572
FXUS61 KLWX 180653
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
253 AM EDT Thu Jun 18 2026
.WHAT HAS CHANGED...
...UPDATED discussion for late Sunday through the middle of
next week...
Weak energy in the mid-levels of the atmosphere has
spawned a few batches of showers across Maryland, northeastern
West Virginia and northern Virginia. No thunder with this
activity as it quickly moves to the east.
&&
.KEY MESSAGES...
- 1) Hotter conditions return today with potential for severe
thunderstorms and strong gradient winds.
- 2) A strong low pressure system could bring the threat for
heavy rainfall and thunderstorms late Sunday through Monday.
- 3) An active upper-level pattern could bring continued rain
chances through mid-week.
&&
.DISCUSSION...
KEY MESSAGE 1...Hotter conditions return today with potential
for severe thunderstorms and strong gradient winds.
As ripples of energy in the mid-levels move east across our
northern zones early this morning, some rain showers will bring
some much needed rain to parts of the region through daybreak.
Most of these showers have occurred or are expected to occur
across the northern half of the Alleghenies, western and central
Maryland, northeastern West Virginia, and northwestern Virginia.
A cold front will drag across the region throughout the rest of
today through early Friday. Hotter temperatures than yesterday
expected this afternoon with highs in the middle 70s to middle
80s west of the Blue Ridge and highs in the lower to middle 90s
east of the Blue Ridge. Heat index values in the mid 90s to
perhaps near 100 expected. This heat, combined with effects
from increasing humidity and wind shear in all levels could
spawn some strong to severe thunderstorms across most of our
region. There is some uncertainty as to the area extent of such
strong to severe thunderstorms given the most recent nighttime
convection, cloud cover, and expected slightly cooler
temperatures in the aforementioned zones of our northwestern
third of our region. Otherwise, all other areas may be more
prone to such strong convection this afternoon into early
evening.
Timing of strong to severe thunderstorms seem more probable
late morning to mid-afternoon in the northwest and north-central
areas, while the afternoon hours seem more legitimate farther
east and southeast into the metros and northern half of
Virginia. The southeastern zones, including southern Maryland
would be more probable later this afternoon and early evening.
The main threats will be damaging wind gusts over 55 mph and
large hail. Lightning may also become a big factor with the
strongest thunderstorms. Not only will damaging winds be
anticipated in strong to severe thunderstorms, but also from a
synoptic or gradient viewpoint as well. Winds just above the
boundary layer are very strong due to a low-level jet. A Wind
Advisory remains in effect throughout the Alleghenies, interior
western zones, and the northern Blue Ridge.
The cold front will push southward Thursday night. The front
will absorb an area of low pressure to the south, likely
originating from Arthur. There is still some spread with how far
north additional rain reaches, but some rain chances will
linger across the southern half of the area in particular
through Friday morning. Skies should clear through the day with
lowering humidity and seasonable temperatures.
KEY MESSAGE 2...A strong low pressure system could bring the threat
for heavy rainfall and thunderstorms late Sunday through Monday.
After a mainly quiet weekend across the region, there is an
increasing signal of active weather returning late Sunday into
Monday. Looking aloft first, the key players are a compact upper low
dropping southeastward from the Great Lakes as well as an open wave
ejecting eastward from the Ohio Valley. The combination of these
features will fuel increasing lift across the Mid-Atlantic region.
While the accompanying surface low is more modest in nature compared
to the one today/Thursday, it still may feature a 1000-mb surface
pressure. Ensemble spread is notable as this low tracks across the
Ohio Valley toward the Mason-Dixon Line. Where this low tracks and
how quickly the warm sector crosses the local area will drive the
degree of instability in the atmosphere. One aspect of the forecast
that does appear a bit more certain is anomalous moisture tracking
up the Eastern Seaboard on Monday. The heavy rainfall signal is
certainly non-zero, but still bears watching as models continue to
resolve the more complex details.
KEY MESSAGE 3...An active upper-level pattern could bring continued
rain chances through mid-week.
As the early week system drives a cold front offshore early Tuesday,
there is a loose ensemble signal of additional unsettled conditions
through mid-week. Mid/upper heights begin to build across the Desert
Southwest into northwestern Mexico. At the same time, cyclonic flow
across south-central Canada begins to dig toward the Midwest and
northeastern U.S. Forcing from this trough could again increase
shower and thunderstorm chances across the region. At this point,
uncertainty is high across the board as shown by the low
probabilities for rainfall in the forecast. Temperatures appear
seasonable heading into mid-week with a gradual uptick in humidity
levels.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A southwest wind gradient increases this morning and could
exceed 30 knots at times. There is some uncertainty in
convection coverage given the overnight convection into early
this morning. This early convection could help to stabilize the
atmosphere most of the morning leading into the afternoon.
PROB30 groups have been used due to the combination of low
coverage and low confidence. MRB may largely miss out on the
potential for stronger storms, but the strongest could produce
severe gusts elsewhere. A second round of showers could affect
portions of the area tonight into Friday morning, but impacts
are uncertain. Skies should gradually clear Friday with gusty
northwest winds.
Gusty NW winds around 20-25 kts can be expected Saturday. While
VFR conditions are expected for much of Sunday, there is an
increasing signal of heavy rainfall and thunderstorms toward the
night and into Monday. Depending on how this plays out,
restrictions would become more likely. Initial winds on Sunday
begin out of the west-southwest before shifting over to
southeasterly by the evening/night. A return to westerlies is
expected for Monday with gusts increasing to around 15 to 20
knots.
&&
.MARINE...
Southwest winds are expected to increase through today. This
will provide an environment for Small Craft Advisories for
portions of the waters by late this afternoon and most waters
tonight. High end advisory conditions are likely today as
strong low pressure passes to the north. Gale Warnings are in
effect for the northern Chesapeake Bay. The strongest gusts
will be near the shore as air temperatures rise into the 90s.
Special Marine Warnings may be needed during the afternoon and
early evening as scattered strong to severe thunderstorms
potentially track over the waters.
There may be a bit of a break in the winds tonight as the front
slows down. Marginal Small Craft Advisories may be needed for
portions of the waters Friday in northwest flow.
Winds on Saturday will be out of the NW and near SCA criteria in the
wake of a secondary cold front. Winds will likely taper off
into Saturday evening as they gradually turn out of the south.
Sub-advisory level winds are expected for Sunday before hazardous
conditions return to the forecast on Monday. Increasing south to
southwesterly winds may lead to Small Craft Advisories across the
area waterways.
&&
.TIDES/COASTAL FLOODING...
An increasing southwesterly flow ahead of a cold front will
allow for anomalies to peak early this morning. Several
locations may experience minor tidal flooding this morning.
Advisories remain in effect for Annapolis and Havre de Grace,
where confidence is currently highest. Annapolis may even
approach moderate flood stage.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 9 AM EDT this morning for MDZ008.
Gale Warning from 9 AM this morning to 8 PM EDT this evening
for MDZ008.
Coastal Flood Advisory until 1 PM EDT this afternoon for
MDZ014.
Wind Advisory from 7 AM this morning to 6 PM EDT this evening
for MDZ501-502-509-510.
Coastal Flood Advisory from 10 AM this morning to 4 PM EDT
this afternoon for MDZ508.
VA...Wind Advisory from 7 AM this morning to 6 PM EDT this evening
for VAZ503-504-507.
WV...Wind Advisory from 7 AM this morning to 6 PM EDT this evening
for WVZ050-055-501>506.
MARINE...Small Craft Advisory until 9 AM EDT this morning for ANZ530-
531-535-538.
Gale Warning from 9 AM this morning to 8 PM EDT this evening
for ANZ530-531-535-538.
Small Craft Advisory until 8 PM EDT this evening for
ANZ532>534-536-537-539>543.
&&
$$
DISCUSSION...BRO/KLW
AVIATION...BRO/KLW
MARINE...BRO/KLW
NWS LWX Office Area Forecast Discussion