012
FXUS61 KGYX 151030
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
630 AM EDT Mon Jul 15 2024

.SYNOPSIS...
Heat and humidity build for the next few days as high pressure
strengthens off the Eastern Seaboard, with chances for
scattered afternoon showers and thunderstorms each day. A cold
front moves through late Wednesday through Thursday, bringing
drier and somewhat cooler conditions for the end of the week and
going into the weekend with high pressure building in from the
west.

&&

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

6:30am Update... A quick update to account for some isolated
showers across northern New Hampshire this morning, and
refreshed temps a bit based on latest high res guidance. Also
adjusted cloud cover a bit through the morning as the remnants
from yesterday`s MCS drifts through.

Previous...

Heat and humidity build today as high pressure strengthens off
the East Coast. A heat advisory remains in effect for today
across southern and interior locations outside of the higher
terrain, and has been expanded to coastal York county. While the
immediate shoreline will not see heat advisory criteria,
anywhere west of I-95 and the population centers in Biddeford
and Saco are likely too, so the advisory was expanded. Coastal
Cumberland has been left out as most of the area will be
modified by the wind direction off Casco Bay. In the areas with
the heat advisory, heat indices are expected to climb to between
95-100 degrees this afternoon as dew points rise into the low
70s.

Within the building ridge, small shortwaves continue to ripple
along through the flow. One such shortwave comes in late this
afternoon and into the early evening hours, helping to kick off
some scattered showers and thunderstorms. Any thunderstorms that
do develop have the potential to bring gusty winds, but the
best chance looks to be across southern and southwestern New
Hampshire today. The SPC has placed this area in a marginal risk
for severe weather with their latest update.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
A warm and humid night is in store for tonight as lows only dip
into the low 70s in most areas. Northern valleys likely dip
into the mid 60s, but elsewhere much of the night will be spent
in the 70s. There is also the chance for some scattered showers
and storms through the overnight hours as a leftover MCS drifts
eastward from the Great Lakes. How organized this system will be
by the time it arrives here will depend on how much development
there is during the daytime today, but the greatest chance for
storms overnight looks to be across northern locations. The HRRR
is also indicating further storms developing across Maine
toward daybreak as the shortwave propagates into New England.
These trends will need to be monitored today, with the potential
for a thundery night across much of the area after midnight.

Any storms that occur overnight only serve to add to the
humidity tomorrow as temps and dew points peak across the area.
Heat headlines will likely be needed, and probably with a bigger
footprint than today`s, but we continue to approach these
headlines one day at a time. Temps warm into the low to mid 90s
outside of the higher terrain, with dew points in the 70s making
it feel like the upper 90s to low 100s. The seabreeze doesn`t
look to bring as much relief to the shoreline tomorrow with a
bit more of a southwesterly wind trajectory, but some afternoon
moderation is expected.

More scattered storms are likely during the afternoon hours,
with the best chance across western New Hampshire. These areas
also stand the best chance to see some gusty winds with the
storms that do develop.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
500 MB pattern cross NOAM moves from a zonal to become more
amplified by late in the week, with ridging over the inter-
mountain west and troughing in the east. But before things
become less warm, we still have several days of heat to go, as
the ridge over the east gets a poleward push from the digging
trough over the Great Lakes and Midwest. The trough will linger
into next weekend, and while it will be cooler, temps will
still be running on the warm edge of the normal envelope.

On Tuesday it looks sunny enough with decent SW flow to mix the
hot air aloft down to the sfc, and this will allow for highs of
90-95 everywhere but the mtns and the mid coast, with mostly
mid 90s in S NH and interior SW ME. The SW flow and mixing
should keep Tds limited to around 70 F, so while it will be hot
and humid Heat indices are expected to top at out a little over
100, and not reach the 105 warning criteria. Still it will be a
day where staying cool and hydrated will be important. It will
be unstable enough to pop a few isolated convective cells almost
anywhere, and with a weak passing well to the N, there will be
a better chance in the mtns. But more areas will stay dry than
see any SHRA/TSRA.

Tuesday night mins will mostly be 70-75, but upper 60s in the
mtns and the mid-coast, perhaps warmer in the more populated
areas of S NH. SCT showers and convection could linger in the
mtns through the evening as well. Given the highs Tds some fog
is possible ins sheltered areas, but the SW flow should remain
strong enough, that it will only be patchy.

Wed will be another hot day, but probably not quite as bead as
Tuesday, as we see more in the way of clouds through the day,
and the chance of SHRA/TSRA ahead oi the cold front to our NW.
Could also see some turning of the flow onshore, with a better
sea breeze in the afternoon, as the storms develop further
inland. However, will probably need a heat advisory for one more
day, although maybe with less coverage than Tuesday. The sfc
front pushes offshore in the evening, but is expected to stall S
of the CWA, so while the mtns and foothills may see the benefit
of cooler temps and lowers Tds Wed night, it is unlike closer
to the coast and in S NH, although it will be cooler than
previous night with lows ranging from around 60 in the N to the
mid to upper 60s in the S. 12Z Euro has stalled that front
further S than some previous runs, but could still see a lot of
clouds around in the S on Thu, with a chance of showers, and a
chance of showers in the N Thu afternoon as the upper level
trough approaches. Highs will be in upper 70s to mid 80s.

The trough stays well to our N Friday and Saturday, and will
usher in more seasonable mid level air, and highs both days look
to be 75-80 in the mtns and in the low to mid 80s S of there,
with over night lows ranging from the mid 50s N to the low to
mid 60s in the S.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Short Term...Brief MVFR conditions are possible at HIE around
sunrise, but otherwise mainly VFR conditions prevail through
this evening at all terminals. Scattered showers and storms may
bring brief restrictions to southern and western terminals this
afternoon, but probs remain too low to include in the TAFS.
Marine fog likely moves into RKD tonight. Some valley fog is
possible at LEB and HIE tonight. Showers and storms are possible
after midnight through daybreak at most terminals. Mainly VFR
prevails tomorrow outside of isolated afternoon storms, and any
lingering fog at RKD.

Long Term...Tuesday and Wednesday will be hot days with high
humidity and warm lows Tue night. A few SCT TSRA are possible on
Tue afternoon as well. Fog will likely be limited to the
KHIE/KLEB Tue night as SW flow does keep it a bit overnight. A
better chance for TSRA is expected Wed aft/eve, as if overnight
fog Wed night. A few isol TSRA remain possible on Thu, but
Friday looks dry attm, with VFR. and the threat of fog each
night. Also SCT TSRA are possible both afternoons. The next
chance of more widespread flight restrictions will be Wed night
into Thu morning as the cold front pushes through and may stall
just off shore.

&&

.MARINE...
Short Term...A building high east of the waters brings south-
southwesterly flow across the waters for the next couple of
days. A few gusts in the afternoon may reach 25kt near the sea
breeze front along the coast. Locally dense fog is possible
after midnight tonight through tomorrow.

Long Term...Generally winds/seas stay below SCA levels through
the coming week, but could approach SCA gusts late Wed or Wed
night in advance of a cold front.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory from noon today to 8 PM EDT this evening for
     MEZ012-018>020-023-033.
NH...Heat Advisory from noon today to 8 PM EDT this evening for
     NHZ004-006-008>010-012>015.
MARINE...None.

&&

$$


NEAR TERM...Clair
SHORT TERM...Clair
LONG TERM...Cempa