Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 355, NWS Philadelphia/Mount Holly

August 18, 2019Berks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 2019, 4:34 PM EDT for Berks County, Montgomery County, Pennsylvania. It was in force for 41 min. 2 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 18, 2019, 4:34 PM EDT (20:34 UTC)
Expired: Aug 18, 2019, 5:15 PM EDT
In force: 41 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Berks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 135 km from the middle of the area, began a volume at 20:36 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 18, 4:39 PM EDT	HAIL 1	Spring Twp, PA
Aug 18, 4:40 PM EDT	HAIL 1.25	Spring Twp, PA

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, 8.6 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.

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: 751 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 1254 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 13 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

191 
WUUS51 KPHI 182034
SVRPHI
PAC011-091-182115-
/O.NEW.KPHI.SV.W.0355.190818T2034Z-190818T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
434 PM EDT Sun Aug 18 2019

The National Weather Service in Mount Holly NJ has issued a

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

* Until 515 PM EDT.

* At 434 PM EDT, a cluster of severe thunderstorms was located 
  across southern Berks County, moving northeast at 5 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...
  Reading, Wyomissing, Birdsboro, Kutztown, Fleetwood, Sinking
  Spring, Laureldale, East Greenville, Wernersville, Topton,
  Leesport, Bally, Bechtelsville, Lyons, Spring Ridge, Fairview Hgts,
  Gilbertsville, Shillington, West Reading and Boyertown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4040 7610 4057 7572 4042 7548 4026 7571
      4024 7603 4032 7616
TIME...MOT...LOC 2034Z 230DEG 6KT 4030 7588 

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

Staarmann

1 follow-up statement

523 
WWUS51 KPHI 182058
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
458 PM EDT Sun Aug 18 2019

PAC011-091-182115-
/O.CON.KPHI.SV.W.0355.000000T0000Z-190818T2115Z/
Berks PA-Montgomery PA-
458 PM EDT Sun Aug 18 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR EASTERN BERKS AND NORTHWESTERN MONTGOMERY COUNTIES...

At 440 PM EDT, trained spotters reported half dollar sized hail in 
Spring Township. This severe thunderstorm is located near 
Laureldale, or near Reading, moving northeast at 10 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Wind damage 
         to roofs, siding, trees, and power lines is possible.

Locations impacted include...
Reading, Wyomissing, Birdsboro, Kutztown, Fleetwood, Sinking Spring,
Laureldale, East Greenville, Wernersville, Topton, Leesport, Bally,
Bechtelsville, Lyons, Spring Ridge, Fairview Hgts, Gilbertsville,
Shillington, West Reading and Boyertown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm, and
the storm will affect the beaches. For your safety, immediately move
off the beach and seek shelter indoors.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4040 7610 4057 7572 4042 7548 4026 7571
      4024 7603 4032 7616
TIME...MOT...LOC 2056Z 233DEG 8KT 4036 7587 

HAIL...1.50IN
WIND...60MPH
 
$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 8:32 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	73 min
Aug 18, 3:32 AM EDT	Heat Advisory	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	4 days
Aug 18, 4:22 PM EDT	Special Weather Statement	PHI	Berks	38 min
Aug 18, 4:36 PM EDT	Special Weather Statement	PHI	Bucks	24 min
Aug 18, 5:01 PM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	3 hr
Aug 18, 5:16 PM EDT	Special Weather Statement	PHI	Berks	29 min
Aug 18, 5:25 PM EDT	Special Weather Statement	PHI	Carbon, Monroe, Northampton	65 min
Aug 18, 5:29 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	2 hr
Aug 18, 5:36 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	39 min
Aug 18, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	52 min
Aug 18, 5:42 PM EDT	Special Weather Statement	PHI	Berks	48 min
Aug 18, 6:28 PM EDT	Special Weather Statement	PHI	Northampton	47 min
Aug 18, 6:40 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	54 min
Aug 18, 7:03 PM EDT	Special Weather Statement	PHI	Berks	27 min
Aug 18, 7:23 PM EDT	Special Weather Statement	PHI	Berks	67 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2019 Every severe thunderstorm warning in 2019

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.