Area Forecast Discussion
Issued by NWS Portland, ME-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KGYX 270728
Area Forecast Discussion
National Weather Service Gray ME
328 AM EDT WED JUL 27 2016
Warm high pressure remains over the area today with temperatures
warming into the 80s and 90s. A weak frontal boundary will drop
south out of Canada and into northern New England tonight into
Thursday, bringing a chance for showers and thunderstorms as it
does so. The front slowly slips offshore on Friday as low pressure
track easts along the front offshore of Cape Cod. This will bring
another chance of showers Friday into Friday night. Cooler, more
seasonable temperatures return for the weekend with additional
periods of shower activity.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Any patchy early morning fog across the interior valleys will
dissipate by 8 or 9 am. Otherwise, a westerly flow will continue
ahead of a slow moving cold front today. 850 mb temperatures top
out near +16C this afternoon. With nearly full sunshine, expect
temperatures to rapidly climb once again mainly into the mid 80s
over the north to lower 90s over the southern interior.
The gradient flow will not be sufficiently strong today to keep
sea breezes from forming along the coast during the late morning
and early afternoon hours. This will allow temperatures to drop
back several degrees along and near the coastline during the
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Cloudiness and scattered shower activity will begin to reach
the northern mountains by late tonight as the surface cold front
approaches from the northwest. Sufficient instability to allow for
a few widely scattered thunderstorms late at night.
By Thursday, scattered showers and thunderstorms throughout
portions of Maine and New Hampshire will gradually spread
southward to the coastline by evening. By Thursday night, the
front will become quasi-stationary along the coastal waters with
showers and storms rippling northeastward along the front. The
best chance for a thunderstorm will be early in the evening.
Areas where any precipitation occurs will be vulnerable to patchy
fog later Thursday night. This fog will be in combination with a
gradual increase in dew point values over the next 36 hours.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
The models are in general agreement on the long wave pattern
through early next week. A weak broad trough will offer some
relief from the heat early in the period as a slow-moving cold
front drops south across the area. The front will cross the area
Thursday night and Friday. A weak low will travel northeast along
this front Friday night before it finally clears the coast early
Saturday. High pressure and drier air follows for Saturday and
Sunday. By Monday...the high will slide offshore with return flow
and rising heights allowing the heat and humidity to gradually
build as we head through next week.
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Short Term...VFR conditions are expected tonight, except for
perhaps a few hours of valley fog early this morning.
Thu Night - Sat am...Areas of MVFR IN shra/tsra.
Short Term...Conditions are expected to remain below small craft
thresholds through Thursday.
Winds and seas are expected to remain below small craft threshold.