559
FXUS61 KLWX 171856
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
256 PM EDT Sun May 17 2026
.WHAT HAS CHANGED...
No changes were made to the forecast at this time, mainly
updated the wording of the discussion. Added some detail about
how hot Wednesday will be in to Key Message 1, while keeping the
severe threat on Wednesday in its own Key Message bullet.
&&
.KEY MESSAGES...
- 1) Near-record warmth Monday through Wednesday, with isolated
storms possible over the mountains Monday and Tuesday.
- 2) A strong cold front moves through on Wednesday,
bringing chances for thunderstorms. Much cooler and showery
conditions are expected to end the week.
&&
.DISCUSSION...
KEY MESSAGE 1...Near-record warmth Monday through Wednesday,
with isolated storms possible over the mountains Monday and
Tuesday.
The remnant MCV is still present this afternoon, but seems to
have lost a lot of steam as it has traversed the region.
Cloudcover has largely dissipated, and we are rapidly warming
into the mid 80s in those areas where clouds were an issue early
on. Further south across central VA, we are already well into
the 80s to near 90. Warm temperatures, combined with dew points
in the low to mid 60s, are currently yielding 1000-1500 J/kg of
CAPE this afternoon. We are starting to see a bit of a cu field
develop, so could see a few storms try to develop in the
remaining hours of peak heating. Any storms that we do see
today could put down locally gusty winds, brief heavy rainfall,
and frequent lightning.
Expect a similar setup Monday and Tuesday although the coverage
of storms will be further reduced as upper level ridging
continues to strengthen east of the region. Showers and t-storms
will be confined to the mountains due to terrain influences and
a lack of lifting mechanism. Very unlikely to see anything make
it east of the I-81 corridor on either afternoon. Monday looks
to be the better chance of the two, with Tuesday looking pretty
dry overall.
Outside of the afternoon/evening shower and thunderstorm threat will
be the bigger story which is the heat. This will become really
pronounced by Monday and continue through Wednesday, with widespread
highs in the low to mid 90s each day. Tuesday will mark the
hottest day of the next 7 with highs in the mid to upper 90s
east of the mountains. Wednesday will then be slightly cooler
compared to Tuesday, but still well into the 90s for most. The
humidity will gradually increase each day, though not to the
extent where heat headlines will be needed. Something that we`ll
continue to monitor since we are early in the season. Don`t
expect too much relief from the heat at night with low
temperatures Monday and Tuesday nights in the mid 60s and low
70s.
KEY MESSAGE 2...A strong cold front moves through on Wednesday,
bringing chances for thunderstorms. Much cooler and showery
conditions are expected to end the week.
A mid-week frontal system remains on track to impact the area,
albeit with some uncertainties in the overall details. Most notably,
the core of the forcing and stronger wind fields with this trough
look to be well north of the region. Both of those components will
lend itself to a less organized convective event. However, the
timing of the cold front does align closely to the peak in diurnal
heating. Given multiple days of well above average temperatures,
this system will be conducive to shower and thunderstorm
development. This should especially be the case along the developing
lee trough and trailing cold front. The severe weather aspect
remains the biggest question mark at this time.
Any convective chances likely wind down on Wednesday night as the
cold front eventually settles near the Virginia Tidewater region on
Thursday morning. This supports a shift to northerly winds on
Thursday which is accompanied by a rather dramatic cool down.
Forecast highs are likely to not escape the upper 60s to low 70s
which is around 15 to 25 degrees lower than previous days. Expect a
similar temperature forecast for Friday as well with the shift to an
onshore easterly wind. A gradual warm up is possible next weekend,
but this will depend on the degree of cloud cover and extent of
rainfall.
This overall pattern remains quite stagnant as the earlier frontal
zone stalls near the southeastern U.S. Meanwhile, strong high
pressure settles across eastern Canada down into New England. Within
the southwesterly flow aloft, a series of mid/upper disturbances
will keep daily chances for rain in the forecast. The setup looks
more convectively-stable in nature which would limit thunderstorm
chances for this late week period.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Can`t rule out a thunderstorm this afternoon, with the best
chance at CHO. We could see one at IAD and DCA as well, but
confidence is a bit lower there. Maintaining PROB30s in the
latest TAFs for those 3 sites to reflect that threat.
Confidence is very low that any storm will hit a terminal, but
think there will at least be a few storms out there this
afternoon.
Prevailing VFR conditions are expected across the terminals
through Tuesday as high pressure strengthens offshore. Light and
variable winds this morning will turn westerly this afternoon
at less than 10 kts. South/southwesterly winds return Monday and
Tuesday gusting between 15 to 20 kts during the afternoon and
evening hours. Daily shower and thunderstorm chances will occur
each afternoon although coverage will be spotty in nature
between the terminals. The highest confidence for showers and
t-storms appears to be west of MRB, HGR, and FDK. where brief
reductions are possible. Elsewhere confidence remains low given
the lack of a lifting mechanism.
Some restrictions are possible on Wednesday, particularly given the
expectation of afternoon/evening showers and thunderstorms with the
cold front. Prevailing winds will be out of the southwest through
much of the day before this front passes through. Some low ceilings
are possible into Wednesday night as the system presses off to the
south and east. Winds shift to north to northwesterly for much of
Thursday before turning more easterly by Friday. With the presence
of low clouds and rain at times, sub-VFR conditions are looking
possible during the Thursday through Friday timeframe.
&&
.MARINE...
Sub-SCA level winds are expected through Monday morning.
South southeasterly winds return Monday with gusts up to 20
knots across the bay and lower tidal Potomac. A Small Craft
Advisory was issued with this forecast cycle. Additional SCAs may
be needed due channeling Tuesday into Tuesday night, especially
over the wider waters. Winds will continue out of the south and
southwest with gusts up to 20 kts.
For Wednesday, marine winds ahead of the front should largely
meander between south and southwesterly. This cold front will
increase the risk of showers and thunderstorms, particularly during
the afternoon/evening hours. Any of the stronger convection may
require Special Marine Warnings. Overall storm chances wind down
late Wednesday night as winds shift to mainly northerly on Thursday.
A frontal surge will bring gusts up to 20 knots which may require
Small Craft Advisories through midday Thursday. Thereafter, winds
drop below advisory thresholds.
&&
.CLIMATE...
Here are some daily temperature records during the May 18-20,
2026 timeframe:
A `+` sign indicates multiple years currently hold that record.
A `!` sign indicates the record is forecast to be tied or broken.
***MONDAY, MAY 18TH, 2026***
LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1877) 72F (2015)
Washington-Dulles (IAD) 91F (1987)! 68F (2015)!
Baltimore (BWI) 97F (1962) 70F (2017)
Baltimore Inner Harbor (DMH) 97F (1962) 75F (2017)
Martinsburg (MRB) 96F (1911) 66F (2015)!
Charlottesville (CHO) 95F (1962)+ 73F (1911)
Annapolis (NAK) 95F (1962)+ 69F (1953)+!
Hagerstown (HGR) 93F (1962) 71F (2017)
***TUESDAY, MAY 19TH, 2026***
LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1997)+ 72F (2015)!
Washington-Dulles (IAD) 92F (1997)+! 66F (2017)+!
Baltimore (BWI) 98F (1962) 75F (1877)
Baltimore Inner Harbor (DMH) 98F (1962) 78F (1962)
Martinsburg (MRB) 98F (1911) 69F (1996)!
Charlottesville (CHO) 97F (1962) 72F (1997)
Annapolis (NAK) 96F (1962) 71F (1911)!
Hagerstown (HGR) 97F (1996) 69F (2017)+!
***WEDNESDAY, MAY 20TH, 2026***
LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1996) 73F (2019)
Washington-Dulles (IAD) 93F (1996) 69F (2019)
Baltimore (BWI) 95F (1962) 71F (2019)+
Baltimore Inner Harbor (DMH) 97F (1962) 74F (1998)+
Martinsburg (MRB) 97F (1911) 70F (1998)
Charlottesville (CHO) 96F (1996) 73F (1996)
Annapolis (NAK) 98F (1997) 76F (1898)
Hagerstown (HGR) 97F (1996) 66F (1998)
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 3 PM Monday to 2 AM EDT Tuesday for
ANZ531>534-537>543.
&&
$$
DISCUSSION...BRO/CJL/KJP
AVIATION...BRO/CJL
MARINE...BRO/CJL
CLIMATE...BRO
NWS LWX Office Area Forecast Discussion