Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 261, NWS Philadelphia/Mount Holly

August 25, 2020Caroline County, Talbot County, Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 25, 2020, 9:12 PM EDT for Caroline County, Talbot County, Maryland; Kent County, Sussex County, Delaware. It was in force for 48 min. 1 report 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
Aug 25, 2020, 9:12 PM EDT (01:12 UTC)
Expired
Aug 25, 2020, 10:00 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 35 km from the middle of the area, began a volume at 01:12 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
Aug 25, 9:14 PM EDTTSTM WND DMGDenton, MDREPORT OF A TREE BLOWN DOWN IN DENTON. 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
Aug 25, 3:34 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 1.2 hours before the alert went out and 87 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 2020-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1713 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 00:00Z on 2020-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.193958Sfc1 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
1713 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
1304 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
215 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.1

Open this sounding in Storm Lab

The text

As transmitted.

710 
WUUS51 KPHI 260112
SVRPHI
DEC001-005-MDC011-041-260200-
/O.NEW.KPHI.SV.W.0261.200826T0112Z-200826T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
912 PM EDT Tue Aug 25 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Western Sussex County in southern Delaware...
  Southwestern Kent County in central Delaware...
  Southeastern Talbot County in eastern Maryland...
  Southeastern Caroline County in eastern Maryland...

* Until 1000 PM EDT.

* At 912 PM EDT, severe thunderstorms were located along a line
  extending from near Greensboro to Secretary, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Milford, Seaford, Denton, Laurel, Harrington,
  Federalsburg, Milton, Bridgeville, Ridgely, Delmar, Preston,
  Ellendale, Harmony, Smithville, Agner, Choptank, Sycamore,
  Andrewsville and Blades.

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 3846 7569 3864 7571 3869 7577 3868 7580
      3870 7580 3871 7584 3868 7594 3859 7600
      3857 7602 3858 7604 3878 7590 3896 7588
      3890 7528 3845 7541
TIME...MOT...LOC 0112Z 283DEG 28KT 3894 7581 3863 7593 

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

JEO
3 follow-up statements
493 
WWUS51 KPHI 260124
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
924 PM EDT Tue Aug 25 2020

MDC041-260134-
/O.CAN.KPHI.SV.W.0261.000000T0000Z-200826T0200Z/
Talbot MD-
924 PM EDT Tue Aug 25 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN 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 1100 PM EDT for
central and southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3864 7571 3869 7577 3868 7580
      3870 7580 3871 7584 3895 7577 3890 7528
      3845 7541
TIME...MOT...LOC 0124Z 283DEG 28KT 3892 7571 3861 7583 

$$

DEC001-005-MDC011-260200-
/O.CON.KPHI.SV.W.0261.000000T0000Z-200826T0200Z/
Sussex DE-Kent DE-Caroline MD-
924 PM EDT Tue Aug 25 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR WESTERN SUSSEX...SOUTHWESTERN KENT AND SOUTHEASTERN CAROLINE
COUNTIES...

At 924 PM EDT, severe thunderstorms were located along a line
extending from near Andrewsville to near Hurlock, moving east at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Georgetown, Milford, Seaford, Laurel, Harrington, Federalsburg,
Milton, Bridgeville, Delmar, Ellendale, Smithville, Agner, Sycamore,
Andrewsville, Blades, Greenwood, Houston, Bethel and Farmington.

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 3846 7569 3864 7571 3869 7577 3868 7580
      3870 7580 3871 7584 3895 7577 3890 7528
      3845 7541
TIME...MOT...LOC 0124Z 283DEG 28KT 3892 7571 3861 7583 

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

JEO
896 
WWUS51 KPHI 260143
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
943 PM EDT Tue Aug 25 2020

DEC001-MDC011-260153-
/O.CAN.KPHI.SV.W.0261.000000T0000Z-200826T0200Z/
Kent DE-Caroline MD-
943 PM EDT Tue Aug 25 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN KENT AND
SOUTHEASTERN CAROLINE 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 1100 PM EDT for
central and southern Delaware.

LAT...LON 3850 7569 3881 7571 3883 7559 3884 7558
      3884 7555 3888 7551 3890 7528 3845 7541
      3845 7542
TIME...MOT...LOC 0143Z 283DEG 28KT 3889 7554 3858 7567 

$$

DEC005-260200-
/O.CON.KPHI.SV.W.0261.000000T0000Z-200826T0200Z/
Sussex DE-
943 PM EDT Tue Aug 25 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR WESTERN SUSSEX COUNTY...

At 943 PM EDT, severe thunderstorms were located along a line
extending from near Harrington to near Sharptown, moving east at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Georgetown, Seaford, Laurel, Milton, Bridgeville, Ellendale,
Sycamore, Blades, Greenwood and Bethel.

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 3850 7569 3881 7571 3883 7559 3884 7558
      3884 7555 3888 7551 3890 7528 3845 7541
      3845 7542
TIME...MOT...LOC 0143Z 283DEG 28KT 3889 7554 3858 7567 

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

JEO
295 
WWUS51 KPHI 260151
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
951 PM EDT Tue Aug 25 2020

DEC005-260201-
/O.EXP.KPHI.SV.W.0261.000000T0000Z-200826T0200Z/
Sussex DE-
951 PM EDT Tue Aug 25 2020

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN SUSSEX COUNTY WILL
EXPIRE AT 1000 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central and southern Delaware.

LAT...LON 3850 7569 3881 7571 3883 7559 3884 7558
      3884 7555 3888 7551 3890 7528 3845 7541
      3845 7542
TIME...MOT...LOC 0151Z 283DEG 28KT 3888 7548 3857 7561 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 25, 8:23 PM EDTSpecial Weather StatementPHICaroline37 min
Aug 25, 8:28 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot47 min
Aug 25, 9:00 PM EDTSpecial Weather StatementPHICaroline45 min

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.