Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 46, NWS Philadelphia/Mount Holly

May 29, 20204 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 29, 2020, 5:03 PM EDT for 4 counties in Pennsylvania. It was in force for 57 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 29, 2020, 5:03 PM EDT (21:03 UTC)
Expired: May 29, 2020, 6:00 PM EDT
In force: 57 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 117 km from the middle of the area, began a volume at 21:03 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 29, 2:25 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.1 hours before the alert went out and 220 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: 648 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 701 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

315 
WUUS51 KPHI 292103
SVRPHI
PAC011-017-077-091-292200-
/O.NEW.KPHI.SV.W.0046.200529T2103Z-200529T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
503 PM EDT Fri May 29 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Eastern Berks County in eastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...

* Until 600 PM EDT.

* At 503 PM EDT, a severe thunderstorm was located near Reading, 
  moving east at 35 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, Reading, Bethlehem, Pottstown, Lansdale, Emmaus,
  Wyomissing, Quakertown, Perkasie, Souderton, Birdsboro, Kutztown,
  Fleetwood, Sinking Spring, Laureldale, Hatfield, East Greenville,
  Topton, Leesport and Schwenksville.

This includes the following highways...
 Interstate 78 in Pennsylvania between mile markers 49 and 63.
 Northeast Extension between exits A31 and A56.
 Interstate 176 in Pennsylvania between mile markers 6 and 11.

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.

&&

LAT...LON 4048 7600 4065 7541 4062 7538 4058 7541
      4053 7533 4025 7521 4024 7563 4024 7568
      4023 7571 4022 7601 4024 7604
TIME...MOT...LOC 2103Z 249DEG 31KT 4035 7591 

HAIL...1.00IN
WIND...60MPH
 
$$

Iovino

2 follow-up statements

582 
WWUS51 KPHI 292124
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
524 PM EDT Fri May 29 2020

PAC011-017-077-091-292200-
/O.CON.KPHI.SV.W.0046.000000T0000Z-200529T2200Z/
Berks PA-Lehigh PA-Montgomery PA-Bucks PA-
524 PM EDT Fri May 29 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHEASTERN BERKS...SOUTHEASTERN LEHIGH...NORTHWESTERN
MONTGOMERY AND NORTHWESTERN BUCKS COUNTIES...

At 524 PM EDT, a severe thunderstorm was located near Bechtelsville,
or 13 miles east of Reading, moving east at 35 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, Bethlehem, Pottstown, Lansdale, Emmaus, Quakertown,
Perkasie, Souderton, Birdsboro, Kutztown, Fleetwood, Hatfield, East
Greenville, Topton, Schwenksville, Bally, Bechtelsville, Green Lane,
Lyons and Fricks.

This includes the following highways...
 Interstate 78 in Pennsylvania between mile markers 50 and 63.
 Northeast Extension between exits A31 and A56.
 Interstate 176 in Pennsylvania between mile markers 6 and 10.

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.

&&

LAT...LON 4054 7577 4065 7541 4062 7538 4058 7541
      4053 7533 4025 7521 4024 7563 4024 7568
      4023 7571 4023 7594 4037 7586
TIME...MOT...LOC 2124Z 249DEG 31KT 4042 7569 

HAIL...1.00IN
WIND...60MPH
 
$$

Iovino

229 
WWUS51 KPHI 292150
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
550 PM EDT Fri May 29 2020

PAC011-017-077-091-292200-
/O.EXP.KPHI.SV.W.0046.000000T0000Z-200529T2200Z/
Berks PA-Lehigh PA-Montgomery PA-Bucks PA-
550 PM EDT Fri May 29 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS...
SOUTHEASTERN LEHIGH...NORTHWESTERN MONTGOMERY AND NORTHWESTERN BUCKS
COUNTIES WILL EXPIRE AT 600 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.

A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
eastern and southeastern Pennsylvania.

LAT...LON 4054 7577 4065 7541 4062 7538 4058 7541
      4053 7533 4025 7521 4024 7563 4024 7568
      4023 7571 4023 7594 4037 7586
TIME...MOT...LOC 2150Z 249DEG 31KT 4050 7542 

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
May 29, 3:38 PM EDT	Special Weather Statement	PHI	Carbon	82 min
May 29, 3:51 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	54 min
May 29, 4:01 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
May 29, 4:18 PM EDT	Areal Flood Advisory	PHI	Carbon	2 hr
May 29, 4:46 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh, Monroe, Northampton	115 min
May 29, 4:54 PM EDT	Special Weather Statement	PHI	Berks, Lehigh, Monroe, Northampton	66 min
May 29, 5:18 PM EDT	Areal Flood Advisory	PHI	Berks, Chester	3 hr
May 29, 6:46 PM EDT	Special Weather Statement	PHI	Chester	29 min
May 29, 7:19 PM EDT	Special Weather Statement	PHI	Chester	41 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2020 Every severe thunderstorm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.