549
FXUS61 KLWX 041943
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
243 PM EST Wed Mar 4 2026

.WHAT HAS CHANGED...
The frontal temperature gradient remains highly uncertain through
Friday. Increasing thunderstorm chances and near record temperatures
for some this weekend.

&&

.KEY MESSAGES...
-1) A meandering front will bring highly variable temperatures,
occasional rain/spotty t-storm chances, and nighttime fog through
Friday.


-2)Near record breaking temperatures for some this weekend. A
 weak cold front will bring increased chances thunderstorms
 Saturday into Sunday before stalling nearby early next week.

&&

.DISCUSSION...
KEY MESSAGE 1..A meandering front will bring highly variable
temperatures, occasional rain/storm chances, and nighttime fog
through Friday.

Not too much change, in the mid and late week period as a front
continues to hopscotch across the region. The front remains south of
Dover, DE/Washington DC and northwest along the Potomac River toward
Cumberland, MD. Areas north of the boundary remain in the 40s while
locations to the south have warmed into the 50s and 60s. Scattered
showers have also been observed along the front, mainly along and
north of US-33 from Pendleton Co. WV east toward US-50 and the Bay
Bridge.

Expect periodic shower activity to continue over this area through
early evening as the front meanders back to the south. A few
elevated rumbles of thunder cannot be ruled out over the Allegheny
Highlands later this afternoon and evening given weak instability
overhead. Shower/sprinkle chances will continue into the overnight,
mainly along and north of I-66/US-50 and along the PA/MD line as the
front lifts back north. This is attributed to a secondary area of
surface high pressure to the south and ridging aloft. With the
stalled front nearby, expect additional low clouds and areas of fog
given the added moisture over the region.

The placement of wavering front will continue to dictate the overall
temperatures today.There is high confidence for temps in the mid 40s
and low 50s over northern/central MD with lower confidence for low
to mid 50s (perhaps upper 50s) along the immediate boundary near the
Potomac River. High confidence remains for low to mid 60s and even a
few upper 60s across the central VA Piedmont/Shenandaoh Valley given
the proximity to the front along with added breaks of sunshine for a
longer period of time. Lows tonight will fall back into the 40s and
50s.

Surface high pressure/upper level ridging build in from the
southeast U.S Thursday as a shortwave trough/low pressure system
move from the mid-MS River Valley into the Great Lakes region. This
will shunt the front back to the north allowing for a bit more
scrubbing of the residual cool air wedge east of the mountains. 12z
hi-res/deterministic guidance continues to struggle in regards to
the placement of the front and to how much cool air is scoured away
given light and variable winds. Once again it looks as if
northeast/central MD will remain the coolest with warmer conditions
south/west into the Shenandoah Valley/Piedmont. Highs will range
from the low to mid 50s north/east of Baltimore to low/mid 70s
across the Shenandoah Valley/central VA Piedmont where more sunshine
will prevail. Any shower chances will remain north of I-70 with some
thunderstorm activity across the Alleghenies/Potomac Highlands late
Thursday afternoon and evening as shortwave energy passes through.

As the low passes off the Mid Atlantic coast Thursday night, high
pressure moving toward the Canadian Maritimes will likely shove the
front back south, which could result in the reemergence of low
clouds, fog, and cooler temperatures. There remains a very high
spread in model forecast temperatures on Friday as the backdoor cold
front will separate an increasingly warm airmass building northward
from the southeastern US. A 30 to 40 degree spread in temperatures
could exist from northeast MD to south-central VA. Comparatively,
precipitation chances will be lower Friday and Friday night as
ridging builds further north into the region. However, there still
could be some light showers or drizzle near and northeast of the
frontal boundary.


KEY MESSAGE 2...Near record breaking temperatures for some this
weekend. A weak cold front will bring increased chances
thunderstorms Saturday into Sunday before stalling nearby early next
week.

Unseasonably warm and humid conditions look to develop this weekend
as the entire area finally enters the warm sector. This is due
largely in part to the stalled boundary/warm front lifting further
north and deep southwesterly flow ahead of an approaching weak cold
front. This front will drop in from the northwest Saturday afternoon
and evening bringing with it showers and perhaps a few
thunderstorms. CSU probabilities continue to highlight areas mainly
west of the Blue Ridge with a 5 to 14 percent chance of severe
weather. This corresponds with 10 percent probs from CIPS over the
same area. With that said, one or two storms could be strong with
locally gusty winds and heavy rainfall (mainly of pulse variety and
terrain driven). Highs Saturday will range from the upper 60s over
northeast MD to around 80 from the Potomac River points south and
west. Lows Saturday night will fall back into the 50s.

By Sunday, the front will drift into central VA and southern MD
bringing additional shower/t-storm chances to these areas. Outside
of these locations no change in sensible weather is expected with
little wind shift either. The front will then wash out over the
region bringing continued shower chances and temperature volatility
into early next week.


&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Sub-VFR conditions continue this afternoon for all terminals outside
of KCHO. This is largely due in part to the wavering frontal
boundary that will result in low ceilings, fog, showers, and
directional wind shifts through at least Friday. The position the
front will be critical for the development of these phenomena, and
forecast confidence remains lower than usual.

Expect a sharp gradient of VFR to IFR in around the wavering frontal
boundary. This is the case around the metro terminals as showers
pivot along the stalled front draped near the Potomac River this
afternoon. Shower chances will likely continue through this evening
before decreasing overnight with low clouds/fog settling in. Expect
IFR/LIFR cigs/vsbys. Vsby reductions as low a 1/4-1 SM at most of
the corridor terminals between 8-12z/4-7am Thursday morning.

Thursday may see improvements from MRB/IAD/DCA points south with
BWI/MTN hanging on to low cigs most of the day. More showers and
perhaps even an embedded thunderstorm will cross the northern
terminals (i.e MRB/HGR) during the late afternoon and evening. Did
not include in the 18z package since the threat is just outside the
period. The southern extent of low ceilings is much more uncertain
Thursday night through Friday night, although the highest chances
remain across MRB/BWI/MTN. Rain chances trend downward Friday given
high pressure building from the south.

Additional rain chances are expected this weekend as a weak cold
front drifts into the region. This front will bring increased
southwesterly flow along with a few thunderstorms especially west of
the corridor terminals Saturday afternoon. The front will be slow
moving late Saturday into Sunday before washing out south and east of
the area early next week. This could result in an extended period of
sub-VFR conditions as a result. SW winds around 15-20 knots on
Saturday, tapering off to around 10-15 knots by Sunday.

&&

.MARINE...
A quasi-stationary boundary will push back to the south of the waters
tonight before lifting back to the north Thursday into Friday.
A cold front will try to cross the waters late Saturday into
Sunday before washing out over the region early next week.

Winds will remain below SCA level through Friday night with
marine dense fog possible each night into the early morning
hours.

The next three days, the northern Chesapeake may largely keep east
to northeast winds, while areas south of Washington and Bay Bridge
could flip to southerly at times. Winds should remain below advisory
criteria.

Winds will gust to near SCA criteria out of the SW on Saturday.
However, thinking that the continued cold waters in comparison to
warmer air temperatures could confine the threat primarily to the
northern/middle waterways, with less wind over the open Bay waters.
Winds taper off on Sunday, with SCAs unlikely at this time.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...ADS/EST
AVIATION...ADS/EST
MARINE...ADS/EST

NWS LWX Office Area Forecast Discussion