Area Forecast Discussion
Issued by NWS Portland, ME-- Highlight Changed Discussion --
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FXUS61 KGYX 251732
Area Forecast Discussion
National Weather Service Gray ME
1232 PM EST Sat Feb 25 2017
An unseasonably warm and moist airmass will remain across the
area today. A strong cold front will sweep across the region
this evening accompanied by showers and a few thunderstorms.
A drier and colder air mass follows this front for Sunday into
Monday. A disturbance will approach from the west late Monday
and Monday night.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Visibilities across the region have largely improved to be above
a quarter of a mile. There are still some isolated pockets where
visibility may not improve until later this afternoon, but the
widespread nature of the fog has come to an end. Therefore, I
have brought down the Dense Fog Advisory.
Southern New Hampshire is quickly heating up once again. Model
guidance has been useless and it will just be a matter of trying
to figure out how much heating will occur. Expect a few
locations to come close to 70F degrees again. Concord is already
only 3 degrees away from breaking their record high. Will update
to bump temperatures up a bit, but further updates may be needed
depending on cloud cover and fog burning off.
Quick update this morning to extend the DenseFog Advisory to
1pm. Most areas still reporting less than a quarter mile
visibility in fog and until we get some wind this afternoon, do
not see anything to significantly break things up. Have also
updated to adjust temperatures a little bit.
543 AM...For this ESTF update I expanded the dense fog advisory
in both time and area. The mesonet was also ingested into near
At 07z...a 994 millibar low was over Lake Huron with a warm
front extending eastward through northern New England and a
trailing cold front southward into the Ohio valley. NWS Doppler
radar mosaic showed scattered return to the north of the warm
front. Otherwise it was mostly cloudy across the forecast area
with areas of fog and patchy drizzle in light southerly flow
over our rapidly shrinking snowpack. For today...strengthening
southerly flow should boost temperatures into the 50s and 60s
with record highs to be challenged if not exceeded once again.
Todays record highs include 63F in Concord set in 2016, 53F in
Portland set in 2016, and 57F in Augusta set in 1984. We should
see a few scattered showers in the warm sector today. The
shortwave impulse evident in GOES water vapor over the western
Great Lakes will go negative tilt later today with strong
surface cold front racing eastward into New England towards
dusk. We should see a line of convection along and just ahead of
this front with a few embedded thunderstorms. The convection
should weaken tonight as it enters the forecast area...but can`t
rule out a few strong wind gusts over the Connecticut valley
with enhanced wording added there.
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.SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/...
The line of convection will sweep east with the cold front this
evening before quickly exiting the coast. We`ll see post frontal
clearing in all but the higher terrain as drier and colder air
flows into the region on a downslope northwest flow. The
mountains should hold on to the clouds and a few snow showers as
the column cools. Lows will range from the upper 20s to mid 30s.
It`ll be blustery and cooler on Sunday with a weak secondary
cold front/surface trough crossing the area. we`ll see clouds
and a few upslope snow showers in the mountains...with partly
sunny skies elsewhere. Highs will be in the 30s across the
mountains and international border and in the lower to mid 40s
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The overall upper level pattern will be rather unmarked by any
system of amplitude through at least mid week. Upper level flow
will be zonal and fast with a sheared out and weakened trof
moving through on Monday. This will increase cloud cover across
the north and may bring a few light showers to the higher
terrain. Temperatures will continue to be above normal with
highs in the upper 30s north to near 50 south.
A warm front lifts north on Tuesday night into Wednesday and
northern New England will be in a strong WAA regime through
Thursday. Have gone considerably higher than guidance during
this time frame for temperatures as we should see readings soar
on Wednesday and Thursday (not too dissimilar to what we had
happen earlier this week, which guidance also performed poorly
on). Have already gone a good 10+ degrees above guidance but
still feel highs may top out above what is in the forecast
(currently 50 to 55 degrees).
The warm front will trigger numerous showers- mostly plain rain
with the chance for higher elevations snows initially and
overnight. A surface low deepens to about 975 mb or lower as it
crosses northern NH and ME late Thursday bringing an end to
widespread precipitation as a cold front sweeps through. Given
the warm temperatures convection/lightning and thunderstorms
will be possibly especially on Thursday as the best dynamics
swing through. The front may stall to the south and could
possibly move back north as a warm front to bring some showers
for coastal zones late Friday into Saturday morning...however it
seems like this baroclinic zone will have enough push to clear
the Gulf of Maine.
High pressure and more seasonable/cooler air- highs in the 20s
to near 40- arrives by Friday behind the front, with even cooler
temperatures for the weekend.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Short Term /through Sunday/...IFR/LIFR in areas of fog and low
clouds improving to MVFR today in -shra. A line of -shra and
embedded -tsra will cross the area this evening ahead of a
strong cold front. Winds will shift to NW behind the front and
gust up to 25 kt with conditions improving to VFR in all but mtn
locations where MVFR ceilings will linger in -shsn. NW sfc winds
will continue to gust up to 25 kt on Sunday.
Long Term...Generally VFR on Monday with a chance for MVFR
ceilings for HIE in -SHSN. -SHRA increasing from SW to NE
Tuesday and increasing in likelihood Wednesday with a possible
-SHSN for HIE and LEB. Gusty SW winds Monday and gusty S winds
Short Term /through Sunday/...Southerly winds will increase
today ahead of a cold front with small craft winds and seas
likely later today and much of tonight. Following the cold
frontal passage...northwest winds may approach gales outside the
bays late tonight and into the day on Sunday. An SCA for all
waters this afternoon into tonight with a Gale Watch for late
tonight and Sunday.
Long Term...SCA conditions to continue through Monday in strong
westerly flow. Winds and seas diminish Monday night through
Tuesday before increasing once again on Wednesday to near gales
as low pressure deepens north of the Gulf of Maine.
The flood watch remains posted for interior portions of Maine
and new Hampshire through 00Z Monday. Daytime temperatures will
soar into the 50s and lower 60s again today. The cold front
moves through this evening with 0.50 to 0.75 inch of rain
possible. The warmth will continue to ripen and melt the
snowpack with rivers and streams responding through Sunday.
Rainfall will add to the runoff through Saturday night. At the
current time, the main threat is ice jam flooding. The threat is
higher in New Hampshire where temperatures will be warmest and
the precipitation will be heaviest.
-- Changed Discussion --ME...Flood Watch through Sunday evening for MEZ007>009-012>014-020-
NH...Flood Watch through Sunday evening for NHZ001>009-011-012-015.
MARINE...Gale Watch from late tonight through Sunday evening for
Small Craft Advisory until 4 AM EST Sunday for ANZ150>154.
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