Area Forecast Discussion
Issued by NWS Portland, ME-- Highlight Changed Discussion --
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FXUS61 KGYX 191342
Area Forecast Discussion
National Weather Service Gray ME
942 AM EDT FRI AUG 19 2016
High pressure will crest over the region today. It wilL then
shift offshore tonight and will hold off the coast through
Saturday night. A cold front will approach from the west late
Sunday and will slowly cross the region Sunday night and early
Monday. High pressure will build in from the west Monday night
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --940 am update: High pressure centered over the region with clear
skies and light winds. Fog in the valleys has all burned off.
Picture perfect day. Input all latest mesonet data with no
changes needed to forecast.
620 AM...minor ESTF update to ingest the 10z mesonet into near
At 06z...a 1005 millibar surface low was vicinity of the Gaspe
peninsula with a trailing cold front through the Gulf of Maine
and southern New England. A 1016 millibar ridge was over southern
Quebec. GOES Infrared imagery showed patchy clouds across the
forecast area. The mainly clear skies and light winds was allowing
patchy valley stratus and fog to develop along the Connecticut
valley as well as northern New Hampshire. For today...the frontal
system will continue to press southeast and offshore while the
surface ridge builds into the forecast area with drier air. By
afternoon...the light synoptic flow should turn onshore along the
coast in a developing seabreeze. Highs today will range from mid
70s to near 80 in the mountains...with readings in the lower and
mid 80s elsewhere along with comfortable dewpoints as we round out
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.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Mostly clear tonight with the surface ridge overhead. There`ll be
some late night night valley stratus and fog developing. Lows will
be mainly in the 50s...with some lower 60s over extreme southeast
New Hampshire. On Saturday...the ridge has retreated offshore will
strengthening return flow introducing slightly more humid air into
the region. It`ll be several degrees warmer then today with highs
in the 80s.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Sufficient gradient to keep most fog out of the region Saturday
night. This is despite increasing low level dew points with time
as moist, southerly winds continue.
By Sunday, low clouds may build off the water as an upper level
trough and strong surface cold front approaches from the west. 00Z
model suite in good agreement pushing the front through New
Hampshire by daybreak Monday and the front over KPWM by 12z. Ahead
of this front, plenty of moisture will ride up the coast in the
form of 2+ inches PWAT. This will interact with approaching upper
level trough and associated height falls with the best dynamics
occurring over northern areas. In the north and mountains, an inch
or more rainfall will remain possible with less to the south and
An embedded thunderstorm is possible during this period, however
instability values are not overly high.
This front slowly moves to our east Monday, allowing gusty
northwesterly winds to follow. An upper level trough may cause a
widely scattered diurnally driven shower during the afternoon
Cool, canadian high pressure will be in control of the Northeast
through midweek next week. Thereafter, a southwesterly breeze and
a warming trends will take hold of New England.
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
Short Term /through Saturday/...Lcl ifr in valley stratus and fog
btw 06z and 12z today then again from 06z to 12z Saturday. otw vfr
Long Term...Sufficient gradient to keep most fog out of the
picture Saturday night. VFR conditions all sections Sunday with
IFR conditions then expanding from west to east in heavy showers
and scattered thunderstorms Sunday night into early Monday.
Short Term /through Saturday/...quiet on the waters as a surface
ridge slides southeast and crosses the waters through the period.
Long Term...Expect sub-SCA conds on the waters Saturday through
Tuesday, however seas will be on the increase over the weekend as
a southerly flow continues ahead of a strong cold front.