Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

229
FXUS61 KLWX 140553
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
153 AM EDT Tue Jul 14 2026

.WHAT HAS CHANGED...
Lowered Tds in coordination with adjacent WFOs through Thu
yielding slightly lower heat index values. Still hot.

&&

.KEY MESSAGES...
1) Increasing heat for midweek with heat likely peaking
Wednesday.

2) Uncertainty remains with how long the high heat persists and
potential for severe t-storms Fri into the weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...Increasing heat for mid week with heat likely peaking
Wednesday.

Upper ridge expands ewrd into the Mid-Atlantic by midweek
bringing an anomalously hot airmass to the area. 00Z suite continues
to show the potential for 850 mb temps near 25C. Following old
rule of adding 10C, shows potential of around 35C max sfc temps
Wed aftn. Difference for this heat spell is the source region
is continental in nature. This will result in potentially higher
MaxTs, but also less humid with more of a w`ly sfc component
rather a s`ly component. Coordinated with neighboring WFOs to
lower Tds through Thu given upcoming pattern and known issues
with NBM Tds. Best chance for advisory criteria is on Wed, as
Thu has trended cooler (talking a couple degrees). There is also
a very low chance of isolated t-storms Thu, while today and Wed
the chance of t-storms looks to be zero.

KEY MESSAGE 2...Forecast confidence decreases substantially late this
week into the upcoming weekend, but the potential is there for both
extreme heat and severe thunderstorms.

Not too much of a change in the overall synoptic pattern as lw
trofing dominates. This sets up a NW flow pattern given the
trough in the Pacific NW and Interior Northeast along with the
broadened ridge over the central U.S. As a result, there remains
considerable discrepancies amongst long range model guidance in
regards to the timing of sw disturbances which lower confidence
in regards to temps and the potential for severe t-storms
heading into the weekend period. Ensemble guidance has members
showing highs anywhere from the upper 70s to the mid 100s each
day Fri through Sun, with above average spread on Thu as well
(mid 80s to mid 100s). So depending on which solution verifies,
we could have anywhere from well below normal temps to record
highs each day. That, in turn, will have impacts on severe
t-storm potential each day.

Right now, the highest chances for t-storms (some severe)
appears to be this weekend as a more potent shortwave drops
south from the Great Lakes within NW flow. Some spread still
remains amongst 18z/00z guidance in respect to where this system
will track and where the associated cold frontal boundary ends
up as it pushes through the region. Most model solutions have
substantial height falls during this period which should lead to
higher t-storm coverage Sat and potentially Sun as well. As for
Thu and Fri, the risk for t-storms and severe wx is lower, but
not zero. SW disturbances should pass to the north given a W to
NW flow pattern aloft and at the surface. This will lead to
downsloping east of the mtns which will keep convection isolated
a relegated to either the terrain or bay/river breeze.

Any storms that we do see will likely be strong to severe given
the hot and humid airmass in place. Damaging wind gusts in
excess of 60 mph and isolated lager hail cannot be ruled out.
This aligns with current SPC Day 4-8 outlooks and CSU/NSSL/CIPS
suggest a 5 to 20 percent probs of severe wx during the weekend
period. Uncertainty continues beyond Sun given the placement of
the front. Some pieces of guidance have the front bisecting the
region Sun into Mon while others force it south of the region.
There are also some indication of an area of low pressure that
look to form along the boundary Mon as it pushes offshore. This
will be something to monitor leading to lingering chances for
showers and t-storms along with potential severe wx during the
back half of the extended period.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Fog is most likely at CHO late tonight through sunrise. IFR
vsby are possible. Brief vsby reductions are possible at MRB as
well, but confidence is too low to include in the TAF.

VFR through Thu into upcoming weekend. SHRA or TSRA possible
each afternoon and evening with the greatest opportunity for
restrictions this weekend. Winds will remain light out of the
west and northwest with speeds less than 15 kts.

&&

.MARINE...
Winds remain below SCA levels this morning. S`ly channeling
could result in SCA gusts this afternoon/evening, but given
short duration/threshold nature leaning MWS.

Sub-SCA level nw`ly winds are expected Thu and Fri. SMWs may
be needed on Thu or Fri if t-storms move over the waters. More
widespread t-storm activity and the need for SMWS will be needed
over the weekend as a cold front sags into the region. S`ly
channeling also returns to portions of the waters Sat into Sun.

&&

.TIDES/COASTAL FLOODING...
Onshore to S/SE`ly flow continues through midweek, keeping
tidal levels elevated. The upcoming new moon is also
accentuating the tide cycle. Minor coastal flooding seems likely
along low lying areas of Anne Arundel County including City of
Annapolis tonight. A Coastal Flood Advisory has been issued.

Guidance does indicate gradually declining anomalies through mid
week, but Annapolis in particular may require another day of
advisories on the astronomically higher tide.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 8 AM EDT this morning for MDZ014.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...CPB/EST
AVIATION...CPB/EST
MARINE...CPB/EST