Clifton, Virginia Weather

312
FXUS61 KLWX 140800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Fri Mar 14 2025

.SYNOPSIS...
A stalled front will waver near the Mid-Atlantic through tonight
before retreating back to the north as a warm front Saturday. A
strong cold front will cross the area Sunday. High pressure
will build in from the west early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A front remains stalled south of the area this morning. High
pressure is moving east of the Canadian Maritimes but continues
to wedge southwestward along the Appalachians. Low stratus
clouds are again spreading westward but at a much slower pace
than yesterday. It appears they will make it to the Blue Ridge,
perhaps spilling westward in spots. With lighter winds this
morning, patchy fog is also developing where skies remain clear.

There is fairly good agreement on the low clouds mixing out
by midday, although they will quickly be replaced by advancing
mid and high clouds. Despite the sun, areas especially east of
the Blue Ridge will continue to feel the cooling marine
influence, as highs struggle into the 50s to perhaps lower 60s.
60s and even some 70s are more likely across the central
Shenandoah Valley and Potomac Highlands.

There`s a strong signal for widespread stratus developing
tonight, though western areas could have fog instead. Drizzle is
also possible. Lows will be in the 40s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
It may take some time for low clouds to lift Saturday due to the
strengthened low level inversion. The slow northward progress of
the warm front is evident in model theta-e forecasts and may not
push through until evening. There will be plentiful cloud cover
even if the stratus does dissipate too. Have thus started a
downward adjustment in temperatures...in the 60s for most areas.
A lead shortwave and some remnant of Friday`s convection may
brush northwestern parts of the CWA, but models have backed off
on precipitation Saturday besides the lingering drizzle.
Assuming the warm front can punch through (the gradient does
steadily strengthen ahead of the dynamic system in the midwest),
winds will increase Saturday night and temperatures will hold
steady (or rise if they didn`t during the day)...with many areas
remaining in the 60s. Wind advisories may be needed on the
ridges as the low level jet increases. Any showers in increasing
isentropic lift will mainly be west of the Blue Ridge.

Forcing from the dynamic trough and strong wind fields will
overspread the area Sunday. An associated band of showers will
slowly move across the area, as steering flow and shear vectors will
be nearly parallel. This could lead to some moderate to heavy
rainfall rates, although there are signals in much of the
guidance of broken bands which could result in stripes of higher
(greater than 1 inch) and lower (less than a quarter inch)
totals. Given recent dry conditions, the flooding threat will be
minimal besides poor drainage issues. While the instability and
resultant thunderstorm potential remain uncertain, it won`t
take much to mix down damaging winds, and the entire forecast
area is in a Slight severe risk. Before the showers arrive,
gradient winds could increase to 30-45 mph, especially west of
the stabilizing influence of the cooler Chesapeake. The
potential for Wind Advisories is highest in the higher terrain,
as the difficulty mixing down winds in warm advection adds
uncertainty (in addition to uncertainty of the mixing depth).
The front will eventually push east Sunday night. However, some
showers could linger behind the front due to the lagging upper
trough. Any upslope precipitation that persists toward dawn may
change over to snow, although accumulation would be minimal.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Shower activity is quickly expected to come to an end Monday morning
as the cold front pushes east of the area. A weak area of surface
high pressure passes through the region into Tuesday, before washing
out by mid week. This allows southerly flow to return and
temperatures to warm each day. Aloft, weak mid-level ridging builds
in and persists through Wednesday that keeps the region dry. Highs
in the 50s to low 60s Monday reach the mid to upper 70s on
Wednesday. Overnight lows also steadily warm through the week, going
from 30s Monday night to 50s for Wednesday night. Models indicate
the next chance for showers could be on Thursday when another strong
upper trough and associated cold front move across the region.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
The area remains between a stalled front to the south and high
pressure to the northeast, resulting in continued easterly
winds. MVFR stratus has moved into the BWI-DCA corridor but is
moving westward much more slowly than yesterday morning, likely
owing to lighter winds. Patchy fog is developing to the west of
the clouds. All TAF sites will likely be affected by either
stratus or fog this morning, although MRB and CHO will be near
the edge of the clouds. While IFR is probable, it is not
definite. The lowest chance is at MTN where low level air is a
bit drier. There is pretty good agreement that clouds mix out
between 14-18Z today, with VFR conditions likely into the
evening.

There is a strong signal for IFR to LIFR conditions developing
tonight into Saturday morning, primarily in the form of
ceilings. MRB and CHO have the highest chance of fog. These
clouds should gradually lift Saturday as the front lifts north,
although there is uncertainty how quickly it does so. In the
front`s wake, southerly winds will steadily increase through
Saturday night, with 20-25 kt gusts possible. If winds are
lighter, LLWS could be an issue as a low level jet strengthens.
Sub-VFR ceilings may also return.

A strong cold front will approach Sunday. S-SW winds will
continue to increase with gusts 25-35 kt possible. A band of
showers and possible thunderstorms will cross, most likely
during the afternoon to early evening. Rain could be moderate to
heavy, and any thunderstorms could bring very strong winds.
Winds shift to the NW Sunday night, gusting to 20 kt.

VFR conditions are likely for the start of next week. Northwest
winds could gust around 20 knots Monday morning into Monday
afternoon, then diminish Monday night.

&&

.MARINE...
A stalled front will remain south of the area through Saturday
morning, resulting in light NE to SE winds. Patchy fog and
drizzle could reduce visibility Friday night into Saturday
morning.

The front will lift north Saturday, but may not clear the area
until evening. While advisory conditions will eventually become
likely, it may not occur until the overnight hours as warm air
over cooler waters will limit gusty winds from mixing to the
surface.

Small Craft Advisory winds are likely on Sunday ahead of a frontal
passage in strong SW flow. Winds may approach gale force, with
the highest (though still uncertain) chance of this occurring
on the middle and upper Potomac. The cool bay waters will likely
keep the atmosphere more stable, and this is apparent in model
wind forecasts. As showers and possible thunderstorms move
across the waters Sunday afternoon and evening, Special Marine
Warnings may be needed due to the threat of strong winds. The
associated cold front will move through Sunday night, with
advisory conditions likely continuing.

Northwest winds are likely to increase to SCA levels Monday morning
behind a cold frontal passage. Frequent gusts of around 20 knots are
possible across all the waters through Monday afternoon. Winds
diminish Monday night and turn south Tuesday at around 10 knots.

&&

.FIRE WEATHER...
Although some locations in the Potomac Highlands could have
humidity briefly dip below 40 percent this afternoon, winds will
be light. Most of the area will remain in a marine-influenced
airmass with higher humidity through Saturday. Then a widespread
wetting rain is likely Sunday, although there are some
indications of stripes of higher (more than an inch) vs. lower
(less than a quarter inch) totals.

The potential for hazardous fire weather conditions Monday to
Wednesday next week will be directly correlated to rainfall
received from the weekend storm system since dry and breezy
weather will return. Wednesday will be the warmest day with the
lowest humidity, so conditions will need to be monitored.

&&

.TIDES/COASTAL FLOODING...
Winds begin to turn onshore later today, then become southerly
tonight through Sunday afternoon. A strong cold front sweeps through
the area Sunday evening and turns winds offshore Sunday night.
Beforehand, the strongest period of southerly channeling will occur
Saturday night into Sunday. Tidal anomalies are forecast to quickly
rise, leading to minor flooding at sensitive locations such as
Annapolis and Havre de Grace during the Sunday morning and Sunday
evening high tide cycles. Other locations, including Baltimore and
Washington DC SW Waterfront could approach minor flood as well. All
locations are likely to reach Action Stage this weekend.

&&

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

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...ADS
LONG TERM...KRR
AVIATION...ADS/KRR
MARINE...ADS/KRR
FIRE WEATHER...ADS
TIDES/COASTAL FLOODING...KRR