Area Forecast Discussion
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FXUS61 KGYX 201648
Area Forecast Discussion
National Weather Service Gray ME
1248 PM EDT WED JUL 20 2016
High pressure will build in from the west before settling offshore
to the south of New England today. The high will then hold to the south
of New England on Thursday. A warm front will approach from the
southwest Thursday night, with warm and humid conditions settling
in for the weekend. A cold front will slowly approach on Friday
but will weaken and dissipate over the area on Saturday. High
pressure settles back in Sunday. Another cold front approaches
from the west early next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update 2...Minor adjustments to temperatures dewpoints and sky
cover based on current observations. Rest of forecast on track.
At 06z...a 1025 millibar high was centered over southern Ontario
province. A warm front was draped along the border of Ontario and
Quebec province. For today...the surface high will build to our
south while the weak warm front over Canada slides eastward and
provides the forecast areas with some high and patchy mid clouds
late today. It`ll be another warm day with comfortable humidity
levels. Westerly flow should keep the seabreeze largely at bay
with high temperatures ranging from 70s in the mountains to the
lower 80s elsewhere.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Fair conditions will continue tonight as high pressure remains
parked south of New England. We should see a slightly warmer
night as return flow introduces somewhat warmer air back into the
region. Lows will range from near 50 north...with 50s to near 60
On Thursday...the warming trend will continue on a westerly flow
as the high remains anchored to our south. A weak impulse could
bring a late day shower to the international border area.
Otherwise...it`ll be a partly sunny day with highs in the
80s...with a few 90 degree readings for southern New Hampshire and
adjacent southwest interior Maine. Like today...humidity levels
should remain in the comfortable range.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Chance of high impact Wx: Scattered severe storms possible Friday.
500 mb ridging to our south continue to be the dominant presence
over the CONUS and adjacent oceans, holding the active jet north
of the intl border. This will lead to a return to warn humid
conditions by Friday and will continue into early next week.
However, the area of weakness in the ridging remains across the NE
US, with several rounds of weak troughing moving through during
the long term forecast, and a couple threats for showers and
Friday will see the first of these threats for showers and storms
as warmer and more humid air moves in from the south and west, and
a weak 500 mb wave approaches from the west. Highs will reach to
around 90 in southern NH and interior western ME, and low to mid
80s most everywhere else. TDs will rise into the mid 60s in many
spots. This should produce enough instability combined with
falling heights from wave aloft wave to produce thunderstorms in
the afternoon, especially in the northern and western zones. There
may be enough shear and wind aloft to produce some severe storms
as well. Showers and storms will linger into the evening, and
perhaps overnight as the frontal boundary slows and eventually
stalls over the CWA. It`ll be a warm night with lows in the upper
60s in the south ranging to the low to mid 60s in the north.
May see some slightly less humid and slightly less warm air mix
down on Saturday as sfc wind shifts winds to the west, but overall
not much of a difference as weak ridging builds back in quickly.
Remnant surface boundaries could be the focus for another round
of showers or storms Saturday afternoon with highs ranging from
the low 80s n to around 90 in the south. Sat night may see mins a
little lower than previous night but still mainly in the 60s.
Sunday looks hot and humid in the south, with highs reaching into
the low 90s, and mid 80s to near 90 in most other places, which
will be followed by a warm humid Sunday night. The next chance of
showers/storms will be on Monday afternoon and Monday evening as
another 500 mb wave moves through. This may bring some relief
from the heat and humidity on Tuesday.
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Short Term /through Thursday/...VFR with lcl ifr psb this morning
and again Thursday morning in valley stratus and fog.
Long Term...Possibility of both valley fog and coastal
fog/stratus Thu night into early Friday, with Thunderstorms
possible Fri afternoon and evening. VFR looks to [prevail over the
weekend...with valley fog each night.
Short Term /through Thursday/...Winds and seas will increase a bit
in southwest flow through Thursday...but remain below small craft
Long Term...SCA likely Friday into Friday night, but winds seas
below SCA Saturday and Sunday.