A few severe thunderstorms developed along a weak, stalled front.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LWX wrote it up.
A few severe thunderstorms developed along a weak, stalled front.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Baltimore/Washington wrote its last area forecast discussion before the first event at Jul 23, 2:01 PM EST, 3 hours 23 minutes earlier.
Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 301 PM EDT Thu Jul 23 2020 .SYNOPSIS... A cold front will drop south across our region late Friday. High pressure will then dominate over the weekend before a warm front advances back northward across the region on Monday. && .NEAR TERM /THROUGH TONIGHT/... Showers and an embedded thunderstorm or two are developing over western Maryland and parts of northern West Virginia. Additional showers and thunderstorms will develop across much of our region the remainder of the afternoon into early this evening. An upper level disturbance will be the culprit as it moves across central West Virginia into southwest Virginia. The main threat will be damaging winds and the possibility of flooding due to the heavy rainfall. Some training of thunderstorms may also lead to possible flooding. Mixed layer CAPE is around 1500 J/kg with about 20 to 30 kts of shear. PWAT values are between 2 and 2.25 inches. As the heaviest activity dissipates later this evening, a couple of showers may still linger into the middle of the night as the humidity hangs on during the period. Temperatures continue to push to near 90 or lower 90s. The humidity levels in the atmosphere, prior to any convection, could lead to heat indice values in the lower 100s. As of 2pm, heat indice values have reach 105 to 106 degrees in parts of southern Maryland and eastern Virginia. A Heat Advisory remains in effect through 8pm this evening. Overnight low temperatures will range from the lower to middle 60s to the middle 70s in the metro areas. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A cold front will push across the region on Friday. Until then, additional showers and thunderstorms will develop late Friday morning and Friday afternoon. Severe threat is substantially lower as well, but non-zero, particularly over southern MD. Marginal risk out from SPC for this area, with damaging winds the primary threat. Showers and thunderstorms should move to our south Friday evening. High pressure will build in Friday night. High temperatures on Friday will be in the upper 80s/low 90s, and perhaps slightly less humid as well. As a result, don't see any need for any heat headlines on Friday at this point. Dry weather is expected for most of the area. Lows will be slightly cooler than Thursday nights lows, with readings in the mid 60s to low 70s. Saturday should remain dry across the region, with high pressure building overhead. Temperatures will generally be seasonable, with highs in the low 90s. Humidity will be slightly lower too in the wake of the cold front, so again not expecting heat headlines on Saturday. Dry conditions continue into Saturday night with lows in the same range as Friday night. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Drier conditions should prevail during the later part of the weekend on Sunday with a strong upper level ridge building in from the Great Plains and Midwest. Hot and humid conditions will return in the early part of next week bringing in a consecutive round of chances for showers and storms through Wednesday with any type of shortwave energy that finds its way into our CWA. Most model guidance favors a fairly dry Monday leading to a wet pattern starting up Tuesday afternoon and evening with a cold front linked to an upper level trough north of the Canadian border. This will progress into early Wednesday with the afternoon and evening hours drying out with high pressure starting to build back in. Hot and humid conditions will build back in on Sunday allowing for temperatures to reach the low to mid 90s with heat index values potentially reaching triple digits through Tuesday with a very warm air mass overhead. Heat advisories will be possible Sunday through Tuesday. Cold front passage Tuesday night into Wednesday will bring the temperatures down to seasonal averages with lower humidity added in, trends are working more in favor for this later in the week but still early in the forecast. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... VFR conditions this afternoon through Saturday night. Any heavy showers or strong thunderstorms that pass over the terminals this afternoon and evening and again Friday afternoon could drop conditions to MVFR briefly. No significant impacts expected for terminals Sunday through Monday. Isolated sub-VFR conditions possible early Tuesday with any storms that initialize in the area. && .MARINE... Mainly light winds outside of storms the next several days. The storms will be the main marine concern, with best odds this afternoon, with reduced storm coverage likely Friday. Conditions are not expected to reach SCA criteria at this time Sunday and Monday with a weak disturbance bringing a few showers and storms to the area. Could see an isolated marine hazard be issued for any adjacent storms along the bay. && .CLIMATE... Aside from the one day last week that broke the streak of consecutive 90+ F days at Ronald Reagan Washington National Airport (KDCA), every day this month has had a high of at least 90 F. As of Wednesday afternoon, that total (for July) was up to 21 days. The most 90+ F days ever in any month in the immediate Washington, DC, area is 25 days (set in July 2011). Looking at the pattern over the next 7 days, as well as probabilities for above normal temperatures from our colleagues at the Climate Prediction Center (CPC) out to 14 days, it seems it will be very difficult to NOT break that record. For the Baltimore, Maryland, and Dulles, Virginia long-term climate records, the record most 90+ F days in a month is 24 days (also set in July 2011). As of Wednesday afternoon, Baltimore site had hit 90 F 18 times so far this month, and the Dulles site had hit 90 F 16 days. Temperature records have been kept at what is now KDCA since 1941. The official temperature records for the immediate Washington, DC, area consist of data from KDCA starting in 1945, and observations taken in downtown Washington, DC, extend the region's period of record back to 1872. Temperature records for the Baltimore, Maryland, area have been kept at what is now Baltimore-Washington International Thurgood Marshall Airport (KBWI) since 1950. Additional temperature records observed in downtown Baltimore extend the period of record back to 1872. Temperature records for the Sterling-Dulles, Virginia, area have been kept at what is now Washington Dulles International Airport (KIAD) since 1960. All climate data are considered preliminary until reviewed by the National Centers for Environmental Information (NCEI). && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Heat Advisory until 8 PM EDT this evening for MDZ016>018. VA...Heat Advisory until 8 PM EDT this evening for VAZ055>057. WV...None. MARINE...None. && SYNOPSIS...CJL NEAR TERM...KLW SHORT TERM...KLW LONG TERM...ADM AVIATION...KLW/ADM MARINE...KLW/ADM CLIMATE...CJL
Hazardous Weather Outlook National Weather Service Baltimore MD/Washington DC 239 PM EDT Thu Jul 23 2020 ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-241845- Chesapeake Bay north of Pooles Island MD- Chesapeake Bay from Pooles Island to Sandy Point MD- Chesapeake Bay from Sandy Point to North Beach MD- Chesapeake Bay from North Beach to Drum Point MD- Chesapeake Bay from Drum Point MD to Smith Point VA- Tidal Potomac from Key Bridge to Indian Head MD- Tidal Potomac from Indian Head to Cobb Island MD- Tidal Potomac from Cobb Island MD to Smith Point VA- Patapsco River including Baltimore Harbor- Chester River to Queenstown MD-Eastern Bay- Choptank River to Cambridge MD and the Little Choptank River- Patuxent River to Broomes Island MD- Tangier Sound and the inland waters surrounding Bloodsworth Island-District of Columbia-Southern Baltimore-Prince Georges- Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford- Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Stafford-Spotsylvania- King George- 239 PM EDT Thu Jul 23 2020 This Hazardous Weather Outlook is for the Maryland portion of the Chesapeake Bay, Tidal Potomac River, and adjacent counties in central Maryland and northern Virginia as well as the District of Columbia. .DAY ONE...This Afternoon and Tonight A Heat Advisory remains in effect until 8 PM this evening for southern Maryland and in the Fredericksburg area in the north- central Virginia piedmont. Scattered thunderstorms this afternoon could produce isolated damaging wind gusts and heavy rainfall, leading to isolated instances of flash flooding. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Heat indices near or above 105 degrees are possible on Monday and Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053- 055-501>506-241845- Washington-Frederick MD-Carroll-Northern Baltimore- Extreme Western Allegany-Central and Eastern Allegany- Northwest Montgomery-Central and Southeast Montgomery- Northwest Howard-Central and Southeast Howard-Northwest Harford- Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke- Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper- Northern Fauquier-Southern Fauquier-Western Highland- Eastern Highland-Western Loudoun-Eastern Loudoun- Northern Virginia Blue Ridge-Central Virginia Blue Ridge- Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant- Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton- Eastern Pendleton- 239 PM EDT Thu Jul 23 2020 This Hazardous Weather Outlook is for eastern West Virginia, northern and central Virginia, and central and western Maryland with the exception of Garrett County. .DAY ONE...This Afternoon and Tonight Scattered thunderstorms this afternoon could produce isolated damaging wind gusts and heavy rainfall, leading to isolated instances of flash flooding. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Heat indices near or above 100 degrees are possible on Monday and Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
533 PM EDT THU JUL 23 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0357 PM TSTM WND DMG 1 ENE TOWN CREEK 39.53N 78.52W
07/23/2020 ALLEGANY MD 911 CALL CENTER
TREE DAMAGE REPORTED NEAR OLD TOWN, INCLUDING ON MD-51
OLDTOWN ROAD SOUTHEAST NEAR CRABTREE LANE.
&&
EVENT NUMBER LWX2001666
DHThe Sterling radar (KLWX), 149 km away, was scanning. The volume nearest the first event began at 22:24 UTC.
6 thunderstorm wind. Local standard time, as filed.
Several trees were blown down in the North Garden area.
Several trees were blown down near Scottsville.
Several trees were blown down southeast of the City of Charlottesville.
Several trees and large branches were blown down (at least one on a power line) near the north side of the I-66 Custis Memorial Parkway and US-50 Lee Jackson Memorial Highway interchange.
Trees and wires were blown down near Lortn and Springfield, including in the 10600 block of Belmont Boulevard.
Tree damage was reported in the southeastern part of Prince William County, including near the intersection of Edgewood Drive and Northgate Drive in the Woodbridge area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2020Every state in 2020This day in weather historyWarnings in Virginia, July 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 900559, 900560, 900561, 900562, 900563, 900564.