Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 87, NWS Philadelphia/Mount Holly

July 9, 2015Berks County, Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2015, 6:15 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 45 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: Jul 9, 2015, 6:15 PM EDT (22:15 UTC)
Expired: Jul 9, 2015, 7:00 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 123 km from the middle of the area, began a volume at 22:17 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
Jul 9, 4:57 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.3 hours before the alert went out and 179 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: 1 J/kg
Mixed-layer CIN: -194 J/kg
Mixed-layer LCL: 1091 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

959 
WUUS51 KPHI 092215
SVRPHI
PAC011-029-091-092300-
/O.NEW.KPHI.SV.W.0087.150709T2215Z-150709T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
615 PM EDT THU JUL 9 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 700 PM EDT

* AT 613 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM
  WAS LOCATED OVER EAST PETERSBURG...AND MOVING EAST AT 45 MPH.

* THIS SEVERE THUNDERSTORM WILL BE NEAR...
  HONEY BROOK AND NEW MORGAN AROUND 640 PM EDT.
  ELVERSON AROUND 645 PM EDT.
  BIRDSBORO AND GLENMOORE AROUND 650 PM EDT.
  PUGHTOWN AROUND 655 PM EDT.
  POTTSTOWN...CEDARVILLE AND CHESTER SPRINGS AROUND 700 PM EDT.

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE WEST
LAWN...STOWE...SHILLINGTON...AMITY GARDENS...ST. LAWRENCE...SOUTH
COATESVILLE...HALFWAY HOUSE...AVONDALE...THORNDALE AND LORANE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DEADLY LIGHTNING AND 
VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN INTERIOR ROOM ON 
THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS 
QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR 
DAMAGING WINDS. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4046 7560 3988 7557 3986 7560 3984 7558
      3980 7571 3978 7605 3983 7604 3987 7599
      3994 7598 3995 7600 4004 7593 4011 7594
      4014 7588 4036 7621
TIME...MOT...LOC 2213Z 259DEG 42KT 4011 7632 

$$

GORSE/FRANCK

1 follow-up statement

902 
WWUS51 KPHI 092241
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
641 PM EDT THU JUL 9 2015

PAC011-029-091-092300-
/O.CON.KPHI.SV.W.0087.000000T0000Z-150709T2300Z/
CHESTER PA-BERKS PA-MONTGOMERY PA-
641 PM EDT THU JUL 9 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR CHESTER...SOUTHEASTERN BERKS AND NORTHWESTERN MONTGOMERY
COUNTIES...

AT 639 PM EDT...DOPPLER RADAR INDICATED A LINE OF SEVERE
THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60
MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM
WERNERSVILLE TO NEAR CHURCHTOWN TO NEAR NEW HOLLAND TO NEAR
HOLTWOOD...MOVING EAST AT 50 MPH.

THIS LINE OF STORMS HAS HAD A HISTORY OF PRODUCING WIND DAMAGE.

THESE SEVERE STORMS WILL BE NEAR...

READING...WYOMISSING...SINKING SPRING...HONEY BROOK...NEW MORGAN   
AND SPRING RIDGE AROUND 645 PM EDT.  BIRDSBORO...LAURELDALE AND 
ELVERSON AROUND 650 PM EDT.  GLENMOORE...HOMEVILLE AND MOUNT VERNON 
AROUND 655 PM EDT.  

POTTSTOWN...PARKESBURG...BECHTELSVILLE...CEDARVILLE...PUGHTOWN... 
COCHRANVILLE...CHESTER SPRINGS...GILBERTSVILLE...LIONVILLE-MARCHWOOD 
AND LIONVILLE AROUND 700 PM EDT.

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE WEST
LAWN...STOWE...SHILLINGTON...AMITY GARDENS...ST. LAWRENCE...SOUTH
COATESVILLE...HALFWAY HOUSE...AVONDALE...THORNDALE AND LORANE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DESTRUCTIVE HAIL...
DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

THESE STORMS HAVE A HISTORY OF PRODUCING WIND DAMAGE. THIS IS A VERY
DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND
STAY AWAY FROM WINDOWS.
 
&&

LAT...LON 4046 7560 3988 7557 3986 7560 3984 7558
      3980 7571 3978 7605 3983 7604 3987 7599
      3994 7598 3995 7600 4004 7593 4011 7594
      4014 7588 4036 7621
TIME...MOT...LOC 2239Z 253DEG 45KT 4032 7606 4017 7599 4008 7603 3987
7629

$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	40 min
Jul 9, 6:46 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Jul 9, 6:50 PM EDT	Severe Thunderstorm Warning	PHI	Chester	40 min
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	48 min
Jul 9, 7:12 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Northampton	48 min
Jul 9, 7:21 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	4 hr
Jul 9, 7:29 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	46 min
Jul 9, 7:39 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	66 min
Jul 9, 7:55 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Philadelphia	40 min
Jul 9, 7:56 PM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2015 Every severe thunderstorm warning in 2015

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.