Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 307, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 17, 2026, 5:09 PM EDT for Berks County, Pennsylvania. It was in force for 36 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
- Aug 17, 2026, 5:09 PM EDT (21:09 UTC)
- Expired
- Aug 17, 2026, 5:45 PM EDT
- In force
- 36 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
County Berks County, PA
The radar
The Philadelphia radar (KDIX), 159 km from the middle of the area, began a volume at 21:11 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 |
|---|---|---|---|
| Aug 17, 5:20 PM EDT | TSTM WND DMG | Jefferson Twp, PA | Tree down on wires. Time estimated from radar. |
| Aug 17, 5:29 PM EDT | TSTM WND DMG | Shoemakersville, PA | Tree down on wires. Time estimated from radar. |
| Aug 17, 5:33 PM EDT | TSTM WND DMG | Mohrsville, PA | Multiple trees down, including one blocking a roadway. Time estimated from radar. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 9.2 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
- 154 J/kg
- Mixed-layer CIN
- -50 J/kg
- Mixed-layer LCL
- 877 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 77 m²/s²
- 0-3 km storm-relative helicity
- 59 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
251
WUUS51 KPHI 172109
SVRPHI
PAC011-172145-
/O.NEW.KPHI.SV.W.0307.260817T2109Z-260817T2145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service Baltimore MD/Washington DC
509 PM EDT Mon Aug 17 2026
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northwestern Berks County in eastern Pennsylvania...
* Until 545 PM EDT.
* At 501 PM EDT, a severe thunderstorm was reported near Summit
Station , and moving southeast at 20 mph.
* HAZARD...60 mph wind gusts and quarter size hail.
* SOURCE...Radar indicated.
* Locations impacted include...
Strausstown, Bernville, Fairview Heights, Centrport, Womelsdorf,
PRECAUTIONARY/PREPAREDNESS ACTIONS...
&&
LAT...LON 4052 7626 4054 7617 4056 7613 4057 7608
4058 7606 4057 7605 4058 7604 4057 7602
4059 7601 4049 7590 4035 7606 4036 7620
4037 7624 4040 7628 4051 7634
TIME...MOT...LOC 2101Z 321DEG 19KT 4055 7626
$$
EST2 follow-up statements
647
WWUS51 KPHI 172132
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service Baltimore MD/Washington DC
532 PM EDT Mon Aug 17 2026
PAC011-172145-
/O.CON.KPHI.SV.W.0307.000000T0000Z-260817T2145Z/
Berks PA-
532 PM EDT Mon Aug 17 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR CENTRAL BERKS COUNTY...
At 531 PM EDT, a severe thunderstorm was located over Bernville,
moving southeast at 20 mph.
* HAZARD...60 mph wind gusts and quarter size hail.
* SOURCE...Radar indicated.
* Locations impacted include...
Strausstown, Bernville, Fairview Heights, Centrport, Womelsdorf,
PRECAUTIONARY/PREPAREDNESS ACTIONS...
&&
LAT...LON 4057 7602 4059 7601 4049 7590 4035 7606
4036 7620 4037 7624 4057 7605 4058 7604
TIME...MOT...LOC 2131Z 321DEG 19KT 4043 7613
$$
EST432
WWUS51 KPHI 172140
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service Baltimore MD/Washington DC
540 PM EDT Mon Aug 17 2026
PAC011-172149-
/O.EXP.KPHI.SV.W.0307.000000T0000Z-260817T2145Z/
Berks PA-
540 PM EDT Mon Aug 17 2026
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BERKS COUNTY WILL
EXPIRE AT 545 PM EDT...
The severe thunderstorm which prompted the warning has weakened.
Therefore the warning will be allowed to expire. Expect gusts up to
50 mph and locally heavy rainfall to continue as the storm pushes
south and east.
LAT...LON 4057 7602 4059 7601 4049 7590 4035 7606
4036 7620 4037 7624 4057 7605 4058 7604
TIME...MOT...LOC 2139Z 321DEG 19KT 4040 7610
$$
ESTThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 11:21 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 16, 11:38 PM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 17, 1:57 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery, Philadelphia | 4 hr |
| Aug 17, 4:43 PM EDT | Special Weather Statement | PHI | Berks | 47 min |
| Aug 17, 5:30 PM EDT | Special Weather Statement | PHI | Berks | 30 min |
| Aug 17, 6:03 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 42 min |
| Aug 17, 6:45 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 32 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2026Every 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.