An approaching cold front coupled with upper level shortwave energy and instability across the region led to the development of afternoon scattered showers and thunderstorms. Several of these thunderstorms became severe.
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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.
An approaching cold front coupled with upper level shortwave energy and instability across the region led to the development of afternoon scattered showers and thunderstorms. Several of these thunderstorms became severe.
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 6, 2:04 PM EST, 1 hour 30 minutes earlier.
Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 304 PM EDT Sat Jul 6 2019 .SYNOPSIS... A weak cold front will approach from the northwest this weekend before settling to our south early next week. High pressure will then build north of the area into the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Hot and humid air mass remains in place, with heat indices into the low 100s in many places. This combination is fueling scattered showers and thunderstorms, but with minimal shear, the main severe mode should be pulse through the afternoon. A linear system is expected to evolve in Pennsylvania this afternoon and drop southward toward our area this evening, but odds favor the storms beginning to weaken when they arrive in the metro. That said, this potential line is the main source of any organized severe threat. With high PW's and relatively slow storm motion, any back-building or training could result in a flash flood risk, but right now it appears a bit too isolated to warrant a watch, so have held off for now. After dark, most convection should start to wane as we lose our main forcing mechanism, and patchy fog/low clouds may develop as they did last night. Lows in the muggy 70s. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... Cold front will slide southward into the region late Sunday and cross the metro by early Monday. An upper level disturbance will also cross the region during this time. These two factors, combined with very high PW's in excess of 2 inches, may result in heavy rain with any storms. The main factor against flooding is CAPE, because clouds may keep instability more limited on Sunday than today, but its possible we need a flash flood watch for Sunday. With minimal CAPE and shear, severe risk should be lower than today. Highs will be in the upper 80s in general, while lows will slip into the 60s outside the cities. Front crosses the metro early Monday morning and clears the rest of the forecast area by later in the afternoon. This will result in a chance of showers and storms in central VA/Shenandoah Valley on Monday, with a lower risk further north where drier and more stable air will be building in. Temps and humidity will both decline somewhat behind the front, with highs in the 80s. Lows at night will also drop into the 60s in most areas. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Tuesday and Wednesday look dry, with high temperatures near, to slightly below, average thanks to surface high pressure building in from the north. High temperatures on both days will be in the mid to upper 80s. High pressure pushes offshore by Thursday ahead of an approaching mid-upper trough and associated surface low. As a result, Thursday will be slightly warmer, and noticeably more humid. The cold front associated with the aforementioned area of low pressure, sliding across the northeast, will slide through the region on Thursday. As a result, showers and thunderstorms are expected. Given the warm and humid air mass and at least modest shear, owing to the close proximity of the mid-upper trough, some storms could produce gusty winds and maybe even some hail. A little too far out to say for sure, but can't rule it out. High pressure builds in on Friday behind the front, with high temperatures expected to be near, to slightly below, average. No precipitation is expected Friday at this time. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... Main concern thru this evening is scattered thunderstorms, which may briefly produce sub-VFR conditions in heavy rain and gusty winds. Storms die out overnight, but will need to watch for reduced visibility and cigs due to patchy fog and low clouds. Biggest concern will be MRB/CHO, but can't rule out it impacting a larger terminal as well, as we saw with the low cigs at DCA this morning. After sunrise Sunday, concern will again become scattered to numerous showers and thunderstorms. Convective risk begins to dwindle on Monday, with only isolated risk in the north (Perhaps no risk at all BWI/MTN). VFR conditions expected Tuesday and Wednesday, as high pressure keeps things dry. Not expecting any wind issues either, with light winds expected both days. && .MARINE... Southerly channeling combined with scattered thunderstorms have prompted the issuance of a small craft advisory through this evening. Winds will be marginal except in thunderstorms, and Special Marine Warnings may still be necessary. Storms should die out overnight, but likely redevelop on Sunday, with similar hazards. Storm risk declines significantly Monday behind a cold front, but cold advection behind the front may result in SCA gusts. Winds remain below SCA criteria for at least Tuesday and Wednesday, as high pressure builds over the region. && .TIDES/COASTAL FLOODING... Southerly flow has resulted in elevated anomalies. As the winds start to shift northerly early next week, anomalies should decline, but until then, sensitive sites likely reach action stage, and could hit minor flood stage. Will continue to monitor. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until midnight EDT tonight for ANZ530>543. && SYNOPSIS...RCM NEAR TERM...RCM SHORT TERM...RCM LONG TERM...CJL AVIATION...RCM/CJL MARINE...RCM/CJL TIDES/COASTAL FLOODING...RCM
Hazardous Weather Outlook National Weather Service Baltimore MD/Washington DC 807 AM EDT Sat Jul 6 2019 ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-071215- 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- 807 AM EDT Sat Jul 6 2019 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...Today and Tonight Scattered thunderstorms this afternoon and evening could lead to isolated instances of flooding and damaging wind gusts. .DAYS TWO THROUGH SEVEN...Sunday through Friday Scattered thunderstorms will lead to an isolated threat for damaging wind gusts Sunday afternoon and evening. Locally heavy rain may cause isolated flooding as well. Confidence remains low on exact timing and location of the potential hazardous weather. .SPOTTER INFORMATION STATEMENT... Spotter activation will be possible Saturday afternoon and evening. Please forward storm reports to the National Weather Service. MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053- 055-501>506-071215- 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- 807 AM EDT Sat Jul 6 2019 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...Today and Tonight Scattered thunderstorms this afternoon and evening could lead to isolated instances of flooding and damaging wind gusts. .DAYS TWO THROUGH SEVEN...Sunday through Friday Scattered thunderstorms will lead to an isolated threat for damaging wind gusts Sunday afternoon and evening. Locally heavy rain may cause isolated flooding as well. Confidence remains low on exact timing and location of the potential hazardous weather. .SPOTTER INFORMATION STATEMENT... Spotter activation will be possible Saturday afternoon and evening. Please forward storm reports to the National Weather Service.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
334 PM EDT SAT JUL 06 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0247 PM MARINE TSTM WIND 1 NNW EASTPORT 38.99N 76.49W
07/06/2019 M52 MPH ANNE ARUNDEL MD ASOS
&&
EVENT NUMBER LWX1905042
MMThe Sterling radar (KLWX), 137 km away, was scanning. The volume nearest the first event began at 20:32 UTC.
8 thunderstorm wind. Local standard time, as filed.
A tree was blown down in the 7000 block of Singers Glen Road blocking one lane of traffic.
A tree was blown down onto power lines in the 300 block of West Duck Street.
A tree was blown down on Marcum Farm Court near the intersection with Evergreen Mills Road.
A 50 knot wind gust was measured at Sterling Middle School. Several reports of trees down in Sterling, including on North Kennedy Road, Pinewood Court, and North Duke Drive.
Numerous trees were blown down along Sterling Boulevard, some as much as 8 inches in diameter, through the center of Sterling Park. Bleachers were overturned at Bill Allen Field.
A tree was blown down across Forest Ridge Road near Crestview Drive.
Six trees were blown down along VA-7 near Reston.
Several trees and large limbs were blown down along the George Washington Memorial Parkway between I-495 and Chain Bridge.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2019Every state in 2019This day in weather historyWarnings in Virginia, July 2019
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: 844015, 844016, 844017, 844018, 844022, 844019, 844021, 844020.