Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 33, NWS Philadelphia/Mount Holly

May 20, 2026Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 20, 2026, 4:00 PM EDT for Berks County, Pennsylvania. It was in force for 45 min. 9 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
May 20, 2026, 4:00 PM EDT (20:00 UTC)
Expired
May 20, 2026, 4:45 PM EDT
In force
45 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 136 km from the middle of the area, began a volume at 20:01 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
May 20, 4:14 PM EDTTSTM WND DMG3 Wnw Robeson Twp, PATree down into a house. Time estimated from radar.
May 20, 4:14 PM EDTTSTM WND DMG3 Wnw Robeson Twp, PATree down into a house. Time estimated from radar.
May 20, 4:15 PM EDTTSTM WND DMG3 Sse Kenhorst, PATrees down on wires along Mount Penn Road. Time estimated from radar.
May 20, 4:15 PM EDTTSTM WND DMG3 Sse Kenhorst, PATrees down on wires along Mount Penn Road. Time estimated from radar.
May 20, 4:30 PM EDTTSTM WND DMGBirdsboro, PATrees down on wires. Time estimated from radar.
May 20, 4:30 PM EDTTSTM WND DMGBirdsboro, PATrees down on wires. Time estimated from radar.
May 20, 4:40 PM EDTTSTM WND GST 531 Ne Reading, PAMesonet station EW3190 Reading.
May 20, 4:47 PM EDTTSTM WND DMG2 Se Douglass Twp, PAWires down along Sunset Drive. Time estimated from radar.
May 20, 4:47 PM EDTTSTM WND DMG2 Se Douglass Twp, PAWires down along Sunset Drive. 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.

IssuedProductOfficeLasted
May 20, 2:10 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.0 hours before the alert went out and 200 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, Washington/Dulle, VA at 12:00Z on 2026-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 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, Washington/Dulle, VA at 12:00Z on 2026-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -79 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
47 J/kg
Mixed-layer CIN
-204 J/kg
Mixed-layer LCL
1752 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-79 m²/s²
0-3 km storm-relative helicity
-47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

438 
WUUS51 KPHI 202000
SVRPHI
PAC011-202045-
/O.NEW.KPHI.SV.W.0033.260520T2000Z-260520T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
400 PM EDT Wed May 20 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Berks County in eastern Pennsylvania...

* Until 445 PM EDT.

* At 400 PM EDT, a severe thunderstorm was located over Robesonia, or
  9 miles east of Myerstown, moving east at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Reading, Wyomissing, Birdsboro, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Wernersville, Robesonia, Leesport,
  Bernville, Bechtelsville, Spring Ridge, Fairview Hgts, Shillington,
  West Reading, Boyertown, Mount Penn, Mohnton, and Kenhorst.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4048 7621 4044 7562 4030 7565 4023 7571
      4020 7578 4024 7603 4037 7623
TIME...MOT...LOC 2000Z 274DEG 22KT 4036 7613 

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

$$

Fitzsimmons
1 follow-up statement
967 
WWUS51 KPHI 202034
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
434 PM EDT Wed May 20 2026

PAC011-202045-
/O.CON.KPHI.SV.W.0033.000000T0000Z-260520T2045Z/
Berks PA-
434 PM EDT Wed May 20 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR CENTRAL BERKS COUNTY...

At 433 PM EDT, a severe thunderstorm was located near Birdsboro, or 
7 miles east of Reading, moving east at 30 mph. This storm has a 
history of producing wind damage. 

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters.

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

Locations impacted include...
Reading, Wyomissing, Birdsboro, Sinking Spring, Laureldale,
Wernersville, Leesport, Bechtelsville, Spring Ridge, Fairview Hgts,
Shillington, West Reading, Boyertown, Mount Penn, Mohnton, Kenhorst,
St. Lawrence, West Lawn, Lorane, and Amity Gardens.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4031 7614 4047 7608 4043 7562 4030 7565
      4023 7571 4020 7578 4024 7603
TIME...MOT...LOC 2033Z 276DEG 25KT 4032 7579 

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

$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 8:04 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia25 min
May 20, 3:57 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh48 min
May 20, 4:29 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery46 min
May 20, 4:43 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Northampton47 min
May 20, 4:46 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery44 min
May 20, 4:50 PM EDTSevere Thunderstorm WarningPHIChester, Delaware40 min
May 20, 5:10 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia50 min
May 20, 5:15 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery, Philadelphia45 min
May 20, 5:24 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton51 min
May 20, 5:29 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Philadelphia46 min
May 20, 5:40 PM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia3 hr
May 20, 5:41 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia49 min
May 20, 5:52 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia38 min
May 20, 6:01 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery, Philadelphia44 min
May 20, 6:09 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia46 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.