819
FXUS61 KGYX 260820
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
420 AM EDT Thu Sep 26 2024

.SYNOPSIS...
Much needed rainfall continues today, heavy at times this
afternoon. Dry weather returns tomorrow into the weekend as
high pressure moves overhead. The next chance for rainfall comes
into mid week next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Rounds of rainfall set for today. Morning WV imagery depicts an
expansive stream of moisture moving up the eastern CONUS.
Blocking upper low across the Ozarks has connected a conveyor
belt of moisture advection from the tropics into the Northeast.
This moisture feed will become focused later today as a triple
point travels through the CWA.

Steady rain will tend to favor interior areas through the first
half of the day, with showers towards the coast. Steady rain
will trend east into the mid afternoon hours, with some elevated
instability bringing the chance for a couple rumbles of thunder.
These will mainly be across southern NH and ME.

Intense upper jet flattens this afternoon, aligning with lower
levels to form a concentrated flow draped across southern NH
into interior and coastal ME. The result will be training
moderate rainfall through the afternoon supported by 2 sigma
PWAT anomaly and the jet dynamics. HREF members depict a stripe
of enhanced rainfall amounts between 1.5 and 2 inches total up
to midnight tonight. This is roughly along a line from Lebanon,
NH to the Midcoast of ME. Some isolated higher amounts are
likely within the Whites and Upper Valley.

Peak rainfall rates will be associated with consolidated triple
point low passing mid to late afternoon. The concern with this
will be these rates coinciding with the afternoon commute
through the population corridor. Urban nuisance flooding and
ponding will be possible during this time period which could
lead to a hydroplaning hazard. Overall, the threat for more in
the way of flash flooding continues to be mute. Flash flood
guidance remains quite high due to our dry stretch, and would
need this whole storm to happen in little over an hour to
increase this concern.

As the low tries to spin up this afternoon and evening, there
may be a rather sharp back edge of the rain. Behind may be a
brief period of drizzle, followed by fog formation into the
evening.

For the immediate coast, will evaluate the need for a high surf
advisory today given increasing wave heights and long period
swell along the southern coasts.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Cold front will be exiting the coast this evening. Not much wind
to filter at the surface to begin. This should promote areas of
fog to develop through the night for much of the CWA.

Friday will be warmer and breezy, especially for the coast and
interior where mid 70s will be possible. To the north, may see
some upslope showers continuing in the mountains during the day.
Otherwise, after a day or so of dreary weather, we pick up
right where we left off with dry weather into the weekend.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A cyclonic flow will continue aloft on Saturday. Therefore,
despite being dry across the region, expect a mix of sun and
clouds, especially during the midday and afternoon hours with
the added diurnal warming. Similar conditions will continue on
Sunday with highs mainly in the upper 60s to near 70 over the
weekend.

Next week will begin as dry conditions as a ridge of high
pressure builds over the region. It won`t be until a potential
pattern change on Wednesday with a strong cold front bringing a
few showers to the region midweek.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Short Term...MVFR becomes IFR for most terminals this morning
through the afternoon. Widespread SHRA will trend more steady RA
today with vis restrictions down to 2 or 3 miles in heavier
rainfall. Onshore winds pick up, gusting to 25 kts along the
coast as a front moves through late afternoon. No real wind
shift with this, more a drop in overall wind speeds. Drizzle/fog
follow this front passage this evening and overnight. This could
bring IFR to LIFR conditions into early Friday morning. Friday
trends VFR after sunrise.

Long Term...VFR should be the prevailing condition right
through the weekend. Winds will be light with gusts generally
10-15kts.

&&

.MARINE...
Short Term...Long period swell peaks today with building wave
heights. Onshore winds will aid in pushing waves 5 to 6 ft
through the afternoon, with periods approaching 12 seconds.
Passing low pressure this evening will put an end to these
onshore winds, with slackening wave heights overnight and into
Friday.

Long Term...Below SCA criteria through the weekend. Winds will
be gusting 15-20 kts on Friday before high pressure begins to
move over the waters and the gradient relaxes over the weekend.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 AM EDT Friday for ANZ150-152-154.
     Small Craft Advisory from 1 PM this afternoon to 8 AM EDT
     Friday for ANZ153.

&&

$$


NEAR TERM...Cornwell
SHORT TERM...Cornwell
LONG TERM...Cannon