Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 12, NWS Philadelphia/Mount Holly

April 21, 2021Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 21, 2021, 1:23 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware. It was in force for 37 min. 2 reports 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
Apr 21, 2021, 1:23 PM EDT (17:23 UTC)
Expired
Apr 21, 2021, 2:00 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Kent County, DE, Caroline County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 36 km from the middle of the area, began a volume at 17:24 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.

What was reported inside it

TimeReportWhereRemark
Apr 21, 1:45 PM EDTHAIL 0.251 Wsw Dover, DESOCIAL MEDIA.
Apr 21, 1:50 PM EDTHAIL 0.72 Nw Edge Hill, DEDIME SIZE HAIL IN DOVER, DE. TIME ESTIMATED FROM RADAR.

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
Apr 21, 12:28 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.4 hours before the alert went out and 131 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, Wallops Is Stn, VA at 12:00Z on 2021-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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, Wallops Is Stn, VA at 12:00Z on 2021-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 136 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
12 J/kg
Mixed-layer CIN
-142 J/kg
Mixed-layer LCL
1437 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

292 
WUUS51 KPHI 211723
SVRPHI
DEC001-MDC011-035-041-211800-
/O.NEW.KPHI.SV.W.0012.210421T1723Z-210421T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
123 PM EDT Wed Apr 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Kent County in central Delaware...
  Northeastern Talbot County in eastern Maryland...
  Eastern Queen Anne's County in northeastern Maryland...
  Northern Caroline County in eastern Maryland...

* Until 200 PM EDT.

* At 122 PM EDT, severe thunderstorms were located along a line
  extending from near Hartly to Queen Anne, moving east at 55 mph.

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

  SOURCE...Trained weather spotters. Quarter size hail was reported 
           near Sudlersville.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Dover, Milford, Denton, Harrington, Camden, Greensboro, Oakland,
  Ridgely, Cheswold, Sudlersville, Bowers, Goldsboro, Queen Anne,
  Woodside, Viola, Hartly, Rising Sun-Lebanon, Starr, Jumptown and
  Hazlettville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3885 7611 3925 7584 3924 7580 3925 7576
      3926 7575 3929 7540 3895 7532 3896 7539
      3892 7541
TIME...MOT...LOC 1722Z 255DEG 46KT 3916 7578 3891 7598 

HAIL...1.00IN
WIND...60MPH
 
$$

JEO
2 follow-up statements
142 
WWUS51 KPHI 211737
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
137 PM EDT Wed Apr 21 2021

MDC041-211746-
/O.CAN.KPHI.SV.W.0012.000000T0000Z-210421T1800Z/
Talbot MD-
137 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN TALBOT COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
central Delaware...and eastern and northeastern Maryland.

LAT...LON 3892 7594 3926 7575 3929 7540 3897 7533
      3895 7543 3894 7575
TIME...MOT...LOC 1736Z 255DEG 46KT 3920 7558 3895 7578 

$$

DEC001-MDC011-035-211800-
/O.CON.KPHI.SV.W.0012.000000T0000Z-210421T1800Z/
Kent DE-Queen Anne's MD-Caroline MD-
137 PM EDT Wed Apr 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR KENT...EASTERN QUEEN ANNE'S AND NORTHEASTERN CAROLINE COUNTIES...

At 136 PM EDT, severe thunderstorms were located along a line
extending from Cheswold to near Greensboro, moving east at 55 mph.

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

SOURCE...Radar indicated. These storms have previously produced 
         quarter size hail.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Dover, Camden, Greensboro, Oakland, Ridgely, Cheswold, Bowers,
Goldsboro, Woodside, Viola, Hartly, Rising Sun-Lebanon, Hazlettville,
Dover Base Housing, Dover Speedway, Sandtown, Rising Sun, Wyoming,
Felton and Frederica.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3892 7594 3926 7575 3929 7540 3897 7533
      3895 7543 3894 7575
TIME...MOT...LOC 1736Z 255DEG 46KT 3920 7558 3895 7578 

HAIL...1.00IN
WIND...60MPH
 
$$

JEO
999 
WWUS51 KPHI 211752
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
152 PM EDT Wed Apr 21 2021

DEC001-MDC011-035-211802-
/O.EXP.KPHI.SV.W.0012.000000T0000Z-210421T1800Z/
Kent DE-Queen Anne's MD-Caroline MD-
152 PM EDT Wed Apr 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR KENT...EASTERN QUEEN ANNE'S
AND NORTHEASTERN CAROLINE COUNTIES WILL EXPIRE AT 200 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
central Delaware...and eastern and northeastern Maryland.

LAT...LON 3892 7594 3926 7575 3929 7540 3897 7533
      3895 7543 3894 7575
TIME...MOT...LOC 1752Z 255DEG 46KT 3925 7535 3900 7555 

$$

JEO

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 12:50 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot40 min
Apr 21, 1:10 PM EDTSevere Thunderstorm WarningPHINew Castle50 min
Apr 21, 2:09 PM EDTSpecial Weather StatementPHISussex36 min
Apr 21, 2:18 PM EDTSevere Thunderstorm WarningPHIKent, Sussex42 min
Apr 21, 2:47 PM EDTSevere Thunderstorm WarningPHISussex16 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2021Severe Thunderstorm Warnings in Delaware, 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.