Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 8, NWS Philadelphia/Mount Holly

April 21, 20214 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 21, 2021, 12:50 PM EDT for 4 counties in Maryland. It was in force for 40 min. 4 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, 12:50 PM EDT (16:50 UTC)
Expired
Apr 21, 2021, 1:30 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 69 km from the middle of the area, began a volume at 16:50 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.

What was reported inside it

TimeReportWhereRemark
Apr 21, 1:00 PM EDTHAIL 0.252 N Centreville, MD
Apr 21, 1:00 PM EDTHAIL 0.252 N Centreville, MD
Apr 21, 1:20 PM EDTHAIL 13 Se Church Hill, MD
Apr 21, 1:20 PM EDTHAIL 13 Se Church Hill, MD

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

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.8 hours before the alert went out and 102 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 2021-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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 2021-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 square meters per square second.19395878Sfc1 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
8 J/kg
Mixed-layer CIN
-277 J/kg
Mixed-layer LCL
1577 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

048 
WUUS51 KPHI 211650
SVRPHI
MDC011-029-035-041-211730-
/O.NEW.KPHI.SV.W.0008.210421T1650Z-210421T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1250 PM EDT Wed Apr 21 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 130 PM EDT.

* At 1250 PM EDT, a severe thunderstorm was located over Romancoke,
  or 9 miles east of South River, moving northeast at 50 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Centerville, Centreville, Romancoke, Oakland, Church Hill,
  Sudlersville, Goldsboro, Grasonville, Starr, Stevensville,
  Jumptown, Chester, Starkey Corner, Wye Mills, Carville, Hope,
  Queenstown, Barclay and Stevensville South.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3902 7632 3898 7628 3897 7622 3900 7617
      3904 7621 3920 7584 3901 7574 3885 7621
      3893 7620 3896 7623 3896 7625 3892 7625
      3894 7628 3893 7631 3896 7631 3891 7634
      3886 7633 3884 7637
TIME...MOT...LOC 1650Z 243DEG 44KT 3889 7633 

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

JEO
1 follow-up statement
276 
WWUS51 KPHI 211704
SVSPHI

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

MDC011-029-035-041-211730-
/O.CON.KPHI.SV.W.0008.000000T0000Z-210421T1730Z/
Talbot MD-Queen Anne's MD-Caroline MD-Kent MD-
104 PM EDT Wed Apr 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR NORTH CENTRAL TALBOT...CENTRAL QUEEN ANNE'S...NORTHEASTERN
CAROLINE AND SOUTHWESTERN KENT COUNTIES...

At 104 PM EDT, a severe thunderstorm was located near Wye Mills, or
near Centerville, moving northeast at 50 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Centerville, Centreville, Oakland, Church Hill, Sudlersville,
Goldsboro, Starr, Jumptown, Starkey Corner, Wye Mills, Carville,
Hope, Queenstown and Barclay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3898 7620 3900 7617 3904 7621 3920 7584
      3901 7574 3886 7618 3893 7620
TIME...MOT...LOC 1704Z 243DEG 44KT 3897 7612 

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

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 1:23 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot37 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.