Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 189, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 6:51 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, New Jersey. It was in force for 39 min. 2 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
- Jul 17, 2021, 6:51 PM EDT (22:51 UTC)
- Expired
- Jul 17, 2021, 7:30 PM EDT
- In force
- 39 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Burlington County, NJ, Bucks County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 56 km from the middle of the area, began a volume at 22:55 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 |
|---|---|---|---|
| Jul 17, 6:55 PM EDT | TSTM WND DMG | Lawndale, PA | SEVERAL POWER OUTAGES REPORTED IN NORTHEAST PHILADELPHIA. TIME ESTIMATED FROM RADAR. |
| Jul 17, 7:00 PM EDT | TSTM WND DMG | Abington, PA | SEVERAL TREES DOWN AND POWER OUTAGES. TIME ESTIMATED FROM RADAR. |
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 |
|---|---|---|---|
| Jul 17, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 12:00Z, 10.9 hours before the alert went out and 204 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
- 1203 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 1054 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.0
The text
As transmitted.
526
WUUS51 KPHI 172251
SVRPHI
NJC005-PAC017-091-101-172330-
/O.NEW.KPHI.SV.W.0189.210717T2251Z-210717T2330Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
651 PM EDT Sat Jul 17 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northwestern Burlington County in southern New Jersey...
Southeastern Montgomery County in southeastern Pennsylvania...
Southeastern Bucks County in southeastern Pennsylvania...
Northern Philadelphia County in southeastern Pennsylvania...
* Until 730 PM EDT.
* At 650 PM EDT, a severe thunderstorm was located over Rockledge, or
near Philadelphia, moving northeast at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Philadelphia, Bensalem, Florence, Burlington, Bristol, Palmyra,
Hatboro, Jenkintown, Beverly, Rockledge, Newtown, Tullytown,
Abington, Langhorne, Bryn Athyn, Wissinoming, Feasterville-Trevose,
Willow Grove, Florence-Roebling and Germantown.
This includes the following highways...
Pennsylvania Turnpike between mile markers 343 and 359.
Interstate 95 in Pennsylvania between mile markers 24 and 40.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3996 7515 4010 7523 4026 7495 4012 7476
TIME...MOT...LOC 2250Z 246DEG 31KT 4007 7510
HAIL...<.75IN
WIND...60MPH
$$
JEO2 follow-up statements
142
WWUS51 KPHI 172305
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
705 PM EDT Sat Jul 17 2021
NJC005-PAC017-091-101-172330-
/O.CON.KPHI.SV.W.0189.000000T0000Z-210717T2330Z/
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
705 PM EDT Sat Jul 17 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR NORTHWESTERN BURLINGTON...EAST CENTRAL MONTGOMERY...SOUTHEASTERN
BUCKS AND NORTHEASTERN PHILADELPHIA COUNTIES...
At 705 PM EDT, a severe thunderstorm was located over Bensalem, or 11
miles southwest of Trenton, moving northeast at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Philadelphia, Bensalem, Florence, Burlington, Bristol, Palmyra,
Hatboro, Jenkintown, Beverly, Rockledge, Newtown, Tullytown,
Abington, Langhorne, Bryn Athyn, Wissinoming, Feasterville-Trevose,
Willow Grove, Florence-Roebling and Northeast Philadelphia.
This includes the following highways...
Pennsylvania Turnpike between mile markers 342 and 359.
Interstate 95 in Pennsylvania between mile markers 26 and 40.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3998 7511 4008 7513 4015 7515 4026 7495
4012 7476
TIME...MOT...LOC 2305Z 246DEG 31KT 4012 7494
HAIL...<.75IN
WIND...60MPH
$$
JEO013
WWUS51 KPHI 172325
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
725 PM EDT Sat Jul 17 2021
NJC005-PAC017-091-101-172335-
/O.EXP.KPHI.SV.W.0189.000000T0000Z-210717T2330Z/
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
725 PM EDT Sat Jul 17 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BURLINGTON...EAST
CENTRAL MONTGOMERY...SOUTHEASTERN BUCKS AND NORTHEASTERN PHILADELPHIA
COUNTIES WILL EXPIRE AT 730 PM EDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty
winds are still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
southern New Jersey...and southeastern Pennsylvania.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.
LAT...LON 3998 7511 4008 7513 4015 7515 4026 7495
4012 7476
TIME...MOT...LOC 2325Z 246DEG 31KT 4019 7475
$$
NCThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 16, 8:14 PM EDT | Special Weather Statement | PHI | Montgomery | 31 min |
| Jul 16, 8:41 PM EDT | Special Weather Statement | PHI | Bucks | 34 min |
| Jul 16, 9:07 PM EDT | Special Weather Statement | PHI | Lehigh | 23 min |
| Jul 16, 9:29 PM EDT | Special Weather Statement | PHI | Lehigh | 31 min |
| Jul 16, 10:21 PM EDT | Special Weather Statement | PHI | Lehigh | 24 min |
| Jul 17, 12:55 PM EDT | Special Weather Statement | PHI | Bucks | 50 min |
| Jul 17, 1:05 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 40 min |
| Jul 17, 1:31 PM EDT | Areal Flood Advisory | PHI | Bucks | 97 min |
| Jul 17, 2:30 PM EDT | Special Weather Statement | PHI | Berks | 45 min |
| Jul 17, 2:36 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 39 min |
| Jul 17, 3:06 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 39 min |
| Jul 17, 5:13 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 4 hr |
| Jul 17, 5:25 PM EDT | Flash Flood Warning | PHI | Bucks | 6 hr |
| Jul 17, 5:30 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 19 min |
| Jul 17, 6:02 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 43 min |
| Jul 17, 6:39 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 51 min |
| Jul 17, 7:01 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 44 min |
| Jul 17, 7:12 PM EDT | Areal Flood Advisory | PHI | Bucks, Philadelphia | 3 hr |
| Jul 17, 7:26 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 49 min |
| Jul 17, 7:36 PM EDT | Special Weather Statement | PHI | Carbon | 54 min |
| Jul 17, 1:50 PM EDT | Special Marine Warning | PHI | 40 min | |
| Jul 17, 1:56 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Somerset, Warren | 36 min |
| Jul 17, 2:02 PM EDT | Areal Flood Advisory | PHI | Monmouth, Ocean | 92 min |
| Jul 17, 2:56 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex, Somerset | 49 min |
| Jul 17, 3:09 PM EDT | Tornado Warning | PHI | Middlesex | 21 min |
| Jul 17, 3:38 PM EDT | Areal Flood Advisory | PHI | Middlesex | 40 min |
| Jul 17, 3:51 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex | 24 min |
| Jul 17, 4:55 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Somerset | 50 min |
| Jul 17, 5:19 PM EDT | Tornado Warning | PHI | Hunterdon | 14 min |
| Jul 17, 5:52 PM EDT | Areal Flood Advisory | PHI | Somerset | 2 hr |
| Jul 17, 6:15 PM EDT | Flash Flood Warning | PHI | Morris, Somerset | 5 hr |
| Jul 17, 6:59 PM EDT | Small Craft Advisory | PHI | 7 hr |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2021Severe Thunderstorm Warnings in New Jersey, 2021Every 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.