Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 186, NWS Philadelphia/Mount Holly

June 29, 2019Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 29, 2019, 8:25 PM EDT for Chester County, Pennsylvania. It was in force for 16 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: Jun 29, 2019, 8:25 PM EDT (00:25 UTC)
Expired: Jun 29, 2019, 8:41 PM EDT
In force: 16 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 107 km from the middle of the area, began a volume at 00:28 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
Jun 29, 12:08 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.4 hours before the alert went out and 184 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: 604 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 2055 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

441 
WUUS51 KPHI 300025
SVRPHI
PAC029-300115-
/O.NEW.KPHI.SV.W.0186.190630T0025Z-190630T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
825 PM EDT Sat Jun 29 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Chester County in southeastern Pennsylvania...

* Until 915 PM EDT.

* At 825 PM EDT, a severe thunderstorm was located over Parkesburg,
  or 14 miles west of West Chester, moving east at 25 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...
  West Chester, Coatesville, Westtown, Downingtown, Kennett Square,
  Parkesburg, Cochranville, Marshallton, Hockessin, West Goshen,
  Atglen, South Coatesville, Avondale, Modena, Thorndale,
  Toughkenamon and Exton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.

&&

LAT...LON 4008 7591 3998 7546 3995 7551 3993 7552
      3993 7554 3988 7559 3985 7559 3984 7558
      3984 7561 3983 7564 3979 7571 3990 7600
TIME...MOT...LOC 0025Z 290DEG 23KT 3997 7587 

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

MPS

1 follow-up statement

748 
WWUS51 KPHI 300041
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
841 PM EDT Sat Jun 29 2019

PAC029-300051-
/O.CAN.KPHI.SV.W.0186.000000T0000Z-190630T0115Z/
Chester PA-
841 PM EDT Sat Jun 29 2019

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CHESTER COUNTY IS
CANCELLED...
                
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 has been cancelled.

A severe thunderstorm watch remains in effect until 900 PM EDT for
northern Delaware...and southeastern Pennsylvania.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 4008 7591 3998 7546 3995 7551 3993 7552
      3993 7554 3988 7559 3985 7559 3984 7558
      3984 7561 3983 7564 3979 7571 3990 7600
TIME...MOT...LOC 0038Z 290DEG 23KT 3993 7574 

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 8:12 PM EDT	Special Weather Statement	PHI	Chester	33 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.