Chillum, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

645
FXUS61 KLWX 070237
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
937 PM EST Fri Mar 6 2026

.WHAT HAS CHANGED...
Marine stratus has overtaken most of the area now, with fog
starting to develop in parts of the area. Expect dense fog to
develop overnight, with Dense Fog Advisories likely to be
issued.

&&

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

- 2) Sunny and calm conditions will start to take over next
  week, before another potential cold front pushes through the
  region midweek.

&&

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

Increasing east winds have advected in a marine stratus deck
from the Atlantic, which has now reached the Blue Ridge and
points west. Some observations in the Shenandoah Valley and
northern MD show that dense fog has developed, so expect Dense
Fog Advisories to be issued for parts of the area as fog
continues to expand. Precip has mostly come to an end, though
some drizzle is possible overnight. Temperatures will remain mild
with lows in the 40s and 50s.

High pressure will shift further east tomorrow, while a potent
shortwave and associated area of low pressure rapidly track
northeastward from the Upper Midwest/Great Lakes toward Quebec.
As this occurs, winds at the surface will turn southerly and
winds aloft will increase out of the southwest. While the day
will once again start out with low clouds and fog across much of
the forecast area, southerly winds will likely allow the cold
air damming wedge to finally break to the east of the Blue Ridge
by the afternoon and evening hours. As a result, temperatures
are forecast to be warmer than today, with most of the forecast
area (with the exception being Northeast Maryland) climbing into
the 60s and 70s by mid-late afternoon. The combination of deeper
moisture advecting into the area in southerly flow (dewpoints
reaching into the upper 50s to lower 60s), daytime heating, and
glancing ascent as the shortwave passes to our north and west
will enable showers and thunderstorms to develop by later
tomorrow afternoon into tomorrow evening.

We`re expecting two rounds of storms tomorrow. The first round
is expected to form within a surface trough just to the east of
the Alleghenies during the mid-late afternoon hours. Model
soundings show a fair amount of dry air in place aloft, and
large scale forcing for ascent won`t be overly strong, so areal
coverage with this first round of storms is only expected to be
isolated to scattered in nature. If storms do become well
established, the background environment will have enough
instability (around 1000 J/kg of MLCAPE) and shear (around 40
knots in the 0-6 km layer) to promote updraft rotation.
Isolated instances of damaging winds or hail may be possible
with these storms as they move eastward from the Potomac
Highlands toward the I-81 corridor and then the Blue
Ridge/Catoctins during the mid-late afternoon hours. Conditions
will likely remain dry to the east of US-15 during the daylight
hours.

A second round of pre-existing storms will approach from the
Ohio Valley, reaching the Allegheny Front around sunset. This
round of storms could be well organized into a squall line, and
may potentially be quite intense. With the loss of daytime
heating, the trend will likely be downward with the strength of
this activity as it moves into our area, but damaging winds may
still be possible, especially along and west of the Allegheny
Front. Large scale forcing for ascent may enable these storms
to hold together in a weakened form as they move eastward across
the forecast area during the first half of the night.

As of now, SPC has Garrett County in Slight Risk for severe
thunderstorms, with locations further east to about US-15 in a
Marginal Risk.

The actual surface cold front will move through the area late
Saturday night into Sunday morning. There is still some
disagreement amongst guidance regarding the timing of the
frontal passage, and how much daytime heating will occur ahead
of the front during the day on Sunday. We`ll likely have some
lingering cloud cover and showers during the morning ahead of
the front. Depending on how fast the front progresses, some
daytime heating could occur ahead of the front across southern
Maryland, potentially leading to the development of a few
thunderstorms. Clearing is expected from northwest to southeast
during the afternoon and evening hours as drier air starts to
work in behind the front. High temperatures on Sunday will be in
the 60s and 70s for most, with 50s in the mountains.

KEY MESSAGE 2...Sunny and calm conditions will start to take over
next week, before another potential cold front pushes through the
region midweek.

Sunshine and warm temperatures to start the week before showers
and a few thunderstorms move into the region middle to late
week. A cold front will cool conditions off and bring drier air
into the region late week. Temperatures mainly in the 70s and
80s Monday through Wednesday with highs in the 50s to follow on
Thursday into Friday with a cold frontal passage.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
MVFR to IFR CIGs are widespread this evening, with the
expectations for CIGS to lower to LIFR through the night. Mist
is already widespread, with fog expected to develop at most
terminals. VLIFR conditions possible at some terminals due to
dense fog reducing visibility to 1/4 SM or less and VV of
001-002 by daybreak.

Gradual improvement is expected through the day tomorrow, with
conditions clearing out first at CHO, and last at MTN. Ceilings
will likely climb a few hours quicker than today during the day
tomorrow as winds turn out of the south. Showers and
thunderstorms will approach from the west tomorrow evening, but
will likely be weakening as they do so. An afternoon storm could
also be possible at MRB. A cold front will move through on
Sunday, leading to a return to VFR conditions and a shift to
westerly winds.

VFR conditions on Monday and Tuesday. A shower or thunderstorm
late Tuesday could reduce conditions to MVFR. Winds south to
southwest 5 to 10 knots through the period.

&&

.MARINE...
Sub-SCA level easterly winds persist tonight. Winds will turn
out of the south tomorrow, and remain sub-SCA in nature through
much of the day. Winds could near low-end SCA levels tomorrow
evening, but warm air moving over cooler waters will likely be a
limiting factor. Winds will shift out of the west by Sunday
afternoon as a cold front moves over the waters.

No marine hazards Monday through Tuesday night. Winds generally
south to southwest 5 to 10 knots.

&&

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

&&

$$

DISCUSSION...KLW/KJP/KRR
AVIATION...KLW/KJP/KRR
MARINE...KLW/KJP/KRR