Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 1, NWS Philadelphia/Mount Holly

March 28, 2021Chester County, Delaware County, Montgomery County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Mar 28, 2021, 6:12 PM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania; New Castle County, Delaware. It was in force for 48 min. 29 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: Mar 28, 2021, 6:12 PM EDT (22:12 UTC)
Expired: Mar 28, 2021, 7:00 PM EDT
In force: 48 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

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

The radar

The Dover AFB radar (KDOX), 114 km from the middle of the area, began a volume at 22:13 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
Mar 28, 6:15 PM EDT	TSTM WND DMG	1 Nw Honey Brook, PA	TREE DOWN ONTO WIRES ON RESERVOIR RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:19 PM EDT	TSTM WND DMG	1 Ssw West Sadsbury Twp, PA	MULTIPLE DOWNED TREE AND WIRE REPORTS ON STRASBURG RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:19 PM EDT	TSTM WND DMG	1 S Wagontown, PA	DOWNED TREES AND WIRES NEAR ZALESKI ROAD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:19 PM EDT	TSTM WND DMG	2 Nnw Highland Twp., PA	DOWNED WIRES NEAR HIGHLAND ROAD AND TIMACULA ROAD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:20 PM EDT	TSTM WND DMG	2 Wnw East Goshen Twp, PA	MULTIPLE DOWNED TREES AND WIRES ON NOTTINGHAM DR. TIME ESTIMATED FROM RADAR.
Mar 28, 6:25 PM EDT	TSTM WND DMG	1 Ese Modena, PA	TREE DOWN BLOCKING MORTONVILLE RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:25 PM EDT	TSTM WND DMG	1 Ssw West Marlborough, PA	DOWNED WIRES NEAR WINTERWOOD LANE. TIME ESTIMATED FROM RADAR.
Mar 28, 6:25 PM EDT	TSTM WND DMG	2 Wnw Elk Twp, PA	DOWNED WIRES NEAR GLEN HOPE ROAD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:31 PM EDT	TSTM WND DMG	1 Sse Downington, PA	DOWNED WIRES ON OLD TROLLEY ROAD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:34 PM EDT	TSTM WND DMG	2 Nne Brookside, DE	SEVERAL REPORTS OF DOWNED TREE LIMBS AND POWER LINES IN THE WINDY HILLS AREA. TIME ESTIMATED FROM RADAR.
Mar 28, 6:34 PM EDT	TSTM WND DMG	North Star, DE	DOWNED TREE ON NORTH STAR ROAD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:35 PM EDT	TSTM WND DMG	2 Sse Landenberg, PA	TREE AND WIRE DOWN AND ON FIRE ON YEATMANS STATION RD AND QUARTZ MILL RD.
Mar 28, 6:35 PM EDT	TSTM WND GST 68	2 Sw Brookside, DE	DE DOT GAUGE.
Mar 28, 6:38 PM EDT	TSTM WND DMG	1 Ssw West Chester, PA	DOWNED TREE ON ROSEDALE AVENUE. TIME ESTIMATED FROM RADAR.
Mar 28, 6:38 PM EDT	TSTM WND DMG	1 Ssw West Chester, PA	DOWNED TREES AND WIRES NEAR COLLEGE AVENUE. TIME ESTIMATED FROM RADAR.
Mar 28, 6:39 PM EDT	TSTM WND DMG	2 Sse West Chester, PA	DOWNED WIRES NEAR MATLACK STREET. TIME ESTIMATED FROM RADAR.
Mar 28, 6:39 PM EDT	TSTM WND DMG	The Cedars, DE	SEVERAL REPORTS OF DOWNED TREE LIMBS AND POWER LINES IN THE ALBERTSON PARK AREA. TIME ESTIMATED FROM RADAR.
Mar 28, 6:40 PM EDT	TSTM WND DMG	Birmingham Twp, PA	TREE AND WIRES DOWN ON CREEK RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:42 PM EDT	TSTM WND DMG	New Castle, DE	A COUPLE OF LIGHT POLES BLOWN OVER IN A PARKING LOT.
Mar 28, 6:44 PM EDT	TSTM WND GST 60	New Castle County Airpo, DE	KILG ASOS.
Mar 28, 6:47 PM EDT	TSTM WND DMG	Cragmere, DE	SEVERAL REPORTS OF DOWNED TREE LIMBS AND POWER LINES IN THE BELLEFONTE AREA. TIME ESTIMATED FROM RADAR.
Mar 28, 6:48 PM EDT	TSTM WND DMG	1 Ene Willistown Twp, PA	TREE DOWN BLOCKING THE ROAD ON WEST CHESTER PIKE AT DELCHESTER RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:48 PM EDT	TSTM WND DMG	2 Ene Berwyn, PA	TREE DOWN BLOCKING MEADOWBANK RD. TIME ESTIMATED FROM RADAR.
Mar 28, 6:50 PM EDT	TSTM WND DMG	Aston Twp, PA	MPING REPORT OF LARGE TREE LIMBS OR POWER POLES DOWN. TIME ESTIMATED FROM RADAR.
Mar 28, 6:50 PM EDT	TSTM WND DMG	Middletown Twp, PA	TREE AND WIRES DOWN ON MIDDLETOWN RD.
Mar 28, 6:50 PM EDT	TSTM WND DMG	Radnor Township, PA	DOWNED TREE AND WIRES IN RADNOR TWP. TIME ESTIMATED FROM RADAR.
Mar 28, 6:50 PM EDT	TSTM WND GST 64	Shellburne, DE	DEDOT GAUGE AT I-95 AND MARSH ROAD.
Mar 28, 6:52 PM EDT	TSTM WND DMG	Boothwyn, PA	DOWNED TREE LIMBS AND WIRES NEAR SECOND AVENUE. TIME ESTIMATED FROM RADAR.
Mar 28, 6:54 PM EDT	MARINE TSTM WIND 46	1 Nne Delaware City, DE

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.

Issued	Product	Office	Lasted
Mar 28, 5:05 PM EDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.2 hours before the alert went out and 163 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: 500 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 232 m²/s²
0-3 km storm-relative helicity: 255 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

115 
WUUS51 KPHI 282212
SVRPHI
DEC003-PAC029-045-091-282300-
/O.NEW.KPHI.SV.W.0001.210328T2212Z-210328T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
612 PM EDT Sun Mar 28 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  South central Montgomery County in southeastern Pennsylvania...
  Chester County in southeastern Pennsylvania...
  Western Delaware County in southeastern Pennsylvania...

* Until 700 PM EDT.

* At 612 PM EDT, severe thunderstorms were located along a line
  extending from Honey Brook to Rising Sun, moving east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Wilmington, Newark, Middletown, West Chester, Norristown,
  Phoenixville, West Norriton, East Norriton, Pennsville,
  Coatesville, Westtown, Carneys Point, Downingtown, Elsmere, Kennett
  Square, New Castle, Penns Grove, Oxford, Parkesburg and West Grove.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 301 and 331.
 Northeast Extension near mile marker 24.
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 0 and 23.
 Interstate 76 in Pennsylvania between mile markers 327 and 330.
 Interstate 476 in Pennsylvania between mile markers 12 and 14.

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 3974 7612 3973 7610 3976 7606 3983 7604
      3987 7599 3995 7600 4004 7593 4011 7594
      4015 7584 4017 7529 3973 7547 3963 7556
      3958 7553 3946 7558 3947 7578 3972 7579
      3972 7613
TIME...MOT...LOC 2212Z 273DEG 37KT 4009 7592 3971 7609 

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

Staarmann

2 follow-up statements

917 
WWUS51 KPHI 282234
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
634 PM EDT Sun Mar 28 2021

DEC003-PAC029-045-091-282300-
/O.CON.KPHI.SV.W.0001.000000T0000Z-210328T2300Z/
New Castle DE-Montgomery PA-Chester PA-Delaware PA-
634 PM EDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN NEW CASTLE...SOUTH CENTRAL MONTGOMERY...CENTRAL CHESTER
AND WESTERN DELAWARE COUNTIES...

At 633 PM EDT, severe thunderstorms were located along a line
extending from Chester Springs to Newark, moving east at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Wilmington, Newark, West Chester, Norristown, Phoenixville, West
Norriton, East Norriton, Pennsville, Westtown, Carneys Point,
Downingtown, Elsmere, Kennett Square, New Castle, Penns Grove, West
Grove, Delaware City, Newport, Arden and Stanton.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 310 and 331.
 Northeast Extension near mile marker 24.
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 1 and 23.
 Interstate 76 in Pennsylvania between mile markers 327 and 330.
 Interstate 476 in Pennsylvania between mile markers 12 and 14.

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 4016 7566 4017 7529 3978 7545 3972 7548
      3963 7556 3958 7553 3956 7554 3954 7578
      3972 7579 3972 7586 3983 7586
TIME...MOT...LOC 2233Z 272DEG 39KT 4008 7559 3970 7576 

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

Staarmann

750 
WWUS51 KPHI 282250
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
650 PM EDT Sun Mar 28 2021

DEC003-PAC029-045-091-282300-
/O.CON.KPHI.SV.W.0001.000000T0000Z-210328T2300Z/
New Castle DE-Montgomery PA-Chester PA-Delaware PA-
650 PM EDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHEASTERN NEW CASTLE...SOUTH CENTRAL MONTGOMERY...EAST CENTRAL
CHESTER AND CENTRAL DELAWARE COUNTIES...

At 649 PM EDT, severe thunderstorms were located along a line
extending from King Of Prussia to Delaware Memorial Bridge, moving
east at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Wilmington, Norristown, West Norriton, East Norriton, Pennsville,
Carneys Point, Elsmere, New Castle, Penns Grove, Newport, Arden,
Cheyney, Talleyville, Wilmington Manor, Elam, Lima, Chelsea, Radnor
Township, Valley Forge and Gradyville.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 322 and 331.
 Northeast Extension near mile marker 24.
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 11 and 23.
 Interstate 76 in Pennsylvania between mile markers 327 and 330.
 Interstate 476 in Pennsylvania between mile markers 12 and 14.

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 4012 7549 4017 7529 3973 7547 3964 7555
      3961 7556 3962 7563
TIME...MOT...LOC 2249Z 272DEG 38KT 4007 7537 3969 7551 

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

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 28, 5:04 PM EDT	Special Weather Statement	PHI	Berks	41 min
Mar 28, 5:13 PM EDT	Special Weather Statement	PHI	Carbon	32 min
Mar 28, 5:45 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	30 min
Mar 28, 6:02 PM EDT	Special Weather Statement	PHI	Chester	28 min
Mar 28, 6:15 PM EDT	Special Weather Statement	PHI	Montgomery	30 min
Mar 28, 6:43 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	47 min
Mar 28, 6:47 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	43 min
Mar 28, 7:54 PM EDT	Special Weather Statement	PHI	Sussex	36 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Severe Thunderstorm Warnings in Delaware, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.