Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 343, NWS Philadelphia/Mount Holly

September 1, 2026Carbon County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 1, 2026, 6:29 PM EDT for Carbon County, Lehigh County, Northampton County, Pennsylvania. It was in force for 46 min. 3 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: Sep 1, 2026, 6:29 PM EDT (22:29 UTC)
Expired: Sep 1, 2026, 7:15 PM EDT
In force: 46 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Carbon County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 136 km from the middle of the area, began a volume at 22:31 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 1, 6:35 PM EDT	TSTM WND DMG	Mahoning Twp, PA	Tree down in Mahoning Township. Time estimated from radar.
Sep 1, 6:40 PM EDT	TSTM WND DMG	East Penn Twp, PA	Tree down in East Penn Township. Time estimated from radar.
Sep 1, 7:06 PM EDT	TSTM WND DMG	1 Ne Weisenberg Twp, PA	Multiple reports of trees and wires down in Weisenberg Township. 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 1, 4:32 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.5 hours before the alert went out and 235 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: 17 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 481 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 177 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

454 
WUUS51 KPHI 012229
SVRPHI
PAC025-077-095-012315-
/O.NEW.KPHI.SV.W.0343.260901T2229Z-260901T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
629 PM EDT Tue Sep 1 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Lehigh County in eastern Pennsylvania...
  Southeastern Carbon County in northeastern Pennsylvania...
  West central Northampton County in eastern Pennsylvania...

* Until 715 PM EDT.

* At 628 PM EDT, a severe thunderstorm was located over Lehighton,
  moving southeast at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Allentown, Lehighton, Bethlehem, Northampton, Palmerton, Jim
  Thorpe, Slatington, Walnutport, Neffs, Coffeetown, Berlinsville,
  Emerald, Claussville, Danielsville, Beltzville State Park, Jordan
  Valley, Beersville, Schnecksville, Catasauqua, and Coplay.

This includes the following highways...
 Northeast Extension between mile markers 57 and 83.
 Interstate 78 in Pennsylvania between mile markers 47 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4065 7537 4054 7567 4056 7570 4073 7577
      4074 7576 4075 7577 4089 7583 4094 7565
TIME...MOT...LOC 2228Z 335DEG 19KT 4082 7570 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DeSilva

1 follow-up statement

526 
WWUS51 KPHI 012259
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
659 PM EDT Tue Sep 1 2026

PAC025-095-012309-
/O.CAN.KPHI.SV.W.0343.000000T0000Z-260901T2315Z/
Carbon PA-Northampton PA-
659 PM EDT Tue Sep 1 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CARBON AND WEST
CENTRAL NORTHAMPTON COUNTIES IS CANCELLED...

The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until midnight EDT for
eastern Pennsylvania.

LAT...LON 4072 7577 4076 7564 4061 7548 4054 7567
      4056 7570
TIME...MOT...LOC 2259Z 331DEG 28KT 4066 7568 

$$

PAC077-012315-
/O.CON.KPHI.SV.W.0343.000000T0000Z-260901T2315Z/
Lehigh PA-
659 PM EDT Tue Sep 1 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR CENTRAL LEHIGH COUNTY...

At 659 PM EDT, a severe thunderstorm was located near Schnecksville,
or 11 miles northwest of Allentown, moving southeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Allentown, Jordan Valley, Neffs, Emerald, Schnecksville, Coffeetown,
New Tripoli, Claussville, and Fullerton.

This includes the following highways...
 Northeast Extension between mile markers 57 and 69.
 Interstate 78 in Pennsylvania between mile markers 47 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4072 7577 4076 7564 4061 7548 4054 7567
      4056 7570
TIME...MOT...LOC 2259Z 331DEG 28KT 4066 7568 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DeSilva

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 2:30 AM EDT	Heat Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	18 hr
Sep 1, 5:45 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	45 min
Sep 1, 5:50 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Northampton	40 min
Sep 1, 6:09 PM EDT	Severe Thunderstorm Warning	PHI	Berks	51 min
Sep 1, 6:21 PM EDT	Severe Thunderstorm Warning	PHI	Berks	39 min
Sep 1, 6:38 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Sep 1, 6:56 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester	49 min
Sep 1, 6:58 PM EDT	Severe Thunderstorm Warning	PHI	Berks	34 min
Sep 1, 7:13 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Lehigh, Montgomery	47 min
Sep 1, 7:43 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware	47 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2026 Every severe thunderstorm warning in 2026

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.