Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 291045
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
645 AM EDT Fri May 29 2020

.SYNOPSIS...
Warm and humid conditions remain in place, but relief is on the
way as a cold front will gradually cross the region late tonight
and Saturday. Ahead of the front...we`ll see scattered showers
and thunderstorms develop by afternoon then become more numerous
tonight. A few of the thunderstorms over inland areas could
produce gusty winds, heavy rain, and small hail this afternoon
and early evening. On Saturday...we`ll see scattered showers and
isolated thunderstorms before the cold front finally slides
offshore and drier less humid air arrives. The cooler and drier
air along with quiet weather will stick around for Sunday and
the start of the new work week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

645 AM...Minor ESTF update to reflect the current mesonet in
near term grids.

Prev Disc...
At 06z...a sprawling high was centered over the western
Atlantic. A 1003 millibar low was vicinity of the Ontario-
Quebec border with a trailing cold front through the Great
Lakes. The southerly flow between these two systems continues to
transport warm humid air northward into the region. GOES infrared
showed low clouds has overspread much of the area with NWS
Doppler Radar mosaic showing some scattered light showers had
developed in the moist flow. For today...the CAMS should low
clouds should scatter out for a time today. Daytime heating
should allow scattered convection to develop by midday with
CAPES from modified soundings as well as CAMS supporting values
near 1500 J/KG by afternoon. The wind field would suggest
multicells along with a few line segments for the afternoon and
early evening hours. DCAPES and windex suggest a few of the
stronger cells could produce gusts to near 60 mph as well as
small hail. The precipitable water values will be above 1.50
inches. Given storm motion of 30 kt we should avoid any serious
flooding issues...unless training of cells were to occur.
Enhanced wording was included across inland areas for this
afternoon and early evening. Highs today will be in the
80s...except 70s along the immediate coast east of Portland
given the onshore wind trajectory there.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Tonight...we`ll see convection weaken with loss of heating just
as the stronger wind field arrives in northern New England. A
few stronger cells that develop over upstate New York today
could reach the Connecticut valley after dusk with a strong wind
gust or two before quickly weakening by late evening.
Overnight...we`ll continue to see convection weaken and diminish
in coverage as it tracks east across the forecast area. It`ll be
another humid night with areas of stratus and fog developing.
Lows will be mainly in the 60s. On Saturday...we`ll start the
day with the cold front stretching from the international
border through western New Hampshire. We`ll see scattered
showers and isolated thunderstorms develop along and ahead of
the boundary. Highs along the coastal plain will be in the lower
and mid 80s...with 70s elsewhere. It`ll be a humid start to the
day with relief arriving during the afternoon in the post-
frontal westerly flow.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Synoptic scale trough will be just entering the area on Sunday, and
will cross the region through Tuesday. By Wednesday we should be in
NW flow on the backside of the trough. More subtle troughing builds
into the NE by Wednesday into Thursday. Ridging follows for Friday,
then another trough stretching from southern Canada into the eastern
CONUS will approach the NE. These disturbances will allow us several
chances for precipitation the next 7+ days.

At the surface, a cold front will be exiting the region Saturday
night with high pressure building in behind it. A couple more
boundaries will cross the region by midweek, bringing scattered
showers.

Sunday into Tuesday PWATs take a nosedive to near a third of an inch
or less. Southerly flow returns Wednesday, bringing dew points up
slightly. Column saturation should be enough to support scattered
showers and thunderstorms. Temperatures Sunday and Monday in the 50s
and 60s will increase into the 60s and 70s by midweek.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Short Term /Through Saturday/...Areas of MVFR in cigs...aft 13z
areas of MVFR with lcl IFR in SHRA/TSRA.

Long Term...VFR conditions will prevail through the beginning
of the week. A disturbance may bring precipitation and MVFR
conditions to terminals by Tuesday night.

&

.MARINE...
Short Term /Through Saturday/...Outside the bays southerly flow
and marginal SCA conditions continue through tonight. The SCA
conditions may linger Saturday as the cold front crosses the
waters.

Long Term...High pressure builds in Sunday with quiet
conditions to start next week. Seas may increase towards the end
of the work week with a front crossing the waters.

&&

.MARINE...


&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ150-152-
     154.

&&

$$

ES



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