Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 148, NWS Philadelphia/Mount Holly

July 28, 2016Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 28, 2016, 12:58 PM EDT for Chester County, Pennsylvania. It was in force for 47 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
Jul 28, 2016, 12:58 PM EDT (16:58 UTC)
Expired
Jul 28, 2016, 1:45 PM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
50.0 mph

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 16:58 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
Jul 28, 1:05 PM EDTTSTM WND DMG1 N Embreeville, PATREE AND WIRES DOWN ON CAR ON STARGAZERS RD
Jul 28, 1:05 PM EDTTSTM WND DMGWest Bradford Twp, PAREPORT OF TREES AND POWER LINES DOWN IN THE TOWNSHIP

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, 5.0 hours before the alert went out and 203 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, Washington/Dulle, VA at 12:00Z on 2016-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 552 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, Washington/Dulle, VA at 12:00Z on 2016-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
552 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
1083 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

946 
WUUS51 KPHI 281658
SVRPHI
PAC029-281745-
/O.NEW.KPHI.SV.W.0148.160728T1658Z-160728T1745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1258 PM EDT THU JUL 28 2016

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 145 PM EDT

* AT 1255 PM EDT...A SEVERE THUNDERSTORM WAS LOCATED OVER
  DOWNINGTOWN... OR 7 MILES NORTHWEST OF WEST CHESTER...MOVING EAST
  AT 35 MPH.

  HAZARD...WIND IN EXCESS OF 58 MPH. 

  SOURCE...RADAR INDICATED. 

  IMPACT...EXPECT DAMAGE TO ROOFS...SIDINGS...AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  WEST CHESTER...PHOENIXVILLE...COATESVILLE...DOWNINGTOWN...
  HONEY BROOK...CHESTER SPRINGS...VALLEY FORGE...MARSHALLTON...
  GLENMOORE...PUGHTOWN...PAOLI...LIONVILLE-MARCHWOOD...LIONVILLE...
  WEST GOSHEN...SPRING CITY...MALVERN...SOUTH COATESVILLE...MODENA...
  THORNDALE AND DEVON-BERWYN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

INTENSE THUNDERSTORM LINES CAN PRODUCE BRIEF TORNADOES AND
WIDESPREAD SIGNIFICANT WIND DAMAGE. ALTHOUGH A TORNADO IS NOT
IMMEDIATELY LIKELY...IT IS BEST TO MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR OF A BUILDING. THIS STORM MAY CAUSE SERIOUS INJURY AND
SIGNIFICANT PROPERTY DAMAGE.

&&

LAT...LON 4020 7558 4015 7552 4015 7550 4014 7551
      4012 7546 4009 7545 4009 7542 4006 7540
      3996 7548 3995 7552 3991 7584 4011 7591
TIME...MOT...LOC 1655Z 260DEG 29KT 4001 7573 

HAIL...<.75IN
WIND...<50MPH
 
$$
JJM
1 follow-up statement
391 
WWUS51 KPHI 281729
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
129 PM EDT THU JUL 28 2016

PAC029-281745-
/O.CON.KPHI.SV.W.0148.000000T0000Z-160728T1745Z/
CHESTER PA-
129 PM EDT THU JUL 28 2016

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM EDT
FOR CENTRAL CHESTER COUNTY...

AT 128 PM EDT...A SEVERE THUNDERSTORM WAS LOCATED OVER
MARSHALLTON...OR NEAR WEST CHESTER...MOVING EAST AT 15 MPH.

HAZARD...60 MPH WIND GUSTS. 

SOURCE...RADAR INDICATED. 

IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

LOCATIONS IMPACTED INCLUDE...
WEST CHESTER...DOWNINGTOWN...MARSHALLTON...
WEST GOSHEN AND THORNDALE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMAIN ALERT FOR A POSSIBLE TORNADO! TORNADOES CAN DEVELOP QUICKLY
FROM SEVERE THUNDERSTORMS. IF YOU SPOT A TORNADO GO AT ONCE INTO THE
BASEMENT OR SMALL CENTRAL ROOM IN A STURDY STRUCTURE.

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

IN ADDITION TO 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 3992 7577 4001 7576 3997 7547 3996 7548
      3995 7552
TIME...MOT...LOC 1728Z 278DEG 15KT 3995 7568 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 1:24 PM EDTSevere Thunderstorm WarningPHIChester, Delaware51 min
Jul 28, 2:30 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery, Philadelphia45 min
Jul 28, 2:36 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia4 hr
Jul 28, 3:28 PM EDTSevere Thunderstorm WarningPHIBerks27 min
Jul 28, 3:41 PM EDTAreal Flood AdvisoryPHIBerks4 hr
Jul 28, 4:50 PM EDTAreal Flood AdvisoryPHIBerks4 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2016Every severe thunderstorm warning in 2016

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.