Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 40, NWS Philadelphia/Mount Holly

April 21, 20205 counties in Maryland; Kent County, New Castle County, Sussex County, Delaware; Cumberland County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 21, 2020, 2:04 PM EDT for 5 counties in Maryland; Kent County, New Castle County, Sussex County, Delaware; Cumberland County, New Jersey. It was in force for 56 min. 9 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, 2020, 2:04 PM EDT (18:04 UTC)
Expired: Apr 21, 2020, 3:00 PM EDT
In force: 56 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Cumberland County, NJ

The radar

The Dover AFB radar (KDOX), 65 km from the middle of the area, began a volume at 18:07 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

Time	Report	Where	Remark
Apr 21, 2:08 PM EDT	TSTM WND DMG	2 Sse Newtown, MD	SEVERAL TREES DOWN NEAR STATE HIGHWAY 298. TIME ESTIMATED FROM RADAR.
Apr 21, 2:08 PM EDT	TSTM WND DMG	3 Nw Langford, MD	TREE UPROOTED. TIME BASED ON RADAR.
Apr 21, 2:22 PM EDT	TSTM WND DMG	2 W Starr, MD	DOWNED WIRES REPORTED. TIME ESTIMATED FROM RADAR.
Apr 21, 2:23 PM EDT	TSTM WND DMG	1 Ene Starr, MD	A FEW REPORTS OF POWER LINES DOWN IN THE AREA. TIME ESTIMATED FROM RADAR.
Apr 21, 2:23 PM EDT	TSTM WND DMG	1 Ene Starr, MD	A FEW REPORTS OF POWER LINES DOWN IN THE AREA. TIME ESTIMATED FROM RADAR.
Apr 21, 2:50 PM EDT	TSTM WND DMG	2 W Hazlettville, DE	DAMAGED UTILITY POLE FROM STRONG WINDS. TIME ESTIMATED FROM RADAR.
Apr 21, 2:51 PM EDT	TSTM WND GST 56	Dover Afb (Kdov), DE	KDOV MEASURES A 56 MPH WIND GUST.
Apr 21, 2:56 PM EDT	TSTM WND DMG	1 Sw Cedarville, NJ	DOWNED TREE AND WIRES. TIME ESTIMATED FROM RADAR.
Apr 21, 2:56 PM EDT	TSTM WND DMG	1 Sw Cedarville, NJ	DOWNED TREES AND WIRES. 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.

Issued	Product	Office	Lasted
Apr 21, 1:27 PM EDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.1 hours before the alert went out and 108 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1922 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 197 m²/s²
0-3 km storm-relative helicity: 207 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

820 
WUUS51 KPHI 211804
SVRPHI
DEC001-003-005-MDC011-015-029-035-041-NJC011-211900-
/O.NEW.KPHI.SV.W.0040.200421T1804Z-200421T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
204 PM EDT Tue Apr 21 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Sussex County in southern Delaware...
  Southwestern New Castle County in northern Delaware...
  Kent County in central Delaware...
  Talbot County in eastern Maryland...
  Queen Anne's County in northeastern Maryland...
  Caroline County in eastern Maryland...
  Kent County in northeastern Maryland...
  Southeastern Cecil County in northeastern Maryland...
  Southwestern Cumberland County in southern New Jersey...

* Until 300 PM EDT.

* At 204 PM EDT, severe thunderstorms were located along a line
  extending from near Aberdeen Proving Ground to near Kent Point,
  moving east at 50 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Dover, Middletown, Easton, Centerville, Talbot, Smyrna, Milford,
  Chestertown, Denton, Centreville, Harrington, Camden, Clayton,
  Bridgeville, Greensboro, Oakland, Ridgely, Cheswold, Rock Hall and
  St. Michaels.

People attending Covid-19 Drive through testing should seek safe
shelter immediately!

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 3904 7631 3898 7628 3900 7617 3901 7620
      3917 7628 3933 7618 3942 7600 3950 7599
      3932 7515 3869 7548 3876 7634 3885 7627
      3879 7620 3879 7619 3880 7619 3897 7625
      3892 7630 3896 7631 3885 7638 3886 7638
TIME...MOT...LOC 1804Z 252DEG 44KT 3945 7604 3885 7644 

HAIL...0.75IN
WIND...60MPH
 
$$

Davis

2 follow-up statements

551 
WWUS51 KPHI 211829
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
229 PM EDT Tue Apr 21 2020

DEC001-003-005-MDC011-015-029-035-041-NJC011-211900-
/O.CON.KPHI.SV.W.0040.000000T0000Z-200421T1900Z/
Sussex DE-New Castle DE-Kent DE-Talbot MD-Queen Anne's MD-
Caroline MD-Kent MD-Cecil MD-Cumberland NJ-
229 PM EDT Tue Apr 21 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR NORTHWESTERN SUSSEX...SOUTHWESTERN NEW CASTLE...KENT...
NORTHEASTERN TALBOT...QUEEN ANNE'S...CAROLINE...NORTHEASTERN KENT...
SOUTHEASTERN CECIL AND SOUTHWESTERN CUMBERLAND COUNTIES...

At 229 PM EDT, severe thunderstorms were located along a line
extending from Saint Georges to Wye Mills, moving east at 50 mph.

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

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Dover, Middletown, Easton, Centerville, Smyrna, Milford, Denton,
Centreville, Harrington, Camden, Clayton, Bridgeville, Greensboro,
Oakland, Ridgely, Cheswold, Church Hill, Cecilton, Millington and
Sudlersville.

People attending Covid-19 Drive through testing should seek safe
shelter immediately!

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 3878 7619 3878 7618 3893 7616 3927 7595
      3947 7590 3931 7515 3869 7548 3872 7582
      3872 7586 3873 7587 3875 7620
TIME...MOT...LOC 1829Z 252DEG 44KT 3954 7567 3894 7607 

HAIL...0.75IN
WIND...60MPH
 
$$

Davis

185 
WWUS51 KPHI 211841
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
241 PM EDT Tue Apr 21 2020

MDC015-029-211850-
/O.CAN.KPHI.SV.W.0040.000000T0000Z-200421T1900Z/
Kent MD-Cecil MD-
241 PM EDT Tue Apr 21 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT AND
SOUTHEASTERN CECIL COUNTIES 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 500 PM EDT for
central, northern and southern Delaware...eastern and northeastern
Maryland...and southern New Jersey.

LAT...LON 3878 7612 3892 7597 3942 7565 3931 7515
      3869 7548 3874 7612 3875 7613
TIME...MOT...LOC 1840Z 252DEG 44KT 3958 7550 3898 7591 

$$

DEC001-003-005-MDC011-035-041-NJC011-211900-
/O.CON.KPHI.SV.W.0040.000000T0000Z-200421T1900Z/
Sussex DE-New Castle DE-Kent DE-Talbot MD-Queen Anne's MD-
Caroline MD-Cumberland NJ-
241 PM EDT Tue Apr 21 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR NORTHWESTERN SUSSEX...SOUTH CENTRAL NEW CASTLE...KENT...
NORTHEASTERN TALBOT...SOUTHEASTERN QUEEN ANNE'S...CAROLINE AND
SOUTHWESTERN CUMBERLAND COUNTIES...

At 240 PM EDT, severe thunderstorms were located along a line
extending from near Salem to Jumptown, moving east at 50 mph.

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

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Dover, Easton, Smyrna, Milford, Denton, Harrington, Camden, Clayton,
Bridgeville, Greensboro, Oakland, Ridgely, Cheswold, Ellendale,
Bowers, Goldsboro, Queen Anne, Woodside, Viola and Hartly.

People attending Covid-19 Drive through testing should seek safe
shelter immediately!

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 3878 7612 3892 7597 3942 7565 3931 7515
      3869 7548 3874 7612 3875 7613
TIME...MOT...LOC 1840Z 252DEG 44KT 3958 7550 3898 7591 

HAIL...0.75IN
WIND...60MPH
 
$$

Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 3:34 AM EDT	Freeze Warning	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	28 hr
Apr 21, 1:38 PM EDT	Special Weather Statement	PHI	Cecil	52 min
Apr 21, 1:49 PM EDT	Severe Thunderstorm Warning	PHI	Cecil	56 min
Apr 21, 2:46 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Talbot	74 min
Apr 21, 11:44 AM EDT	Coastal Flood Statement	PHI	Ocean	5 hr
Apr 21, 12:23 PM EDT	Special Weather Statement	PHI	Monmouth	37 min
Apr 21, 1:04 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	26 min
Apr 21, 1:28 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Hunterdon, Mercer, Middlesex, Morris and 1 more	32 min
Apr 21, 1:59 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Hunterdon, Mercer, Middlesex, Monmouth and 3 more	61 min
Apr 21, 2:17 PM EDT	Special Marine Warning	PHI		58 min
Apr 21, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more	66 min
Apr 21, 2:55 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Monmouth, Ocean	35 min
Apr 21, 3:04 PM EDT	Special Marine Warning	PHI		116 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2020 Severe Thunderstorm Warnings in Delaware, 2020 Severe Thunderstorm Warnings in New Jersey, 2020 Every severe thunderstorm warning in 2020

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.