Alert archive / Maryland / Tornado Warnings in 2021

Tornado Warning 24, NWS Baltimore/Washington

August 18, 2021Allegany County, Washington County, Maryland

NWS Baltimore/Washington issued this tornado warning at Aug 18, 2021, 3:12 PM EDT for Allegany County, Washington County, Maryland. It was in force for 16 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: Aug 18, 2021, 3:12 PM EDT (19:12 UTC)
Expired: Aug 18, 2021, 3:28 PM EDT
In force: 16 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Allegany County, MD, Washington County, MD

The radar

The Sterling radar (KLWX), 108 km from the middle of the area, began a volume at 19:13 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
Aug 18, 11:37 AM EDT	Tornado Watch	SPC	11 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.2 hours before the alert went out and 116 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: 1011 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 592 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

As transmitted.

255 
WFUS51 KLWX 181912
TORLWX
MDC001-043-181945-
/O.NEW.KLWX.TO.W.0024.210818T1912Z-210818T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Baltimore MD/Washington DC
312 PM EDT Wed Aug 18 2021

The National Weather Service in Sterling Virginia has issued a

* Tornado Warning for...
  Northwestern Washington County in north central Maryland...
  Eastern Allegany County in western Maryland...

* Until 345 PM EDT.
    
* At 312 PM EDT, a severe thunderstorm capable of producing a tornado
  was located near Barnes Gap, or 10 miles west of Hancock, moving
  northeast at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...For those in the direct path of a tornado touchdown, 
           flying debris will be dangerous to those caught without 
           shelter. Damage to roofs, siding, and windows may occur. 
           Mobile homes may be damaged or destroyed. Tree damage is 
           likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  northwestern Washington and eastern Allegany Counties, including
  the following locations... Bellegrove and Forest Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3972 7827 3966 7838 3967 7840 3972 7834
TIME...MOT...LOC 1912Z 226DEG 24KT 3968 7837 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

SMZ

2 follow-up statements

796 
WWUS51 KLWX 181921
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
321 PM EDT Wed Aug 18 2021

MDC001-043-181945-
/O.CON.KLWX.TO.W.0024.000000T0000Z-210818T1945Z/
Washington MD-Allegany MD-
321 PM EDT Wed Aug 18 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM EDT FOR
NORTHWESTERN WASHINGTON AND NORTHEASTERN ALLEGANY COUNTIES...
    
At 321 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Barnes Gap, or 7 miles west of Hancock, moving
northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...For those in the direct path of a tornado touchdown, flying 
         debris will be dangerous to those caught without shelter. 
         Damage to roofs, siding, and windows may occur. Mobile 
         homes may be damaged or destroyed. Tree damage is likely.

Locations impacted include...
Bellegrove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3972 7828 3970 7833 3971 7835 3972 7834
TIME...MOT...LOC 1921Z 225DEG 30KT 3973 7831 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

SMZ

126 
WWUS51 KLWX 181928
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
328 PM EDT Wed Aug 18 2021

MDC001-043-181938-
/O.CAN.KLWX.TO.W.0024.000000T0000Z-210818T1945Z/
Washington MD-Allegany MD-
328 PM EDT Wed Aug 18 2021

...THE TORNADO WARNING FOR NORTHWESTERN WASHINGTON AND NORTHEASTERN
ALLEGANY COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

A Tornado Watch remains in effect until 800 PM EDT for western and
north central Maryland.

LAT...LON 3972 7828 3970 7833 3971 7835 3972 7834
TIME...MOT...LOC 1927Z 226DEG 24KT 3977 7826 

$$

SMZ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 4:29 PM EDT	Severe Thunderstorm Warning	LWX	Saint Mary's	14 min
Aug 18, 5:13 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick, Washington	47 min
Aug 18, 5:26 PM EDT	Tornado Warning	LWX	Frederick, Washington	17 min
Aug 18, 6:31 PM EDT	Tornado Warning	LWX	Cecil	29 min
Aug 18, 7:01 PM EDT	Coastal Flood Advisory	LWX	Anne Arundel, Baltimore, Harford, City of Baltimore	14 hr

Nearby

Tornado Warnings in Maryland, 2021 Every tornado warning in 2021 Tornadoes 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.