Area Forecast Discussion
Issued by NWS Sterling, VA

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505
FXUS61 KLWX 081909
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
309 PM EDT Wed May 8 2024

.SYNOPSIS...
A backdoor cold front will move into northern areas tonight
before stalling on Thursday. A second stronger cold front will
move across the area Thursday night. A third cold front will
move across the area early on Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...

Strengthening westerly flow has resulted in significant drying
today with sfc dewpoints having fallen from 66F this morning to
59F this past hour. Latest trends suggest that any convection
would develop over extreme southern areas, more likely in
Wakefied`s area late this afternoon or early in the evening. It
should remain quiet through midnight tonight. Overnight,
strengthening warm air and moisture advection will lead to
showers and possible thunderstorms across western areas
spreading northeast toward daybreak. The risk of severe wx
appears zero through 12Z Thursday.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...

Showers and perhaps thunderstorms should be ongoing Thu morning
driven by warm air and moisture advection atop a frontal zone.
Additional showers and thunderstorms are anticipated during the
afternoon and early evening driven by strengthening low-level
convergence and height falls from approaching upper level trough
from the NW. The severe risk for Thu has shifted considerably
south from previous days and will likely be tied to where
backdoor front is fcst to stall tomorrow or roughly I-64
corridor. All modes of severe wx appear possible, but the areal
coverage should be confined to areas around Charlottesville and
south of Fredericksburg.

More showers appear likely Friday as upper trough crosses the
area.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

Longwave troughing will persist over the Mid-Atlantic and
Northeast states through the weekend before pushing offshore
early next week. Saturday will start out dry in the wake of a
departing shortwave trough pushing offshore. Skies should trend
mostly sunny to mostly cloudy as the day progresses with the
bulk of the cloud cover especially for the VFR conditions are expected to prevail through the weekend at all
terminals. front half of the day confined to areas along and
west of the Blue Ridge. As one shortwave trough departs, another
will follow from the Ohio River Valley late Saturday night and
into the day Sunday.

Cloud cover will increase from west to east across the forecast area
late Saturday afternoon and into Sunday. Precipitation chances will
also increase as well with large scale ascent overspreading the
region. The bulk of any shower or thunderstorm activity Saturday
will mainly be confined along and west of the Blue Ridge during the
morning and afternoon hours. This activity will spread eastward with
time late Saturday into Sunday. Coverage will remain scattered
across the area both days with more numerous to widespread activity
Saturday night into Sunday as the upper trough axis passes overhead.
With the added cloud cover and west to northwesterly flow expect
weekend high temperatures in the upper 60s and low 70s. Low
temperatures will fall back into the upper 40s and low to mid 50s.

Rain chances finally decrease Monday as upper level troughing
progresses east of the region. High pressure will briefly build over
the region from the south before shifting offshore midweek. With the
high shifting offshore Tuesday expect diurnal chances for showers
and thunderstorms to return to the region. High temperatures Monday
will reach into the low to mid 70s with mid to upper 70s expected on
both Tuesday and Wednesday. Lows will remain in the upper 40s and
low to mid 50s.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...

MVFR cigs expected Thu with off and on showers. Severe threat
should be limited to areas around Charlottesville. More showers
Fri with low cigs again.

Passing showers and perhaps a thunderstorm could lead to sub-
VFR reductions mainly during the afternoon and evening hours
each day as multiple shortwave troughs pivot through. West to
southwest winds are expected Saturday before switching to the
northwest Sunday. Speeds will sit between 5 to 15 kts with gusts
10 to 20 kts at times. VFR conditions continue Monday and
Tuesday as brief high pressure sits overhead.

&&

.MARINE...

Possible SCA conditions all weekend, but winds and waves could
be higher near thunderstorms especially across southern waters.

Low end SCA level winds in west to southwest flow are expected
Saturday before turning toward the northwest Sunday. SCA level winds
will continue into Monday especially over the open waters of the bay
and tidal Potomac under southeasterly flow.

&&

.TIDES/COASTAL FLOODING...
Westerly winds should allow water levels to continue to decrease
this afternoon and evening. Southerly winds late tonight into
Thursday morning, will allow for the potential of additional minor
flooding at most sensitive locations (i.e Annapolis, Straits Point,
and DC Waterfront). Water levels will drop again late Thursday
morning into Thursday evening as the flow turns to the west and
eventually north/northeasterly direction. Additional minor flooding
is possible at these same locations late Thursday night into early
Friday morning as southwest flow returns. It`s not until Sunday is
when water levels should drop off with offshore northwest flow.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ530>532-535-536-538>540.

&&

$$

SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...LFR
LONG TERM...EST
AVIATION...LFR/EST
MARINE...LFR/EST