A weak mid level trough crossed the region on August 19th, and that combined with significant amounts of instability led to the development of isolated to scattered showers and thunderstorms. A few of these thunderstorms became strong to locally severe.
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 weak mid level trough crossed the region on August 19th, and that combined with significant amounts of instability led to the development of isolated to scattered showers and thunderstorms. A few of these thunderstorms became strong to locally 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 Aug 19, 1:32 PM EST, 2 hours 19 minutes earlier.
Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 232 PM EDT Mon Aug 19 2019 .SYNOPSIS...Hot and humid conditions will persist through Thursday with daily chances of afternoon and evening thunderstorms. A cold front will cross the area Thursday night with Canadian high pressure building in for the weekend, && .NEAR TERM /THROUGH TONIGHT/... A surface trof is noted along and east of I-95 with towering cumulus and cumulus congestus developing in that area as seen on GOES-16 imagery. This is where convective development is most likely to occur in the next hour or so. With better shear today than past few days, expect a few more severe storms today with damaging wind gusts and some hail the primary threats. Any activity will likely try to organize into a line and move to the east and exit the Chesapeake Bay this evening. Very warm and muggy tonight with low temperatures in the upper 60s to mid 70s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Hot and humid conditions will persist through mid week until cdfnt clears the fcst area late Thu or Thu night. Expect more of the same with showers and thunderstorms each afternoon with Wed being the more active day with a shortwave-trough passing by and more significant height falls. Fcst storm motions are not expected to be particularly very fast, so storms may produce heavy rainfall and isolated instances of flash flooding in addition to damaging winds and hail. Heat indices may approach the heat advisory criteria of 105F east of the Blue Ridge both Tue and Wed. && .LONG TERM /THURSDAY THROUGH MONDAY/... On Thursday, a cold front will approach the area from the Ohio Valley. This front will bring some much needed relief from the heat into the weekend. On Thursday however, with the front coming through in the afternoon, high temperatures probably still reach the upper 80s to low 90s. With dew points in the low 70s too, this will lead to heat indices into the mid to upper 90s, with a few spots approaching 100 in southern MD/central VA. The cold front moving into this environment will certainly result in some thunderstorms across the region, as evident by likely POPs Thursday afternoon. Thunderstorms that do form along the front will have 1000-2000 J/kg of CAPE and around 30kts of deep layer shear to work with. This will mean a threat for severe weather, with damaging winds and large hail being the expected threats. A lot will depend on how quickly the front moves through the area. Obviously, if the front comes through earlier than anticipated, severe threat would be more limited. So, will have to monitor over the coming days for tends in the speed of the front. Models are not very sure at all where the front goes after Thursday. The ECMWF hangs the front up near the forecast area on Friday, with norther parts of the area likely being behind the front, and areas farther south still being in warmer and more humid air. However, the GFS pushes the front out to sea very quickly Thursday night into Friday, resulting in a dry and cooler than average day area-wide. EPS ensembles show some support of both solutions honestly, with the mean hanging the front up in central VA through Saturday. Temperatures across the area will heavily depend on where that front ends up on Friday, with some areas in likely barely in the low 80s, and others closer to the upper 80s farther south. Carrying chance POPs through Friday at least, with best chances farther south. With a stalled front over the area, and a warm and humid airmass to the south, can't rule out an isolated flooding threat as well, especially if storms train along the frontal boundary. Rain chances decrease into Saturday, but could still see some in southern areas. Even the ECMWF clears the front from the area by Saturday afternoon, so expecting a dry afternoon at the very least. But could not rule out a showers or storms, especially down south, if the front is stubborn to leave. Temperatures on Saturday will be in the low 80s, and with dew points in the low 60s, it will feel much less humid. By Sunday, model guidance all agrees that the front will be long gone. Surface high pressure will be set up to our northeast. Dry conditions expected Sunday, with highs into the mid 80s or so. Again, low dew points will make it feel very comfortable out. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Sct showers/t-storms expected today mainly eastern terminals, and then all terminals Tue-Thu until cdfnt clears the area Thu night. Thunderstorms are expected on Thursday afternoon, in association with a passing cold front. These storms may produce strong winds and some hail. Coverage seems to be pretty high, so all terminals face the risk of restrictions during storms. Other than that, VFR conditions are expected for the rest of the day. More showers and storms possible on Friday, as the cold front could hang up over the region, with the best chance of coverage near CHO. Could see some lower cigs down near the front, as well as showers and storms. && .MARINE... Sct shower/t-storms expected today through Fri. Winds and waves higher near t-storms. SCA conditions possible Wed through Thu night. Generally expecting winds to remain below SCA criteria on Thursday and Friday. Though the central Bay and lower tidal Potomac may get close each afternoon. Additionally, there is a threat for showers and thunderstorms for all waters on Thursday, with potentially severe wind gusts. So Special Marine Warnings may be needed. For Friday, the threat for showers and storms will really be more confined to the central Bay and lower tidal Potomac. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...CJL AVIATION...LFR/CJL MARINE...LFR/CJL
Hazardous Weather Outlook National Weather Service Baltimore MD/Washington DC 512 AM EDT Mon Aug 19 2019 ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-200915- 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- 512 AM EDT Mon Aug 19 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 A thunderstorm may produce gusty winds on the waters today into this evening. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Thunderstorms may produce isolated damaging wind gusts and isolated instances of flooding on 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>506-200915- 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- 512 AM EDT Mon Aug 19 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 No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Thunderstorms may produce isolated damaging wind gusts and isolated instances of flooding on Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1145 AM EDT MON AUG 19 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0849 PM TSTM WND DMG 1 NW DICKERSON 39.23N 77.43W
08/18/2019 MONTGOMERY MD PUBLIC
LARGE TREE DOWN AT A RESIDENCE ON MOUTH OF MONOCACY RD.
&&
EVENT NUMBER LWX1905742
CJLPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1148 AM EDT MON AUG 19 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0849 PM TSTM WND DMG 1 NW DICKERSON 39.23N 77.43W
08/18/2019 MONTGOMERY MD PUBLIC
MULTIPLE TREES DOWN AT A RESIDENCE ON MOUTH OF MONOCACY
RD.
&&
CORRECTED REMARKS
EVENT NUMBER LWX1905742
CJLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
132 PM EDT MON AUG 19 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0307 PM TSTM WND DMG 1 SSE ELKRIDGE 39.19N 76.74W
08/18/2019 HOWARD MD FIRE DEPT/RESCUE
TREES AND WIRES DOWN NEAR IVY TERRACE AND ATHOL AVE
&&
EVENT NUMBER LWX1905743
SMZThe Sterling radar (KLWX), 130 km away, was scanning. The volume nearest the first event began at 20:49 UTC.
12 thunderstorm wind, 2 hail. Local standard time, as filed.
A barn roof was blown off near the intersection of US-11 and Smithland Road.
Multiple trees were reported blown down in the Mountain Valley Road area near Keezletown. Multiple trees were reported down in the area of Indian Trail Road near Keezletown.
Numerous large tree limbs were blown down in Massanutten.
Quarter-sized hail (1.0 in diameter) was observed near the intersection of Dick Woods Road and Ortman Road.
A tree was blown down on Sperryville Pike near Griffinsburg Road.
Multiple trees were blown down across Hydraulic Road.
A tree was blown down near Greenbrier Drive and Rio Road. A large tree was blown down blocking parts of Four Seasons Drive in the Rio area. Trees were also reported blown down on Commonwealth Drive.
A tree was blown down on River Oaks Lane in the Dunlora area of the City of Charlottesville.
A tree was blown down in the 13300 block of Albano Road. Multiple trees were also reported down on Ridge Road near Scuffletown. A tree was blown down in the 5300 block of Ridge Road.
Multiple trees were blown down on Tatums School Road.
A tree was blown down on Braddock Road near Lacys Tavern Court.
A tree was blown down on Sudley Road near Gum Springs Road.
A tree was blown down on US-50 near Cedar Lane.
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, August 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: 850154, 850155, 850156, 850152, 850153, 850157, 850158, 850159, 850160, 850161, 850162, 850163, 850164, 850165.