573
FXUS61 KLWX 221356
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
956 AM EDT Mon Jun 22 2026
.WHAT HAS CHANGED...
No changes were made to the forecast. We continue to monitor the
threat for severe weather this afternoon and into the evening
with current visible satellite showing clouds tracking east
across the Blue Ridge. Will monitor over the next few hours to
see how the cloud debris impacts instability development for
this afternoon.
&&
.KEY MESSAGES...
- 1) Strong to severe thunderstorms along with locally heavy
rainfall possible this afternoon into early this evening.
- 2) After a mid-week dry spell, daily thunderstorm chances will
return late in the week, possibly into the weekend.
&&
.DISCUSSION...
KEY MESSAGE 1...Strong to severe thunderstorms along with
locally heavy rainfall possible this afternoon into early this
evening.
A low pressure system is forecast to track from the Ohio River
Valley northeastward across Pennsylvania today with the
associated warm front lifting north across the region throughout
the day. This will bring the next chance of severe weather to
the region, with the Storm Prediction Center having most of the
forecast area in a Slight Risk for severe thunderstorms.
Guidance is coming into better agreement that an initial round
of storms will form along a pre-frontal trough during the early
afternoon hours and then move across the forecast area from
west to east. This round of storms should press off to the east
of the area by the early evening hours. Some guidance shows
additional storms developing behind this initial activity, while
other solutions show little redevelopment after the initial
round. If the second round of storms were to occur, they would
likely move through during the evening to early overnight hours,
with most storms winding down by around 1 AM or so.
With southerly flow, a warm and moist airmass is expected
leading to adequate instability. Additionally, winds will
increase aloft, leading to 30-50 knots of effective bulk shear.
The combination of instability and shear leads to a risk of
organized storms, some of which could be supercells. Damaging
wind gusts appear to be the primary threat, but a brief tornado
can`t be completely ruled out.
While storm motion is expected to be progressive, PWATS nearing
and/or exceeding 2 inches will lead to locally heavy rainfall within
the strongest storms. In addition, some models are showing the
potential for two rounds of thunderstorms in the afternoon and
evening. The Weather Prediction Center has most of the area in a
Slight Risk for excessive rainfall with scattered instances of
flooding possible. The threat for flooding seems to be highest
across the Northeast U.S. and see no reason to issue a Flood
Watch.
KEY MESSAGE 2...After a mid-week dry spell, daily thunderstorm
chances will return late in the week, possibly into the weekend.
Tranquil weather is expected on Wednesday behind the early week
frontal passage. This will provide seasonable temperatures with low
humidity levels. Forecast highs are in the low/mid 80s (upper 60s to
70s across mountain locales), with dew points holding steady in the
50s. The reprieve from the summer heat and humidity likely comes to
an end in response to a slow moving upper trough approaching from
the Great Lakes.
There is decent agreement among the global ensemble systems in
bringing this trough from the Upper Midwest toward the Great Lakes
on Wednesday through Friday. As this occurs, winds shift from
northwesterly over to south-southeasterly which aids in ample
moistening of the column. This eventually lends itself to increasing
chances for daily showers and thunderstorms. Based on the frontal
progression, the system is to push from the Missouri Valley/Upper
Great Lakes on Wednesday over to the Ohio Valley by Friday. This
would suggest the main opportunity for storm chances would occur on
Thursday and Friday before a potential frontal passage. Given
uncertainty in the position/strength of the upper trough, timing a
cold frontal passage this far out is of lower confidence.
During the mid to late week period, expect seasonable temperatures
with daily highs in the mid/upper 80s (mountains in the 70s to low
80s). On the contrary, forecast lows are bit below climatology with
widespread low/mid 60s expected, locally a bit cooler across the
higher terrain.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
Showers and thunderstorms are expected this afternoon and
evening with flight restrictions likely. Outside of storms,
southerly winds could gust to 25 kt.
There may be some lingering showers Tuesday depending on how quickly
the cold front moves through. Northwest winds may gust to 20 kt
Tuesday. Wednesday will likely be dry. Thunderstorms are possible
again on Thursday (especially CHO and MRB) and Friday
(areawide).
&&
.MARINE...
Winds have shifted to the south with a Small Craft Advisory in
effect from 9AM to 6PM. SCAs were extended through mid evening
and new ones were issued for Tuesday. Additionally, showers and
thunderstorms are expected across the waters this afternoon and
evening with SMWs likely needed.
Northwest winds behind a cold front may result in marginal
advisory conditions on Tuesday. Light winds are expected
Wednesday under high pressure. Small Craft Advisories may be
needed Thursday afternoon into Thursday night in southerly flow.
The next upper level disturbance could bring more thunderstorms
Thursday and Friday afternoon and evening.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 10 PM EDT this evening for MDZ008.
Small Craft Advisory from 2 PM to 6 PM EDT Tuesday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ530-
537-538-542.
Small Craft Advisory from 2 PM to 6 PM EDT Tuesday for
ANZ530>534-537>541-543.
Small Craft Advisory until 2 AM EDT Tuesday for ANZ531>534-
539>541-543.
Small Craft Advisory until 6 PM EDT this evening for ANZ535-
536.
&&
$$
DISCUSSION...ADS/AVS/LFR/BRO
AVIATION...ADS/LFR/BRO
MARINE...ADS/LFR/BRO
NWS LWX Office Area Forecast Discussion