778
FXUS61 KLWX 161828
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
228 PM EDT Sat May 16 2026
.WHAT HAS CHANGED...
No major changes were made to the forecast. We continue to
monitor showers and thunderstorms as they track into the
forecast area this afternoon and evening.
&&
.KEY MESSAGES...
- 1) A more organized threat for severe thunderstorms Wednesday
along a strong cold front. Turning much cooler by late week.
- 2) Hot temperatures and daily shower and thunderstorm chances
continue daily through Tuesday.
&&
.DISCUSSION...
KEY MESSAGE 1...A more organized threat for severe thunderstorms
Wednesday along a strong cold front. Turning much cooler by
late week.
Amplified mid-latitude flow continues across the country as a
sprawling upper ridge remains across the eastern U.S. down into the
Gulf of America. Looking upstream, a series of shortwaves are slated
to track toward the east and northeast in time. This eventually
flattens the northern extent of this ridge which sets the stages for
a pattern change. A much cooler pattern ensues for the latter
portions of next week.
Looking a bit more closely at the mid-week system, the stronger
height falls and wind fields may stay off to the north across New
England. Meanwhile, models do show an uptick in low-level moisture
as dew points rise into the upper 50s to low 60s. This occurs in
concert with the development of a lee trough. Ample heating that
carries high temperatures into the low/mid 90s should be enough to
yield to destabilization of the atmosphere. While showers and
thunderstorms are likely to occur given forcing from the trough and
low-level convergence along the lee trough, the severe component is
more an unknown. If the stronger wind fields with the trough to the
north near the local area, a more discernible severe threat may
emerge.
As the associated cold front exits the Mid-Atlantic region on
Thursday morning, a much cooler air mass ensues for late in the
week. This comes with an unsettled weather pattern as high pressure
builds to the north and additional disturbances track overhead in
the southwesterly flow. Given the anticyclone center across the
Great Lakes into southern Ontario, a persistent low-level north to
northeasterly wind is expected. This comes with plenty of clouds and
daily high temperatures in the mid 60s to low 70s (50s to low 60s
across the mountains).
KEY MESSAGE 2...Hot temperatures and daily shower and thunderstorm
chances continue through Tuesday.
Surface high pressure shifts offshore through early next week as
a cold front remain stalled to our northwest. Upper level
ridging building overhead combined with southerly flow at the
surface from high pressure yields above average temperatures
through Tuesday. High temperatures today will be in the 80s with
high elevations staying in the 70s. Showers and thunderstorms
approaching from the west will track east across the area this
afternoon. The best chance for any thunder is west of the Blue
Ridge as showers weaken as they track east.
By Monday, highs will be in the upper 80s to low 90s for most
with Tuesday being the warmest day of the period. Heat indices
are forecast to remain below heat headline criteria across the
area although may approach the upper 90s. In addition to hot
temperatures, daily showers and thunderstorms are possible
mainly west of the Blue Ridge. The threat for severe weather
remains low due to a lacking forcing mechanism.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Primarily VFR conditions are expected across the terminals
through early next week as high pressure remains offshore.
Southerly winds gust 15 to 20 knots this afternoon before
diminishing overnight. Light and variable winds are expected
Sunday with south winds gusting up to 15 knots Monday afternoon.
For this afternoon, showers and thunderstorms are tracking east
this afternoon and are expected to weaken as they move further
east. Have a PROB30 for -TSRA at KMRB this afternoon where
chances for any thunder are the highest. For the rest of the
airports with the exception of KCHO, have a PROB30 for -SHRA as
rain showers move across this evening. KCHO is expected to
remain dry.
Daily shower and thunderstorm chances continue into early next
with confidence on timing and location of impactful showers too
low to include in TAFs.
VFR conditions are likely on Tuesday while underneath the upper
ridge. While a stray shower or two cannot be ruled out, this should
be focused near the terrain. This comes with continued southerly
winds with afternoon gusts to around 20 knots. Heading into
Wednesday, restrictions will become more likely at times given the
widespread nature of the showers and thunderstorms. Any storm threat
gradually winds down overnight as the cold front slides off to the
east. Southwesterly winds will shift over to northwesterly before
turning northerly much of Thursday.
&&
.MARINE...
A Small Craft Advisory is in effect for the southern portions of
the tidal Potomac and the Chesapeake Bay until 11PM this
evening. South winds 10 to 15 knots with gusts up to 20 knots
are expected. Rain showers cross the waters this evening and
overnight, although no hazardous marine conditions are expected
at this time. South winds diminish overnight and are expected to
remain below SCA criteria through Monday morning. Winds increase
slightly in the afternoon, nearing advisory criteria with
additional SCAs possible.
An uptick in southerly flow may lead to some channeling effects on
Tuesday afternoon into the night, especially over the wider waters
of the Chesapeake Bay. This would support Small Craft Advisory
issuances. However, vertical mixing may be limited at times given
how warm the air is versus the colder waters beneath. Winds
eventually decrease into much of Wednesday although this comes with
a risk of convection. Showers and thunderstorms become more
widespread as a cold front nears from the west. Special Marine
Warnings may be needed as this convection rolls through on Wednesday
into Wednesday night. Behind the cold front, Small Craft Advisories
will likely be needed as northwesterlies begin to increase.
&&
.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...Small Craft Advisory until 11 PM EDT this evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for
ANZ530>534-537>543.
&&
$$
DISCUSSION...AVS/BRO
AVIATION...AVS/BRO
MARINE...AVS/BRO
NWS LWX Office Area Forecast Discussion