Mechanicsville, Maryland Weather Forecast Discussion

776
FXUS61 KLWX 080739
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
339 AM EDT Mon Sep 8 2025
.SYNOPSIS...
High pressure will build in from the west today before settling
north of the area by the middle of the week. Meanwhile, a wave
of low pressure passes offshore around mid-week. A dry cold
front will cross the region Thursday, reinforcing below normal
temperatures and a continued dry stretch. High pressure will
return for the end of the week into next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Overnight lows dropped into to the 40s to mid 50s, with mid to
upper 30s for parts of the Allegheny Mountains. A Frost Advisory
remains in effect for Garrett, western Grant, western Pendleton,
and western Highland Counties until 8 AM, where frost is likely
in the many sheltered elevated valleys.
We will quickly warm to high temperatures in the mid 70s (60s
in the mountains). This is all due to the influence of high
pressure building to our north in the wake of this past
weekend`s frontal passage. Mostly sunny skies can be expected
today, with only a few fair weather cumulus during the
afternoon.
Temperatures will be chill yet again tonight, but model guidance
does actually warm the mountains up just a few degrees tonight.
So, no Frost Advisories for now, but some isolated spots may
see some yet again, especially in very sheltered high elevation
valleys.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
High pressure will build to the north of the mid-Atlantic region
through Tuesday, with a surface ridge axis wedging down the
eastern side of the Appalachians.
A wave of low pressure will develop offshore by Tuesday.
resulting in north to northeasterly breezes and a continuation
of below normal temperatures in the 70s (60s in the mountains).
As this area of low pressure passes offshore, clouds will
increase along and east of I-95 Tuesday. A coastal front could
spread some shower activity westward toward southern MD Tuesday
night into Wednesday, but chances remain below 15 percent at
this time.
A dry wedge of high pressure will keep all other areas dry into
Wednesday, with cooler than normal temperatures continuing. We
may add a degree or two to highs on Wednesday, but nothing
significant. Also, will gradually be warming each night on
Tuesday and Wednesday, so no frost headlines expected.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A secondary cold front will move through on Thursday. High pressure
to the north will remain in control behind the front through the
weekend. This will favor continued below average temperatures, cool
mornings, and dry weather ahead.
Thursday and Friday will be a tad warmer as winds shift to a
northwesterly downslope flow behind the cold front. Abundant
sunshine is likely through late in the week and into next weekend in
response to broad subsidence in the atmosphere. High temperatures
peak on Thursday and Friday with a forecast into the upper 70s to
low 80s (mid 60s to mid 70s for the mountains). As high pressure
settles off to the north, winds next weekend turn more onshore in
nature. This helps usher temperatures back into the mid/upper 70s.
Overnight lows during much of this forecast period will be in the
upper 40s to 50s, locally a bit lower along the Allegheny Front.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
High pressure will build toward and to the north of the region
through Tuesday night. Winds will be or become northwest to
northerly in general over the next 24 to 48 hours. Winds around
10 knots gusts 15 knots. VFR conditions will be observed this
entire time, with the only clouds today being some afternoon
cumulus at around 5 kft. Clouds increase along/east of I-95 on
Tuesday as a coastal system slides by to our southeast, but will
have no impact on aviation in our TAF sites.
VFR conditions are expected at all TAF sites during the middle to
latter portions of next week. A secondary cold front will move
through on Thursday shifting winds to north-northwesterly. Gusts up
to 10 to 15 knots are possible during the afternoon hours. As high
pressure re-builds to the north, winds shift to east-northeasterly
by Friday.
&&
.MARINE...
Winds are expected to remain elevated out of the NNE through
perhaps Tuesday. Small Craft Advisories are in effect until
Tuesday morning, as they were just extended with this latest
update. There could perhaps be a few hours today where winds
taper off a bit, but overall, expecting a prolonged period of
SCA conditions across the central Bay and lower Tidal Potomac
waters. These will likely need to be extended further in time
into tomorrow and perhaps even Wednesday, but will wait to see
today`s model guidance before making that call.
A secondary cold front will track through the waters on Thursday.
This may lead to another ramp up in wind fields as they turn more
northwesterly in nature, gusting up to 15 kts.
&&
.TIDES/COASTAL FLOODING...
Due to the combination of winds not quite aligned to push water
south and out of the Bay, and the recent full moon, tides will
be somewhat elevated in the coming days. Particularly those
sites along the west shores of the Chesapeake Bay, where NW
winds will help to bump up the water levels during the middle of
the week. No sites are forecast to hit minor, but Annapolis
especially is expected to be very close by Wednesday.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 6 AM EDT early this morning for
     MDZ008.
     Frost Advisory until 8 AM EDT this morning for MDZ509-510.
VA...Frost Advisory until 8 AM EDT this morning for VAZ503.
WV...Frost Advisory until 8 AM EDT this morning for WVZ501-505.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
     ANZ530-531-538-540.
     Small Craft Advisory until 6 AM EDT Tuesday for ANZ532>534-537-
     541>543.
&&
$$
SYNOPSIS...CJL
NEAR TERM...DHOF/CJL
SHORT TERM...DHOF/CJL
LONG TERM...CPB
AVIATION...CJL/CPB
MARINE...CJL/CPB
TIDES/COASTAL FLOODING...CJL

NWS LWX Office Area Forecast Discussion