736
FXUS61 KLWX 080915
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
515 AM EDT Mon Jun 8 2026
.WHAT HAS CHANGED...
Updated aviation discussion regarding approaching low clouds.
&&
.KEY MESSAGES...
- 1) High pressure brings mainly dry weather and near normal
temperatures early this week before drifting offshore.
- 2) Hot, humid conditions and scattered thunderstorms return
late this week.
&&
.DISCUSSION...
KEY MESSAGE 1...High pressure brings mainly dry weather and
near normal temperatures early this week before drifting
offshore.
Early morning analysis shows the weekend`s cold front steadily
pushing southward through the Carolinas as strong late season
high pressure builds into northern New England. This area of
high pressure will drop southward to a position along the Mid-
Atlantic coast through Tuesday. Despite onshore flow around the
high, the source region is dry which will keep humidity modest
through tonight; dew points actually drop through the 50s as
temperatures hover near to slightly below normal.
As the high drifts offshore Tuesday, heights aloft will begin to
fall a bit especially further west. This coupled with increasing
heat, humidity, and orographic effects may result in showers and
thunderstorms popping up near and west of the Appalachians by
Tuesday afternoon. Most of this activity should weaken with the
loss of daytime heating as it presses eastward toward I-81, but
the 00Z NAM has enough warm/moist advection associated with an
approaching warm front to keep activity going as it moves east
through the night across the rest of the area. This is an
outlier solution at this time, but can`t be completely discarded
given the presence of the approaching warm front.
Higher chances for showers and thunderstorms spread across the
area Wednesday as the high drifts further away and a warm front
lifts across. The increase in heat and humidity could lead to
locally stronger storms especially given the presence of the
warm front. We will have to watch for any glancing effects from
upstream waves emanating from convection over the middle of the
country as well, as this could result in more numerous and
potentially slightly more organized/stronger storms.
KEY MESSAGE 2...Hot, humid conditions and scattered thunderstorms
return late this week.
Surface high over the southwest Atlantic continues to drift well
offshore through the end of this week. In its wake, low-level
southwesterly flow advects tropical moisture into the Mid-Atlantic.
Aloft, mid-level ridging builds over the region Thursday and
Friday, though some guidance does show a fast-moving shortwave
traversing the ridge axis. Thursday and Friday are likely to
bring true summer conditions as highs reach the low to mid 90s,
with heat indices in the lower 100s possible. Even though shear
is lacking, scattered thunderstorms are forecast to develop each
afternoon, influenced by terrain circulations, lee troughs, and
likely bay/river breezes. There will be ample instability
present, and if that subtle shortwave does move through at the
right time, it could provide additional forcing for more
organized convection. A cold front then sweeps through the area
Friday night.
The higher CAPE, low shear environment could support strong to
severe thunderstorms Thursday and Friday, which is hinted at by most
of the AI guidance (CSU, NSSL, Google DeepMind). Uncertainty is
mostly due to timing of convection and passage of any upper-level
features. Given this week is the start of many summer activities and
celebrations across the area, it will be important to remain weather
aware.
Saturday brings a short reprieve from the very hot temps and
thunderstorms as a quick moving surface high traverses the area. A
large upper trough and cold front approach from the OH Valley Sunday
into early next week, bringing showers and thunderstorms back to the
forecast.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
Light winds have readily come around to the NE and E early this
morning, and will become SE tonight into Tuesday morning. Speeds
will generally be 3-7 kts, though a period of 8-14 kts with
gusts 16-22 kts is expected this afternoon. VFR conditions will
prevail, though onshore flow could waft in some scattered to
broken MVFR clouds at times (FL020-FL035) as seen upstream over
NJ. Just how widespread/persistent any lower CIGs are (as well
as southwest extent) is uncertain given the source region of
the flow is from a dry area of high pressure descending out of
New England and increasing diurnal mixing. Covered metro TAFs
with a TEMPO and will continue to monitor.
VFR conditions likely prevail through the middle of the week,
with two possible exceptions: (1) early morning patchy fog in
outlying areas, and (2) showers/t-storms especially during the
afternoon/evening Wednesday. Flow will be southerly with daytime
gusts of 15-20 kts possible.
VFR conditions are expected to prevail for the end of this week.
Daily chances for showers and thunderstorms continue Thursday and
Friday, though coverage will be less than Wednesday. Brief periods
of sub-VFR conditions, gusty winds, and lightning could produce
impacts at affected terminals. Winds shift SW to W.
&&
.MARINE...
Onshore flow increases from midday into this evening, with gusts
of 15-25 knots anticipated. Winds become a bit lighter and more
southeasterly later this evening into Tuesday morning, before a
prolonged period of southerly flow/channeling brings more gusty
conditions Tuesday afternoon through Wednesday night. Dry
weather is expected through Tuesday night, then shower and
thunderstorm chances increase readily Wednesday as a warm front
lifts across the waters.
Sub-SCA winds are expected through the end of this week. Scattered
thunderstorms develop each afternoon to evening Thursday and Friday,
which will pose a threat to mariners from gusty winds and lightning.
&&
.TIDES/COASTAL FLOODING...
A somewhat prolonged period of southerly flow will result in
rising tidal anomalies Tuesday through Wednesday night. The
typically more aggressive guidance (CBOFS, SFAS) shows potential
for solid minor to perhaps near moderate flooding at Annapolis
by mid week, with minor flooding possible along other vulnerable
shoreline areas (Havre de Grace and Alexandria, for example).
I believe the higher guidance may be warranted in this case
given onshore flow through tonight pushing water into the
Chesapeake Bay, then southerly flow holding it/pushing it
northward into our neck of the woods through mid week.
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. Therefore, no watches (or HWO
mention) have been introduced on this forecast cycle.
&&
.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...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
ANZ530>532.
Small Craft Advisory from 3 PM this afternoon to midnight EDT
tonight for ANZ530>533-535>542.
Small Craft Advisory until 9 AM EDT this morning for ANZ533-
537-541.
Small Craft Advisory until midnight EDT tonight for ANZ534-543.
&&
$$
DISCUSSION...DHOF/KRR
AVIATION...DHOF/KRR
MARINE...DHOF/KRR
TIDES/COASTAL FLOODING...DHOF
CLIMATE...DHOF
NWS LWX Office Area Forecast Discussion