201
FXUS61 KLWX 060037
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
837 PM EDT Sun Jul 5 2026
.WHAT HAS CHANGED...
A Severe Thunderstorm Watch was issued for portions of the area
through 1 AM.
&&
.KEY MESSAGES...
- 1) A risk of a few severe thunderstorms and spotty flash
flooding exists through Monday.
- 2) Seasonable temperatures return mid to late week
despite continued chances for showers and thunderstorms.
&&
.DISCUSSION...
KEY MESSAGE 1...A risk of a few severe thunderstorms and spotty
flash flooding exists through Monday.
A messy storm mode on radar this evening with convection being
driven by outflow boundaries, mesoscale confluence (earlier
across central MD/northern VA), and large scale lift provided by
an approaching upper air ripple. The greatest combination of
CAPE and DCAPE has been found from the Blue Ridge to the
Chesapeake Bay, and more robust updrafts and downdrafts have
been noted in this area. Shear is relatively weak, so most
convection will be pulse in nature, but briefly more persistent
storms could form with favorable outflow interactions. A Severe
Thunderstorm Watch has been issued for a large part of the area
through 1 AM.
Localized heavy rain totals and flooding have already been
observed, but this may ultimately become the bigger concern as
the evening progresses as storms backbuild on outflows, and
multiple rounds of storms may eventually affect some areas. As
PWs increase to 2+ inches, very heavy rain rates could result in
flash flooding of urban areas and small streams. Earlier, the
Flood Watch was expanded to include north central Maryland and
the Washington DC metro area. 18Z CAMs and the experimental WoFS
all show localized QPF maxima in this general area, with
localized totals of 2 to 4 inches of rain possible (even up to 6
inches in some runs).
Later tonight, fog could develop in areas that clear.
For Monday, a slow moving frontal system accompanying the
stagnant upper trough will yield another day of active weather.
The better instability profiles begin to shift south of I-66
where the SPC features a Marginal Risk. Further, the Weather
Prediction Center has a Slight Risk for flash flooding from the
Blue Ridge eastward. Well above average precipitable water
values (1.75 to 2.25 inches) combined with repeated convection
and slow cell motions will aid in such a risk. Of course this
will also be driven by how much rainfall occurs over previous
days. Although the region remains in drought, this may only
limit flash flood potential for so long.
KEY MESSAGE 2...Seasonable temperatures return mid to late week
despite continued chances for showers and thunderstorms.
Temperatures get back to more seasonable levels Tuesday through the
upcoming weekend ahead. This is due largely in part to a cold front
sagging south of the region Tuesday and a secondary front to follow
within zonal flow Friday into the weekend. With a series of fronts
and modest impulses passing through mid-level flow, expect continued
chances for showers and thunderstorms mainly during the afternoon
and evening hours. As for severe weather, the threat is low, but
not zero. CSU, CIPS, NSSL, and Google WxNet AI/ML continue to
hold probabilities around 5 to 15 percent each afternoon and
evening. Something to continue to monitor on subsequent forecast
cycles given the non-descripte upper-level flow pattern.
High temperatures will remain the 80s (70s mountains) through
Wednesday with a warm up back into the low 90s east of the Blue
Ridge late in the week. Overnight lows each night will mainly range
from the 60s into the low 70s.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Specific details are of low confidence in the TAFs despite
storms already being on radar due to messy motions and
interactions. While earlier storms largely missed DCA and IAD,
am still carrying a TEMPO group as additional storms could move
in from the west in the coming hours. It`s also uncertain if
additional activity can make it to CHO and MRB. Highest
confidence of continuing impacts will be at BWI and MTN. Storms
will be capable of strong erratic outflow winds, very heavy rain
rates, and frequent lightning. By 11 PM or midnight, activity
should be winding down to just some lingering showers.
Tonight, a front will drop in from the north, shifting winds to
the northeast. Low clouds will likely form north of the
boundary, with MVFR to IFR conditions expected at most terminals
by morning. Some fog could also be in the mix depending how
thick and/or low the ceilings are. While low clouds are less
likely at CHO, fog may be more probable if skies can clear.
Conditions will likely return to VFR in the late morning to
early afternoon hours Monday.
Monday presents one more day of more widespread showers and
thunderstorms. This comes with a shift to mainly easterly flow
as a frontal system meanders about the area. Prevailing VFR
conditions are expected Tuesday through the remainder of the
week with winds out of the east/northeast through Wednesday
before turning back to the south and southwest Thursday into the
weekend. Showers and thunderstorms will be possible each
afternoon and evening yielding temporary restrictions.
&&
.MARINE...
While summertime synoptic gradients will limit the need for
Small Craft Advisories most of the time, daily convection and
the associated outflow boundaries should make for hazardous
marine conditions at times. One exception is that a Small
Craft Advisory has been issued around southern Maryland this
evening as flow briefly strengthens around a mesolow over the
northern neck of VA. Numerous showers and thunderstorms
expected each afternoon and evening through Monday. Thus,
Special Marine Warnings will be needed at times so boaters
should certainly plan for deteriorating conditions. Always have
multiple ways to receive weather alerts while out on the waters.
Thunderstorm chances decrease Tuesday into Wednesday as the front
pushes south of the region. An additional cold front is expected
Friday into the weekend allowing thunderstorm chances to increase
once again. Some SCA level southerly channeling is possible ahead of
the front Thursday into Friday.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch until 1 AM EDT Monday for DCZ001.
MD...Flood Watch until 1 AM EDT Monday for MDZ004>006-008-011-013-
014-503>508.
VA...Flood Watch until 1 AM EDT Monday for VAZ053-054-506.
WV...None.
MARINE...Flood Watch until 1 AM EDT Monday for ANZ530.
Small Craft Advisory until 11 PM EDT this evening for ANZ533-
534-537-542-543.
&&
$$
DISCUSSION...ADS/BRO/DHOF/EST
AVIATION...ADS/BRO/DHOF/EST
MARINE...ADS/BRO/DHOF/EST
NWS LWX Office Area Forecast Discussion