Alert archive / Pennsylvania / Tornado Warnings in 2020

Tornado Warning 29, NWS Philadelphia/Mount Holly

August 7, 2020New Castle County, Delaware; Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 7, 2020, 5:49 PM EDT for New Castle County, Delaware; Chester County, Delaware County, Pennsylvania. It was in force for 26 min. 13 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: Aug 7, 2020, 5:49 PM EDT (21:49 UTC)
Expired: Aug 7, 2020, 6:15 PM EDT
In force: 26 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties New Castle County, DE, Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 101 km from the middle of the area, began a volume at 21:52 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
Aug 7, 5:50 PM EDT	TSTM WND DMG	1 Ne Wooddale, DE	SEVERAL TREES DOWN ALONG CENTERVILLE ROAD IN WESTERN GREENVILLE. TIME ESTIMATED FROM RADAR AND NEARBY REPORTS.
Aug 7, 5:50 PM EDT	TSTM WND DMG	1 N Montchanin, DE	TREES AND WIRES DOWN ALONG MONTCHANIN RD NORTH OF WILMINTON. TIME ESTIMATED BY RADAR.
Aug 7, 5:50 PM EDT	TSTM WND DMG	Greenville, DE	TREES DOWN IN GREENVILLE. TIME ESTIMATED BY RADAR.
Aug 7, 5:50 PM EDT	TSTM WND DMG	West Haven, DE	NUMEROUS TREES DOWN OR SNAPPED WITH SOME ONTO HOMES. TIME ESTIMATED FROM RADAR.
Aug 7, 5:52 PM EDT	TSTM WND DMG	Greenville, DE	A FEW TREES SNAPPED HALFWAY UP THE TRUNK. TIME ESTIMATED FROM RADAR AND NEARBY REPORTS.
Aug 7, 5:52 PM EDT	TSTM WND DMG	Greenville Manor, DE	TREES AND POWER POLES DOWN IN GREENVILLE. TIME ESTIMATED FROM RADAR.
Aug 7, 5:55 PM EDT	TSTM WND DMG	Phillips Heights, DE	TREE DOWN ONTO POWER LINES AT WILMINGTON WASHINGTON STREET EXTENSION AND HANOVER ROAD IN NORTH WILMINGTON. TIME ESTIMATED FROM RADAR.
Aug 7, 5:55 PM EDT	TSTM WND DMG	Rock Manor, DE	LARGE TREE UPROOTED AND BLOCKING SCHOOL ROAD IN ALAPOCAS. TIME ESTIMATED FROM RADAR.
Aug 7, 5:55 PM EDT	TSTM WND DMG	Wilmington, DE	TREES DOWN OR SNAPPED ON NORTH MADISON STREET BETWEEN WEST 9TH AND WEST 10TH STREETS IN WILMINGTON. TIME ESTIMATED FROM RADAR.
Aug 7, 5:55 PM EDT	TSTM WND DMG	Wilmington, DE	SEVERAL REPORTS OF TREES DOWN IN WILMINGTON. TIME ESTIMATED FROM RADAR.
Aug 7, 5:55 PM EDT	TSTM WND GST 54	Winterthur, DE	GREENVILLE DEOS (DGRN) MEASURED A 54 MPH WIND GUST.
Aug 7, 5:57 PM EDT	TSTM WND DMG	Edgemoor Gardens, DE	TREE ONTO A HOUSE WITH PEOPLE TRAPPED IN EDGEMOOR GARDENS. POWER LINES DOWN. TIME ESTIMATED FROM RADAR.
Aug 7, 6:09 PM EDT	TSTM WND DMG	Winterthur, DE	TREES AND WIRES DOWN AT KENNETT PIKE AND OLD KENNETT ROAD.

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 12:00Z, 9.8 hours before the alert went out and 183 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: 301 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 665 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

426 
WFUS51 KPHI 072149
TORPHI
DEC003-PAC029-045-072215-
/O.NEW.KPHI.TO.W.0029.200807T2149Z-200807T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
549 PM EDT Fri Aug 7 2020

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Northeastern New Castle County in northern Delaware...
  South central Chester County in southeastern Pennsylvania...
  Southwestern Delaware County in southeastern Pennsylvania...

* Until 615 PM EDT.
    
* At 549 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Greenville, or near Wilmington, moving east at 15
  mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Wilmington, Elsmere, New Castle, Newport, Arden, Greenville,
  Stanton, Talleyville, Delaware Memorial Bridge, Elam, Ashland,
  Hockessin, Pike Creek, Wilmington Manor, Marcus Hook, Trainer,
  Bellefonte, Ardentown, Ardencroft and Edgemoor.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 11 and 23.

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.

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3989 7565 3983 7540 3968 7552 3972 7569
TIME...MOT...LOC 2149Z 280DEG 12KT 3979 7558 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Robertson

2 follow-up statements

500 
WWUS51 KPHI 072204
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
604 PM EDT Fri Aug 7 2020

PAC029-072213-
/O.CAN.KPHI.TO.W.0029.000000T0000Z-200807T2215Z/
Chester PA-
604 PM EDT Fri Aug 7 2020

...THE TORNADO WARNING FOR SOUTH CENTRAL CHESTER COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has  moved out 
of the warned area. Therefore, the warning has been cancelled. A 
severe thunderstorm warning remains in effect.

LAT...LON 3985 7549 3983 7540 3968 7552 3970 7560
TIME...MOT...LOC 2203Z 280DEG 12KT 3978 7552 

$$

DEC003-PAC045-072215-
/O.CON.KPHI.TO.W.0029.000000T0000Z-200807T2215Z/
New Castle DE-Delaware PA-
604 PM EDT Fri Aug 7 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM EDT FOR
NORTHEASTERN NEW CASTLE AND SOUTHWESTERN DELAWARE COUNTIES...
    
At 603 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Arden, or near Wilmington, moving east at 15 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Wilmington, New Castle, Newport, Arden, Delaware Memorial Bridge,
Wilmington Manor, Marcus Hook, Trainer, Bellefonte, Ardentown,
Ardencroft, Edgemoor, Boothwyn, Linwood and Claymont.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 12 and 23.

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.

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3985 7549 3983 7540 3968 7552 3970 7560
TIME...MOT...LOC 2203Z 280DEG 12KT 3978 7552 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Robertson

122 
WWUS51 KPHI 072211
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
611 PM EDT Fri Aug 7 2020

DEC003-PAC045-072221-
/O.EXP.KPHI.TO.W.0029.000000T0000Z-200807T2215Z/
New Castle DE-Delaware PA-
611 PM EDT Fri Aug 7 2020

...THE TORNADO WARNING FOR NORTHEASTERN NEW CASTLE AND SOUTHWESTERN
DELAWARE COUNTIES WILL EXPIRE AT 615 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 3985 7549 3983 7540 3968 7552 3970 7560
TIME...MOT...LOC 2211Z 280DEG 12KT 3974 7542 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 5:03 PM EDT	Flash Flood Warning	PHI	New Castle	5 hr
Aug 7, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	52 min
Aug 7, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	48 min
Aug 7, 6:00 PM EDT	Tornado Warning	PHI	New Castle	30 min
Aug 7, 6:12 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	63 min
Aug 7, 6:43 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	4 hr
Aug 7, 7:04 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	41 min
Aug 7, 7:21 PM EDT	Flash Flood Warning	PHI	Kent, New Castle	5 hr
Aug 7, 7:28 PM EDT	River Flood Warning	PHI	New Castle	2 hr
Aug 7, 7:36 PM EDT	Special Weather Statement	PHI	Kent	39 min
Aug 7, 6:49 AM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Aug 7, 9:22 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Aug 7, 10:34 AM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh	56 min
Aug 7, 11:28 AM EDT	Special Weather Statement	PHI	Carbon, Lehigh	47 min
Aug 7, 2:34 PM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Aug 7, 3:46 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Northampton	4 hr
Aug 7, 4:10 PM EDT	Flash Flood Warning	PHI	Berks	2 hr
Aug 7, 4:20 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	4 hr
Aug 7, 4:32 PM EDT	Flash Flood Warning	PHI	Chester	3 hr
Aug 7, 4:47 PM EDT	Special Weather Statement	PHI	Chester	28 min
Aug 7, 5:00 PM EDT	Severe Thunderstorm Warning	PHI	Chester	60 min
Aug 7, 5:15 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Aug 7, 5:25 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	3 hr
Aug 7, 5:43 PM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	4 hr
Aug 7, 6:39 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	27 min
Aug 7, 7:10 PM EDT	River Flood Warning	PHI	Delaware	7 hr
Aug 7, 7:17 PM EDT	Areal Flood Warning	PHI	Bucks, Montgomery	3 hr

Nearby

Tornado Warnings in Pennsylvania, 2020 Tornado Warnings in Delaware, 2020 Every tornado warning in 2020 Tornadoes 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.