Area Forecast Discussion
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FXUS61 KGYX 281609 AAC
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1209 PM EDT SUN AUG 28 2016
High pressure will move east of the area today. A cold front will
approach Maine and New Hampshire tonight and move off the coast
monday morning. High pressure will build over the region Monday
and move of the coast Tuesday. Another cold front will move
through Wednesday afternoon. Cool high pressure will build in
over the remainder of the week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --12:10 am Update...
Ingested the latest temperature data. A few showers are trying to
reach the ground over northern NH and ME but currently it appears
we are too dry in the lower levels for anything more than virga.
This should change in the next couple of hours however.
10:35 am Update...
No major changes to the going forecast which is in good shape.
Adjusted the diurnal temperature and dew point trends based on
latest short term guidance. Clouds now cover most of Maine as well
as north and central New Hampshire.
930 am update...Satl pic shows fog has now burned off in
Connecticut River Valley. Have updated forecast to remove fog and
account for current conditions.
Update...Minor changes to reflect latest observational trends.
Mainly adjusted sky cover based on morning IR satellite
imagery...and increased PoP across Nrn NH during the morning to
capture showers moving across Nrn VT at this hour.
Previous discussion...A warm front will continue lifting thru the
region aloft this morning. Shower activity look to be tied to that
mid level front...and so should remain N of the international
border. Gradually as the cold front approaches...showers will
start to move into Nrn zones around mid morning. To the S of the
boundary warmer temps and increasing moisture will build some
instability into the local area. The best heating and moisture
transport will be to our W...where around 1000 J/kg is possible.
Across parts of NH we will probably only be able to muster around
500 J/kg...but good enough for an isolated thunderstorm or two.
Shear does increase later in the afternoon too...to around 30 kts.
So a stronger storm is not out of the question...but again I think
the best chances for storm organization will be to our W. SREF and
NCAR ensembles favor NY state...and I tend to agree. But it would
not take much heating and stronger moisture return to get that
environment into far Wrn NH. For now I will have thunder in the
forecast...but leave enhanced wording out.
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.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
A SWly low level jet develops tonight and moves across the
forecast area. This should sustain WAA showers for much of the
night until the front passes. On the nose of the low level jet the
layer may be just warm and moist enough to provide a bit of
elevated CAPE for thunder. I will include isolated thunder
wording thru the night until the column begins to dry out.
The front really mixes down Mon...with drier air working into the
region. Winds may gust to near 20 kts in the afternoon. Temps near
the coast should be slightly warmer than today...with some
compressional warming ahead of the front.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Models are in fair agreement for the long term. fairly benign
weather for much of the up coming week. High pressure will build
in Monday night and move off the coast Tuesday. Wednesday we will
get briefly warm and humid ahead of a cold front that will move
through late in the day or evening. Showers and possible thunder
will occur ahead of this front. High pressure will build in
Wednesday night and Thursday. Models are indicating that a fairly
strong shortwave will move from north to south across the forecast
area Friday resulting in a burst of showers and possibly an
isolated thunderstorm. Have just mentioned a 30 pop for now in the
mountains for Friday. However if the current trend continues I
expect the pop to increase with showers making it to the coast
during the day. High pressure will build in on Saturday.
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
Short Term...Patchy valley fog will lead to local IFR or lower
conditions thru the CT River Valley this morning. VFR conditions
should prevail for most of today...until late when a cold front
will approach from the W. Widely scattered SHRA or TSRA could lead
to MVFR or lower conditions...especially across the CT River
Valley. SHRA or an isolated TSRA will sweep across the forecast
area with the front...with areas of MVFR and maybe local IFR in
heavier convection. Coastal stratus may develop too...which would
affect PSM...PWM...AUG...and RKD. Gusty Wly winds around 20 kts Mon
will clear things back out to VFR...except at HIE where upslope
clouds may keep some near MVFR CIGs.
Long Term...Expect VFR Monday night through much of Wednesday.
late on Wednesday mvfr in showers possible. VFR Thursday.
Short Term...SW flow will bring moisture back N over the waters
thru today. That may allow for some coastal fog/stratus to form by
tonight. Model forecasts are uncertain about if or when it
forms...so confidence is not high enough to have in the forecast
just yet. As front crosses the waters Mon...seas may build outside
of the bays to near 5 ft. A SCA may be needed for some of the
Long Term...SCA is possible Wednesday ahead of the cold front as
southwest winds increase and push seas to near 5 feet. SCA is also
possible Friday on an increasing northwest wind.