Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 59, NWS Philadelphia/Mount Holly

June 23, 20154 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 23, 2015, 5:05 PM EDT for 4 counties in Pennsylvania. It was in force for 40 min. 5 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: Jun 23, 2015, 5:05 PM EDT (21:05 UTC)
Expired: Jun 23, 2015, 5:45 PM EDT
In force: 40 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 123 km from the middle of the area, began a volume at 21:07 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
Jun 23, 5:13 PM EDT	TSTM WND DMG	Honey Brook, PA	MULTIPLE REPORTS OF TREES DOWN
Jun 23, 5:21 PM EDT	TSTM WND DMG	West Bradford Twp, PA	MULTIPLE REPORTS OF TREES DOWN
Jun 23, 5:35 PM EDT	TSTM WND DMG	Lower Providence Twp, PA	NUMEROUS TREES AND WIRES DOWN
Jun 23, 5:37 PM EDT	TSTM WND DMG	Glen Mills, PA	TREE DOWN ON A HOUSE
Jun 23, 5:48 PM EDT	TSTM WND DMG	Upland, PA	OVER 70 TREES REPORTED DOWN IN UPLAND PARK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

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 23, 10:20 AM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 23, 4:09 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.1 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: 387 J/kg
Mixed-layer CIN: -168 J/kg
Mixed-layer LCL: 1544 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 121 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

250 
WUUS51 KPHI 232105
SVRPHI
PAC011-029-045-091-232145-
/O.NEW.KPHI.SV.W.0059.150623T2105Z-150623T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
505 PM EDT TUE JUN 23 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN DELAWARE COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  WEST CENTRAL MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 545 PM EDT

* AT 504 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM
  WAS LOCATED NEAR CHURCHTOWN...OR NEAR NEW HOLLAND...AND MOVING EAST
  AT 45 MPH.

* THIS SEVERE THUNDERSTORM WILL BE NEAR...
  HONEY BROOK AROUND 510 PM EDT.
  ELVERSON AROUND 515 PM EDT.
  COATESVILLE AND GLENMOORE AROUND 520 PM EDT.
  DOWNINGTOWN AROUND 525 PM EDT.
  LIONVILLE...LIONVILLE-MARCHWOOD...CHESTER SPRINGS AND PUGHTOWN
  AROUND 530 PM EDT.
  WEST CHESTER AROUND 535 PM EDT.
  PHOENIXVILLE...PAOLI AND VALLEY FORGE AROUND 540 PM EDT.
  WEST NORRITON...RADNOR TOWNSHIP...KING OF PRUSSIA AND GRADYVILLE
  AROUND 545 PM EDT.

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE SOUTH
COATESVILLE...WEST GOSHEN...MALVERN...EVANSBURG...MODENA...
THORNDALE...DEVON-BERWYN...EXTON...ATGLEN AND CHESTERBROOK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...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.

IN ADDITION TO 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 ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 4004 7593 4011 7594 4014 7588 4016 7590
      4020 7542 3990 7541 3988 7599 3992 7600
      3994 7598 3995 7600
TIME...MOT...LOC 2104Z 274DEG 39KT 4009 7601 

$$

1 follow-up statement

727 
WWUS51 KPHI 232153
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
553 PM EDT TUE JUN 23 2015

PAC011-029-045-091-232202-
/O.EXP.KPHI.SV.W.0059.000000T0000Z-150623T2145Z/
DELAWARE PA-CHESTER PA-BERKS PA-MONTGOMERY PA-
553 PM EDT TUE JUN 23 2015

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN DELAWARE...
CHESTER...SOUTHERN BERKS AND WEST CENTRAL MONTGOMERY COUNTIES HAS
EXPIRED...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING IS MOVING MOVED 
OUT OF THE WARNED AREA. THEREFORE THE WARNING WILL BE ALLOWED TO 
EXPIRE.

LAT...LON 4004 7593 4011 7594 4014 7588 4016 7590
      4020 7542 3990 7541 3988 7599 3992 7600
      3994 7598 3995 7600
TIME...MOT...LOC 2151Z 274DEG 39KT 4009 7601 

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 23, 8:30 AM EDT	Special Weather Statement	PHI	Monroe	60 min
Jun 23, 9:10 AM EDT	Special Weather Statement	PHI	Monroe	35 min
Jun 23, 10:37 AM EDT	Special Weather Statement	PHI	Carbon, Monroe	38 min
Jun 23, 11:13 AM EDT	Special Weather Statement	PHI	Monroe	32 min
Jun 23, 1:31 PM EDT	Special Weather Statement	PHI	Carbon, Monroe, Northampton	59 min
Jun 23, 1:41 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	49 min
Jun 23, 2:29 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	46 min
Jun 23, 3:49 PM EDT	Special Weather Statement	PHI	Berks, Bucks, Chester, Montgomery	86 min
Jun 23, 4:11 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	24 min
Jun 23, 4:44 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	61 min
Jun 23, 5:19 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	4 hr
Jun 23, 5:22 PM EDT	Tornado Warning	PHI	Chester	23 min
Jun 23, 5:28 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	47 min
Jun 23, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	52 min
Jun 23, 5:44 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Jun 23, 6:18 PM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.