692
FXUS61 KLWX 200641
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
241 AM EDT Wed May 20 2026
.WHAT HAS CHANGED...
Some subtle changes in regards to the timing of scattered to
numerous thunderstorms this afternoon along with placement of
greatest coverage. A sharp cooldown with on and off rain chances
expected Thursday through the upcoming holiday weekend.
&&
.KEY MESSAGES...
1) Widespread strong to severe thunderstorms expected this afternoon
and evening as a strong cold front crosses ending the record heat.
2) Turning showery and sharply cooler Thursday into early next week
with several days of much needed rainfall.
&&
.DISCUSSION...
KEY MESSAGE 1... Record heat continues through Wednesday. A strong
cold front brings widespread strong to severe thunderstorm chances
Wednesday afternoon and evening.
Relief is on the way today as a strong cold front approaches the
region. The front will break the record heat while bringing renewed
strong to severe thunderstorm chances to the region. Temperatures
will quickly climb from the mid 60s and low 70s this morning back
into the mid to upper 90s east of the mountains. Dewpoints will also
hover close to 70 degrees making for more of that true summertime
feel in the DMV. The added heat and humidity combined with the
strong cold front will be the catalyst for thunderstorm development
today.
The entire region remains in a Marginal Risk (Level 1 out 5) for
severe weather per SPC. This aligns with CSU Learning Machine
probabilities along with NCARS AI NWP Convective Forecast and NSSL
Probs for the afternoon and evening period. The coverage storms
looks to be scattered to numerous although the severe threat will be
isolated given west to southwest flow aloft. MLCAPE values will peak
in the 1000-2000 j/kg range this afternoon with 0-6km shear values
less than 30 kts. This would support multicellular clusters capable
of producing damaging winds (downbursts) and large hail. Current 00z
CAM guidance shows a variety of solutions when it comes to timing.
General consensus is for convection to fire along a lee side trough
east of the Alleghenies/toward I-81 early to mid afternoon between 1-
4 pm before sliding east into the metros between 3-9pm. The greatest
coverage of storms (i.e best organization) appears to be north of I-
66/US-50 given the progression of the front as it drops in from the
northwest. Locations further south may see more of a smattering of
storms (in multiple rounds) pushing through. Still believe there
will be enough coverage of severe thunderstorms for a Severe
Thunderstorm Watch to be issued at some point this afternoon for
portions of the area. Not expecting flash flooding given current 6
hr QPF values around 1-2" and 3 hr FFG values just above those
marks. Could see some increased runoff in typical urban /poor
drainage areas and areawide with recent drought concerns.
Convection should start to wane between 9-11pm tonight, but showers
could linger well into the overnight as the cold front crosses. Lows
tonight will fall back into the mid 50s and low 60s.
KEY MESSAGE 2...Turning showery and sharply cooler Thursday into
early next week with several days of much needed rainfall.
Synoptically, looking at a transient/wedge pattern Thursday into the
upcoming holiday week. Weak troughing will reside over the Ohio
River Valley with high pressure locked across New England/Great
Lakes region. The combination of these two features along a stalled
front to the south will lead to persistent onshore flow into the
region.
As a result, expect several days of on and off shower/thunderstorm
activity through the remainder of week into the Memorial Day
holiday. Sunshine will be limited with plenty of cloud cover
expected and cooler than normal temperatures as a result of the east
to northeast flow. Highs Thursday will take a 25 to 30 degree dive
behind the front with many locations struggling to push 70 degrees.
Temperatures will continue to run below normal on Friday, struggling
to make it into the 60s. Ensemble guidance shows much larger spread
in temperatures Saturday through Monday, with some solutions keeping
us locked into low cloud cover and temperatures in the 50s/60s,
while some other solutions try to break us out of the low clouds,
causing temperatures to climb into the 70s.
The most notable thing in the extended, outside of the sharp
cooldown will be the much needed rainfall as a result of this active
pattern. Periods of on and off showers with overrunning along the
boundary will yield rain totals of 1 to 3 inches through early next
week. Some localized amounts of 4"+ are possible back across the
Alleghenies and up into central/northeast MD. With that said, this
should ease some of the severe and extreme drought across the
region.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected to continue across the terminals through
18z/2pm ahead of a strong cold front. Sub-VFR restrictions return at
times this afternoon and evening due to widespread showers and
strong/severe thunderstorms. Expect convection to initiate in the
vicinity of KMRB/KHGR/KSHD between 18-21/2-5pm advancing east toward
the I-95 corridor terminals between 20-24z/4-8pm. Did opt for TEMPOs
toward BWI/MTN/MRB with PROB30s further south toward IAD/CHO/DCA
given hi-res model output suggesting a greater focus of convection
north of I-66/US-50. Winds will remain out of the west/southwest
ahead of the front before shifting back to the north and northwest
Thursday at 5 to 15 kts with gusts 20 to 25 kts at times. Some low
CIGS may hang on through Thursday morning as the front slowly sags
south of the region.
Periodic rain showers moving through the region on Thursday
afternoon and evening bring additional sub-VFR periods at terminals
Wind gusts could reach 15 to 20 knots on Thursday before gradually
decreasing. Sub-VFR conditions possible Friday through Sunday with
multiple rounds of showers and embedded thunderstorms. Winds
generally northeast to east 5 to 10 knots, more gusty in heavy
showers.
&&
.MARINE...
Winds may near low-end SCA levels in south to southwesterly
channeling this afternoon and evening (mainly open/wider waters),
and then again in northerly channeling on Thursday. SMWs appear
possible this afternoon and evening as thunderstorms move over the
waters.
East to northeast SCA level winds are expected over much of the bay
and surrounding inlets Friday and Saturday given increased onshore
flow. No marine hazards are expected Sunday and Monday with winds
switching back to the south and southeast.
&&
.CLIMATE...
Here are some daily temperature records during the May 19-20,
2026 timeframe:
A `+` sign indicates multiple years currently hold that record.
A `!` sign indicates the record is forecast to be tied or broken.
***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 this afternoon to 8 PM EDT this
evening for ANZ533-534-537-542-543.
Small Craft Advisory until 3 AM EDT early this morning for
ANZ534-543.
&&
$$
DISCUSSION...KLW/DHOF/EST
AVIATION...KLW/DHOF/EST
MARINE...KLW/DHOF/EST
NWS LWX Office Area Forecast Discussion