041
FXUS61 KLWX 301429
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1029 AM EDT Mon Mar 30 2026
.WHAT HAS CHANGED...
No major changes in the current forecast package outside of the
coverage of scattered showers heading into the afternoon.
Environment is looking more favorable for a few strong to
perhaps severe t-storms with gusty winds Wednesday.
&&
.KEY MESSAGES...
- 1) Near record temps through Wednesday ahead of an approaching cold
front that looks to bring showers and perhaps a few strong to severe
thunderstorms.
- 2) The front stalls near or over the region during the second
half of the week before being overtaken by another front late
in the upcoming weekend.
&&
.DISCUSSION...
.KEY MESSAGE 1...Near record temps through Wednesday ahead of an
approaching cold front that looks to bring showers and perhaps
a few strong to severe thunderstorms.
Synoptically, it`s predominantly zonal flow with high pressure
anchored offshore and a cold front slowly sinking south from the
Great Lakes and interior Northeast. This front will eventually push
into the Mid-Atlantic during the Wednesday into Wednesday night
timeframe. Ahead of the boundary will be some weak impulses and
increased isentropic ascent/warm air advection across the
region. This has been observed this morning with scattered light
showers pivoting across the immediate I-66/US-50 corridor. This
activity will likely decrease in coverage by late
afternoon/early evening although a spotty shower and perhaps
t-storm cannot be ruled out, especially over the mountains.
Despite increased mid and high level cloud cover expect highs to
push into the mid 60s and low 70s. Breezy south to southwest wind
gusts 20 to 25 mph will also aid in pushing warmer air into the
region. Skies will remain mostly cloudy to overcast with a few
breaks of sun off to the south this afternoon.Cloud cover will
try to break east of the mountains late tonight into Tuesday as
a 850 mb low level jet pivots into the region. This could result
in a few wind gusts around 45 MPH for elevations above 3500
feet in the Appalachians, but the threat appears localized for
headlines right now. A more expansive a somewhat stronger low-
level jet pivots overhead Tuesday evening through early
Wednesday morning, but the flow is a bit veered/not
unidirectional through the lower atmosphere and the pattern is
one of warm advection which can preclude more efficient mixing.
The end result may be the same a few wind gusts to around 45 MPH
above 3500 feet over the Appalachian crest.
Turning much warmer Tuesday and Wednesday with temperatures expected
to push near record levels. Highs both days will punch into the
upper 70s and low 80s with overnight lows in the mid 50s and low
60s. Shortwave ridging should keep most of the area dry Tuesday with
an isolated shower or t-storms mainly west of the Blue Ridge.
More widespread t-storm coverage is expected Wednesday afternoon and
evening as the cold front drops into the region. Some of the latest
CAMS and deterministic guidance has some morning convection
Wednesday which could hamper the severe threat afternoon. The
environment also appears capped above 700 mb given the morning
convection as well as increased mid and high level cloud cover. A
few things to note though would be modest 30-35 kts (0-6 km shear)
mainly along and north of I-66/US-50. There is also a remnant plume
of elevated mixed-layer (EML) air evident in forecast soundings
above a cap at 700 hPa. This results in steepening mid-level lapse
rates of 7-8 C/km. If enough low-level heating and moistening take
place, and the convergence along either the approaching cold front
or a pre-frontal trough are sufficient, then the cap would likely
break. Steep mid-level lapse rates above the cap and steep low-level
lapse rates below the cap would then lend a threat to gusty winds
with inverted-V profiles. The severe threat may be tempered by
modest low-level downsloping flow and moisture, as well as height
rises aloft in spite of a shortwave shearing out to the north across
PA.
SPC does not currently have the area highlighted in a severe
risk while CSU learning machine probs and NSSL probabilities
have a 15-30 percent chance for severe t-storms mainly along and
north of I-66/US-50. If severe weather, were to occur damaging
winds and small hail would be the primary concerns.
.KEY MESSAGE 2...The front stalls near or over the region during
the second half of the week before being overtaken by another
front late in the upcoming weekend.
Rather remarkably large spread remains among the latest guidance
during the second half of the week into the upcoming weekend, in
particular with high temperatures. This is because the front is
likely to stall overhead with a strong temperature gradient
across it. To put numbers to it (using Thursday`s high
temperature forecast as an example), the NBM 5th percentile/cool
scenario has highs ranging from 50 in northeast MD to the low to
mid 60s in the WV valleys into central VA. Meanwhile, the NBM
95th percentile/warm scenario has highs well into the 80s to
near 90 outside the highest terrain. This casual 40-degree
spread in the high temperature forecast has been apparent for
several days, with individual deterministic models wavering back
and forth on the placement of the front Thursday into the
weekend. The current forecast package basically splits the
difference, but with the caveat that large errors are likely.
Repeated chances for showers and a few thunderstorms are in the
forecast through the upcoming weekend as the front wiggles
around nearby. The coverage and magnitude of shower and
thunderstorm strength will depend highly on available
instability and shear, both of which are very much in flux given
the uncertain placement of the front and background temperature
and wind fields.
By late in the upcoming weekend, a stronger upper trough and
cold front likely approach from the Midwest/Ohio Valley. A more
organized and cohesive threat for showers and perhaps a few
strong to severe thunderstorms may develop as a result prior to
the passage of this front heading into early next week.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR conditions are expected to continue through Wednesday
although a brief shower and perhaps an isolated t-storm cannot
be ruled out amongst the terminals from time to time. LLWS is
possible overnight as a low level jet pivots overhead, though
minimal directional change and elevated surface winds may limit
this threat across the corridor. Still went ahead and added it
in throughout the corridor between 00-12z Tuesday. Outside of
LLWS, breezy conditions will remain with south to southwest
gusts of 15 to 20 kts during the overnight periods and 20 to 25
kts likely during the daytime hours.
A cold front drops into the area Wednesday bringing higher
potential for showers and a few thunderstorms. These may be
accompanied by at least brief restrictions. Lower CIGs are
feasibly possible in onshore flow in the wake of the front later
in the week (along with repeated shower and thunderstorm
chances), though the forecast is highly uncertain given unknowns
in exactly where the front stalls.
&&
.MARINE...
Gusty south to southwest winds will continue over the next few
days given high pressure anchored offshore and a cold front
slowly approaching from the Great Lakes. SCAs may need to be
extended through late tonight for portions of the waters,
though uncertainty in extent of mixing and any potential lulls
tonight keeps confidence a bit lower. Additional SCAs are
probable through the middle of the week ahead of the front, and
are quite possible behind the front out of the east/southeast.
Shower and thunderstorm chances appear highest Wednesday
afternoon and evening at the moment when the cold front drops
in, but additional activity is possible Thursday and Friday as
the front remains stalled nearby or overhead. Uncertainty in the
extent of precipitation as well as wind direction is high late
this week.
&&
.CLIMATE...
Temperatures of 15 to 25 degrees above normal are expected
Tuesday and Wednesday. Below is a list of record daily high
temperatures for our regional climate sites.
=========================================================
Record Daily Highs and Warm Lows for March 31
Site High/Year(s) Set Warm Low/Year(s) Set
DCA 85/2025, 1981, 1979 63/1998
BWI 86/2025, 1998 68/1998
IAD 85/1998 62/1998
DMH 93/1998 73/1998
NAK 83/1979, 1945 61/1977
HGR 85/1998 57/1998
MRB 86/1998 62/1998
CHO 88/1986 67/1910
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...Small Craft Advisory until midnight EDT tonight for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ530>543.
&&
$$
DISCUSSION...DHOF/EST
AVIATION...DHOF/EST
MARINE...DHOF/EST
NWS LWX Office Area Forecast Discussion