Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 22, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 9, 2020, 1:26 PM EDT for 6 counties in Pennsylvania. It was in force for 49 min. 4 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, 1:26 PM EDT (17:26 UTC)
- Expired
- Apr 9, 2020, 2:15 PM EDT
- In force
- 49 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 111 km from the middle of the area, began a volume at 17:30 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, 1:29 PM EDT | TSTM WND GST 59 | Philadelphia Internatio, PA | KPHL MEASURED 51 KT WIND GUST. |
| Apr 9, 1:35 PM EDT | TSTM WND GST 54 | Chester County Airport, PA | |
| Apr 9, 1:48 PM EDT | TSTM WND DMG | Lansdale, PA | LARGE TREE BRANCH FELL INTO THE STREET. TIME ESTIMATED FROM RADAR. |
| Apr 9, 2:03 PM EDT | TSTM WND GST 59 | 1 S Eastwick, PA | ITWS MEASURED GUST. |
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 |
|---|---|---|---|
| Apr 9, 12:01 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 5.4 hours before the alert went out and 191 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.
- Mixed-layer CAPE
- 20 J/kg
- Mixed-layer CIN
- -589 J/kg
- Mixed-layer LCL
- 1002 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 394 m²/s²
- 0-3 km storm-relative helicity
- 416 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
428
WUUS51 KPHI 091726
SVRPHI
PAC011-017-029-045-091-101-091815-
/O.NEW.KPHI.SV.W.0022.200409T1726Z-200409T1815Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
126 PM EDT Thu Apr 9 2020
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Southeastern Berks County in eastern Pennsylvania...
Montgomery County in southeastern Pennsylvania...
South central Bucks County in southeastern Pennsylvania...
Chester County in southeastern Pennsylvania...
Western Philadelphia County in southeastern Pennsylvania...
Delaware County in southeastern Pennsylvania...
* Until 215 PM EDT.
* At 125 PM EDT, a severe thunderstorm was located over Glenmoore, or
12 miles northwest of West Chester, moving east 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...
Philadelphia, West Chester, Norristown, Chester, Pottstown,
Phoenixville, Lansdale, West Norriton, East Norriton, Coatesville,
Yeadon, Westtown, Downingtown, Conshohocken, Hatboro, Folcroft,
Ambler, Swarthmore, Birdsboro and Collegeville.
People attending Covid-19 Drive through testing should seek safe
shelter immediately!
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 7 and 16, and
near mile marker 22.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
Pennsylvania Turnpike between exits 298 and 343.
Northeast Extension between exits A20 and A31.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Interstate 76 in Pennsylvania between mile markers 327 and 350.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4004 7593 4009 7594 4012 7593 4014 7588
4016 7590 4026 7585 4026 7499 3988 7518
3985 7526 3995 7600
TIME...MOT...LOC 1725Z 276DEG 46KT 4011 7576
HAIL...<.75IN
WIND...60MPH
$$
SFJ3 follow-up statements
857
WWUS51 KPHI 091737
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
137 PM EDT Thu Apr 9 2020
PAC011-017-029-045-091-101-091815-
/O.CON.KPHI.SV.W.0022.000000T0000Z-200409T1815Z/
Berks PA-Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-
Delaware PA-
137 PM EDT Thu Apr 9 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR SOUTHEASTERN BERKS...MONTGOMERY...SOUTH CENTRAL BUCKS...CENTRAL
CHESTER...WESTERN PHILADELPHIA AND DELAWARE COUNTIES...
At 137 PM EDT, a severe thunderstorm was located near Chester
Springs, or 9 miles north of West Chester, moving east at 55 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Philadelphia, West Chester, Norristown, Chester, Pottstown,
Phoenixville, Lansdale, West Norriton, East Norriton, Coatesville,
Yeadon, Westtown, Downingtown, Conshohocken, Hatboro, Folcroft,
Ambler, Swarthmore, Collegeville and Royersford.
People attending Covid-19 Drive through testing should seek safe
shelter immediately!
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 7 and 16, and
near mile marker 22.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
Pennsylvania Turnpike between exits 312 and 343.
Northeast Extension between exits A20 and A31.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Interstate 76 in Pennsylvania between mile markers 327 and 350.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4026 7576 4026 7499 3988 7518 3985 7526
3993 7588
TIME...MOT...LOC 1737Z 276DEG 46KT 4009 7556
HAIL...<.75IN
WIND...60MPH
$$
SFJ835
WWUS51 KPHI 091750
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
150 PM EDT Thu Apr 9 2020
PAC011-091759-
/O.CAN.KPHI.SV.W.0022.000000T0000Z-200409T1815Z/
Berks PA-
150 PM EDT Thu Apr 9 2020
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled. However
gusty winds will continue and a wind advisory remains in effect.
A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
southern New Jersey...and southeastern Pennsylvania.
LAT...LON 4026 7562 4026 7499 3988 7518 3985 7526
3992 7577
TIME...MOT...LOC 1749Z 276DEG 46KT 4007 7535
$$
PAC017-029-045-091-101-091815-
/O.CON.KPHI.SV.W.0022.000000T0000Z-200409T1815Z/
Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-Delaware PA-
150 PM EDT Thu Apr 9 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR MONTGOMERY...SOUTH CENTRAL BUCKS...NORTHEASTERN CHESTER...WESTERN
PHILADELPHIA AND DELAWARE COUNTIES...
At 149 PM EDT, a severe thunderstorm was located over King Of
Prussia, or 12 miles west of Philadelphia, moving east at 55 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Philadelphia, West Chester, Norristown, Chester, Pottstown,
Phoenixville, Lansdale, West Norriton, East Norriton, Yeadon,
Westtown, Downingtown, Conshohocken, Hatboro, Folcroft, Ambler,
Swarthmore, Collegeville, Royersford and Jenkintown.
People attending Covid-19 Drive through testing should seek safe
shelter immediately!
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 7 and 16, and
near mile marker 22.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
Pennsylvania Turnpike between exits 312 and 343.
Northeast Extension between exits A20 and A31.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Interstate 76 in Pennsylvania between mile markers 327 and 350.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4026 7562 4026 7499 3988 7518 3985 7526
3992 7577
TIME...MOT...LOC 1749Z 276DEG 46KT 4007 7535
HAIL...<.75IN
WIND...60MPH
$$
SFJ771
WWUS51 KPHI 091807
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
207 PM EDT Thu Apr 9 2020
PAC017-029-045-091-101-091816-
/O.EXP.KPHI.SV.W.0022.000000T0000Z-200409T1815Z/
Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-Delaware PA-
207 PM EDT Thu Apr 9 2020
...THE SEVERE THUNDERSTORM WARNING FOR MONTGOMERY...SOUTH CENTRAL
BUCKS...NORTHEASTERN CHESTER...WESTERN PHILADELPHIA AND DELAWARE
COUNTIES WILL EXPIRE AT 215 PM EDT...
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. However gusty
winds are still possible and a wind advisory remains in effect.
A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
southern New Jersey...and southeastern Pennsylvania.
LAT...LON 4026 7562 4026 7499 3988 7518 3985 7526
3992 7577
TIME...MOT...LOC 1806Z 276DEG 46KT 4005 7507
$$
SFJThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 12:05 PM EDT | Special Weather Statement | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 40 min |
| Apr 9, 12:23 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Chester, Lehigh, Montgomery | 52 min |
| Apr 9, 1:00 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 45 min |
| Apr 9, 1:12 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Philadelphia | 48 min |
| Apr 9, 1:23 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 52 min |
| Apr 9, 1:33 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Philadelphia | 42 min |
| Apr 9, 3:32 PM EDT | Wind Advisory | PHI | Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more | 27 hr |
Nearby
Severe 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.