720
FXUS61 KLWX 222004
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
304 PM EST Wed Jan 22 2025

.SYNOPSIS...
Arctic high pressure will maintain control leading to well below
average temperatures through Thursday morning. Temperatures
will begin to moderate late this week as high pressure begins to
lift away. A weak system may approach the region early next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Expansive surface high pressure remains in place over the entire
eastern U.S. Arctic air continues to dominate supporting well
below average temperatures for mid/late January. Although no
daily records are being broken locally, temperatures are running
around 15 to 25 degrees below average. Given the nearly cloud-
free skies, GOES-16 visible satellite imagery shows a snowpack
quite well west of I-95. Otherwise, thickening high cirrus
continue to spread from the Alleghenies toward the I-81
corridor. These clouds should not have too much influence on
any further daytime heating. Overall high temperatures are
likely to be capped around the upper teens to low 20s, locally
nearing 25 degrees in the mild spots. Across the mountains,
upper single digits to lower teens are expected.

Despite some high clouds passing by overhead, high pressure
combining with calm winds and very dry air (dew points are
currently around -5 to 0F) will make for quite a frigid night
ahead. Given the above environment, have opted to go toward the
colder side of the model envelope. This places a bulk of the
region between 3 and 10 degrees, locally into the lower teens in
the city centers and in far southern Maryland. For the
Alleghenies, lows will be near 0 degrees with some added wind.
This supports wind chill temperatures dropping to around -10F.
Consequently, Cold Weather Advisories are in place from this
evening through the night along the Allegheny Front and into the
central Shenandoah Valley.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Coming off another frigid night, temperatures are likely to
rebound a bit more given a shift to light south-southwesterly
winds. This overall rebound in temperatures will at least bring
high temperatures to the upper 20s to mid 30s on Thursday,
locally in the 20s across the higher terrain. This comes with a
mix of clouds and sun as the next upper trough approaches from
the west. A brief period of snow showers is expected along the
Alleghenies with around an inch or two possible through early
Friday morning, particularly closer to the ridgeline.

Wind fields should stay light enough to allow for decent
radiational cooling effects on Thursday night. This yields low
temperatures that are forecast to range from 10 to 20 degrees,
with mid/upper single digits west of the Shenandoah Valley. It
could be slightly cooler in some of these locations owing to the
current snowpack.

Heading into Friday, trailing northwesterly flow will ensure a
cold finish to the work week. Forecast highs will average in the
upper 20s to mid 30s, with teens to mid 20s across mountain
locales. The forecast does remain dry after the bout of snow
showers along the Allegheny Front. Another frigid night is on
tap over the area on Friday night with lows only in the mid
single digits to mid teens.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
High pressure will remain overhead on Saturday before sliding to the
south and east Sunday. Below normal temperatures will remain for
Saturday but will rise closer to normal Sunday. A weak frontal
system may pass through Sunday into Monday. There could be some
upslope snow in the Alleghenies but otherwise moisture looks
limited (outside of increased cloud cover). 12Z guidance continues
to trend drier, with potential for precipitation with a trailing low
pressure system likely remaining south of the area.

Model spread increases toward the middle of next week. Tuesday will
most likely remain dry with near normal temperatures as high
pressure remains to the southwest. Amplifying troughing along the
east coast could support precipitation chances Wednesday or beyond
but uncertainty is high. The NBM temperature spread also becomes
quite large at this point, although near to above normal is most
likely.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected at all terminals through the
remainder of the work week. Wind fields should remain on the
light side given high pressure in place. Winds remain light out
of the south/southwest on Thursday before shifting to
northwesterly into Friday behind a cold front. Afternoon gusts
up to 10 to 15 knots are possible then.

No significant weather is expected Saturday and Sunday as high
pressure gradually retreats.

&&

.MARINE...
The presence of high pressure over the region will keep marine
winds on the lighter side the next couple of days. Initial
northwesterly winds give way to southwesterly flow by Thursday.
The next frontal system leads to a shift to northwesterlies
again into Friday with some gusts possibly approaching Small
Craft Advisory levels.

High pressure will retreat over the weekend. A period of increased
southerly channeling could lead to marginal advisory conditions
along the bay Saturday night.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Cold Weather Advisory from 7 PM this evening to 10 AM EST
     Thursday for MDZ001.
VA...Cold Weather Advisory from 7 PM this evening to 10 AM EST
     Thursday for VAZ503-504.
     Cold Weather Advisory from 9 PM this evening to 10 AM EST
     Thursday for VAZ025-026.
WV...Cold Weather Advisory from 7 PM this evening to 10 AM EST
     Thursday for WVZ501-502-505-506.
MARINE...None.

&&

$$

SYNOPSIS...BRO
NEAR TERM...BRO
SHORT TERM...BRO
LONG TERM...ADS
AVIATION...ADS/BRO
MARINE...ADS/BRO