Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 107, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2021, 3:50 PM EDT for 5 counties in Pennsylvania; New Castle County, Delaware. It was in force for 40 min. 6 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 1, 2021, 3:50 PM EDT (19:50 UTC)
- Expired
- Jul 1, 2021, 4:30 PM EDT
- In force
- 40 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties New Castle County, DE, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 89 km from the middle of the area, began a volume at 19:49 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 1, 3:51 PM EDT | TSTM WND DMG | 1 Wnw Valley Forge, PA | SEVERAL REPORTS OF DOWNED TREE LIMBS AND WIRES NEAR VALLEY FORGE AND PHOENIXVILLE. TIME ESTIMATED FROM RADAR. |
| Jul 1, 3:59 PM EDT | TSTM WND DMG | 2 W North Wales, PA | DOWNED TREES AND WIRES NEAR GARFIELD PARK IN LANSDALE. |
| Jul 1, 4:00 PM EDT | TSTM WND DMG | 2 Sse Kennett Square, PA | DOWNED TREES AND WIRES ON MARSHALL BRIDGE ROAD IN KENNETT SQUARE. TIME ESTIMATE FROM RADAR. |
| Jul 1, 4:12 PM EDT | TSTM WND DMG | 1 E Conshohocken, PA | DOWNED TREE LIMBS ON JOSHUA ROAD NEAR CEDAR GROVE ROAD. TIME ESTIMATED FROM RADAR. |
| Jul 1, 4:19 PM EDT | TSTM WND DMG | 2 S Doylestown, PA | DOWNED TREES AND WIRES NEAR TURK ROAD IN DOYLESTOWN. TIME ESTIMATED FROM RADAR. |
| Jul 1, 4:30 PM EDT | TSTM WND DMG | 1 Ne Jenkintown, PA | DOWNED TREE ON WIRES NEAR THE INTERSECTION OF WASHINGTON LANE AND PEPPER ROAD. 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 1, 12:46 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.8 hours before the alert went out and 198 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
- 604 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 928 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 61 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
The text
As transmitted.
721
WUUS51 KPHI 011950
SVRPHI
DEC003-PAC017-029-045-091-101-012030-
/O.NEW.KPHI.SV.W.0107.210701T1950Z-210701T2030Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
350 PM EDT Thu Jul 1 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northern New Castle County in northern Delaware...
Montgomery County in southeastern Pennsylvania...
Central Bucks County in southeastern Pennsylvania...
Southeastern Chester County in southeastern Pennsylvania...
Northwestern Philadelphia County in southeastern Pennsylvania...
Delaware County in southeastern Pennsylvania...
* Until 430 PM EDT.
* At 350 PM EDT, severe thunderstorms were located along a line
extending from Perkasie to near Valley Forge to near Pleasant Hill,
moving east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Law enforcement.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Philadelphia, Wilmington, Newark, West Chester, Norristown,
Chester, Phoenixville, Lansdale, West Norriton, East Norriton,
Pennsville, Yeadon, Westtown, Perkasie, Doylestown, Conshohocken,
Hatboro, Souderton, Folcroft and Ambler.
This includes the following highways...
Pennsylvania Turnpike between mile markers 319 and 348.
Northeast Extension between mile markers 21 and 36.
Interstate 95 in Pennsylvania between mile markers 0 and 10.
Interstate 95 in Delaware between mile markers 1 and 23.
Interstate 76 in Pennsylvania between mile markers 327 and 343.
Interstate 295 in New Jersey near mile marker 0.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4010 7553 4040 7535 4042 7506 4040 7497
4017 7499 3985 7530 3984 7536 3977 7546
3966 7552 3963 7556 3959 7555 3955 7559
3955 7578 3972 7579 3972 7587
TIME...MOT...LOC 1950Z 256DEG 27KT 4035 7530 4012 7544 3963 7589
HAIL...<.75IN
WIND...60MPH
$$
CMS1 follow-up statement
708
WWUS51 KPHI 012014
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
414 PM EDT Thu Jul 1 2021
DEC003-PAC017-029-045-091-101-012030-
/O.CON.KPHI.SV.W.0107.000000T0000Z-210701T2030Z/
New Castle DE-Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-
Delaware PA-
414 PM EDT Thu Jul 1 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHERN NEW CASTLE...SOUTHEASTERN MONTGOMERY...CENTRAL BUCKS...
SOUTHEASTERN CHESTER...NORTHWESTERN PHILADELPHIA AND DELAWARE
COUNTIES...
At 413 PM EDT, severe thunderstorms were located along a line
extending from Gardenville to Ambler to near Bear, moving east at 30
mph.
HAZARD...60 mph wind gusts.
SOURCE...Law enforcement. Several reports of wind damage have been
received from Chester County.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Philadelphia, Wilmington, Newark, West Chester, Norristown, Chester,
Lansdale, West Norriton, East Norriton, Pennsville, Yeadon, Westtown,
Doylestown, Conshohocken, Hatboro, Folcroft, Ambler, Swarthmore,
Elsmere and New Castle.
This includes the following highways...
Pennsylvania Turnpike between mile markers 322 and 348.
Northeast Extension between mile markers 21 and 29.
Interstate 95 in Pennsylvania between mile markers 0 and 10.
Interstate 95 in Delaware between mile markers 1 and 23.
Interstate 76 in Pennsylvania between mile markers 327 and 343.
Interstate 295 in New Jersey near mile marker 0.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4010 7548 4042 7516 4042 7506 4040 7497
4017 7499 3985 7530 3984 7536 3977 7546
3966 7552 3963 7556 3959 7555 3955 7559
3955 7578 3972 7579
TIME...MOT...LOC 2013Z 256DEG 27KT 4039 7509 4016 7523 3967 7568
HAIL...<.75IN
WIND...60MPH
$$
CMSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 8:16 PM EDT | Special Weather Statement | PHI | Bucks, Montgomery | 44 min |
| Jun 30, 8:37 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 38 min |
| Jul 1, 2:51 PM EDT | Special Weather Statement | PHI | Chester, Montgomery | 39 min |
| Jul 1, 3:13 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Chester, Lehigh, Montgomery | 47 min |
| Jul 1, 3:23 PM EDT | Areal Flood Advisory | PHI | Chester, Montgomery | 77 min |
| Jul 1, 3:48 PM EDT | Areal Flood Advisory | PHI | Bucks, Delaware, Montgomery, Philadelphia | 112 min |
| Jul 1, 4:27 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 48 min |
| Jul 1, 4:59 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Philadelphia | 46 min |
| Jul 1, 5:02 PM EDT | Tornado Warning | PHI | Bucks | 28 min |
| Jun 30, 9:21 PM EDT | Special Weather Statement | PHI | New Castle | 39 min |
| Jul 1, 4:08 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 52 min |
| Jul 1, 4:08 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 52 min |
| Jul 1, 4:10 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 94 min |
| Jul 1, 4:32 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle, Sussex | 43 min |
| Jul 1, 4:57 PM EDT | Tornado Warning | PHI | Kent, Sussex | 22 min |
| Jul 1, 5:12 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 48 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2021Severe Thunderstorm Warnings in Delaware, 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.