Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 101, NWS Baltimore/Washington

June 4, 20214 counties in Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Jun 4, 2021, 1:36 PM EDT for 4 counties in Maryland. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jun 4, 2021, 1:36 PM EDT (17:36 UTC)
Expired
Jun 4, 2021, 2:15 PM EDT
In force
39 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Calvert County, MD, Charles County, MD, Prince George's County, MD, Saint Mary's County, MD

The radar

The Sterling radar (KLWX), 77 km from the middle of the area, began a volume at 17:37 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.

What was reported inside it

TimeReportWhereRemark
Jun 4, 1:53 PM EDTTSTM WND DMG1 S Bryantown, MDTREES BLEW DOWN NEAR T.C. MARTIN ELEMENTARY SCHOOL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 4, 12:59 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.6 hours before the alert went out and 70 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 381 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
381 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

921 
WUUS51 KLWX 041736
SVRLWX
MDC009-017-033-037-041815-
/O.NEW.KLWX.SV.W.0101.210604T1736Z-210604T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
136 PM EDT Fri Jun 4 2021

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Northwestern St. Marys County in southern Maryland...
  West central Calvert County in southern Maryland...
  Southeastern Prince Georges County in central Maryland...
  Northeastern Charles County in southern Maryland...

* Until 215 PM EDT.

* At 136 PM EDT, a severe thunderstorm was located over Waldorf,
  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...
  Waldorf, La Plata, Prince Frederick, Hallowing Point, Sheridan
  Point, Golden Beach, Saint Charles, Huntingtown, Hughesville,
  Baden, Mechanicsville, Charlotte Hall, Aquasco, Bryantown,
  Benedict, Eagle Harbor, Barstow and Oakville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3855 7696 3867 7681 3861 7653 3838 7664
TIME...MOT...LOC 1736Z 291DEG 23KT 3862 7687 

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

DHOF
2 follow-up statements
453 
WWUS51 KLWX 041803
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
203 PM EDT Fri Jun 4 2021

MDC009-017-033-037-041815-
/O.CON.KLWX.SV.W.0101.000000T0000Z-210604T1815Z/
St. Marys MD-Calvert MD-Prince Georges MD-Charles MD-
203 PM EDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR NORTHWESTERN ST. MARYS...WEST CENTRAL CALVERT...SOUTHEASTERN
PRINCE GEORGES AND EAST CENTRAL CHARLES COUNTIES...

At 203 PM EDT, a severe thunderstorm was located near Hallowing
Point, 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...
Prince Frederick, Hallowing Point, Sheridan Point, Golden Beach,
Huntingtown, Hughesville, Baden, Mechanicsville, Charlotte Hall,
Aquasco, Bryantown, Benedict, Eagle Harbor, Barstow and Oakville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3854 7693 3857 7680 3864 7673 3861 7653
      3838 7664
TIME...MOT...LOC 1803Z 291DEG 23KT 3856 7666 

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

RCM
300 
WWUS51 KLWX 041806
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
206 PM EDT Fri Jun 4 2021

MDC009-017-033-037-041816-
/O.EXP.KLWX.SV.W.0101.000000T0000Z-210604T1815Z/
St. Marys MD-Calvert MD-Prince Georges MD-Charles MD-
206 PM EDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ST. MARYS...WEST
CENTRAL CALVERT...SOUTHEASTERN PRINCE GEORGES AND EAST CENTRAL
CHARLES COUNTIES WILL EXPIRE AT 215 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.

A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
southern Maryland.

LAT...LON 3854 7693 3857 7680 3864 7673 3861 7653
      3838 7664
TIME...MOT...LOC 1806Z 291DEG 23KT 3856 7665 

$$

RCM

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 9:00 PM EDTAreal Flood WarningLWXBaltimore, Harford113 min
Jun 4, 12:36 PM EDTSevere Thunderstorm WarningLWXPrince George's39 min
Jun 4, 12:50 PM EDTSevere Thunderstorm WarningLWXCharles, Prince George's55 min
Jun 4, 2:17 PM EDTSevere Thunderstorm WarningLWXCalvert, Charles, Saint Mary's43 min
Jun 4, 2:50 PM EDTSevere Thunderstorm WarningLWXCalvert, Charles, Saint Mary's40 min
Jun 4, 3:19 PM EDTSevere Thunderstorm WarningLWXSaint Mary's41 min
Jun 4, 3:54 PM EDTSevere Thunderstorm WarningLWXSaint Mary's51 min
Jun 4, 4:44 PM EDTSevere Thunderstorm WarningLWXCecil22 min

Nearby

Severe 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.