Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 30, NWS Philadelphia/Mount Holly

May 26, 20216 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 26, 2021, 4:46 PM EDT for 6 counties in Pennsylvania. It was in force for 44 min. 30 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 26, 2021, 4:46 PM EDT (20:46 UTC)
Expired
May 26, 2021, 5:30 PM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Berks County, PA, Bucks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 96 km from the middle of the area, began a volume at 20:48 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 26, 4:48 PM EDTTSTM WND DMG3 W Douglass Twp, PADOWNED TREE ON POWDER MILL HOLLOW ROAD. TIME ESTIMATED FROM RADAR.
May 26, 4:50 PM EDTTSTM WND DMG1 Nw Bally, PADOWNED TREES AND WIRES NEAR HILLCREST ROAD. TIME ESTIMATED FROM RADAR.
May 26, 4:53 PM EDTTSTM WND DMG1 Ene Huffs Church, PADOWNED TREES AND WIRES NEAR MULBERRY HILL ROAD. TIME ESTIMATED FROM RADAR.
May 26, 4:53 PM EDTTSTM WND DMG1 Nnw Colebrookdale Twp, PADOWNED TREES AND WIRES NEAR IRONSTONE DRIVE. TIME ESTIMATED FROM RADAR.
May 26, 4:55 PM EDTTSTM WND DMG1 Nnw Upper Hanover Twp, PADOWNED TREE ON ZIEGLER ROAD NEAR GRAVEL PIKE. TIME ESTIMATED FROM RADAR.
May 26, 4:55 PM EDTTSTM WND DMGAllentown, PASOCIAL MEDIA PHOTO OF A SNAPPED TREE IN A NEIGHBORHOOD NEAR ALLENTOWN. TIME CORRECTED BASED ON RADAR.
May 26, 4:58 PM EDTTSTM WND DMG1 Ese New Hanover Twp, PADOWNED TREE ON REIFSNYDER ROAD NEAR SWAMP PICNIC ROAD. TIME ESTIMATED FROM RADAR.
May 26, 4:58 PM EDTTSTM WND DMG2 Ese Douglass Twp, PADOWNED TREES AND WIRES NEAR FARMINGTON AVENUE ON THE BERKS/MONTGOMERY COUNTY BORDER. TIME ESTIMATED FROM RADAR.
May 26, 4:58 PM EDTTSTM WND DMG2 W Upper Hanover Twp, PADOWNED TREE IN WIRES ON KUTZTOWN ROAD NEAR TOWNSHIP WOODS ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:00 PM EDTTSTM WND GST 401 Se Macungie, PACWOP MEASURED GUST.
May 26, 5:05 PM EDTTSTM WND DMG1 Wnw Perkiomenville, PASEVERAL DOWNED TREES AND A POWER POLE DOWN. TIME ESTIMATED FROM RADAR.
May 26, 5:05 PM EDTTSTM WND DMG1 W Upper Salford Twp, PADOWNED TREE ON SALFORD STATION ROAD NEAR CEPP ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:05 PM EDTTSTM WND DMG2 Wsw Red Hill, PADOWNED TREE ON WARD ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:05 PM EDTTSTM WND DMG3 E Zionsville, PADOWNED TREE NEAR THE INTERSECTION OF LIMEPORT PIKE AND CHESTNUT HILL CHURCH ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:07 PM EDTTSTM WND DMG1 Wnw Sellersville, PASEVERAL REPORTS OF DOWNED TREES AND WIRES NEAR AND WEST OF SELLERSVILLE. TIME ESTIMATED FROM RADAR.
May 26, 5:09 PM EDTTSTM WND DMG1 Ene West Rockhill Twp, PADOWNED TREES AND WIRES NEAR MOUNTAIN VIEW ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:10 PM EDTTSTM WND DMG1 S Milford Twp, PADOWNED TREE LIMBS AND WIRES NEAR WALNUT LANE. TIME ESTIMATED FROM RADAR.
May 26, 5:12 PM EDTHAIL 0.7Gilbertsville, PA
May 26, 5:14 PM EDTTSTM WND DMGHellertown, PADOWNED TREES AND WIRES NEAR FRONT STREET. TIME ESTIMATED FROM RADAR.
May 26, 5:16 PM EDTTSTM WND DMG2 Wnw Richland Twp, PADOWNED TREES AND WIRES NEAR KELLERS ROAD AND MINE ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:18 PM EDTHAIL 0.751 Wnw Washington Twp, PAREPORT FROM BARTO.
May 26, 5:20 PM EDTTSTM WND GST 601 Ne Salford Twp, PABROADCAST METEOROLOGIST ESTIMATES 60-65 MPH WIND GUSTS NEAR ALLENTOWN ROAD AND COUNTY LINE ROAD.
May 26, 5:21 PM EDTTSTM WND DMG1 Ne Montgomeryville, PADOWNED TREES AND WIRES NEAR COUNTY LINE ROAD AND BUSINESS ROUTE 202. TIME ESTIMATED FROM RADAR.
May 26, 5:21 PM EDTTSTM WND DMG1 W Ottsville, PADOWNED TREES AND WIRES NEAR PARK ROAD. TIME ESTIMATED FROM RADAR AND UTILITY REPORT.
May 26, 5:22 PM EDTTSTM WND DMGWilliams Twp, PADOWNED TREE LIMBS AND WIRES NORTH OF RAUBSVILLE ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:23 PM EDTTSTM WND DMG2 N Blue Bell, PADOWNED TREE BLOCKING OVERBROOK DRIVE NEAR GWYNEDD VALLEY DRIVE. TIME ESTIMATED FROM RADAR.
May 26, 5:25 PM EDTTSTM WND DMG1 Sw Durham Twp, PADOWNED TREES AND WIRES NEAR ROUTE 212 IN DURHAM TWP. TIME ESTIMATED FROM RADAR.
May 26, 5:25 PM EDTTSTM WND DMG2 Nw Riegelsville, PADOWNED TREE LIMBS AND WIRES NEAR COFFETOWN ROAD. TIME ESTIMATED FROM RADAR.
May 26, 5:30 PM EDTTSTM WND DMG1 Ssw Phoenixville, PADOWNED TREE LIMBS ON FOURTH AVENUE AND LINCOLN AVENUE. TIME ESTIMATED FROM RADAR.
May 26, 5:35 PM EDTHAIL 0.88Bedminster, PATIME 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 26, 2:48 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.8 hours before the alert went out and 217 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 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 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 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 164 square meters per square second.193958Sfc1 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
5 J/kg
Mixed-layer CIN
-233 J/kg
Mixed-layer LCL
554 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
164 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

334 
WUUS51 KPHI 262046
SVRPHI
PAC011-017-029-077-091-095-262130-
/O.NEW.KPHI.SV.W.0030.210526T2046Z-210526T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
446 PM EDT Wed May 26 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Berks County in eastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Montgomery County in southeastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  South central Northampton County in eastern Pennsylvania...

* Until 530 PM EDT.

* At 445 PM EDT, severe thunderstorms were located along a line
  extending from near Coffeetown to near Bechtelsville to New Morgan,
  moving east at 45 mph.

  HAZARD...70 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Allentown, Easton, Bethlehem, Norristown, Pottstown, Phoenixville,
  Lansdale, West Norriton, East Norriton, Emmaus, Quakertown,
  Perkasie, Doylestown, Souderton, Bedminster, Hellertown,
  Collegeville, Royersford, Chalfont and Tinicum.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 298 and 304, and between
mile markers 330 and 333.
 Northeast Extension between mile markers 21 and 53.
 Interstate 78 in Pennsylvania between mile markers 57 and 73.
 Interstate 476 in Pennsylvania between mile markers 18 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

These storms are producing widespread wind damage across Berks 
County. SEEK SHELTER NOW inside a sturdy structure and stay away 
from windows!

&&

LAT...LON 4041 7564 4065 7545 4064 7519 4057 7519
      4057 7516 4058 7512 4054 7507 4045 7507
      4042 7506 4041 7499 4009 7530 4013 7589
      4014 7588 4015 7590
TIME...MOT...LOC 2045Z 269DEG 40KT 4062 7555 4043 7567 4020 7591 

HAIL...0.75IN
WIND...70MPH
 
$$

Meola
1 follow-up statement
917 
WWUS51 KPHI 262119
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
519 PM EDT Wed May 26 2021

PAC011-017-029-077-091-095-262130-
/O.CON.KPHI.SV.W.0030.000000T0000Z-210526T2130Z/
Berks PA-Lehigh PA-Montgomery PA-Bucks PA-Chester PA-Northampton PA-
519 PM EDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHEASTERN BERKS...SOUTHEASTERN LEHIGH...MONTGOMERY...
NORTHWESTERN BUCKS...NORTHEASTERN CHESTER AND SOUTH CENTRAL
NORTHAMPTON COUNTIES...

At 518 PM EDT, severe thunderstorms were located along a line
extending from Springtown to near Geryville to Pughtown, moving east
at 30 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Bethlehem, Norristown, Pottstown, Phoenixville, Lansdale, West
Norriton, East Norriton, Quakertown, Perkasie, Doylestown, Souderton,
Bedminster, Hellertown, Collegeville, Royersford, Chalfont, Tinicum,
Trappe, Hatfield and East Greenville.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 298 and 304, and between
mile markers 330 and 333.
 Northeast Extension between mile markers 21 and 48.
 Interstate 78 in Pennsylvania between mile markers 66 and 72.
 Interstate 476 in Pennsylvania between mile markers 18 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

These storms are producing widespread wind damage across Berks 
county. SEEK SHELTER NOW inside a sturdy structure and stay away 
from windows.
 
&&

LAT...LON 4040 7556 4064 7532 4064 7519 4057 7519
      4057 7516 4058 7512 4054 7507 4045 7507
      4042 7506 4041 7499 4009 7530 4013 7589
      4014 7588 4015 7590 4025 7580
TIME...MOT...LOC 2118Z 273DEG 27KT 4058 7529 4039 7541 4016 7565 

HAIL...0.75IN
WIND...70MPH
 
$$

Deal

The office that day

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

IssuedProductOfficeCountiesLasted
May 26, 3:39 PM EDTSevere Thunderstorm WarningPHIBerks56 min
May 26, 4:10 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh65 min
May 26, 4:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery38 min
May 26, 5:27 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Delaware, Montgomery, Philadelphia48 min
May 26, 5:34 PM EDTSevere Thunderstorm WarningPHINorthampton41 min
May 26, 5:37 PM EDTSevere Thunderstorm WarningPHIChester53 min
May 26, 5:53 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia67 min
May 26, 6:52 PM EDTSevere Thunderstorm WarningPHIBerks38 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 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.