FOR STEADY RAIN IN THE OVERNIGHT TIME
PERIOD. BY THURSDAY MORNING THE LOW TRIES TO MOVE OUT TO OUR EAST
IN THE GULF OF MAINE, HOWEVER THE PERSISTENT ONSHORE FLOW WILL
ALLOW FOR DRIZZLE TO LINGER WELL INTO THURSDAY AFTERNOON. WITH THE
UPPER LEVEL LOW BECOMING CUT OFF OVER THE SOUTHERN APPALACHIANS
THE SYSTEM MAY STALL FURTHER...KEEPING THE DRIZZLE AND OVERCAST
INTO THURSDAY NIGHT. WITH ALL THE MOISTURE AROUND, PATCHY FOG CAN
ALSO BE EXPECTED.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THU NIGHT UPPER LOW PRES CONTINUES ITS SLOW MIGRATION ACROSS THE
SOUTHEAST. S/WV TROF WILL ROUND THE BASE AND MOVE UP THE EAST
COAST INTO FRI MORNING. COULD SEE ANOTHER PERIOD OF RNFL AND
GENERAL LOW CLOUDS/COOL ONSHORE FLOW. A BRIEF PERIOD OF S/WV
RIDGING WILL BE FOLLOWED BY THE LOWER HEIGHTS FROM THE UPPER LOW
THEN MOVING INTO THE NORTHEAST. THAT SHOULD SUPPORT DIURNAL
INCREASES IN SHOWER ACTIVITY AND TEMPS REMAINING A LITTLE COOLER
THAN NORMAL.

LATE IN THE WEEKEND AND EARLY NEXT WEEK...ENSEMBLE GUIDANCE IS NOW
TRENDING TOWARDS A STRONGER NRN STREAM UPPER LOW SENDING A COLD
FNT THRU THE REGION. THAT WILL PROLONG THE STRETCH OF COOLER THAN
NORMAL TEMPS AND HIGHER THAN NORMAL CHANCES FOR RA. BEYOND
THAT...THERE IS STILL A CONSENSUS FOR RIDGING ON THE EAST COAST
AND WARMER TEMPS BY MIDWEEK.

&&

.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...SOLID CLOUD DECK OF 3500 TO 4000FT PRESENT ACROSS THE
ENTIRE REGION AT THIS POINT. CEILINGS WILL LOWER THROUGH THE DAY
WITH PRECIPITATION IMPACTING MHT CON PSM AND PWM BY 21Z. OVERNIGHT
IFR CONDITIONS WILL DEVELOP... ESPECIALLY ALONG THE COAST. PERIODS
OF LIFR IN FOG IS POSSIBLE FOR PSM PWM AND RKD.

LONG TERM...IFR OR LOWER CONDITIONS POSSIBLE THU NIGHT INTO
FRI...AS A WAVE OF LOW PRES MOVES THRU THE GULF OF ME. LATE FRI
AND INTO THE WEEKEND...UPPER LOW PRES MOVES CLOSER TO OVERHEAD.
THIS SHOULD BRING WIDESPREAD MVFR CONDITIONS...AND AFTERNOON SHRA.
CANNOT RULE OUT IFR OR LOWER IN ANY HEAVIER SHRA.

&&

.MARINE...
SHORT TERM...SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS THROUGH
TODAY. INCREASING EASTERLY FLOW MAY ALLOW FOR SCA WINDS/SEAS TO
BUILD LATER WEDNESDAY NIGHT.

LONG TERM...SUSTAINED ONSHORE FLOW INTO THE WEEKEND WILL KEEP SEAS
ON THE OUTER WATERS RUNNING NEAR 5 FT.

&&

.FIRE WEATHER...
WILL CONTINUE TO SEE A PROLONGED PERIOD OF MOIST ONSHORE FLOW
HELPING TO KEEP RELATIVE HUMIDITY VALUES HIGH AND RAIN IN THE
FORECAST.

&&

.TIDES/COASTAL FLOODING...
BEGINNING THURSDAY THROUGH THE WEEKEND...WE ARE SET FOR A PERIOD
OF HIGH ASTRONOMICAL TIDES. THE HIGHEST TIDES WILL BE FRIDAY AND
SATURDAY NIGHTS WHEN PORTLAND IS FORECAST TO REACH 11.9 FEET AT
1135 PM AND 1226 AM RESPECTIVELY. COASTAL FLOODING MAY BE POSSIBLE
DURING THIS TIME PERIOD...AS WINDS WILL GENERALLY BE EASTERLY TO
NORTHEASTERLY. IF LOW PRESSURE DEVELOPS A LITTLE SOONER OR
STRONGER...MINOR COASTAL FLOODING ISSUES COULD BEGIN AS EARLY AS
THE THURSDAY EVENING TIDE. ANY FLOODING WOULD LIKELY BE LIMITED
TO AREAS NEAR AND SOUTH OF PORTLAND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



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