Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 58, NWS Philadelphia/Mount Holly

June 23, 2015Berks County, Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 23, 2015, 4:44 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 61 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: Jun 23, 2015, 4:44 PM EDT (20:44 UTC)
Expired: Jun 23, 2015, 5:45 PM EDT
In force: 61 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), 119 km from the middle of the area, began a volume at 20:46 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, 5:23 PM EDT	TSTM WND DMG	Brecknock Twp, PA	TREES DOWN.

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, 8.7 hours before the alert went out and 206 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.

660 
WUUS51 KPHI 232044
SVRPHI
PAC011-029-091-232145-
/O.NEW.KPHI.SV.W.0058.150623T2044Z-150623T2145Z/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

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

* UNTIL 545 PM EDT

* AT 443 PM EDT...DOPPLER RADAR INDICATED A DEVELOPING SEVERE 
  THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING 
  WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR 
  ADAMSTOWN...OR 8 MILES SOUTHWEST OF READING...AND MOVING EAST AT 
  35 MPH.

* THIS SEVERE THUNDERSTORM WILL BE NEAR...
  ELVERSON AND NEW MORGAN AROUND 455 PM EDT.
  BIRDSBORO AROUND 505 PM EDT.
  POTTSTOWN...CEDARVILLE AND PUGHTOWN AROUND 515 PM EDT.
  GILBERTSVILLE AROUND 520 PM EDT.
  ROYERSFORD AROUND 525 PM EDT.
  COLLEGEVILLE...TRAPPE...SCHWENKSVILLE...GREEN LANE AND SPRING MOUNT
  AROUND 535 PM EDT.

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE STOWE...
SHILLINGTON...KENILWORTH...AMITY GARDENS...POTTSGROVE...PENNSBURG...
ST. LAWRENCE...RED HILL...EVANSBURG AND HALFWAY HOUSE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...LARGE 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 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 ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 4028 7609 4043 7552 4040 7544 4019 7543
      4014 7588
TIME...MOT...LOC 2043Z 262DEG 29KT 4022 7600 

$$

1 follow-up statement

184 
WWUS51 KPHI 232144
SVSPHI

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

PAC011-029-091-232154-
/O.EXP.KPHI.SV.W.0058.000000T0000Z-150623T2145Z/
CHESTER PA-BERKS PA-MONTGOMERY PA-
544 PM EDT TUE JUN 23 2015

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL CHESTER...
SOUTHEASTERN BERKS AND NORTHWESTERN MONTGOMERY COUNTIES WILL EXPIRE
AT 545 PM EDT...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF 
THE WARNED AREA. THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 4028 7609 4043 7552 4040 7544 4019 7543
      4014 7588
TIME...MOT...LOC 2142Z 262DEG 29KT 4022 7600 

$$

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, 5:05 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware, Montgomery	40 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.