004
FXUS61 KLWX 101439
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1039 AM EDT Wed Jun 10 2026
.WHAT HAS CHANGED...
The next round of heavy showers and embedded strong to severe
thunderstorms will be arriving between 11am and 2pm for areas
west of the Blue Ridge and from 2pm to 6pm east of the Blue
Ridge to the Chesapeake Bay.
&&
.KEY MESSAGES...
- 1) Hot and humid conditions return through Friday with a
daily threat for strong to severe thunderstorms.
- 2) Drier conditions expected to start this weekend, before
chances for showers and storms return by early next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Hot and humid conditions return through Friday
with a daily threat for strong to severe thunderstorms.
A subtle shortwave will approach during the afternoon. Current
CAPE values are in the 1500 J/kg realm east of the Alleghenies
to the Shenandoah Valley with 20-30 knots of wind shear. The
next area of heavy showers and strong thunderstorms will be
crossing the Alleghenies in the next hour or so and result in an
active afternoon for most from west to east. Damaging winds and
hail could occur with strong to severe thunderstorms. Heavy
downpours also may be imminent as precipitable water is in the
1.7 to 2 inch range west of the metros.
Low-level southwesterly flow will continue to advect a hot and
humid airmass into the area for Thursday and Friday, with
temperatures climbing into the 90s and dewpoints reaching into
the upper 60s and lower 70s. This will result in heat indices
climbing into the upper 90s to low 100s on both Thursday and
Friday afternoon, likely nearing Heat Advisory criteria in some
locations. Westerly downsloping winds may tend to lower dew
points during peak heating, however.
Upper-level ridging will be centered over the Ohio/Tennessee
Valleys Thursday, with several models also showing a shortwave
disturbance passing through the top of the ridge. How this
disturbance evolves will have a large impact on our forecast
locally. If the timing/placement of any such disturbance is
offset from peak heating, large scale subsidence could limit
convective initiation. However, if it were to approach at/near
peak heating, we could have a much greater coverage of
thunderstorms. Upstream convection will likely have a large
impact on how that disturbance evolves, so confidence in the
forecast details on Thursday is lower than normal. Westerly
downslope flow could inhibit convection as well, with the best
initiation point closer to a surface trough or the bay breeze
(I-95 corridor). What models are in good agreement about is that
the background environment will be highly unstable. There will
also be enough dry air in the mid levels to support strong
downdrafts (high DCAPE), and just enough shear (around 20 kt)
to give storms some weak organization. Such an environmental
setup is common in many of our more impactful summer
pulse/multicell severe thunderstorm events. As a result, there
appears to be a conditional threat for severe thunderstorms on
Thursday, some of which could produce very strong winds if they
do indeed develop and tap into the background environment.
That threat for severe thunderstorms likely continues on Friday
as a shortwave disturbance passes to our northwest through the
Great Lakes causing the upper ridge to break down and a surface
cold front to approach from the northwest. With greater synoptic
scale forcing, confidence in the occurrence of storms is higher
on Friday, but instability might be slightly less (but still
moderately strong). More widespread and potentially organized
strong to severe thunderstorms appear possible as a result.
Machine learning guidance is very bullish on the severe
thunderstorm threat for both Thursday and Friday. We will
continue to monitor this potential threat over the upcoming
days. Stay tuned to later forecast updates.
KEY MESSAGE 2...Drier conditions expected to start this weekend,
before chances for showers and storms return by early next week.
Drier air moves into the region on Saturday in the wake of a cold
front bringing down heat risk overall as dewpoints drop back
down to the upper 50s and low 60s. Temperatures will still
remain elevated overall with highs in the upper 80s and lower
90s likely.
Upper-level zonal flow temporarily takes over through the
weekend, although a few afternoon showers or thunderstorms
can`t be ruled out Sunday as a cold front approaches from the
west. There is uncertainty in exactly when this front gets here.
Starting early next week, a deep upper-level trough starts to
track through the Great Lakes region and towards the East Coast,
bringing back elevated humidity as a strong cold front moves
through the region. Surface low pressure will likely move
through the Mid-Atlantic by Tuesday/Wednesday, bringing more
chances for widespread showers and possibly thunderstorms.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
A disturbance will bring another round of scattered showers and
thunderstorms during the afternoon. Otherwise, SW flow is
expected through the day, generally 10 kt or less.
Some patchy fog may develop tonight in areas that receive more
appreciable rain and see some clearing/lighter winds.
Prevailing VFR conditions are expected on both Thursday and
Friday. Thunderstorm initiation/coverage is very uncertain
Thursday afternoon and evening, but any storm could contain hail
and strong wind gusts. There is a higher chance of strong to
severe thunderstorms Friday afternoon and evening as a cold
front approaches. Winds will be fairly light out of the west or
southwest both days.
VFR conditions are predominantly expected through the weekend,
with some reduced conditions possible on Sunday evening
associated with a low chance of showers and thunderstorms.
Winds flow out of the NW before shifting S Sunday.
&&
.MARINE...
Southerly flow remains in place through this evening. Small
Craft Advisories may need to be extended/reissued in somewhat
marginal but stubborn southerly channeling through tonight. The
next round of showers and intense thunderstorms will move into
the waters later in the mid to later afternoon. Activity should
clear the waters early this evening. SMWs may be needed, mainly
this afternoon.
Sub-SCA level winds are expected on both Thursday and Friday. A
surface pressure trough lingering near the waters may cause some
variability between south and west. Special Marine Warnings may
be needed on both Thursday and Friday afternoon/evening as
thunderstorms move over the waters. There is a higher chance of
more widespread storms Friday, but the overall environment is
favorable for very gusty storms either day.
SCA conditions are possible in the wake of a cold front Friday
night into Saturday morning. Otherwise, sub-SCA conditions are
expected through most of the weekend. Marginal SCAs may occur
late Sunday in southerly flow as a cold front approaches.
Northwest winds may become variable for a time before ultimately
shifting southeast by Monday morning.
&&
.CLIMATE...
Temperatures are expected to soar to as much as 15 to 20 degrees
above average Thursday and Friday. This approaches or exceeds
daily record values at some sites.
Below is a list of record daily high and warm low temperatures
for June 11th and 12th (Thursday and Friday).
=================================================================
June 11th Record Daily Highs and Warm Lows
=================================================================
Site Record High Record Warm Low
DCA 101 F (set in 1911) 74 F (set in 2020 +6 others)
IAD 95 F (set in 2016) 72 F (set in 2005)
BWI 99 F (set in 1911) 75 F (set in 1914)
DMH 100 F (set in 1984) 79 F (set in 1984)
NAK 96 F (set in 2000) 79 F (set in 1973)
HGR 97 F (set in 1911) 73 F (set in 2005)
MRB 101 F (set in 1911) 71 F (set in 1927 and 1922)
CHO 99 F (set in 1911) 76 F (set in 2020)
=================================================================
June 12th Record Daily Highs and Warm Lows
=================================================================
Site Record High Record Warm Low
DCA 95 F (set in 2017 +6 others) 77 F (set in 2015)
IAD 96 F (set in 1986) 72 F (set in 1986)
BWI 96 F (set in 1986 and 1914) 77 F (set in 1947)
DMH 96 F (set in 2025 +2 others) 77 F (set in 2017 and 2015)
NAK 98 F (set in 1914) 77 F (set in 2000 and 1973)
HGR 92 F (set in 2017 +5 others) 71 F (set in 2010 +5 others)
MRB 97 F (set in 1938 and 1933) 73 F (set in 1914)
CHO 98 F (set in 1914) 72 F (set in 1947 +2 others)
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 8 PM EDT this evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
ANZ530>543.
&&
$$
DISCUSSION...BRO/KLW/DHOF/KJP
AVIATION...BRO/KLW/DHOF/KJP
MARINE...BRO/KLW/DHOF/KJP
NWS LWX Office Area Forecast Discussion