North Bethesda, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

389
FXUS61 KLWX 131418
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1018 AM EDT Wed Aug 13 2025

.SYNOPSIS...
Shower and thunderstorm chances look to increase today through
Thursday as a cold front approaches from the west and trough of low
pressure cross the region. Warm and muggy conditions will also
continue with lowering humidity and seasonable temperatures
expected behind the front Friday into Saturday. The heat returns
Sunday and Monday ahead of another cold front set to pass
through. Cooler temperatures with Canadian high pressure by the
middle and end of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...

Shower and thunderstorm chances look to increase this afternoon and
evening as the result of multiple pieces of shortwave energy
pivoting through the area. One piece of energy is to the north of
the area (over western/central PA) with another two pieces to the
south and west. Outflows from the northern and southern pieces of
shortwave energy could collide over the area this afternoon in which
an uptick in convective development may be noted. The main show
looks to come from the piece of shortwave energy ejecting out of
northern/central West Virginia toward eastern WV, western MD, and
eventually the Shenandoah Valley. This piece of energy should
be the kicker combined with a residual trough over the
Shenandaoh Valley to springboard convection heading into mid to
late afternoon. Overall it`s a very chaotic environment which
will play into some uncertainty in how things develop into the
afternoon. Morning showers and cloud cover could either squander
an isolated to scattered severe threat or help push things along
this afternoon and evening. The question yet to be answered is
to where the CAPE/SHEAR gradient will set up and how quickly
cloud cover will clear out to allow instability to build. What
we do know is that will have plenty of moisture to work with
with PWATS per the 12z IAD/RNK soundings running between 1.7-1.8
inches. These values look to push toward 2 inches + this
afternoon and evening leading isolated pockets of rain rates up
to 2"/hr. The combination of the moist environment, incoming
pieces of shortwave energy, and perhaps 2-4 hours of
partly/mostly cloudy skies should allow for scattered to
numerous showers and thunderstorms across the region.

Hi-res CAMS continue to target locations along and north of I-66/US-
50 and west of the Blue Ridge for the highest coverage of convection
today. Even with that said, the entirety of the area looks fair game
outside of the northern neck of VA, eastern VA, southern MD, and
portions of the central VA Piedmont which look to get in on any
convection last. Isolated instances of flooding and damaging winds
appear to be the main threats with thunderstorms today. SPC and WPC
continue their marginal risks for severe weather/excessive rainfall
to encompass the aforementioned threat above for the
afternoon/evening ahead. Despite the chaotic nature of today`s
forecast and ongoing shower activity this morning, expect convection
to pop anytime between 2-8pm this evening. Things may get going a
bit earlier to the west of I-81 and out across western MD/eastern WV
between 12-3pm before advancing east toward the metros between 3-
8pm. Any convection should gradually wane after sunset as shortwave
energy passes east of the area.

A residual shower or two cannot be ruled out overnight with areas of
fog late. Highs today will push into the mid to upper 80s due to the
extra cloud cover and multiple rounds of showers. Some locations may
pop 90 degrees depending on how much solar insolation can occur.
Lows tonight will fall back into the upper 60s and low 70s.
Dewpoints will remain in the 70s allowing the muggy feel to continue
at least until the end of the workweek.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
A summertime pattern persists through Thursday with heat,
humidity, and daily chances for showers and thunderstorms in the
forecast. A potent longwave trough crosses through Quebec while
the stalled front across our south will be the focal zone for
developing showers and thunderstorms Thursday afternoon and
early evening.

Afternoon highs each day in the upper 80s to near 90F, with heat
indices in the mid to upper 90s to around 100F. Overnight lows will
be muggy in the low to mid 70s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Not much of a change in the overall pattern for the upcoming weekend
and early next week. The subtropical ridge over the southeastern U.S
should strengthen/build with 500 mb heights hovering between 589-592
dm. Meanwhile, a cold front will dissipate over the area this
weekend. By the weekend, t-storm chances become more suppressed with
the building upper level ridge. Any convection looks to be terrain
based or relegated to the initiation of the bay/river breeze. High
temperatures Saturday should push into the mid 80s to low 90s, with
mountain locations in the mid 70s to low 80s. Low temperatures will
fall into the low to mid 60s over the mountains with mid 60s to low
70s further east toward the Baltimore/Washington DC metro areas.

Sunday brings on more heat and humidity ahead of a encroaching cold
frontal boundary from the Great Lakes and northern Ohio River
Valley. High temperatures will climb back into the low to mid 90s
for most with heat index values hovering between 95-100 degrees. A
few spotty showers or t-storms cannot be ruled out especially over
the mountains and northern portions of the forecast area given the
amplified northern stream.

Slightly higher chances for diurnally driven shower and thunderstorm
chances exists for the early and middle part of next week. Current
guidance continues to show a fairly amplified northern stream.
Ridging high pressure remains over the southeastern U.S with a
secondary ridge over central and eastern Canada. Caught in between
the two upper level ridges is a decent frontal zone extending over
the northern tier of the U.S. Within this frontal zone will be a
series of fronts that will drop south from the Great Lakes/Ohio
River Valley Monday through Wednesday next week. The first front
looks to cross the area Monday before washing out over the central
and southern part of the forecast area Tuesday. Another front will
follow midweek. With the several fronts crossing expect an uptick of
shower and thunderstorm chances mainly during the afternoon/evening
hours.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
IFR cigs will slowly improve to MVFR and eventually VFR over the
next 1-3 hrs. This low cloud cover and morning shower activity is
in association with multiple ripples of shortwave energy set to
push through the corridor today. Showers and thunderstorms will
develop around midday and linger through this evening as energy
ejects eastward from West Virginia. Greatest coverage of
thunderstorms over the terminals looks to occur between
17-01z/1-9pm Storms could pack a punch with gusty/chaotic winds
and locally heavy rainfall which will lead to sub-VFR vsby
reductions. Showers and thunderstorms will again develop on
Thursday with a front nearby. These could produce brief periods
of sub- VFR conditions at any terminal. Most of the activity
should dissipate in the evening each day.

A weak cold frontal boundary will lead to some temporary reductions
Friday afternoon and evening due to showers/thunderstorms.
Additional reductions are possible during the afternoon and evening
hours this weekend as the front dissipates nearby. Convection
overall will be fairly spotty this weekend given the strengthening
subtropical ridge overhead. Winds Friday will be out of the east and
southeast Friday at less than 15 kts.

Convection overall will be fairly spotty this weekend given the
strengthening subtropical ridge overhead. Winds east and
southeast Saturday at less than 15 kts. Winds will switch back
south and southwest Sunday into Monday.

&&

.MARINE...
The main concern for mariners will be from this afternoon and
evening thunderstorm activity that could return to the forecast
and continue into Thursday. Special Marine Warnings may be
needed at times for strong gusty winds. A cold front will also
cross the area, though it will only bring a brief wind shift.

Sub-SCA level winds will continue through the period. Winds will
remain light out of the east and southeast Friday at less than
15 kts. This is due in part to a dissipating frontal boundary
over the region.

Sub-SCA level winds will continue through the period. Winds will
remain light out of the east and southeast Saturday at less than 15
kts. This is due in part to a dissipating frontal boundary over the
region. Winds will switch to the south and southwest Sunday and
Monday at less than 15 kts. Some southerly channeling remains
possible Monday into Tuesday over the open waters, but overall
confidence is low.

&&

.TIDES/COASTAL FLOODING...
Elevated tidal anomalies look to continue today given the
recent full moon and light winds. While minor tidal flooding is
not expected, some cycles could go into Action stage during the
high astronomical tides (especially at Annapolis and perhaps
Dahlgren/Alexandria).

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...KRR
LONG TERM...CPB/EST
AVIATION...KLW/CPB/KRR/EST
MARINE...KLW/CPB/KRR
TIDES/COASTAL FLOODING...LWX