Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 511, NWS Baltimore/Washington

September 1, 2021Anne Arundel County, Prince George's County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Sep 1, 2021, 4:00 AM EDT for Anne Arundel County, Prince George's County, Maryland. It was in force for 60 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 1, 2021, 4:00 AM EDT (08:00 UTC)
Expired: Sep 1, 2021, 5:00 AM EDT
In force: 60 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Anne Arundel County, MD, Prince George's County, MD

The radar

The Sterling radar (KLWX), 86 km from the middle of the area, began a volume at 08:04 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 watch it was issued in

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

Issued	Product	Office	Lasted
Sep 1, 12:56 AM EDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 8.0 hours before the alert went out and 79 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: 723 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 969 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 171 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

991 
WUUS51 KLWX 010800
SVRLWX
MDC003-033-010900-
/O.NEW.KLWX.SV.W.0511.210901T0800Z-210901T0900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
400 AM EDT Wed Sep 1 2021

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Anne Arundel County in central Maryland...
  Northeastern Prince Georges County in central Maryland...

* Until 500 AM EDT.

* At 400 AM EDT, a severe thunderstorm was located over
  Lanham-Seabrook, or over Greenbelt, moving northeast at 30 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  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...
  Baltimore, Bowie, Severn, Annapolis, Crofton, Riviera Beach, Naval
  Academy, Baltimore-Washington Airport, Severn River, Fort Smallwood
  State Park, Gibson Island, Sillery Bay, Bodkin Point, Magothy
  River, Dobbins Island, Pinehurst, Glen Burnie, Severna Park,
  Odenton and Laurel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 AM EDT for central and
northern Maryland.

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

A Tornado Watch remains in effect until 800 AM EDT for central and
northern Maryland.

&&

LAT...LON 3896 7645 3889 7680 3907 7689 3922 7657
      3920 7655 3921 7653 3923 7656 3924 7652
      3921 7649 3922 7646 3920 7645 3921 7642
      3918 7644 3920 7650 3914 7641 3906 7642
      3901 7638
TIME...MOT...LOC 0800Z 246DEG 27KT 3898 7684 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJL

2 follow-up statements

674 
WWUS51 KLWX 010823
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
423 AM EDT Wed Sep 1 2021

MDC003-033-010900-
/O.CON.KLWX.SV.W.0511.000000T0000Z-210901T0900Z/
Anne Arundel MD-Prince Georges MD-
423 AM EDT Wed Sep 1 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 AM EDT
FOR NORTHERN ANNE ARUNDEL AND NORTHEASTERN PRINCE GEORGES COUNTIES...

At 423 AM EDT, a severe thunderstorm was located over Millersville,
or near Crofton, moving northeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

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...
Bowie, Severn, Crofton, Riviera Beach, Baltimore-Washington Airport,
Magothy River, Dobbins Island, Fort Smallwood State Park, Pinehurst,
Gibson Island, Sillery Bay, Bodkin Point, Glen Burnie, Severna Park,
Odenton, Pasadena, Arnold, Lake Shore, Ferndale and Parole.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 AM EDT for central and
northern Maryland.

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3898 7676 3911 7680 3922 7657 3921 7658
      3920 7655 3921 7653 3923 7656 3924 7652
      3921 7649 3921 7648 3920 7646 3922 7646
      3920 7645 3920 7642 3918 7644 3920 7650
      3918 7646 3914 7641 3906 7642 3901 7638
TIME...MOT...LOC 0823Z 246DEG 27KT 3905 7663 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJL

737 
WWUS51 KLWX 010846
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
446 AM EDT Wed Sep 1 2021

MDC033-010855-
/O.CAN.KLWX.SV.W.0511.000000T0000Z-210901T0900Z/
Prince Georges MD-
446 AM EDT Wed Sep 1 2021

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

A Tornado Watch remains in effect until 800 AM EDT for central and
northern Maryland.

LAT...LON 3906 7642 3906 7661 3917 7667 3922 7657
      3920 7655 3921 7653 3923 7656 3924 7652
      3921 7649 3921 7648 3920 7646 3922 7646
      3920 7645 3920 7642 3918 7644 3920 7650
      3919 7649 3914 7641
TIME...MOT...LOC 0845Z 242DEG 24KT 3912 7656 

$$

MDC003-010900-
/O.CON.KLWX.SV.W.0511.000000T0000Z-210901T0900Z/
Anne Arundel MD-
446 AM EDT Wed Sep 1 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 AM EDT
FOR NORTHEASTERN ANNE ARUNDEL COUNTY...

At 445 AM EDT, a severe thunderstorm was located over Green Haven, or
near Riviera Beach, moving northeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

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...
Baltimore, Severn, Riviera Beach, Baltimore-Washington Airport, Fort
Smallwood State Park, Pinehurst, Dobbins Island, Gibson Island,
Sillery Bay, Bodkin Point, Glen Burnie, Severna Park, Pasadena,
Arnold, Lake Shore, Ferndale, Brooklyn Park, South Gate, Green Haven
and Edgemere.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 AM EDT for central and
northern Maryland.

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3906 7642 3906 7661 3917 7667 3922 7657
      3920 7655 3921 7653 3923 7656 3924 7652
      3921 7649 3921 7648 3920 7646 3922 7646
      3920 7645 3920 7642 3918 7644 3920 7650
      3919 7649 3914 7641
TIME...MOT...LOC 0845Z 242DEG 24KT 3912 7656 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJL

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 9:06 PM EDT	Coastal Flood Watch	LWX	Anne Arundel	22 hr
Aug 31, 9:36 PM EDT	River Flood Warning	LWX	Washington	68 hr
Aug 31, 9:44 PM EDT	River Flood Watch	LWX	Frederick	25 hr
Aug 31, 9:44 PM EDT	River Flood Watch	LWX	Montgomery	48 hr
Aug 31, 9:44 PM EDT	River Flood Watch	LWX	Washington	25 hr
Aug 31, 9:44 PM EDT	River Flood Watch	LWX	Montgomery	25 hr
Sep 1, 3:23 AM EDT	Areal Flood Warning	LWX	Montgomery	8 hr
Sep 1, 3:24 AM EDT	Severe Thunderstorm Warning	LWX	Montgomery, Prince George's	51 min
Sep 1, 3:50 AM EDT	Areal Flood Warning	LWX	Montgomery, Prince George's	6 hr
Sep 1, 4:10 AM EDT	Areal Flood Warning	LWX	Anne Arundel, Baltimore, Howard, City of Baltimore	6 hr
Sep 1, 4:34 AM EDT	Areal Flood Warning	LWX	Montgomery	6 hr
Sep 1, 4:39 AM EDT	Areal Flood Warning	LWX	Anne Arundel, Baltimore, Howard, City of Baltimore	5 hr
Sep 1, 4:50 AM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, City of Baltimore	40 min
Sep 1, 5:41 AM EDT	Areal Flood Warning	LWX	Cecil, Harford	5 hr
Sep 1, 6:15 AM EDT	Areal Flood Warning	LWX	Cecil	5 hr
Sep 1, 8:39 AM EDT	Flash Flood Warning	LWX	Allegany, Garrett	5 hr
Sep 1, 10:14 AM EDT	Coastal Flood Advisory	LWX	Anne Arundel, Baltimore, Calvert, Cecil, Harford, Saint Mary's and 1 more	19 hr
Sep 1, 12:52 PM EDT	Areal Flood Warning	LWX	Allegany	22 hr
Sep 1, 1:11 PM EDT	Tornado Warning	LWX	Charles, Prince George's	34 min
Sep 1, 1:23 PM EDT	Tornado Warning	LWX	Charles	17 min
Sep 1, 1:30 PM EDT	Areal Flood Warning	LWX	Carroll, Frederick, Washington	27 hr
Sep 1, 1:31 PM EDT	Tornado Warning	LWX	Charles, Saint Mary's	29 min
Sep 1, 1:46 PM EDT	Areal Flood Warning	LWX	Allegany, Garrett	16 hr
Sep 1, 1:56 PM EDT	Tornado Warning	LWX	Anne Arundel, Prince George's	34 min
Sep 1, 2:12 PM EDT	Tornado Warning	LWX	Baltimore	33 min
Sep 1, 2:23 PM EDT	Tornado Warning	LWX	Baltimore	15 min
Sep 1, 2:26 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Carroll, Frederick	6 hr
Sep 1, 2:26 PM EDT	Tornado Warning	LWX	Baltimore, Harford	14 min
Sep 1, 2:27 PM EDT	Tornado Warning Tornado observed	LWX	Anne Arundel	15 min
Sep 1, 2:48 PM EDT	Tornado Warning Tornado observed	LWX	Baltimore, Harford	27 min
Sep 1, 3:10 PM EDT	Tornado Warning	LWX	Baltimore	16 min
Sep 1, 3:17 PM EDT	Tornado Warning	LWX	Harford	28 min
Sep 1, 3:25 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Carroll, Frederick	5 hr
Sep 1, 3:34 PM EDT	Flash Flood Warning Considerable damage threat	LWX	Cecil, Harford	3 hr
Sep 1, 3:36 PM EDT	Wind Advisory	LWX	Allegany, Carroll, Frederick, Washington	7 hr
Sep 1, 3:49 PM EDT	Tornado Warning	LWX	Cecil, Harford	26 min
Sep 1, 4:13 PM EDT	River Flood Watch	LWX	Cecil	7 hr
Sep 1, 4:13 PM EDT	River Flood Warning	LWX	Allegany	7 hr
Sep 1, 4:14 PM EDT	River Flood Warning	LWX	Allegany	9 hr
Sep 1, 4:37 PM EDT	Areal Flood Warning	LWX	Baltimore, Carroll, Harford	13 hr
Sep 1, 5:46 PM EDT	Tornado Warning	LWX	Cecil	29 min
Sep 1, 6:08 PM EDT	Areal Flood Warning	LWX	Cecil, Harford	17 hr
Sep 1, 6:12 PM EDT	Tornado Warning	LWX	Cecil	19 min
Sep 1, 7:03 PM EDT	Coastal Flood Warning	LWX	Anne Arundel	8 hr
Sep 1, 7:27 PM EDT	Areal Flood Warning	LWX	Allegany, Washington	15 hr
Sep 1, 7:59 PM EDT	Areal Flood Warning	LWX	Carroll, Frederick	2 hr

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.