Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 302, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 13, 2021, 9:21 PM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania; Hunterdon County, Somerset County, Warren County, New Jersey. It was in force for 38 min. 1 report 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
- Sep 13, 2021, 9:21 PM EDT (01:21 UTC)
- Expired
- Sep 13, 2021, 9:59 PM EDT
- In force
- 38 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.88 in
- Wind
- 60.0 mph
Counties Hunterdon County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 01:23 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 |
|---|---|---|---|
| Sep 13, 9:27 PM EDT | TSTM WND DMG | 1 Sw Lyons, NJ | VALLEY RD IN BERNARDS TWP BETWEEN LURLINE DR AND ESSEX PL CLOSED DUE TO A TREE AND WIRES DOWN. 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 |
|---|---|---|---|
| Sep 13, 7:44 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 1.4 hours before the alert went out and 178 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
- 90 J/kg
- Mixed-layer CIN
- -236 J/kg
- Mixed-layer LCL
- 1411 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 82 m²/s²
- 0-3 km storm-relative helicity
- 139 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
305
WUUS51 KPHI 140121
SVRPHI
NJC019-035-041-PAC017-077-095-140215-
/O.NEW.KPHI.SV.W.0302.210914T0121Z-210914T0215Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
921 PM EDT Mon Sep 13 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Hunterdon County in northwestern New Jersey...
Southwestern Warren County in northwestern New Jersey...
Northwestern Somerset County in northern New Jersey...
Southeastern Lehigh County in eastern Pennsylvania...
Northwestern Bucks County in southeastern Pennsylvania...
South central Northampton County in eastern Pennsylvania...
* Until 1015 PM EDT.
* At 920 PM EDT, severe thunderstorms were located along a line
extending from High Bridge to near Milford to near Hellertown to
Zionsville, moving southeast at 45 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Allentown, Somerville, Bethlehem, Bridgewater, Emmaus, Quakertown,
Perkasie, Doylestown, Byram, Bedminster, Hellertown, Flemington,
Tinicum, High Bridge, Clinton, New Hope, Dublin, Glen Gardner,
Ferndale and Frenchtown.
This includes the following highways...
Northeast Extension between mile markers 45 and 52.
Interstate 78 in Pennsylvania between mile markers 59 and 70.
Interstate 78 in New Jersey between mile markers 6 and 36.
Interstate 287 in New Jersey between mile markers 16 and 24.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
In addition to hail and damaging winds, frequent cloud to ground
lightning is occurring with these storms. Move indoors immediately.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.
&&
LAT...LON 4051 7465 4042 7478 4042 7480 4029 7502
4050 7559 4058 7545 4063 7520 4070 7501
4067 7453 4066 7452
TIME...MOT...LOC 0120Z 293DEG 38KT 4069 7491 4061 7511 4055 7536 4050
7552
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Gorse2 follow-up statements
540
WWUS51 KPHI 140137
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
937 PM EDT Mon Sep 13 2021
NJC041-PAC077-095-140147-
/O.CAN.KPHI.SV.W.0302.000000T0000Z-210914T0215Z/
Warren NJ-Lehigh PA-Northampton PA-
937 PM EDT Mon Sep 13 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WARREN...
SOUTHEASTERN LEHIGH AND SOUTH CENTRAL NORTHAMPTON COUNTIES IS
CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
central, northern and northwestern New Jersey...and southeastern
Pennsylvania.
LAT...LON 4051 7465 4042 7478 4042 7480 4034 7493
4045 7511 4068 7485 4067 7453 4066 7452
TIME...MOT...LOC 0137Z 289DEG 40KT 4061 7455 4054 7475 4052 7488 4042
7503
$$
NJC019-035-PAC017-140215-
/O.CON.KPHI.SV.W.0302.000000T0000Z-210914T0215Z/
Hunterdon NJ-Somerset NJ-Bucks PA-
937 PM EDT Mon Sep 13 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM EDT
FOR SOUTHEASTERN HUNTERDON...WEST CENTRAL SOMERSET AND NORTH CENTRAL
BUCKS COUNTIES...
At 937 PM EDT, severe thunderstorms were located along a line
extending from Martinsville to near Flagtown to Flemington to
Lumberville, moving east at 45 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Somerville, Bridgewater, Byram, Flemington, Tinicum, Clinton, New
Hope, Lebanon, Far Hills, Stockton, Flagtown, Sergeantsville,
Cloverhill, White House Station, Lumberville, Sand Brook, Annandale,
Raritan and Lambertville.
This includes the following highways...
Interstate 78 in New Jersey between mile markers 18 and 36.
Interstate 287 in New Jersey between mile markers 16 and 24.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 4051 7465 4042 7478 4042 7480 4034 7493
4045 7511 4068 7485 4067 7453 4066 7452
TIME...MOT...LOC 0137Z 289DEG 40KT 4061 7455 4054 7475 4052 7488 4042
7503
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Gorse315
WWUS51 KPHI 140159
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
959 PM EDT Mon Sep 13 2021
NJC019-035-PAC017-140209-
/O.CAN.KPHI.SV.W.0302.000000T0000Z-210914T0215Z/
Hunterdon NJ-Somerset NJ-Bucks PA-
959 PM EDT Mon Sep 13 2021
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL HUNTERDON...WEST
CENTRAL SOMERSET AND NORTH CENTRAL BUCKS COUNTIES IS CANCELLED...
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 100 AM EDT for
central and northern New Jersey.
LAT...LON 4051 7465 4042 7478 4042 7480 4034 7493
4045 7511 4068 7485 4067 7453 4066 7452
TIME...MOT...LOC 0158Z 293DEG 38KT 4052 7428 4045 7448 4043 7461 4033
7476
$$
GorseThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 13, 8:16 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 44 min |
| Sep 13, 8:41 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 49 min |
| Sep 13, 8:51 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 108 min |
| Sep 13, 9:03 PM EDT | Areal Flood Advisory | PHI | Monroe, Northampton | 109 min |
| Sep 13, 9:12 PM EDT | Flash Flood Warning | PHI | Northampton | 114 min |
| Sep 13, 9:03 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Somerset, Warren | 57 min |
| Sep 13, 9:34 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex, Morris, Somerset | 38 min |
| Sep 13, 9:53 PM EDT | Severe Thunderstorm Warning | PHI | Mercer, Middlesex, Monmouth, Somerset | 52 min |
| Sep 13, 10:03 PM EDT | Special Marine Warning | PHI | 57 min |
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.