Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 46, NWS Philadelphia/Mount Holly

July 3, 2018Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 3, 2018, 6:54 PM EDT for Chester County, Delaware County, Pennsylvania. It was in force for 51 min. 1 report 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: Jul 3, 2018, 6:54 PM EDT (22:54 UTC)
Expired: Jul 3, 2018, 7:45 PM EDT
In force: 51 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Chester County, PA, Delaware County, PA

What was reported inside it

Time	Report	Where	Remark
Jul 3, 7:03 PM EDT	TSTM WND GST 60	Downingtown, 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, 10.9 hours before the alert went out and 174 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: 574 J/kg
Mixed-layer CIN: -189 J/kg
Mixed-layer LCL: 1257 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 55 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

004 
WUUS51 KPHI 032254
SVRPHI
PAC029-045-032345-
/O.NEW.KPHI.SV.W.0046.180703T2254Z-180703T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
654 PM EDT TUE JUL 3 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 745 PM EDT.

* At 654 PM EDT, a severe thunderstorm was located near Coatesville,
  or 8 miles west of West Chester, and is nearly stationary.

  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, West Grove, Cochranville, Cheyney, Glenmoore,
  Marshallton, Ladenberg, Lionville-Marchwood, North Star, Hockessin,
  West Goshen, Atglen, South Coatesville, Avondale and Christiana.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4000 7596 4014 7585 3996 7547 3983 7560
      3982 7568 3976 7575 3992 7600 3994 7598
      3995 7600
TIME...MOT...LOC 2254Z 274DEG 1KT 3995 7577 

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

SFJ

1 follow-up statement

887 
WWUS51 KPHI 032341
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
741 PM EDT TUE JUL 3 2018

PAC029-045-032350-
/O.EXP.KPHI.SV.W.0046.000000T0000Z-180703T2345Z/
Chester PA-Delaware PA-
741 PM EDT TUE JUL 3 2018

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CHESTER AND WEST
CENTRAL DELAWARE COUNTIES WILL EXPIRE AT 745 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

Remember, a Severe Thunderstorm Warning still remains in effect for
portions of Chester County.

LAT...LON 4000 7596 4014 7585 3996 7547 3983 7560
      3982 7568 3976 7575 3992 7600 3994 7598
      3995 7600
TIME...MOT...LOC 2340Z 274DEG 1KT 3995 7575 

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 3, 2:15 PM EDT	Special Weather Statement	PHI	Delaware	30 min
Jul 3, 3:00 PM EDT	Special Weather Statement	PHI	Philadelphia	60 min
Jul 3, 3:11 PM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	50 min
Jul 3, 4:06 PM EDT	Special Weather Statement	PHI	Montgomery	54 min
Jul 3, 4:30 PM EDT	Special Weather Statement	PHI	Bucks	60 min
Jul 3, 5:24 PM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	4 hr
Jul 3, 5:29 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	4 hr
Jul 3, 5:30 PM EDT	Special Weather Statement	PHI	Philadelphia	30 min
Jul 3, 5:45 PM EDT	Flash Flood Warning	PHI	Delaware, Montgomery, Philadelphia	4 hr
Jul 3, 6:03 PM EDT	Special Weather Statement	PHI	Monroe	57 min
Jul 3, 6:15 PM EDT	Special Weather Statement	PHI	Chester	60 min
Jul 3, 6:18 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	42 min
Jul 3, 6:21 PM EDT	Special Weather Statement	PHI	Delaware	24 min
Jul 3, 6:25 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Philadelphia	50 min
Jul 3, 6:37 PM EDT	Flash Flood Warning	PHI	Bucks, Philadelphia	3 hr
Jul 3, 6:40 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	4 hr
Jul 3, 6:50 PM EDT	Special Weather Statement	PHI	Delaware	55 min
Jul 3, 6:58 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	4 hr
Jul 3, 7:03 PM EDT	Special Weather Statement	PHI	Northampton	57 min
Jul 3, 7:06 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	2 hr
Jul 3, 7:22 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	21 min
Jul 3, 7:35 PM EDT	Special Weather Statement	PHI	Chester	25 min
Jul 3, 7:39 PM EDT	Severe Thunderstorm Warning	PHI	Chester	51 min
Jul 3, 7:54 PM EDT	Flash Flood Warning	PHI	Chester	4 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2018 Every severe thunderstorm warning in 2018

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.