Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 131, NWS Philadelphia/Mount Holly

July 6, 2020Cecil County, Maryland; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2020, 5:14 PM EDT for Cecil County, Maryland; Chester County, Pennsylvania. It was in force for 61 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 6, 2020, 5:14 PM EDT (21:14 UTC)
Expired
Jul 6, 2020, 6:15 PM EDT
In force
61 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 117 km from the middle of the area, began a volume at 21:14 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 6, 1:38 PM EDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.2 hours before the alert went out and 147 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 2020-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1250 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 2020-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 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
1250 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
1150 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

365 
WUUS51 KPHI 062114
SVRPHI
MDC015-PAC029-062215-
/O.NEW.KPHI.SV.W.0131.200706T2114Z-200706T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
514 PM EDT Mon Jul 6 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Cecil County in northeastern Maryland...
  Southwestern Chester County in southeastern Pennsylvania...

* Until 615 PM EDT.

* At 514 PM EDT, a severe thunderstorm was located over Rock Springs,
  or 13 miles north of Havre De Grace, moving east at 5 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Calvert, Oxford, North East, Rising Sun, Charlestown, Homeville,
  Glen Roy, Zion, Blake, Lombard, Richardsmere, Woodlawn, West
  Nottingham, Pleasant Hill, Mount Vernon, Conowingo, Rock Springs,
  Bay View and Farmington.

This includes Interstate 95 in Maryland between mile markers 95 and
102.
 
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 3972 7614 3973 7610 3974 7610 3976 7606
      3981 7603 3983 7604 3983 7602 3985 7602
      3987 7599 3989 7599 3974 7585 3956 7595
      3970 7622 3972 7622
TIME...MOT...LOC 2114Z 282DEG 5KT 3975 7613 

HAIL...1.00IN
WIND...60MPH
 
$$

BAH
1 follow-up statement
006 
WWUS51 KPHI 062202
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
602 PM EDT Mon Jul 6 2020

MDC015-PAC029-062215-
/O.CON.KPHI.SV.W.0131.000000T0000Z-200706T2215Z/
Cecil MD-Chester PA-
602 PM EDT Mon Jul 6 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR NORTHWESTERN CECIL AND SOUTHWESTERN CHESTER COUNTIES...

At 601 PM EDT, a severe thunderstorm was located over Glen Roy, or 13
miles north of Havre De Grace, moving east at 5 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Calvert, Oxford, North East, Rising Sun, Charlestown, Homeville, Glen
Roy, Zion, Blake, Lombard, Richardsmere, Woodlawn, West Nottingham,
Pleasant Hill, Mount Vernon, Conowingo, Rock Springs, Bay View and
Farmington.

This includes Interstate 95 in Maryland between mile markers 95 and
102.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. 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 3972 7614 3973 7610 3974 7610 3976 7606
      3981 7603 3983 7604 3983 7602 3985 7602
      3987 7599 3989 7599 3974 7585 3956 7595
      3970 7622 3972 7622
TIME...MOT...LOC 2201Z 282DEG 5KT 3974 7605 

HAIL...1.00IN
WIND...60MPH
 
$$

BAH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 12:52 PM EDTFlash Flood WatchPHICecil8 hr
Jul 6, 4:49 PM EDTSpecial Weather StatementPHICecil56 min
Jul 6, 5:43 PM EDTAreal Flood AdvisoryPHICecil3 hr
Jul 6, 6:13 PM EDTSevere Thunderstorm WarningPHICecil48 min
Jul 6, 6:37 PM EDTSevere Thunderstorm WarningPHICecil53 min
Jul 6, 7:03 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's42 min
Jul 6, 7:23 PM EDTTornado WarningPHICaroline, Kent, Queen Anne's19 min
Jul 6, 7:41 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot64 min
Jul 6, 7:48 PM EDTAreal Flood AdvisoryPHICaroline, Cecil, Kent, Queen Anne's, Talbot117 min
Jul 6, 3:16 AM EDTHeat AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia12 hr
Jul 6, 12:34 PM EDTSpecial Weather StatementPHIPhiladelphia26 min
Jul 6, 12:45 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia60 min
Jul 6, 12:57 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia2 hr
Jul 6, 1:08 PM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Jul 6, 1:15 PM EDTSevere Thunderstorm WarningPHIBucks60 min
Jul 6, 1:20 PM EDTSpecial Weather StatementPHIMontgomery25 min
Jul 6, 1:24 PM EDTSpecial Weather StatementPHIMonroe36 min
Jul 6, 1:43 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia62 min
Jul 6, 1:44 PM EDTSpecial Weather StatementPHIMontgomery31 min
Jul 6, 1:50 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery4 hr
Jul 6, 1:50 PM EDTSevere Thunderstorm WarningPHIMonroe40 min
Jul 6, 2:02 PM EDTAreal Flood AdvisoryPHIBucks118 min
Jul 6, 2:04 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery41 min
Jul 6, 2:10 PM EDTAreal Flood AdvisoryPHIMonroe2 hr
Jul 6, 2:18 PM EDTSpecial Weather StatementPHIMontgomery27 min
Jul 6, 2:27 PM EDTSevere Thunderstorm WarningPHIMontgomery48 min
Jul 6, 2:28 PM EDTSevere Thunderstorm WarningPHIMonroe28 min
Jul 6, 2:39 PM EDTAreal Flood AdvisoryPHIBucks, Chester, Montgomery4 hr
Jul 6, 2:39 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia66 min
Jul 6, 2:41 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery49 min
Jul 6, 2:48 PM EDTAreal Flood AdvisoryPHIPhiladelphia4 hr
Jul 6, 2:51 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery24 min
Jul 6, 2:57 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIBucks, Delaware, Montgomery, Philadelphia4 hr
Jul 6, 3:00 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton45 min
Jul 6, 3:11 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia49 min
Jul 6, 3:38 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Northampton52 min
Jul 6, 3:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia38 min
Jul 6, 3:56 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton64 min
Jul 6, 4:06 PM EDTSevere Thunderstorm WarningPHILehigh24 min
Jul 6, 4:07 PM EDTFlash Flood WarningPHIChester, Delaware, Montgomery4 hr
Jul 6, 4:31 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Monroe, Northampton44 min
Jul 6, 4:51 PM EDTAreal Flood AdvisoryPHICarbon, Monroe114 min
Jul 6, 5:00 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton45 min
Jul 6, 5:01 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton119 min
Jul 6, 5:17 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton43 min
Jul 6, 5:20 PM EDTSevere Thunderstorm WarningPHIChester, Delaware42 min
Jul 6, 5:29 PM EDTSevere Thunderstorm WarningPHIChester46 min
Jul 6, 5:53 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery52 min
Jul 6, 6:14 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery3 hr
Jul 6, 6:18 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery35 min
Jul 6, 6:54 PM EDTFlash Flood WarningPHIBerks, Chester, Montgomery109 min
Jul 6, 7:18 PM EDTSevere Thunderstorm WarningPHIMonroe36 min
Jul 6, 7:36 PM EDTSevere Thunderstorm WarningPHIChester69 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2020Severe Thunderstorm Warnings in Pennsylvania, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.