Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 289, NWS Philadelphia/Mount Holly

September 3, 20204 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 3, 2020, 5:47 PM EDT for 4 counties in Maryland. It was in force for 73 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
Sep 3, 2020, 5:47 PM EDT (21:47 UTC)
Expired
Sep 3, 2020, 7:00 PM EDT
In force
73 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
70.0 mph

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

The radar

The Dover AFB radar (KDOX), 67 km from the middle of the area, began a volume at 21:51 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
Sep 3, 6:30 PM EDTTSTM WND GST 644 Nnw Copperville, MDCORRECTS TIME OF PREVIOUS TSTM WND GST REPORT FROM 4 NNW COPPERVILLE. MEASURED BY A TEMPEST WEATHER STATION ON BENNET POINT RD.
Sep 3, 6:30 PM EDTTSTM WND GST 644 Nnw Copperville, MDCORRECTS TIME OF PREVIOUS TSTM WND GST REPORT FROM 4 NNW COPPERVILLE. MEASURED BY A TEMPEST WEATHER STATION ON BENNET POINT RD.

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
Sep 3, 3:42 PM EDTTornado WatchSPC6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.8 hours before the alert went out and 103 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 2020-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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 2020-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
12 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
1011 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

219 
WUUS51 KPHI 032147
SVRPHI
MDC011-029-035-041-032300-
/O.NEW.KPHI.SV.W.0289.200903T2147Z-200903T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
547 PM EDT Thu Sep 3 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 700 PM EDT.

* At 545 PM EDT, severe thunderstorms were located along a line
  extending from near Parole to near Bowie to Landover, moving east
  at 35 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Locations impacted include...
  Easton, Centerville, Talbot, Centreville, Oakland, Ridgely, St.
  Michaels, Queen Anne, Tanyard, Grasonville, Starr, Stevensville,
  Skipton, Copperville, Jumptown, Chester, Matthews, Wye Mills,
  Cordova, and Carville.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the 
basement or small central room in a sturdy structure. A Tornado 
Watch remains in effect until 1000 PM EDT for eastern and 
northeastern Maryland.

&&

LAT...LON 3894 7636 3904 7631 3900 7617 3911 7624
      3912 7583 3911 7582 3873 7597 3871 7623
      3876 7623 3868 7634 3886 7626 3886 7625
      3879 7620 3879 7619 3894 7621 3896 7631
      3884 7637 3885 7638
TIME...MOT...LOC 2145Z 278DEG 30KT 3903 7656 3894 7670 3892 7688 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann
2 follow-up statements
690 
WWUS51 KPHI 032222
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
622 PM EDT Thu Sep 3 2020

MDC029-032232-
/O.CAN.KPHI.SV.W.0289.000000T0000Z-200903T2300Z/
Kent MD-
622 PM EDT Thu Sep 3 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN KENT COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1000 PM EDT for eastern and
northeastern Maryland.

LAT...LON 3904 7631 3898 7628 3897 7622 3900 7617
      3905 7620 3905 7585 3873 7597 3871 7623
      3876 7623 3869 7634 3873 7630 3884 7626
      3879 7622 3879 7619 3893 7620 3896 7624
      3895 7625 3896 7631 3884 7637 3885 7638
TIME...MOT...LOC 2222Z 279DEG 31KT 3899 7617 3888 7629 3887 7655 

$$

MDC011-035-041-032300-
/O.CON.KPHI.SV.W.0289.000000T0000Z-200903T2300Z/
Talbot MD-Queen Anne's MD-Caroline MD-
622 PM EDT Thu Sep 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR TALBOT...SOUTHERN QUEEN ANNE'S AND NORTHWESTERN CAROLINE
COUNTIES...

At 622 PM EDT, severe thunderstorms were located along a line
extending from near Grasonville to near Romancoke to Rhode River,
moving east at 35 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Easton, Centerville, Centreville, Oakland, Ridgely, St. Michaels,
Queen Anne, Tanyard, Grasonville, Starr, Stevensville, Skipton,
Copperville, Jumptown, Chester, Matthews, Wye Mills, Cordova,
Carville and Hope.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the 
basement or small central room in a sturdy structure. A Tornado 
Watch remains in effect until 1000 PM EDT for eastern and 
northeastern Maryland.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 3904 7631 3898 7628 3897 7622 3900 7617
      3905 7620 3905 7585 3873 7597 3871 7623
      3876 7623 3869 7634 3873 7630 3884 7626
      3879 7622 3879 7619 3893 7620 3896 7624
      3895 7625 3896 7631 3884 7637 3885 7638
TIME...MOT...LOC 2222Z 279DEG 31KT 3899 7617 3888 7629 3887 7655 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann
227 
WWUS51 KPHI 032250
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
650 PM EDT Thu Sep 3 2020

MDC011-035-041-032300-
/O.CON.KPHI.SV.W.0289.000000T0000Z-200903T2300Z/
Talbot MD-Queen Anne's MD-Caroline MD-
650 PM EDT Thu Sep 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR TALBOT...SOUTH CENTRAL QUEEN ANNE'S AND WEST CENTRAL CAROLINE
COUNTIES...

At 649 PM EDT, severe thunderstorms were located along a line
extending from Ridgely to Cordova to Talbot, moving east at 35 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Easton, Oakland, Ridgely, St. Michaels, Queen Anne, Tanyard, Skipton,
Copperville, Jumptown, Matthews, Wye Mills, Cordova, Starr and
Hillsboro.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the 
basement or small central room in a sturdy structure. A Tornado 
Watch remains in effect until 1000 PM EDT for eastern and 
northeastern Maryland.

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

&&

LAT...LON 3890 7620 3890 7619 3902 7591 3902 7586
      3873 7597 3871 7623 3876 7623 3869 7634
      3873 7630 3884 7626 3879 7622 3879 7619
TIME...MOT...LOC 2249Z 278DEG 30KT 3896 7589 3885 7601 3884 7627 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 8:07 PM EDTSevere Thunderstorm WarningPHICecil53 min
Sep 2, 8:47 PM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's, Talbot58 min
Sep 2, 10:08 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot67 min
Sep 3, 6:48 PM EDTSevere Thunderstorm WarningPHICaroline, Talbot57 min

Nearby

Severe Thunderstorm Warnings in Maryland, 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.