Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS Baltimore/Washington

May 3, 2021Frederick County, Washington County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at May 3, 2021, 6:50 PM EDT for Frederick County, Washington County, Maryland. It was in force for 40 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: May 3, 2021, 6:50 PM EDT (22:50 UTC)
Expired: May 3, 2021, 7:30 PM EDT
In force: 40 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Frederick County, MD, Washington County, MD

The radar

The Sterling radar (KLWX), 47 km from the middle of the area, began a volume at 22:50 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, 10.8 hours before the alert went out and 52 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1510 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 210 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

079 
WUUS51 KLWX 032250
SVRLWX
MDC021-043-032330-
/O.NEW.KLWX.SV.W.0021.210503T2250Z-210503T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
650 PM EDT Mon May 3 2021

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Southeastern Washington County in north central Maryland...
  Southwestern Frederick County in north central Maryland...

* Until 730 PM EDT.

* At 650 PM EDT, a severe thunderstorm was located near Harpers
  Ferry, or near Shepherdstown, moving east at 25 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...
  Frederick, Harry Grove Stadium, Ballenger Creek, Brunswick,
  Walkersville, Braddock Heights, Clover Hill, Jefferson,
  Buckeystown, Rosemont, Rohrersville, Burkittsville, Gapland,
  Brownsville, Bloomfield, Clifton, Arnoldtown, Utica, Petersville
  and Bolivar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3933 7772 3943 7771 3955 7736 3933 7738
TIME...MOT...LOC 2250Z 253DEG 22KT 3938 7771 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

ADS

2 follow-up statements

890 
WWUS51 KLWX 032314
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
714 PM EDT Mon May 3 2021

MDC043-032324-
/O.CAN.KLWX.SV.W.0021.000000T0000Z-210503T2330Z/
Washington MD-
714 PM EDT Mon May 3 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3936 7763 3946 7762 3955 7736 3937 7738
TIME...MOT...LOC 2314Z 253DEG 22KT 3942 7753 

$$

MDC021-032330-
/O.CON.KLWX.SV.W.0021.000000T0000Z-210503T2330Z/
Frederick MD-
714 PM EDT Mon May 3 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR WEST CENTRAL FREDERICK COUNTY IN NORTH CENTRAL MARYLAND...

At 714 PM EDT, a severe thunderstorm was located over Braddock
Heights, or near Frederick, moving east at 25 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...
Frederick, Harry Grove Stadium, Ballenger Creek, Walkersville,
Braddock Heights, Clover Hill, Jefferson, Burkittsville, Bloomfield,
Clifton, Arnoldtown, Utica, Bolivar and Middletown In Frederick Md.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3936 7763 3946 7762 3955 7736 3937 7738
TIME...MOT...LOC 2314Z 253DEG 22KT 3942 7753 

HAIL...<.75IN
WIND...60MPH
 
$$

ADS

346 
WWUS51 KLWX 032330
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
730 PM EDT Mon May 3 2021

MDC021-032339-
/O.EXP.KLWX.SV.W.0021.000000T0000Z-210503T2330Z/
Frederick MD-
730 PM EDT Mon May 3 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL FREDERICK COUNTY
IN NORTH CENTRAL MARYLAND WILL EXPIRE AT 730 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 3936 7763 3946 7762 3955 7736 3937 7738
TIME...MOT...LOC 2329Z 253DEG 22KT 3945 7742 

$$

ADS

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 3, 6:26 PM EDT	Tornado Warning	LWX	Washington	34 min
May 3, 7:08 PM EDT	Areal Flood Warning	LWX	Washington	3 hr
May 3, 7:40 PM EDT	Tornado Warning	LWX	Frederick	35 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2021 Every 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.