330
FXUS61 KLWX 021840
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
240 PM EDT Thu Jul 2 2026
.WHAT HAS CHANGED...
Extreme Heat Watch for Saturday was upgraded to an Extreme Heat
Warning, with Heat Advisories posted for Saturday in the
Shenandoah Valley, as well.
&&
.KEY MESSAGES...
- 1) Extreme heat and humidity continue through the
Independence Day holiday weekend with some relief early next
week.
- 2) An increased risk for severe thunderstorms Friday through
the Independence Day holiday weekend.
&&
.DISCUSSION...
KEY MESSAGE 1..Extreme heat and humidity continue through the
Independence Day holiday weekend with some relief early next
week.
Extreme Heat Warnings and Heat Advisories have now been issued
for each day through Independence Day (July 2-4). These are
focused around the time of the worst heat, generally from 10 AM
to 8 PM.
The strong upper-level ridge across the eastern CONUS will
maintain the ongoing heat wave through this weekend. Very hot
and humid conditions are ongoing this afternoon, with heat
indices wavering between 108 to 112 across much of the DC and
Baltimore metro areas. Dew points have not mixed out as quickly
as forecast, thus keeping highs right around the century mark.
Additional mixing through the early evening should drop dew
points to around 70F, and this will allow temps to reach the low
100s. Even in the elevated valleys of the Alleghenies there are
a few locations approaching 100 heat indices.
Expect similar, if not slightly worse, heat and humidity for
Friday across the area. High temperatures in the low 100s, with
heat indices of 110-113 east of the Blue Ridge, and 100-108 to
the west. There may be a few pop up thunderstorms in central VA
to central Shenandoah Valley tomorrow, but coverage won`t be
high enough to bring widespread relief from the extreme heat.
It is possible we may need to add most, if not all, of our
mountain locations to the Heat Advisory for Friday given
tomorrow will be the hottest day of this heat wave.
For Independence Day, temperatures are forecast to be just a tad
less than today and Friday, but it is still going to be very
hot. Highs reach the upper 90s to around 100F, with heat indices
ranging from 100-108. There is some lingering uncertainty
regarding temps on Saturday, due to any possible cloud cover or
early start to afternoon convection. There is similar
uncertainty for Sunday regarding temperatures, though
unfortunately it looks to remain very humid and hot enough for
heat indices to reach 95-105 during the afternoon.
Very warm and muggy each night as temps struggle to fall to the
mid to upper 70s, with the immediate DC and Baltimore city areas
staying above 80F through the night. Daily record high
temperatures may be challenged at several locations over the
next few days. See the climate section at the bottom of the
forecast discussion for more details.
KEY MESSAGE 2..An increased risk for severe thunderstorms Friday
through the Independence Day holiday weekend.
Strong capping and downsloping flow should aid in no convective
development today as the upper level ridge axis sets up overhead.
Shower and thunderstorm chances return Friday into the weekend as
the ridge slowly buckles and several shortwave disturbances pivot
around it`s northern edge. Looking at isolated coverage Friday given
the residual capping inversion. Current 06/12z CAMS favor the
terrain as well as the Shenandoah Valley/central VA Piedmont for the
highest odds to see thunderstorm development Friday
afternoon/evening. A secondary area of note may be across north-
central MD due to convection over PA/NJ from a spoke of shortwave
energy running over top of the ridge. Even with that said, an
isolated shower or t-storm cannot be ruled out areawide due in part
to the bay/river breezes as well as the excessive heat/humidity.
Shear will be lacking, but pulse storms that produce strong
downbursts will be possible, given the very high CAPE/DCAPE, steep
low-level lapse rate environment in place. SPC continues to place a
majority of the forecast area outlooked in a Marginal Risk (Level 1
out of 5) for severe thunderstorms Friday between 2-9pm.
Scattered to numerous thunderstorms are looking likely for
Saturday/Independence Day and Sunday. Less of a capping inversion
will be in place Saturday as the ridge continues to buckle.
Meanwhile, height falls will continue aloft as a leading shortwave
trough ahead of a cold front pushes through. The trough will pass
through Saturday with the cold front slow to cross Sunday into early
next week. MLCAPE Saturday will sit around 3000 J/kg with DCAPE
values well over 1000 J/kg. However, winds in the 700-500 hPa layer
(shear) will start to increase to near 30 knots, which when combined
with the lesser capping and stronger large scale forcing for ascent
may lead to both higher coverage, and greater organization of storms
Very strong downbursts and damaging winds (gusts up to 70 mph) will
be possible with any thunderstorms on Saturday. SPC currently has
the majority of the forecast area outlooked in a Slight Risk (Level
2 out of 5) for severe thunderstorms. Similar conditions are
expected Sunday given the cold front dropping through the region.
SPC continues to highlight a 15 percent probability for severe
weather Sunday afternoon and evening which aligns with 15-30 percent
probs from CSU/CIPS/NSSL probabilities. Wind will once again be the
main threat along with locally heavy rainfall/isolated instances of
urban flooding due to potentially slow moving storms along the
boundary.
The upper level ridge continues to break down early next week as the
upper level trough kicks east from the Great Lakes and it`s
associated cold front sags south into the region. The front will be
slow to move south Monday into Tuesday with additional waves of low
pressure moving along it leading to additional chances of showers
and thunderstorms. Once again, coverage could be scattered to
numerous with winds and locally heavy rainfall as the predominant
concerns. This aligns with NCAR`s AI NWP Convective Hazards
forecast and CSU/NSSL/CIPS probs which continue to show 10-20
percent probs for severe weather across the region. These
probabilities remain elevated through midweek as an additional
trough/cold front move toward the region mid to late next week. Even
with that said, the synoptic/mesoscale setup in the days beforehand
will be critical in understanding the nature & scope of
thunderstorms during this period.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Prevailing VFR conditions expected through Friday, then
showers and thunderstorms expected Saturday through Tuesday.
There could be a few thunderstorms Friday around CHO, then more
widespread thunderstorms Saturday through Monday during the
diurnal periods (18z/2pm-02/10pm). Some of the storms could
potentially turn strong to severe with damaging winds, frequent
lightning, and locally heavy rainfall as the primary threats.
Outside of storms, winds will largely be light and variable over
the next several days given the bay/river breezes and high
pressure overhead. Wind speeds will be less than 10 kts
sustained with intermittent gusts up to 15 kts.
&&
.MARINE...
Southerly channeling will bring gusts up to around 20 knots over
the main channel of the Chesapeake Bay late this afternoon to
evening. Thunderstorm chances return to the waters Friday into
the Independence Day holiday weekend. Coverage will be isolated
Friday mainly along the western shore of the bay due to the bay
breeze influence. By Saturday and Sunday, scattered to numerous
thunderstorms are expected as a leading trough of low pressure
ahead of a cold front passes through. Some of these storms may
potentially be on the stronger side, with SMWs likely at times.
Winds stay below SCA levels Sunday & Monday. Showers &
thunderstorms are possible in the afternoon & evening hours
through early next week.
&&
.CLIMATE...
There is a significant heat risk this week. The numbers below
aren`t a forecast, but rather a reference for historical context
for comparison. Latest forecast: weather.gov/lwx. Note that
Dulles did break a record today with the high temperature of 97
degrees (July 1, 2026).
==================================================================
*** ALL-TIME RECORD HIGHS ***
==================================================================
Baltimore 107 (set on Jul 10, 1936)
Washington 106 (set on Jul 20, 1930 + Aug 06, 1918)
Sterling-Dulles Airport 105 (set on Jul 22, 2011)
Baltimore Downtown 108 (set on Jul 07, 2012 + Jul 22, 2011)
Annapolis 106 (set on Aug 06, 1918)
Hagerstown 105 (set on Jul 14, 1954)
Martinsburg 112 (set on Jul 11, 1936)
Charlottesville 107 (set on Sep 07, 1954 + 3 other times)
==================================================================
*** ALL-TIME RECORD WARM LOWS ***
==================================================================
Baltimore 83 (set on Aug 05, 1930 + 2 other times)
Washington 84 (set on Jul 24, 2011 + 2 other times)
Sterling-Dulles Airport 79 (set on Aug 08, 2007)
Baltimore Downtown 88 (set on Jul 22, 2011 and Jul 10, 1993)
Annapolis 92 (set on Jul 07, 1994)
Hagerstown 86 (set on Jun 15, 1899)
Martinsburg 86 (set on Jul 21, 1930)
Charlottesville 85 (set on Aug 07, 1918)
==================================================================
*** JULY MONTHLY RECORD HIGHS ***
==================================================================
Baltimore 107 (set on Jul 10, 1936)
Washington 106 (set on Jul 20, 1930)
Sterling-Dulles Airport 105 (set on Jul 22, 2011)
Baltimore Downtown 108 (set on Jul 07, 2012 + Jul 22, 2011)
Annapolis 105 (set on Jul 21, 1930 + Jul 02, 1901)
Hagerstown 105 (set on Jul 14, 1954)
Martinsburg 112 (set on Jul 11, 1936)
Charlottesville 107 (set on Jul 10, 1936 + Jul 20, 1930)
==================================================================
*** JULY MONTHLY RECORD WARM LOWS ***
==================================================================
Baltimore 83 (set on Jul 21, 1930)
Washington 84 (set on Jul 24, 2011 + 2 other times)
Sterling-Dulles Airport 78 (set on Jul 24, 2010 + Jul 08, 2010)
Baltimore Downtown 88 (set on Jul 22, 2011 + Jul 10, 1993)
Annapolis 92 (set on Jul 07, 1994)
Hagerstown 83 (set on Jul 24, 2010)
Martinsburg 86 (set on Jul 21, 1930)
Charlottesville 84 (set on Jul 22, 1930)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: Jul 02
==================================================================
Baltimore 103 (1901) | 80 (1901)
Washington 101 (1898) | 79 (2012 + 1872)
Sterling-Dulles Airport 98 (1966) | 75 (2022)
Baltimore Downtown 102 (1966) | 84 (2002)
Annapolis 105 (1901) | 80 (1901)
Hagerstown 100 (1966) | 74 (2018 + 1901)
Martinsburg 102 (1933 + 1931) | 75 (1933 + 1901)
Charlottesville 100 (1954) | 76 (1910)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: Jul 03
==================================================================
Baltimore 104 (1898) | 80 (1898)
Washington 101 (1966 + 2) | 80 (2018)
Sterling-Dulles Airport 103 (1966) | 73 (2018 + 2)
Baltimore Downtown 102 (1997) | 82 (2018 + 1983)
Annapolis 100 (1901) | 84 (1896)
Hagerstown 102 (1966) | 76 (2002)
Martinsburg 102 (1941 + 1911) | 74 (1980)
Charlottesville 100 (1966 + 1954) | 79 (1911)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: Jul 04
==================================================================
Baltimore 100 (2002 + 2) | 78 (1911)
Washington 100 (1919) | 80 (2018 + 2002)
Sterling-Dulles Airport 97 (2002 + 1999) | 75 (2018)
Baltimore Downtown 101 (2002 + 1990) | 83 (2002)
Annapolis 98 (1999) | 81 (2018)
Hagerstown 100 (1966 + 1919) | 76 (2018)
Martinsburg 103 (1898) | 76 (1999)
Charlottesville 100 (2012) | 78 (1919)
-----------------------------------------------------------------
Number of Consecutive Days Max Temp >=100
Area (obs site) Records since
------------------------------------------------------------------
Baltimore (BWI) 4 days July 14-17,2024 & July 19-22,1930
Washington (DCA) 4 days July 14-17, 2024 & July 5-8, 2012
Sterling-Dulles (IAD) 2 days July 7-8, 2012, July 21-22, 2011
July 6-7, 2010, July 16-17, 1997
Baltimore Downtown (DMH) 5 days July 3-7, 2010 & July 7-11, 1993
Annapolis (NAK) 1 day July 21, 2019, July 7, 2012,
July 22, 2011, June 29, 1959
Hagerstown (HGR) 3 days July 5-7, 2010
Martinsburg (MRB) 6 days June 1-6, 1925
Charlottesville (CHO) 5 days July 4-8, 2012
Period of Record (POR) context...
Area (obs site) Records since
------------------------------------------------------------------
Baltimore (BWI) Jan 1872
Washington (DCA) Jul 1872
Sterling-Dulles Airport (IAD) Jan 1960
Baltimore Downtown (DMH) Jul 1950
Annapolis (NAK) Jan 1894
Hagerstown (HGR) Jan 1899
Martinsburg (MRB) Jan 1891
Charlottesville (CHO) Jan 1893
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Extreme Heat Warning until 8 PM EDT this evening for DCZ001.
Extreme Heat Warning from 10 AM to 8 PM EDT Friday for DCZ001.
Extreme Heat Warning from 10 AM to 8 PM EDT Saturday for
DCZ001.
MD...Extreme Heat Warning until 8 PM EDT this evening for
MDZ003>006-008-011-013-014-016>018-502>508.
Extreme Heat Warning from 10 AM to 8 PM EDT Friday for
MDZ003>006-008-011-013-014-016>018-502>508.
Extreme Heat Warning from 10 AM to 8 PM EDT Saturday for
MDZ004>006-008-011-013-014-016>018-503>508.
Small Craft Advisory until 2 AM EDT Friday for MDZ008.
Heat Advisory from 10 AM to 8 PM EDT Saturday for MDZ003.
Heat Advisory until 8 PM EDT this evening for MDZ501.
Heat Advisory from 10 AM to 8 PM EDT Friday for MDZ501.
VA...Extreme Heat Warning until 8 PM EDT this evening for
VAZ027>031-036>040-050-051-053>057-501-502-505-506-526-
527.
Extreme Heat Warning from 10 AM to 8 PM EDT Friday for
VAZ027>031-036>040-050-051-053>057-501-502-505-506-526-
527.
Extreme Heat Warning from 10 AM to 8 PM EDT Saturday for
VAZ036>040-050-051-053>057-501-502-505-506-526-527.
Heat Advisory from 10 AM to 8 PM EDT Saturday for VAZ025>031.
Heat Advisory until 8 PM EDT this evening for VAZ025-026-504.
Heat Advisory from 10 AM to 8 PM EDT Friday for VAZ025-026-504.
WV...Extreme Heat Warning until 8 PM EDT this evening for
WVZ050>053-055-502-504.
Extreme Heat Warning from 10 AM to 8 PM EDT Friday for
WVZ050>053-055-502-504.
Heat Advisory from 10 AM to 8 PM EDT Saturday for WVZ050>053-
055.
Heat Advisory until 8 PM EDT this evening for WVZ503-506.
Heat Advisory from 10 AM to 8 PM EDT Friday for WVZ503-506.
MARINE...Extreme Heat Warning until 8 PM EDT this evening for ANZ530.
Extreme Heat Warning from 10 AM to 8 PM EDT Friday for ANZ530.
Extreme Heat Warning from 10 AM to 8 PM EDT Saturday for
ANZ530.
Small Craft Advisory until 2 AM EDT Friday for ANZ530>534-
537>543.
&&
$$
DISCUSSION...KRR/EST/KJP
AVIATION...KRR/EST/KJP
MARINE...KRR/EST/KJP
NWS LWX Office Area Forecast Discussion