408
FXUS61 KLWX 191357 AAA
AFDLWX
Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
957 AM EDT Tue May 19 2026
.WHAT HAS CHANGED...
Adjusted PoPs for this afternoon. Otherwise, very little change
was made.
&&
.KEY MESSAGES...
1) Record heat continues through Wednesday. A strong cold front
brings widespread strong to severe thunderstorm chances Wednesday
afternoon and evening.
2) Conditions remain showery and cool Thursday into early next week,
bringing much needed rain to the region.
&&
.DISCUSSION...
KEY MESSAGE 1... Record heat continues through Wednesday. A strong
cold front brings widespread strong to severe thunderstorm chances
Wednesday afternoon and evening.
Another day of challenging record high temperatures given the
strengthened upper level ridge over the region. After a warm
start this morning in the upper 60s and low to mid 70s,
temperatures will quickly surge. 850 mb temperatures will run
+19 to +23 degrees C yielding highs well into the mid to upper
90s this afternoon. The hottest temperatures look to be across
the immediate I-95 metros and down into the central VA Piedmont
where temperatures will run between 96 and 98 degrees. Heat
index values will be similar to the air temperatures given the
drier air at the surface and aloft. Even with that said, expect
a slight bump in humidity with afternoon dewpoints in the upper
50s and 60s making it uncomfortable for extended time outdoors.
The strengthened ridge overhead combined with the high heat should
put a lid on convection today. Still looking at a spotty shower or t-
storm this afternoon and evening as another weak piece of energy
passes through. Most of this convection will be tied to the
mountains or perhaps the bay breeze given the lack of a mean lifting
mechanism.
Wednesday will mark the last day of the high heat before
temperatures take a 25 to 30 degree nose dive late week. The front
will bring widespread showers and thunderstorms to the region
Wednesday afternoon and evening. Current 00z CAMS, and deterministic
guidance show a prefrontal trough ahead of the front Wednesday
afternoon with the actual front crossing Wednesday night into early
Thursday morning. The prefrontal trough will be the catalyst for
strong to severe thunderstorms given the ample instability and
increased shear ahead of the boundary. SPC continue to highlight the
area in a Level 1 out of 5 Marginal Risk for severe weather with
damaging winds and large hail as the primary threats. This aligns
with the NCAR`s AI NWP Convective Hazards Forecast currently has our
region outlined in its 45%-60% probability for severe weather to
occur, while CSU`s Day 2 probabilities ranks the severe threat
between 15 to 30 percent. Regardless of the severe threat, this
front will likely result in widespread beneficial rain at a minimum
as well as a 20-30 degree drop in temperatures expected later in the
week. Lingering rain showers may still be moving out of the area by
Thursday morning, while a meandering front to the south could bring
additional rain showers to the region.
Highs Wednesday will push back into the low to mid 90s with a few
upper 90s across the I-95 metros and down into the Piedmont region.
Mountain locations will be a touch cooler in the upper 70s and low
to mid 80s.
KEY MESSAGE 2...Conditions remain showery and cool Thursday into
early next week, bringing much needed rain to the region.
The synoptic scale pattern will remain relatively stagnant through
the long term period, with weak upper troughing off to our west over
the Ohio Valley, and surface high pressure off to our north and
northeast. This will lead to a pattern where marine influence low-
level easterly flow is nearly continuously overrun by south to
southwesterly flow aloft. This persistent warm advection regime
aloft atop stable low-level air will lead to cloudy skies with on
and off showers Thursday through Monday. This will bring much
needed, beneficial rains to the forecast area, with ensemble means
showing around one to two inches of rain across much of the forecast
area during that time.
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.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
VFR conditions are expected to continue across the terminals through
Wednesday morning as high pressure strengthens offshore.
South/southwesterly winds are expected again today gusting between
15 to 20 kts during the afternoon and evening hours. Spotty shower
and thunderstorm chances will occur this afternoon although coverage
will be even less today given the strengthened high pressure
overhead. With that said, did not add PROB30s in the TAFS today
given the lack of confidence although the two areas of concern would
be terminals near the terrain and close to the water given the bay
breeze influence.
Sub-VFR restrictions return at times Wednesday afternoon and evening
as a cold front brings widespread showers and thunderstorms to the
region. Winds will remain out of the southwest ahead of the front
before shifting back to the north and northwest Thursday. Some low
CIGS may hang on through Wednesday night before lifting Thursday as
the front sits 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 15-20
knots on Thursday before gradually decreasing. Sub-VFR conditions
appear likely on Friday and Saturday in association with low clouds
and showers. Winds will generally be out of the east to southeast on
both Friday and Saturday.
&&
.MARINE...
SCA southerly channeling can be expected again this afternoon and
evening. Winds will remain out of the south and southwest with gusts
up to 25 kts.
Winds may near low-end SCA levels in south to southwesterly flow on
Wednesday, and then again in northerly flow on Thursday. SMWs appear
possible Wednesday into Wednesday night as thunderstorms move over
the waters.
East to southeasterly winds may near low-end SCA levels late
Thursday through Saturday.
&&
.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.
***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...Small Craft Advisory from 2 PM this afternoon to 2 AM EDT
Wednesday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 2 AM EDT
Wednesday for ANZ530>534-537>543.
&&
$$
DISCUSSION...LFR/KJP/KRR/EST
AVIATION...LFR/KJP/EST
MARINE...LFR/KJP/EST
NWS LWX Office Area Forecast Discussion