Gaithersburg, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

295
FXUS61 KLWX 041420
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1020 AM EDT Fri Jul 4 2025

.SYNOPSIS...
High pressure will build across the area this weekend, while low
pressure develops off the southeast coast. A cold front will
approach from the northwest Monday, before potentially
stalling near the area during the middle of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A dry cold front has now cleared the region with this morning`s
surface analysis placing this boundary over southern Virginia.
In the wake, a noticeably drier air mass has settled over the
area with the 12Z KIAD sounding indicating a precipitable water
value of 0.69 inches. Relative to 12 hours ago, this is a half
inch decrease (1.19 inch value at 00Z last evening). North to
northwest trajectories remain in place through the day, as
surface high pressure spreads eastward from the Great Lakes and
mid/upper troughing moves east from New England. There will be
plenty of sunshine with temperatures topping out in the mid 80s
for most areas. Dew points in the 50s are already apparent
behind the boundary, which will result in a much more
comfortable feeling compared to the past few weeks.

While not currently mentioned in the forecast database,
multiple models show the potential for a pop up shower or
thunderstorm over the Alleghenies this afternoon and evening,
particularly Highland and Pendleton Counties. There will be a
combination of surface convergence, terrain circulations, and
higher dew points in this area on the southwest flank of the
high. However, subsidence aloft should keep updrafts weak and
may ultimately prevent development.

The high will move to the Mid Atlantic coast by Saturday
morning. Clear skies and light winds may result in some patchy
river valley fog late tonight. Lows will be in the 60s, with
potentially some upper 50s where radiational cooling is
maximized.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The surface high will progress off the coast through the weekend
as upper level ridging builds overhead. This ridge should
largely keep a low suppressed along the southeast coast (which
NHC has highlighted for possible tropical cyclone development).
Saturday should remain mostly sunny and dry with temperatures
and dew points a few degrees higher than Friday. Sunday will
continue that trend, as more areas potentially reach 90 degrees
and some locations fail to drop below 70 Sunday night. One wild
card will be moisture associated with the southeast low. This
moisture could result in a little additional cloud cover on
Sunday. However, there is a low chance a few showers could even
sneak into southern parts of the forecast area.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A an approaching cold front will bring the return of precipitation
chances on Monday with showers and thunderstorms possible in the
afternoon. Precipitation chances increase on Tuesday as the cold
front pushes through the forecast area. As the boundary stalls over
the southern portions of the forecast area, shower and thunderstorm
chances linger Wednesday and Thursday. Each day, warm temperatures
and humidity will lead to plenty of instability (CAPE) although
convection will be limited by the lack of shear. This will inhibit
widespread strong to severe thunderstorms.

Temperatures Monday and Tuesday will be in the the 80s to low 90s
with higher elevations staying in the upper 70s. Overnight low
temperatures will dip into the 60s and 70s. High temperatures cool
slightly on Wednesday in the wake of the cold front. Highs will be
in the 80s for most with only isolated locations reaching the 90s
both Wednesday and Thursday. Higher elevations will stay in the 70s
both days.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
High pressure will build across the area through the weekend,
resulting in VFR conditions. Light northerly winds today will
start veering toward evening, becoming south to southeast by
Saturday morning (and continuing through Sunday). Depending on
the effects of low pressure off the southeast coast, some sub-
VFR ceilings may develop over portions of the area Sunday night.

Sub-VFR conditions are possible Monday and Tuesday afternoon as
showers and thunderstorms impact the terminals due to an approaching
cold front. Winds will be light and variable on Monday and Tuesday
before shifting to northwesterly in the wake of the front Tuesday
evening.

&&

.MARINE...
Behind the cold front which has now settled into southern
Virginia, northerly winds are prevailing this morning with
maximum gusts between 5 to 10 knots. Light winds largely
prevail through the weekend with dry conditions as high pressure
pushes off the coast. Winds will turn south/southeast by
Saturday morning. The greatest chance for advisory conditions
(albeit marginal) will come Sunday evening/night due to a
slightly enhanced wind field between the departing high and
nearly stationary low pressure along the southeast coast.

Showers and thunderstorms are possible over the waters as a cold
front approaches the forecast area next week. Winds are
expected to stay below SCA criteria both Monday and Tuesday,
although SMWs are possible during afternoon showers and
thunderstorms.

&&

.TIDES/COASTAL FLOODING...
Southerly winds will return this weekend, driving slight
increases in water level anomalies. While flooding is unlikely
for most areas, a push of slightly stronger winds could result
in Annapolis nearing the minor threshold early Monday morning.

&&

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

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS/BRO
SHORT TERM...ADS
LONG TERM...AVS
AVIATION...ADS/AVS
MARINE...ADS/BRO/AVS
TIDES/COASTAL FLOODING...ADS