Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 231, NWS Philadelphia/Mount Holly

July 27, 2026Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2026, 3:41 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 49 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
Jul 27, 2026, 3:41 PM EDT (19:41 UTC)
Expired
Jul 27, 2026, 4:30 PM EDT
In force
49 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 74 km from the middle of the area, began a volume at 19:41 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

TimeReportWhereRemark
Jul 27, 3:48 PM EDTHAIL 0.5Chestnut Hill, PA0.25 to 0.50 inch hail reported in Chestnut Hill. Winds estimated around 40 mph.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.7 hours before the alert went out and 219 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2026-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 199 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2026-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
199 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
928 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

401 
WUUS51 KPHI 271941
SVRPHI
PAC091-101-272030-
/O.NEW.KPHI.SV.W.0231.260727T1941Z-260727T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
341 PM EDT Mon Jul 27 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Northwestern Philadelphia County in southeastern Pennsylvania...

* Until 430 PM EDT.

* At 341 PM EDT, a severe thunderstorm was located over Plymouth
  Meeting, or 8 miles northwest of Philadelphia, moving northeast at
  10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Philadelphia, East Norriton, Conshohocken, Ambler, Jenkintown,
  Narberth, Rockledge, Morris Park, Plymouth Meeting, Germantown,
  Bryn Mawr, Chestnut Hill, West Conshohocken, Penn Wynne, Fort
  Washington, Blue Bell, Glenside, Flourtown, Spring House, and
  Ardmore.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 332 and 340.
 Northeast Extension between mile markers 21 and 23.
 Interstate 76 in Pennsylvania between mile markers 330 and 339.
 Interstate 476 in Pennsylvania between mile markers 15 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4022 7525 4009 7508 3997 7527 4005 7535
      4007 7535
TIME...MOT...LOC 1941Z 223DEG 8KT 4008 7526 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Guzzo
2 follow-up statements
366 
WWUS51 KPHI 271956
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
356 PM EDT Mon Jul 27 2026

PAC091-101-272030-
/O.CON.KPHI.SV.W.0231.000000T0000Z-260727T2030Z/
Montgomery PA-Philadelphia PA-
356 PM EDT Mon Jul 27 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHEASTERN MONTGOMERY AND NORTHWESTERN PHILADELPHIA COUNTIES...

At 355 PM EDT, a severe thunderstorm was located over Chestnut Hill,
or 7 miles northwest of Philadelphia, moving northeast at 10 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...
Philadelphia, East Norriton, Conshohocken, Ambler, Jenkintown,
Rockledge, Plymouth Meeting, Germantown, Chestnut Hill, Roxborough,
West Conshohocken, Fort Washington, Blue Bell, Glenside, Flourtown,
Spring House, Oreland, Wyndmoor, Wyncote, and Maple Glen.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 332 and 340.
 Northeast Extension between mile markers 21 and 23.
 Interstate 76 in Pennsylvania between mile markers 330 and 339.
 Interstate 476 in Pennsylvania between mile markers 16 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4022 7525 4009 7508 4000 7522 4007 7535
TIME...MOT...LOC 1955Z 223DEG 8KT 4009 7522 

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

$$

Guzzo
210 
WWUS51 KPHI 272023
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
423 PM EDT Mon Jul 27 2026

PAC091-101-272033-
/O.EXP.KPHI.SV.W.0231.000000T0000Z-260727T2030Z/
Montgomery PA-Philadelphia PA-
423 PM EDT Mon Jul 27 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY AND
NORTHWESTERN PHILADELPHIA COUNTIES WILL EXPIRE AT 430 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.

LAT...LON 4022 7525 4009 7508 4000 7522 4007 7535
TIME...MOT...LOC 2023Z 223DEG 8KT 4013 7517 

$$

Guzzo

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 2:15 PM EDTFlood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more38 hr
Jul 27, 2:57 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia48 min
Jul 27, 3:01 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery44 min
Jul 27, 3:50 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton40 min
Jul 27, 3:58 PM EDTFlash Flood WarningPHIDelaware, Montgomery, Philadelphia3 hr
Jul 27, 5:25 PM EDTFlash Flood WarningPHILehigh2 hr
Jul 27, 5:51 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh23 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.