855
FXUS61 KGYX 281330
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
930 AM EDT Sun Apr 28 2024

.SYNOPSIS...
A warm front will bring scattered showers today into tonight
with temperatures warming into Monday. A back door cold front
moves through Monday night which will cool things down for
Tuesday. Low pressure develops along this front to our south,
and brings another round of showers Tuesday night. Wednesday
remains cool with some clearing in the afternoon. Warmer high
pressure will build in for the end of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM Update... Area of rain showers with embedded thunder
across the mountains into the foothills has been holding
together much better than models have been showing with
additional showers developing across southern NH. Have
increased PoPs for areas down stream of the mountains and across
southern NH to account for these trends. Latest RAP analysis
suggest that there will continue to be instability to work with
so have included isolated thunder wording across the area. These
showers and embedded thunder are progged to move offshore and
diminish around noon.

730 AM Update... An area of showers with embedded thunderstorms
is beginning to cross into northern NH, which moved south from
Ottawa overnight. Latest RAP mesoanalysis shows this activity
is within a weakening EML and lightning has been trending
downward. Latest hi-res guidance indicates this weakening trend
will persist as this activity tracks southeastward into NH and
eventually western ME. Nevertheless, did add thunder mentioning
to northern areas for a few hours this morning. Otherwise, just
made some mostly minor adjustments to sky cover and PoPs.

Previously...
Latest RAP13 surface pressure analysis this morning shows high
pressure located to our south and east with New England sitting on
the northern edge of an h5 ridge axis. Nighttime microphysics
satellite imagery shows a band of clouds moving from west to east in
association with a weak vorticity maximum that is crossing ahead of
a sfc warm front that is approaching from the west. Latest hi-res
guidance indicates this initial band of light showers will continue
to drift east through around 6am before mostly dissipating as it
encounters dry air over western ME and the forcing for ascent
weakens. Current temperatures are primarily into the 40s and other
than another degree or two of cooling from wet bulbing, lows
will not differ much from their current readings.

Another band of showers are progged to arrive towards the Upper CT
River Valley within an hour either side of 8AM before quickly
dropping south and weakening over western ME and exiting the
coastline by late morning. Otherwise, today will feature partly
to mostly cloudy skies and increasing humidity as a warm front
crosses the region. This will place our region within the warm
sector with h925 temperatures warming to around +14C, which will
be around our maximum mixing heights for today. This will allow
interior locations to warm into the middle to upper 60s with
lower 70s over southern and western NH. Cooler readings into the
50s to near 60 will be common closer to the coast due to
southerly onshore flow.

Latest mesoscale guidance suggests some decent destabilization
will occur over portions of interior NH this afternoon,
particularly towards the CT River Valley. The combination of
sfc temperatures into the lower 70s and increasing moisture
advection pushing sfc dewpoints well into the 50s could allow
for several hundred joules of MUCAPE to develop. This in
combination with around 50 kts of 0-6km bulk shear and decent
lapse rates could result in an isolated thunderstorm during the
afternoon and early evening. As a result, went ahead and added
some thunder mentioning to just these areas for a few hours
later today. While severe weather is not expected, a localized
gusty storm cannot be ruled out. Whatever convection does occur
will quickly weaken as it moves towards the coast and encounters
the marine airmass but any location will be at play for a
shower.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Surface cold front will cross tonight, bringing an end to the shower
activity as drier air advects back into the region under northwest
flow. Lows will range from the 40s to middle 50s from north to
south.

Surface high pressure and mid-level ridging will then build over New
England on Monday, resulting in a mainly sunny and very warm day
despite northerly winds. Highs will range from the middle 70s in
interior southern NH to the middle and upper 60s elsewhere. Even
coastal locations should warm well into the 60s as the northerly
winds will help to fight off a sea breeze. Speaking of winds, deep
afternoon mixing will allow gusts to approach around 25 mph at
times. This in combination with low afternoon RH into the teens to
lower 20s percent range could result in some fire weather concerns.
It will otherwise be a beautiful day.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
500 MB pattern across NOAM is highlighted, for the most part, by
a double omega block with ridging be the dominant player across
the E CONUS. Early on, the proximity to the closed low S of Nova
Scotia will bring us either NE or onshore flow, which will not
let us benefit much from the warm air aloft, but later in the
week the flow at the sfc and aloft will be more W-SW and allow
for warmer air to mix down to the sfc, with mainly dry
conditions. After this models projecting 500 MB low to our NW
to crash into the ridge which brings the threat of showers for
next weekend.

Tuesday looks partly sunny but cooler. Especially in the
eastern zones and along the coast where highs will be in the low
to mid 50s. Inland areas nay get closer to 60 with the warmest
being in the CT valley where highs will be 60 65. It should be
mainly sunny by morning with clouds increasing from the SW later
in the day. Weak low pressure then develops along the cold
front that sits just to our S, and this will bring a threat
showers to the area Tue night. These showers may end up being
more convective and scattered, and mins will generally be in the
low to mid 40s.

Once the low passes, it leave the mid level front sitting over
the CWA, and this will make for more clearing to the N and E by
afternoon, and more clouds to the SW on the warm side of the
front. Maxes will mostly be in the 55-60 range, but again the CT
vly will likely be 60-65.

At this point it looks like Thu-Fri stay dry and warm,
especially inland with highs in the mid to upper in the eastern
ME zone and 70-75 across all but coastal NH and interior SW ME.
The coast will be the coolest with highs in 60-65 range. Friday
looks similar, although with more clouds. The weekend we start
to see the ridging being overtaken by a 500 MB closed low to the
W, but today this is happening 24 hours later than yesterdays
model runs, so this is low confidence, as models tend to break
the ridge Atlantic ridging too soon, although its always tough
to tell in the spring.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
Short Term...Pockets of MVFR restrictions will remain possible
through mid-day along with scattered -SHRA. An isolated -TSRA is
possible between roughly 19Z-23Z, especially at KHIE and KLEB.
Southerly winds will prevail through 00Z Sunday with a few gusts
nearing 15 kts. Winds will become northwesterly behind a cold
front tonight as scattered -SHRA ends. Pockets of MVFR
restrictions are possible (mainly at KHIE) but otherwise VFR
will dominate. VFR conditions and gusty northerly winds are then
expected on Monday with gusts up to 20 kts. No LLWS is expected
through the period.

Long Term...Some MVFR possible in SHRA and maybe some fog Tue
night, which may linger into Wed morning, especially at
KPSM/KMHT/KCON. VFR returns Wed afternoon and should prevail
through Thursday at least.

&&

.MARINE...
Short Term...A few southerly wind gusts could approach 25 kts
today over the outer waters but otherwise winds and seas will
remain below SCA criteria. Winds will become northerly on Monday
behind a cold front.


Long Term...Winds/seas stay below SCA criteria Mon night through
Thu.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$


NEAR TERM...Schroeter/Tubbs
SHORT TERM...Tubbs
LONG TERM...Cempa