Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 192, NWS Philadelphia/Mount Holly

July 17, 2021Caroline County, Queen Anne's County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 7:59 PM EDT for Caroline County, Queen Anne's County, Maryland; Kent County, Delaware. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 17, 2021, 7:59 PM EDT (23:59 UTC)
Expired
Jul 17, 2021, 8:45 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 19 km from the middle of the area, began a volume at 00:04 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 17, 1:13 PM EDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 12.0 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 12:00Z on 2021-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2012 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 2021-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
2012 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
988 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

275 
WUUS51 KPHI 172359
SVRPHI
DEC001-MDC011-035-180045-
/O.NEW.KPHI.SV.W.0192.210717T2359Z-210718T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
759 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Kent County in central Delaware...
  Southeastern Queen Anne's County in northeastern Maryland...
  Caroline County in eastern Maryland...

* Until 845 PM EDT.

* At 759 PM EDT, a severe thunderstorm was located over Denton, or 15
  miles southeast of Centerville, moving northeast 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...
  Dover, Milford, Denton, Harrington, Camden, Greensboro, Oakland,
  Ridgely, Bowers, Goldsboro, Queen Anne, Woodside, Viola, Rising
  Sun-Lebanon, Jumptown, Hazlettville, Dover Base Housing, Dover
  Speedway, Sandtown and Andrewsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3900 7599 3929 7543 3923 7536 3898 7529
      3895 7536 3896 7539 3893 7540 3891 7547
      3885 7559 3883 7567 3883 7572 3881 7572
      3877 7588
TIME...MOT...LOC 2359Z 235DEG 25KT 3892 7583 

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

NC
2 follow-up statements
139 
WWUS51 KPHI 180022
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
822 PM EDT Sat Jul 17 2021

MDC035-180031-
/O.CAN.KPHI.SV.W.0192.000000T0000Z-210718T0045Z/
Queen Anne's MD-
822 PM EDT Sat Jul 17 2021

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

LAT...LON 3910 7577 3929 7543 3923 7536 3898 7529
      3895 7536 3896 7539 3893 7540 3891 7547
      3885 7559 3883 7567 3883 7572 3881 7572
      3879 7580
TIME...MOT...LOC 0021Z 235DEG 25KT 3901 7566 

$$

DEC001-MDC011-180045-
/O.CON.KPHI.SV.W.0192.000000T0000Z-210718T0045Z/
Kent DE-Caroline MD-
822 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR KENT AND NORTHEASTERN CAROLINE COUNTIES...

At 821 PM EDT, a severe thunderstorm was located near Sandtown, or 12
miles southwest of Dover, moving northeast 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...
Dover, Milford, Harrington, Camden, Bowers, Woodside, Viola, Rising
Sun-Lebanon, Hazlettville, Dover Base Housing, Dover Speedway,
Sandtown, Andrewsville, Rising Sun, Big Stone Beach, Wyoming, Felton,
Frederica, Houston and Magnolia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3910 7577 3929 7543 3923 7536 3898 7529
      3895 7536 3896 7539 3893 7540 3891 7547
      3885 7559 3883 7567 3883 7572 3881 7572
      3879 7580
TIME...MOT...LOC 0021Z 235DEG 25KT 3901 7566 

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

NC
763 
WWUS51 KPHI 180038
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
838 PM EDT Sat Jul 17 2021

DEC001-MDC011-180048-
/O.EXP.KPHI.SV.W.0192.000000T0000Z-210718T0045Z/
Kent DE-Caroline MD-
838 PM EDT Sat Jul 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR KENT AND NORTHEASTERN CAROLINE
COUNTIES WILL EXPIRE AT 845 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

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

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 3910 7577 3929 7543 3923 7536 3898 7529
      3895 7536 3896 7539 3893 7540 3891 7547
      3885 7559 3883 7567 3883 7572 3881 7572
      3879 7580
TIME...MOT...LOC 0038Z 235DEG 25KT 4017 7470 

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 5:09 PM EDTSpecial Weather StatementPHIKent51 min
Jul 17, 5:54 PM EDTSpecial Weather StatementPHIKent, Queen Anne's36 min
Jul 17, 7:36 PM EDTSpecial Weather StatementPHICaroline39 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.