472
FXUS61 KLWX 091940
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
340 PM EDT Tue Jun 9 2026
.WHAT HAS CHANGED...
A Coastal Flood Advisory has been issued for Anne Arundel County
late tonight. Little has changed in the big picture forecast,
with the greatest uncertainties revolving around convective
initiation Thursday and precipitation timing early next week.
&&
.KEY MESSAGES...
- 1) Hot and humid conditions return Wednesday through Friday
with a daily threat for strong to severe thunderstorms.
- 2) Drier conditions expected this weekend, before chances for
showers and thunderstorms return early next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Hot and humid conditions return Wednesday
through Friday with a daily threat for strong to severe
thunderstorms.
Surface high pressure is moving off the east coast this
afternoon. Low level clouds have finally been scattering out,
allowing for some filtered sunshine to work through and boost
temperatures into the 80s. Dew points are gradually increasing
from west to east. An initial batch of precipitation moving into
the Appalachians seems to be based in the mid levels, with very
little reaching the ground. A more notable arc of convection
ahead of a shortwave trough extends from southern Ohio into
southwest Virginia, which will likely approach our western zones
during the late afternoon to early evening. Most guidance
indicates this activity will fizzle as it moves eastward and
encounters drier and more stable air.
A warm frontal zone will lift through the area tonight into
Wednesday morning as the shortwave aloft slowly traverses
eastward. A second round of showers and embedded thunderstorms
will likely spread east into the area after midnight on the nose
of a low level jet and deep moist advection. Severe weather is
not expected with weak, mainly elevated instability. Convection
could produce heavy rainfall rates as precipitable water values
approach 2 inches, but should have enough motion to preclude any
hydro issues.
There will likely be a break behind this activity during the
late morning/early afternoon hours, although some low level
clouds may be left behind. Another shortwave will approach
during the afternoon. While there is some uncertainty what the
recovery period will be like, there should be some heating of
the very humid airmass (highs likely well into the 80s if not
nearing 90 where there is more sun). Thus most guidance shows
another round of scattered showers and thunderstorms moving
across the area. Moderate instability and shear of 20 to perhaps
up to 30 kt could lead to a few stronger storms with gusty
winds and hail. SPC has the area highlighted in a Level
1/Marginal Risk. Heights will rise Wednesday night, resulting
in a minimum of rain chances, but it will remain muggy with lows
in the upper 60s and lower 70s.
Low-level southwesterly flow will continue to advect a very 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, large scale subsidence could limit convective initiation.
However, if it were to approach at 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 (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, currently highlight by and SPC
Marginal Risk.
That threat for severe thunderstorms may continue 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. SPC does have
parts of the area in a Day 4 15 percent severe risk. 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.
KEY MESSAGE 2...Drier conditions expected this weekend, before
chances for showers and thunderstorms return early next week.
In the wake of a cold frontal passage, much drier air will advect
into the area at lower to middle levels of the atmosphere by
Saturday, with dewpoints dropping to around 60 and precipitable
water values dropping to below one inch. With this drier airmass in
place, dry conditions are expected on Saturday. The drier weather
will likely persist through Sunday as well, although a stray
afternoon shower or storm can`t be completely ruled out.
Temperatures will still remain hot, with highs in the upper 80s and
lower 90s this weekend.
Forecast confidence decreases substantially heading into early next
week. There are some signs that low-level moisture may start to
return northward on Monday as height falls aloft associated with a
trough off to our northwest start to overspread the area. This
combination of increasing low-level moisture and cooling aloft may
lead to increased chances for afternoon showers and
thunderstorms.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected through this evening, with mid and
high level ceilings persisting. A few southerly gusts could
reach 20 kt this afternoon. A warm front will lift through the
area tonight into Wednesday. Some scattered showers will
approach late tonight/Wednesday morning. While embedded
thunderstorms are possible, the chance is currently too low to
include in the TAF. Briefly heavy rain rates could reduce
visibility though. Some MVFR ceilings are possible with the
showers, lingering into the midday hours. There will be a break
in the precipitation though. A second disturbance could bring
another round of scattered showers and thunderstorms during mid
afternoon to early evening, currently covered with a PROB30.
Otherwise southwest flow is expected through the day, generally
10 kt or less.
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 slightly greater 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.
Sub-SCA northwesterly winds are expected over the waters on
Saturday. Winds will shift to out of the south on Sunday, and could
potentially near low-end SCA levels at times.
&&
.MARINE...
Southerly flow remains in place through Wednesday, enhanced
tonight by channeling effects. While winds have been slow to
tick up, a Small Craft Advisory remains in effect for all waters
through this evening, tapering back to the main bay channel and
lower Potomac late tonight. The advisory tapers further by
midday Wednesday to the wider waters, although it`s possible
marginal advisory conditions could be a bit more widespread.
Such marginal conditions could persist over the bay into
Wednesday night. In addition, heavier showers and embedded
thunderstorms may reach the waters early Wednesday, with a
greater chance of thunderstorms developing Wednesday afternoon
into the early evening.
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.
VFR conditions are expected at the terminals this weekend. Winds
will generally be out of the northwest on Saturday, and out of the
south on Sunday.
&&
.TIDES/COASTAL FLOODING...
A period of southerly flow will result in rising tidal
anomalies through Wednesday. The typically more aggressive
guidance (CBOFS, SFAS) shows potential for solid minor flooding
at Annapolis, with minor flooding possible along other
vulnerable shoreline areas (Havre de Grace and Alexandria, for
example). This scenario is plausible given southerly flow
holding/pushing water northward into the bay. Despite the
favorable flow pattern, relatively lower astronomical tides due
to a third quarter/waning gibbous today and relatively modest
wind magnitudes should keep the threat for moderate tidal
flooding low. A Coastal Flood Advisory is in effect for
Annapolis late tonight. Additional locations will be monitored
for the latest trends.
As southerly winds relax Wednesday, it does appear there will be
enough of a drop in water levels to prevent additional flooding.
&&
.CLIMATE...
Temperatures are expected to soar to as much as 15 to 20 degrees
above normal 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 10 PM EDT this evening for MDZ008.
Coastal Flood Advisory from 11 PM this evening to 4 AM EDT
Wednesday for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ530-
535-536-538-542.
Small Craft Advisory until noon EDT Wednesday for ANZ531>533-
537-539>541.
Small Craft Advisory until 6 PM EDT Wednesday for ANZ534-543.
&&
$$
DISCUSSION...ADS/DHOF/KJP
AVIATION...ADS/DHOF/KJP
MARINE...ADS/DHOF/KJP
NWS LWX Office Area Forecast Discussion