Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

290
FXUS61 KLWX 301730
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
130 PM EDT Thu Jul 30 2026

.WHAT HAS CHANGED...
Only small touch-ups have been made to the afternoon forecast.
Timing for showers this weekend has been delayed slightly.

&&

.KEY MESSAGES...
- 1) Increasing shower and thunderstorm chances Sunday through
  early next week as low pressure and a series of fronts cross
  the region.

- 2) Primarily dry conditions through Saturday.

&&

.DISCUSSION...
KEY MESSAGE 1...Increasing shower and thunderstorm chances
Sunday through early next week as low pressure and a series of
fronts cross the region.

Back toward the typical summertime regime Sunday into the first half
of next week with daily chances for showers and thunderstorms. The
greatest coverage of showers and thunderstorms appears to be Sunday
into Monday as a potent upper level trough ejects eastward from the
Great Lakes into the Ohio River Valley. The incumbent upper level
trough looks to be pinched off as it dives south and east yielding a
cut low pressure system which looks to cross the area late Sunday
into Monday. The cutoff low and associated cold front will bring
widespread shower and thunderstorm chances to the region both days
along with abundant cloud cover. Shear and instability values look
to remain low due to weak winds aloft and widespread cloudiness.
Even with that said, GoogleWxNext2 and NSSL probabilities have 10 to
30 percent contours over the region during the Sunday and Monday
timeframe. This will be dictated by the placement and timing of the
low/associated front as it crosses the region. Moisture will be
ample ahead of the boundary on southerly flow although instability
will be lacking with modeled CAPE values less than a few hundred
j/kg given the extra cloud cover and timing of the system beyond the
peak heating window.

Beneficial rainfall is likely given the coverage of showers and
thunderstorms. Overall looking at half an inch to one inch of rain
Sunday through the middle of next week. Locally higher totals are
possible under heavier thunderstorms and across portions of the
Alleghenies/Shenandoah Valley where the low looks to track through.
The flooding threat remains lo, but not zero given repetitive rounds
of thunderstorms (especially over urban/poor drainage areas).

Beyond Monday, diurnal chances for showers and thunderstorms look to
continue as the front stalls near or just south of the area. The
next cold front and upper level trough will follow with another
round of widespread thunderstorm chances later in the workweek. High
temperatures will remain at or just above normal through the period.
Sunday and Monday look to be the coolest with highs in the upper 70s
and mid 80s. Highs get back close to 90 Tuesday through Thursday
next week. Overnight lows will fall back into the mid to upper
60s.

KEY MESSAGE 2...Primarily dry conditions through Saturday.

Upper level low pressure is spinning over southern New England
today, while a surface low moves off Cape Cod. The gradient
between this low and high pressure in the Great Lakes/Ohio
Valley is resulting in another day of gusty northwest winds.
Water vapor imagery is showing deeper moisture with the upper
low is pulling to the east. Even so, some models still show
another spoke of energy rotating southward this afternoon and
evening, perhaps producing a few showers across northeastern
Maryland. The current forecast is dry, and am not convinced
there is a high enough chance of rain to add it to the forecast.
RH forecasts do suggest cumulus or altocumulus clouds may
increase across the northeastern quadrant of the CWA this
afternoon. Temperatures will remain seasonable or slightly below
normal through tonight, when lighter winds may allow rural
areas to decouple. Highs this afternoon are generally in the
80s, with lows tonight from the mid 50s to mid 60s (perhaps
locally even cooler in the higher elevations).

The surface high will reach the area Friday. Shortwave ridging
will approach from the west as the upper low departs New England.
Dry conditions are expected with high temperatures closer to
climatology in the mid 80s to near 90 and lows in the 60s to
around 70.

Temperatures may warm a couple more degrees Saturday as the high
moves off the coast and increasing southerly flow develops.
Clouds will likely start increasing as low pressure at the
surface and aloft moves into the Ohio Valley. There is some
uncertainty with how quickly rain chances arrive. Some showers
could reach the Alleghenies as early as Saturday afternoon, but
recent trends are suggesting it will be delayed until Saturday
night. Much of the area, especially east of the Blue Ridge, may
remain dry until Sunday.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR conditions are expected through the TAF period. Northwest
winds will gust 20 to 25 kt through this afternoon (lighter at
CHO). Broken cumulus or altocumulus may affect all the TAF sites
except CHO this afternoon. Winds will diminish with sunset and
remain light through Friday as high pressure moves overhead.

Southerly flow may become gusty Saturday afternoon. Showers
along with sub-VFR ceilings may reach CHO and MRB late Saturday
night, but confidence is low.

More widespread sub-VFR conditions are expected Sunday as showers
and thunderstorms return to the terminals due to a front crossing
the region. The severe weather threat appears low, but not zero at
this time. Expect temporary restrictions at times due to
thunderstorms. Gusts will remain out of the south/southeast at less
than 20 kts.

Expect sub-VFR conditions to continue at times Monday as the front
and low pressure system slowly exit the region. The front will stall
nearby or just to the south of the region Tuesday and Wednesday
keeping temporary restrictions in place, especially at terminals
south of the corridor. Winds will blow out of the northeast Monday
before becoming light and variable midweek.

&&

.MARINE...
Northwest winds gusts of 20 to 25 knots are occurring today
with Small Craft Advisories in effect now for all waters until 6
PM. Winds should diminish this evening and remain light Friday
as high pressure moves overhead. On Saturday, wind shifts to
southerly with advisories likely by afternoon.

SCA conditions are likely to continue Sunday with showers and
thunderstorms leading to potential SMWs Sunday afternoon and
evening. Sub-SCA level winds return Monday through Wednesday next
week.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies remain steady through the end of the week with
sensitive tidal locations remaining in Action stage during the
high tide cycles. This weekend, tidal anomalies rise with
southerly winds. Annapolis is forecast to approach Minor flood
stage as early as Saturday morning.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 6 PM EDT this evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ530>543.

&&

$$

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