468
FXUS61 KGYX 252003
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
403 PM EDT Wed Sep 25 2024

.SYNOPSIS...
High pressure retreats northward as moisture works its way into
the region tonight. Low pressure keeps north as a triple point
of fronts moves through the area Thursday. This brings much
needed rainfall to the area, albeit heavy at times. Dry weather
returns in time for the weekend as high pressure moves overhead.

&&

.NEAR TERM /TONIGHT/...
Impacts
*No significant weather impacts expected.

The first round of light rain showers is moving through western
Maine at this hour. Most of the area will see a decent break
between these and the system tonight. The only exception may be
an additional light shower along the Vermont- New Hampshire
border in the next few hours. Otherwise, the bulk of the rain
begins to arrive in Western New Hampshire after 10PM,
overspreading the region by day break Thursday. Deeper moisture
will be moving into the area during this time as well with the
12Z GYX RAOB observing PWATs around 0.83" already in place this
morning. Overcast skies will keep us well insulated tonight with
temperatures bottoming out in the upper 40s and low 50s.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Impacts
*A convective fine line containing heavy rain may develop in
 the population corridor around the evening commute. Ponding
 water on the roads may lead to minor travel impacts.

Widespread rain will be ongoing Thursday morning with some
embedded heavier showers possible during this portion of the
forecast period as well. PWATs will be up around 1.25" in
Northern zones and closer to 1.50" in southern zones and along
the coast. This, combined with warm cloud depths up around
12kft, will promote efficient and locally heavy rainfall. To
this point many areas were making a run for their driest
September on record, so 1hr and 3hr flash flood guidance is 2"
and 3" respectively. HREF ensemble probability of just 1"/hr
rain rates is near zero, so any flooding should be limited to
ponding on road ways or around storm drains that may be clogged
with leaves. As the day progresses CAMs continue to develop a
fine line of convection during the late afternoon. This would be
the focus for heavy rain in southern New Hampshire and southern
Maine. Instability is limited as we will be pretty thickly
overcast through the day, but an isolated rumble of thunder is
not out of the realm of possibility. For this reason, any
impactful wind gusts look likely as well, except for when it
gets closer to the coast and out over the water where mixing
will be better, then a stray gust 25-30 mph is more likely.
Daytime highs will again be limited to the upper 50s and low
60s.

The bulk of the rain will be exiting the area after midnight
with just lingering showers overnight. When all is said and done
rainfall amounts will generally be around 1.50" with locally
higher amounts up around 2.5". With clouds clearing, patchy fog
may be pretty widespread heading toward daybreak Friday.
Nighttime lows will again bottom out in the upper 40s and low
50s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As low pressure exits the region, increasing sunshine will be
the theme across much of the forecast area. Most breaks in the
cloud cover will be over downslope region where temperatures
will be reaching the upper 60s to lower 70s. Across the northern
higher terrain, expect a few widely scattered rain showers to
develop in the west to northwesterly flow.

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 /18Z WEDNESDAY THROUGH MONDAY/...
Short Term...Rain moving in will keep the area MVFR tonight.
Overnight and during the day Thursday there may be some
localized IFR restrictions as the rain will be heavy at times
and low stratus develops. This will continue right through
Thursday night as ceilings lift and fog likely develops in the
systems wake. A fine line of convection may develop affecting
CON, MHT, PSM and PWM. HIE is likely see down slope wind gusts
of 15-20 kts during this time period with all other sites
staying calmer outside of convection.

Long Term...Friday morning may feature some fog but afterward
VFR should be the prevailing condition right through the
weekend. Winds will be light with gusts generally 10-15kts.

&&

.MARINE...
Short Term...SCA conditions continue as swell increases once
again during the day tomorrow. Seas will be generally 4-6ft,
with 3-5 ft in the waters outside of Penobscot Bay. Offshore
winds may also gust 25-30kts as a front moves offshore Thursday
night.

Long Term...Max wave heights of 5ft remain through at least
Friday morning before finally dropping below 5 ft later in the
day and remaining 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 PM EDT Thursday for ANZ152>154.

&&

$$

NEAR/SHORT TERM...Baron
LONG TERM...Cannon