474
FXUS61 KLWX 010600
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
200 AM EDT Wed Apr 1 2026
.WHAT HAS CHANGED...
Showers and a few strong to severe thunderstorms may tend to
focus east of the Blue Ridge and Catoctin Mountains late this
afternoon through early this evening.
&&
.KEY MESSAGES...
- 1) Near record temperatures ahead of an approaching cold
front that looks to bring showers and perhaps a few strong to
severe thunderstorms.
- 2) The front will waver near or just north of the area
Thursday through Saturday resulting in warm conditions and
daily shower and thunderstorm chances.
- 3) A strong cold front passing through the region on Sunday
likely brings widespread rainfall and a sharp drop in
temperatures by early next week.
&&
.DISCUSSION...
.KEY MESSAGE 1...Near record temperatures ahead of an approaching
cold front that looks to bring showers and perhaps a few strong
to severe thunderstorms.
A few remnant showers may continue to pivot across northern
Maryland this morning. Higher thunderstorm coverage is expected
late this afternoon and early this evening as a cold front
drops into the region. There is some question regarding
thunderstorm coverage due to height rises later in the day along
with deep westerly (downsloping) flow. However, steeper mid-
level lapse rates (7-7.5 C/km) will result in tall CAPE profiles
with around 30 kt of shear. This could result in multicell
clusters capable of locally damaging winds and perhaps some
marginally severe hail. Very steep lapse rates in the low levels
combined with the steep lapse rates aloft could compensate for
modest (15-30 kt) flow in the 850-700 hPa layer, lending to a
damaging wind risk. Latest CAM guidance continues to suggest
coverage/intensity may be slightly greater east of the Blue
Ridge/Catoctin Mountains. Although the threat of a tornado is
rather low, any storms that track along the front could have a
narrow and brief corridor favorable for transient rodation.
The convective threat should diminish by late evening, although
some showers may continue into the night as moisture overruns
the front dropping south. While still mild, cooler air will
start to filter in from the northeast behind the front tonight.
.KEY MESSAGE 2...The front will waver near or just north of the
area Thursday through Saturday, resulting in warm conditions
and daily shower and thunderstorm chances.
Most guidance continues to show the front stalling out directly
over the forecast area on Thursday between strong high pressure
cells over the western Atlantic and Quebec. This will lead to a
large contrast in temperatures from northeast to southwest
across the area, with continued uncertainty with how the
gradient will lie. To the northeast, temperatures will likely
remain in the 50s (with low clouds), while reaching the mid 80s
to the southwest. With strong upper ridging affecting the area,
precipitation chances will be limited. Some models suggest that
scattered showers and thunderstorms could form over the terrain
and/or near the front. A few hi-res models print out some heavy
rainfall given the stalled front and weak steering flow. Recent
drought conditions may mitigate a greater flood threat, but at
least a conditional risk for flooding may exist near the front.
The aforementioned front will lift northward Friday as low
pressure lifts northeastward from the Great Lakes. Temperatures
will moderate in return flow with widespread 70s to low 80s.
Precipitation chances Friday look to remain low with the main
forcing well to the north, but some convection could develop
near the terrain. Behind the low, the front may try to drop back
south toward the area, but likely halts as another low quickly
moves toward the Great Lakes Saturday. Thus Saturday may end up
pretty similar to Friday with well above normal temperatures and
the greatest chance for convection over the mountains.
.KEY MESSAGE 3...A strong cold front passing through the region
on Sunday likely brings widespread rainfall and a sharp drop in
temperatures by early next week.
The primary feature to note for this upcoming weekend is a
significant upper-level trough expected to form over the
Northern Plains region later this week and make its way eastward
towards the Great Lakes, from which a strong cold front would
track through the East Coast on Sunday. Widespread rainfall (a
few tenths of an inch) and a significant drop in temperatures
across the region likely result from this. As far as
thunderstorm risk goes, ensemble instability still looks
relatively low overall; most early parameters currently show
this predominantly being a widespread rain event. The NCAR AI
NWP Convective Hazards Forecast does show the Mid-Aatlantic in
its 15-30% severe probability outlook, however, so it is
something to still watch for as the day gets closer (forcing and
flow are strong but instability is weak). The GFS and ECMWF
remain relatively aligned on timing and track of the center low
as of the latest model runs. But, both models have seen
significant changes in the north/south track over the last
couple days, so that will be something to watch for as well.
Rain should move past the area by Monday, with a sharp cooldown
expected in the wake of the front.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
LLWS should abate as a LLJ weakens and moves away by 08Z-10Z.
Winds won`t be quite as gusty today, but could occasionally
gust to 20 kt especially this morning. A cold front will drop
toward the area late in the day, resulting in increasing chances
for showers and thunderstorms. While coverage is still
uncertain (thus PROB30 TAFs), there could be locally higher
chances of stronger thunderstorms for the Baltimore/Washington
metro. AMDs will likely be needed for any TS threat as well as
timing of wind shifts as the front approaches and crosses.
The thunder threat should end by late evening, although a few
showers may linger into the night. Winds will shift to the
northeast or east, and IFR ceilings will likely move in north of
the boundary. The front will stall across the area Thursday,
although ceilings may gradually improve. CHO may remain south of
the boundary and never see the wind shift or lower ceilings.
Any shower or thunderstorm chance on Thursday would likely
remain near MRB.
The front moves back northward Friday and Saturday with
southerly wind gusts to 20 kts possible. Convective chances each
day will likely be limited near or west of MRB.
A Sunday cold front will potentially bringing lower CIGs,
VSBYs, and a northwesterly wind shift. Widespread rainfall could
bring local impacts to terminals. Wind gusts will potentially
be somewhat elevated on Sunday in the wake of this frontal
boundary before gradually decreasing on Monday.
&&
.MARINE...
Gusty south to southwest flow will remain through this morning
given the gradient between high pressure offshore and a slow-
moving cold front approaching from the Great Lakes region. Winds
may drop subtly into this afternoon, so will keep the Small
Craft Advisory expiration at noon. Shower and thunderstorm
chances return to the waters this afternoon and evening as a
cold front drops into the area. Special Marine Warnings may be
needed for gusty winds and hail.
Wind direction is a bit uncertain tonight through Thursday
night the front will be stalled near the area. It`s possible a
push of northeasterly winds behind the front could briefly reach
advisory criteria tonight. At some point Thursday, gusty
southerly flow may take back over, especially for the southern
waters.
The front will lift back north Friday and Saturday, with
advisories possible in the ensuing southerly flow. Thunderstorm
chances will likely remain well west of the waters both days. A
Sunday cold front will introduce a northwesterly wind shift.
SCA conditions are possible Sunday going into Monday morning in
the wake of this frontal boundary before gradually decreasing.
Gusty showers and thunderstorms are also possible.
&&
.CLIMATE...
Temperatures of 15 to 25 degrees above normal are expected
today. Below is a list of record daily high temperatures for
our regional climate sites.
=========================================================
Record Daily Highs and Warm Lows for April 1
Site High/Year(s) Set Warm Low/Year(s) Set
DCA 88/1978 64/2016
BWI 88/1978 62/2016
IAD 85/1978 64/2016
DMH 90/1978 69/1998
NAK 87/1978 60/1998
HGR 84/1978 60/1912
MRB 85/1943 58/2016
CHO 88/1978 68/1998
=========================================================
Period of Record (POR) context...
.Washington DC area (DCA)...
Weather records for the Washington DC area have been recorded
at what is now Ronald Reagan Washington National Airport (KDCA)
since 1941. The official weather record consists of that data
back to 1945, and observations taken in downtown Washington from
1871 to 1944. Temperature records for the Washington DC area
extend back to January 1872.
.Baltimore MD area (BWI)...
Weather records for the Baltimore MD area have been recorded at
what is now Baltimore/Washington International Thurgood
Marshall Airport (KBWI) since 1950. The official weather record
consists of that data back to 1950, and observations taken in
downtown Baltimore from 1871 through 1949. Temperature records
for the Baltimore MD area extend back to July 1872.
.Sterling-Dulles Airport VA area (IAD)...
Weather records for the Sterling-Dulles Airport VA area have
been recorded at what is now Washington Dulles International
Airport (KIAD) since 1960. The official record consists solely
of data recorded at the airport.
.Baltimore Downtown MD area (DMH)...
Weather records for the Baltimore Downtown MD area have been
recorded at what is now the Maryland Science Center (KDMH)
since 1999. The official weather record consists of that data
back to 1999, and observations taken in the City of Baltimore
from July 1950 through 1998. Data is missing from June 3 of 2020
through August 14 of 2022 when the observing system had to be
removed due to a large construction project.
.Annapolis MD area (NAK)...
Weather records for the Annapolis MD area have been recorded at
what is now the Annapolis U.S. Naval Academy (KNAK) since
October 11 of 2001. The official weather record consists of that
data back to 2001, and observations that were taken between the
Annapolis U.S. Naval Academy and the Annapolis Police Barracks
from July of 1894 through October 10 of 2001.
.Hagerstown MD area (HGR)....
Weather records for the Hagerstown MD area have been recorded at
what is now Hagerstown Regional Airport (KHGR) since October of
1998. The official weather record consists of that data back to
October of 1998, and observations taken one mile east of
Hagerstown from 1899 through September of 1998.
.Martinsburg WV area (MRB)...
Weather records for the Martinsburg WV area have been recorded
at what is now Eastern West Virginia Regional Airport/Shepherd
Field (KMRB) since 1938. The official weather record consists of
that data back to 1944, and observations taken in downtown
Martinsburg from 1891 through 1943.
.Charlottesville VA area (CHO)...
Weather records for the Charlottesville VA area have been
recorded at what is now Charlottesville-Albemarle Airport (KCHO)
since April 20 of 1961. The official weather record consists of
that data back to April 20 of 1961, and observations taken two
miles west of downtown Charlottesville from 1983 through April
19 of 1961.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ530>543.
&&
$$
DISCUSSION...ADS/DHOF/SRT
AVIATION...ADS/DHOF/SRT
MARINE...ADS/DHOF/SRT
NWS LWX Office Area Forecast Discussion