Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 25, NWS Philadelphia/Mount Holly

April 9, 2020Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 9, 2020, 11:24 PM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 36 min. 10 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: Apr 9, 2020, 11:24 PM EDT (03:24 UTC)
Expired: Apr 10, 2020, 12:00 AM EDT
In force: 36 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 111 km from the middle of the area, began a volume at 03:25 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

Time	Report	Where	Remark
Apr 9, 11:30 PM EDT	HAIL 0.25	Oxford, PA	MPING REPORT.
Apr 9, 11:35 PM EDT	TSTM WND DMG	1 S Oxford, PA	DOWNED WIRES NEAR THE INTERSECTION OF MOUNT PLEASANT ROAD AND GRANT STREET. TIME ESTIMATED FROM RADAR.
Apr 9, 11:40 PM EDT	TSTM WND DMG	2 Ssw Lincoln Universit, PA	DOWNED TREE ON STATE HIGHWAY 472. TIME ESTIMATED FROM RADAR.
Apr 9, 11:45 PM EDT	TSTM WND GST 60	2 E Londonderry Twp, PA	DEOS SENSOR.
Apr 9, 11:46 PM EDT	HAIL 0.25	1 Sse Pleasant Hill, MD	TIME ESTIMATED FROM RADAR.
Apr 9, 11:50 PM EDT	TSTM WND DMG	Landenberg, PA	SEVERAL REPORTS OF DOWNED TREES AND POWER LINES IN THE WEST GROVE AND LANDENBERG AREAS. TIME ESTIMATED FROM RADAR.
Apr 9, 11:50 PM EDT	HAIL 0.25	North East, MD	TIME ESTIMATED FROM RADAR.
Apr 9, 11:52 PM EDT	TSTM WND DMG	1 N Landenberg, PA	DOWNED TREE ON LAUREL HEIGHTS ROAD. TIME ESTIMATED FROM RADAR.
Apr 9, 11:52 PM EDT	TSTM WND DMG	Ladenberg, PA	DOWNED WIRES NEAR THE INTERSECTION OF CHESTERVILLE ROAD AND PENN GREEN ROAD. TIME ESTIMATED FROM RADAR.
Apr 9, 11:53 PM EDT	TSTM WND DMG	Glen Westover, MD	DOWNED TREES AND POWER LINES. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.4 hours before the alert went out and 151 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1936 m above ground
0-6 km bulk shear: 97 kt
0-1 km storm-relative helicity: -34 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

236 
WUUS51 KPHI 100324
SVRPHI
MDC015-PAC029-100400-
/O.NEW.KPHI.SV.W.0025.200410T0324Z-200410T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1124 PM EDT Thu Apr 9 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until midnight EDT.

* At 1124 PM EDT, a severe thunderstorm was located near Wakefield,
  or 14 miles south of Willow Street, moving southeast at 55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  West Chester, Elkton, Calvert, Coatesville, Downingtown, Kennett
  Square, Oxford, Parkesburg, North East, West Grove, Rising Sun,
  Honey Brook, Charlestown, Homeville, Glen Roy, Zion, Blake,
  Barksdale, Cochranville and West Nottingham.

This includes Interstate 95 in Maryland between mile markers 91 and
107.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3972 7623 3973 7610 3976 7606 3983 7604
      3987 7599 3995 7600 4004 7593 4011 7594
      4014 7587 3997 7561 3980 7569 3972 7579
      3968 7579 3937 7597 3939 7604 3943 7600
      3946 7601 3952 7598 3955 7608
TIME...MOT...LOC 0324Z 299DEG 48KT 3978 7625 

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

Robertson

1 follow-up statement

348 
WWUS51 KPHI 100337
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1137 PM EDT Thu Apr 9 2020

MDC015-PAC029-100400-
/O.CON.KPHI.SV.W.0025.000000T0000Z-200410T0400Z/
Cecil MD-Chester PA-
1137 PM EDT Thu Apr 9 2020

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

At 1135 PM EDT, severe thunderstorms were located along a line
extending from near Paradise to Homeville to near Delta to 7 miles
south of Railroad, moving east at 60 mph.

HAZARD...60 mph wind gusts and small hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Elkton, Calvert, Coatesville, Kennett Square, Oxford, Parkesburg,
North East, West Grove, Rising Sun, Charlestown, Homeville, Glen Roy,
Zion, Blake, Barksdale, Cochranville, West Nottingham, Octoraro,
Mount Vernon and Marshallton.

This includes Interstate 95 in Maryland between mile markers 91 and
107.
 
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 3940 7595 3940 7603 3943 7600 3946 7601
      3952 7598 3955 7608 3972 7623 3973 7610
      3976 7606 3983 7604 3987 7599 3995 7600
      4004 7593 3996 7562 3980 7569 3972 7579
      3968 7579
TIME...MOT...LOC 0335Z 290DEG 51KT 4005 7615 3988 7599 3967 7626 3966
7667

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

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 9, 11:49 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Philadelphia	41 min
Apr 9, 11:54 PM EDT	Special Weather Statement	PHI	Lehigh	36 min
Apr 10, 3:33 AM EDT	Freeze Watch	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	12 hr
Apr 10, 3:29 PM EDT	Freeze Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	18 hr

Nearby

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