Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 297, NWS Philadelphia/Mount Holly

November 15, 2020Kent County, New Castle County, Sussex County, Delaware; 4 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Nov 15, 2020, 7:40 PM EST for Kent County, New Castle County, Sussex County, Delaware; 4 counties in Maryland. It was in force for 80 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
Nov 15, 2020, 7:40 PM EST (00:40 UTC)
Expired
Nov 15, 2020, 9:00 PM EST
In force
80 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, Kent County, MD, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 41 km from the middle of the area, began a volume at 00:41 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
Nov 15, 8:24 PM ESTTSTM WND GST 621 Ne Massey, MDWEATHER UNDERGROUND SITE KMDMASSE2.
Nov 15, 8:55 PM ESTTSTM WND GST 48Harrington, DEDEOS GAUGE AT HARRINGTON.

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
Nov 15, 5:35 PM ESTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.7 hours before the alert went out and 115 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 00:00Z on 2020-11-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2020-11-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 517 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
883 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
517 m²/s²
0-3 km storm-relative helicity
602 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

314 
WUUS51 KPHI 160040
SVRPHI
DEC001-003-005-MDC011-029-035-041-160200-
/O.NEW.KPHI.SV.W.0297.201116T0040Z-201116T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
740 PM EST Sun Nov 15 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  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...

* Until 900 PM EST.

* At 738 PM EST, severe thunderstorms were located along a line
  extending from near Salem to near La Plata, moving southeast at 95
  mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Dover, Middletown, Easton, Georgetown, Centerville, Talbot, Smyrna,
  Milford, Seaford, Chestertown, Denton, Centreville, Millsboro,
  Laurel, Harrington, Camden, Clayton, Lewes, Federalsburg and
  Milton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3846 7569 3869 7577 3870 7590 3857 7604
      3877 7632 3867 7634 3896 7631 3884 7637
      3884 7638 3895 7636 3904 7631 3900 7617
      3915 7628 3932 7618 3938 7577 3952 7578
      3956 7566 3877 7486 3857 7484 3845 7502
TIME...MOT...LOC 0038Z 318DEG 82KT 3961 7546 3859 7704 

HAIL...<.75IN
WIND...60MPH
 
$$

NC
1 follow-up statement
807 
WWUS51 KPHI 160133
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
833 PM EST Sun Nov 15 2020

DEC001-003-005-MDC011-029-035-041-160200-
/O.CON.KPHI.SV.W.0297.000000T0000Z-201116T0200Z/
Sussex DE-New Castle DE-Kent DE-Talbot MD-Queen Anne's MD-
Caroline MD-Kent MD-
833 PM EST Sun Nov 15 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EST
FOR SUSSEX...SOUTHWESTERN NEW CASTLE...KENT...TALBOT...QUEEN
ANNE'S...CAROLINE AND KENT COUNTIES...

At 832 PM EST, severe thunderstorms were located along a line
extending from 29 miles southeast of Diamond Beach to 10 miles south
of Tangier, moving southeast at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Dover, Middletown, Easton, Georgetown, Centerville, Talbot, Smyrna,
Milford, Seaford, Chestertown, Denton, Centreville, Millsboro,
Laurel, Harrington, Camden, Clayton, Lewes, Federalsburg and Milton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3846 7569 3869 7577 3870 7590 3857 7604
      3877 7632 3867 7634 3896 7631 3884 7637
      3884 7638 3895 7636 3904 7631 3900 7617
      3915 7628 3932 7618 3938 7577 3952 7578
      3956 7566 3877 7486 3857 7484 3845 7502
TIME...MOT...LOC 0132Z 318DEG 82KT 3869 7442 3768 7600 

HAIL...<.75IN
WIND...60MPH
 
$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 15, 7:50 PM ESTSevere Thunderstorm WarningPHINew Castle70 min
Nov 15, 8:57 PM ESTSevere Thunderstorm WarningPHIKent, Sussex63 min
Nov 15, 11:02 PM ESTCoastal Flood StatementPHISussex3 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2020Severe Thunderstorm Warnings in Delaware, 2020Every 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.