462
FXUS61 KLWX 251313
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
913 AM EDT Thu Jun 25 2026

.WHAT HAS CHANGED...
Humidity may drop briefly through mid afternoon before moisture
starts advecting into the region. Slightly refined the timing of
modest wind gusts (15-25 mph) heading into tonight, and chances
of showers and thunderstorms over the next 24 hours.

&&

.KEY MESSAGES...
- (1) Showers and thunderstorms expected this weekend as a cold
  front approaches at the end of the week.

- (2) Increasing heat and humidity are expected next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Showers and thunderstorms expected this weekend as a
cold front approaches at the end of the week.

An upper trough and associated surface low will develop over the
Great Lakes and move into the northeast CONUS through Friday.
The trailing cold front will slowly sag south into the region
through Saturday. Isolated to scattered showers and perhaps a
thunderstorm will return to the forecast late today or this
evening for northern and western MD into eastern WV before
dropping south into the rest of the region Friday morning.
Overall, the risk of thunderstorms today seems low given lack of
deep moisture (i.e. 850 mb dewpoints less than 10C) and 850-700
mb ridging and associated mid-level capping seen on model
soundings, but some shallow convection is possible west of the
Blue Ridge Mountains. In the vicinity of western MD, slightly
deeper moisture and better lift ahead of an approaching cold
front as well as strong mid-level flow could lead to a strong to
severe storm or two this evening as convection shifts east
across the OH Valley/lower Great Lakes.

Moisture deepens Fri into Sat with 850 mb dewpoints rising
above 10C Fri and over 15C on Sat. This when combined with
increasing temperatures should result in a more unstable
environment. 850-700 mb height falls are progged after 18Z Fri
associated with an approaching secondary shortwave-trough from
the mid MS River Valley. This should prove more than sufficient
to generate sct-nmrs deep convection. Fri poses the greater
risk of some severe wx/downburst winds due to hot air mass and
mid-level dry air, while Saturday poses a bigger risk for
heavy rainfall due to deeper moisture and nearly moist
adiabatic/skinny CAPE profiles. The front finally starts
crossing the area Saturday night, but it will be a slow gradual
process.

KEY MESSAGE 2...Increasing heat and humidity are expected next
week.

There is some uncertainty with how far south the front makes it
Sunday. However, it will likely be a relatively cooler day with the
front over or south of the area. There may be a lingering shower and
thunderstorm chance. The front will likely start losing its
definition Monday as weak high pressure builds in. Thus expect lower
rain chances and a slight uptick in temperatures.

Heat will likely ramp up Tuesday and Wednesday with the building
upper level ridge over the Ohio Valley, although there is still a
fairly large spread in ensemble high temperature data, ranging from
the mid 80s to near 100. Humidity will also likely be elevated, so
heat index values could top 100 if the hotter solutions verify. The
strength and position of the ridge will determine if subsidence wins
out, or if there might be an opportunity for diurnal thunderstorm
development.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR/dry conditions are expected through the TAF period (18Z Fri),
though can`t totally rule out a pop up shower near MRB 01Z-05Z.
Winds will be southerly (more SE at MTN) 9-12 kts with gusts
15-23 kts with the highest gusts most likely 21Z-03Z.

After 18Z Friday, SHRA/TS chances increase markedly. A boundary
will slide slowly southward across the area with moisture
advection overrunning it, and this is expected to cause
scattered to numerous showers and a few thunderstorms.
Additional activity is possible through Friday night, with a
chance of remnant TS activity approaching from the OH Valley
late into Saturday morning. Additional activity and lower CIGs
are possible through Saturday as a front slowly slides south.
Wind direction may be a bit variable between S and NW depending
on the placement of the front, but should be generally light
outside of convection.

There may be a lingering shower or thunderstorm chance Sunday
depending on how quickly the cold frontal zone moves south. VFR/dry
conditions are more likely Monday.

&&

.MARINE...
SCAs are in effect for all the waters through tonight. Southerly
winds pick up this afternoon, peak this evening, then gradually
diminish through Friday morning. Sct-nmrs convection Fri
afternoon and evening may pose a risk of strong winds, which may
require Special Marine Warnings. Convection Saturday will pose
a bigger threat for intense rainfall rates and poor visibility
at times.

Light northerly winds are forecast Sunday with a cold front
gradually pushing to the south. A thunderstorm could remain possible
if the front is slower. Weak high pressure builds across the area
Monday with light east to southeast winds.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 3 AM EDT
     Friday for ANZ530-531-538-539.
     Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
     Friday for ANZ532>534-537-540>543.
     Small Craft Advisory from 5 PM this afternoon to 3 AM EDT
     Friday for ANZ535-536.

&&

$$

DISCUSSION...ADS/LFR/DHOF/CJL
AVIATION...ADS/LFR/DHOF/CJL
MARINE...ADS/LFR/DHOF/CJL

NWS LWX Office Area Forecast Discussion