Alert archive / West Virginia / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 521, NWS Baltimore/Washington
NWS Baltimore/Washington issued this severe thunderstorm warning at Sep 15, 2021, 6:23 PM EDT for Berkeley County, Jefferson County, West Virginia; Frederick County, Washington County, Maryland. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 15, 2021, 6:23 PM EDT (22:23 UTC)
- Expired
- Sep 15, 2021, 7:15 PM EDT
- In force
- 52 min
- Issued by
- NWS Baltimore/Washington
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Frederick County, MD, Washington County, MD, Berkeley County, WV, Jefferson County, WV
The radar
The Sterling radar (KLWX), 61 km from the middle of the area, began a volume at 22:24 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.4 hours before the alert went out and 67 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 13 J/kg
- Mixed-layer CIN
- -270 J/kg
- Mixed-layer LCL
- 1457 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 73 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
487
WUUS51 KLWX 152223
SVRLWX
MDC021-043-WVC003-037-152315-
/O.NEW.KLWX.SV.W.0521.210915T2223Z-210915T2315Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
623 PM EDT Wed Sep 15 2021
The National Weather Service in Sterling Virginia has issued a
* Severe Thunderstorm Warning for...
East central Washington County in north central Maryland...
West central Frederick County in north central Maryland...
Northeastern Jefferson County in the Panhandle of West Virginia...
East central Berkeley County in the Panhandle of West Virginia...
* Until 715 PM EDT.
* At 623 PM EDT, a severe thunderstorm was located near Martinsburg,
moving east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damaging winds will cause some trees and large branches
to fall. This could injure those outdoors, as well as
damage homes and vehicles. Roadways may become blocked by
downed trees. Localized power outages are possible.
Unsecured light objects may become projectiles.
* Locations impacted include...
Martinsburg, Shepherdstown, Boonsboro, Mount Aetna, Mount Lena, San
Mar, Wolfsville, Saint James, Berkeley, Myersville, Keedysville,
Sharpsburg, Fairplay, Rohrersville, Winebrenners Cross, Pleasant
Walk and Bolivar.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3940 7797 3949 7802 3960 7756 3946 7750
TIME...MOT...LOC 2223Z 253DEG 26KT 3946 7792
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
MSS3 follow-up statements
220
WWUS51 KLWX 152235
SVSLWX
Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
635 PM EDT Wed Sep 15 2021
MDC021-043-WVC003-037-152315-
/O.CON.KLWX.SV.W.0521.000000T0000Z-210915T2315Z/
Washington MD-Frederick MD-Jefferson WV-Berkeley WV-
635 PM EDT Wed Sep 15 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR EAST CENTRAL WASHINGTON AND WEST CENTRAL FREDERICK COUNTIES IN
NORTH CENTRAL MARYLAND...NORTHEASTERN JEFFERSON AND EAST CENTRAL
BERKELEY COUNTIES IN THE PANHANDLE OF WEST VIRGINIA...
At 634 PM EDT, a severe thunderstorm was located near Shepherdstown,
moving east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damaging winds will cause some trees and large branches to
fall. This could injure those outdoors, as well as damage
homes and vehicles. Roadways may become blocked by downed
trees. Localized power outages are possible. Unsecured
light objects may become projectiles.
Locations impacted include...
Shepherdstown, Boonsboro, Mount Aetna, Mount Lena, San Mar,
Wolfsville, Saint James, Myersville, Keedysville, Sharpsburg,
Fairplay, Rohrersville, Winebrenners Cross, Pleasant Walk and
Bolivar.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3941 7793 3952 7789 3960 7756 3946 7750
TIME...MOT...LOC 2234Z 253DEG 26KT 3948 7782
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
MSS403
WWUS51 KLWX 152245
SVSLWX
Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
645 PM EDT Wed Sep 15 2021
MDC021-043-WVC003-037-152315-
/O.CON.KLWX.SV.W.0521.000000T0000Z-210915T2315Z/
Washington MD-Frederick MD-Jefferson WV-Berkeley WV-
645 PM EDT Wed Sep 15 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR EAST CENTRAL WASHINGTON AND WEST CENTRAL FREDERICK COUNTIES IN
NORTH CENTRAL MARYLAND...NORTHEASTERN JEFFERSON AND EAST CENTRAL
BERKELEY COUNTIES IN THE PANHANDLE OF WEST VIRGINIA...
At 645 PM EDT, a severe thunderstorm was located near Boonsboro, or
near Shepherdstown, moving east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damaging winds will cause some trees and large branches to
fall. This could injure those outdoors, as well as damage
homes and vehicles. Roadways may become blocked by downed
trees. Localized power outages are possible. Unsecured
light objects may become projectiles.
Locations impacted include...
Shepherdstown, Boonsboro, Mount Lena, San Mar, Wolfsville,
Myersville, Keedysville, Sharpsburg, Fairplay, Rohrersville, Pleasant
Walk and Bolivar.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3941 7790 3951 7784 3960 7756 3946 7750
TIME...MOT...LOC 2245Z 253DEG 26KT 3950 7772
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
MSS856
WWUS51 KLWX 152305
SVSLWX
Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
705 PM EDT Wed Sep 15 2021
MDC021-043-WVC003-037-152315-
/O.EXP.KLWX.SV.W.0521.000000T0000Z-210915T2315Z/
Washington MD-Frederick MD-Jefferson WV-Berkeley WV-
705 PM EDT Wed Sep 15 2021
...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WASHINGTON AND
WEST CENTRAL FREDERICK COUNTIES IN NORTH CENTRAL MARYLAND...
NORTHEASTERN JEFFERSON AND EAST CENTRAL BERKELEY COUNTIES IN THE
PANHANDLE OF WEST VIRGINIA WILL EXPIRE AT 715 PM EDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Sterling Virginia.
LAT...LON 3941 7790 3951 7784 3960 7756 3946 7750
TIME...MOT...LOC 2305Z 253DEG 26KT 3954 7756
$$
MSSThe office that day
Everything else NWS Baltimore/Washington issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 15, 3:45 PM EDT | Severe Thunderstorm Warning | LWX | Morgan | 16 min |
| Sep 15, 5:52 PM EDT | Severe Thunderstorm Warning | LWX | Berkeley | 38 min |
| Sep 15, 6:28 PM EDT | Severe Thunderstorm Warning | LWX | Berkeley | 34 min |
| Sep 15, 2:54 PM EDT | Coastal Flood Advisory | LWX | Anne Arundel, Baltimore, Harford, City of Baltimore | 13 hr |
| Sep 15, 5:15 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 30 min |
| Sep 15, 5:42 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 48 min |
| Sep 15, 5:52 PM EDT | Areal Flood Warning | LWX | Washington | 115 min |
| Sep 15, 6:20 PM EDT | Flash Flood Warning | LWX | Washington | 2 hr |
| Sep 15, 6:35 PM EDT | Areal Flood Warning | LWX | Frederick, Washington | 113 min |
| Sep 15, 7:22 PM EDT | Flash Flood Warning | LWX | Frederick, Washington | 64 min |
Nearby
Severe Thunderstorm Warnings in West Virginia, 2021Severe Thunderstorm Warnings in Maryland, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.