Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 109, NWS Philadelphia/Mount Holly

July 1, 2021Caroline County, Queen Anne's County, Talbot County, Maryland; Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2021, 4:08 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Sussex County, Delaware. It was in force for 52 min. 6 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
Jul 1, 2021, 4:08 PM EDT (20:08 UTC)
Expired
Jul 1, 2021, 5:00 PM EDT
In force
52 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
70.0 mph

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

The radar

The Dover AFB radar (KDOX), 48 km from the middle of the area, began a volume at 20:08 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
Jul 1, 4:16 PM EDTTSTM WND DMG2 S Skipton, MDMULTIPLE TREES AND WIRES DOWN IN WYE MILLS AND BETWEEN WYE MILLS AND EASTON. TIME ESTIMATED FROM RADAR.
Jul 1, 4:21 PM EDTTSTM WND DMGFederalsburg, MDSEVERAL REPORTS OF POWER LINES DOWN AND NUMEROUS POWER OUTAGES IN THE FEDERALSBURG AREA. TIME ESTIMATED FROM RADAR.
Jul 1, 4:30 PM EDTTSTM WND DMG2 Nnw Federalsburg, MDTREES AND UTILITY WIRES DOWN WITH DEBRIS ON THE ROADWAY ALONG MARYLAND ROUTE 313 NEAR OLD DENTON ROAD.
Jul 1, 4:42 PM EDTTSTM WND DMG4 Wsw Seaford, DEDOWNED TREES AND POWER LINES NEAR WOODPECKER ROAD. TIME ESTIMATED FROM RADAR.
Jul 1, 4:50 PM EDTTSTM WND DMG2 Sw Seaford, DEDOWNED TREE LIMBS AND WIRES NEAR CRAIGS MILL ROAD AND WOODLAND ROAD. TIME ESTIMATED FROM RADAR.
Jul 1, 4:53 PM EDTTSTM WND DMGSeaford, DEDOWNED WIRES ON HALL STREET, ALDER LANE, AND NEAR THE INTERSECTION OF NEALS SCHOOL ROAD AND BOYCE ROAD IN SEAFORD. 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
Jul 1, 12:46 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.1 hours before the alert went out and 98 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 2021-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1445 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 2021-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.1939Sfc1 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
1445 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

343 
WUUS51 KPHI 012008
SVRPHI
DEC005-MDC011-035-041-012100-
/O.NEW.KPHI.SV.W.0109.210701T2008Z-210701T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
408 PM EDT Thu Jul 1 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  West central Sussex County in southern Delaware...
  Talbot County in eastern Maryland...
  Southwestern Queen Anne's County in northeastern Maryland...
  Southern Caroline County in eastern Maryland...

* Until 500 PM EDT.

* At 407 PM EDT, a severe thunderstorm was located over Cambridge,
  moving northeast at 55 mph.

  HAZARD...70 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Easton, Seaford, Federalsburg, Trappe, Preston, Oxford, Tanyard,
  Harmony, Copperville, Agner, Matthews, Choptank, Hambleton,
  Windyhill, Cordova, Blades and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3864 7571 3869 7577 3868 7580 3871 7584
      3870 7590 3866 7596 3860 7599 3857 7604
      3863 7608 3864 7615 3868 7618 3869 7619
      3867 7620 3871 7624 3889 7614 3889 7611
      3891 7613 3865 7551 3848 7569
TIME...MOT...LOC 2007Z 214DEG 50KT 3854 7609 

HAIL...0.88IN
WIND...70MPH
 
$$

Davis
1 follow-up statement
549 
WWUS51 KPHI 012037
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
437 PM EDT Thu Jul 1 2021

MDC035-012046-
/O.CAN.KPHI.SV.W.0109.000000T0000Z-210701T2100Z/
Queen Anne's MD-
437 PM EDT Thu Jul 1 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN QUEEN ANNE'S
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southern Delaware...and eastern Maryland.

LAT...LON 3864 7571 3869 7577 3868 7580 3871 7584
      3870 7590 3866 7596 3860 7599 3857 7604
      3863 7608 3885 7602 3871 7566 3848 7569
TIME...MOT...LOC 2036Z 214DEG 50KT 3888 7580 

$$

DEC005-MDC011-041-012100-
/O.CON.KPHI.SV.W.0109.000000T0000Z-210701T2100Z/
Sussex DE-Talbot MD-Caroline MD-
437 PM EDT Thu Jul 1 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR WEST CENTRAL SUSSEX...SOUTHEASTERN TALBOT AND SOUTHERN CAROLINE
COUNTIES...

At 436 PM EDT, a severe thunderstorm was located over Denton, or 16
miles northeast of Easton, moving northeast at 60 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Easton, Federalsburg, Trappe, Preston, Agner, Matthews, Choptank,
Tanyard, Harmony, Windyhill and Cordova.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3864 7571 3869 7577 3868 7580 3871 7584
      3870 7590 3866 7596 3860 7599 3857 7604
      3863 7608 3885 7602 3871 7566 3848 7569
TIME...MOT...LOC 2036Z 214DEG 50KT 3888 7580 

HAIL...0.88IN
WIND...70MPH
 
$$

Davis

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 3:12 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's, Talbot48 min
Jul 1, 3:56 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot49 min
Jul 1, 4:08 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's52 min
Jul 1, 4:10 PM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot94 min
Jul 1, 4:32 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot43 min
Jun 30, 9:21 PM EDTSpecial Weather StatementPHINew Castle39 min
Jul 1, 3:48 PM EDTAreal Flood AdvisoryPHINew Castle112 min
Jul 1, 3:50 PM EDTSevere Thunderstorm WarningPHINew Castle40 min
Jul 1, 4:27 PM EDTSevere Thunderstorm WarningPHINew Castle48 min
Jul 1, 4:57 PM EDTTornado WarningPHIKent, Sussex22 min
Jul 1, 5:12 PM EDTSevere Thunderstorm WarningPHIKent, Sussex48 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.