Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 146, NWS Philadelphia/Mount Holly

July 27, 2014Berks County, Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2014, 9:21 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 54 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 27, 2014, 9:21 PM EDT (01:21 UTC)
Expired: Jul 27, 2014, 10:15 PM EDT
In force: 54 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 119 km from the middle of the area, began a volume at 01:23 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
Jul 27, 9:34 PM EDT	TSTM WND DMG	Honey Brook, PA	ROUTE 10 CLOSED AT WAWASSAN DRIVE DUE TO DOWNED POLES AND WIRES.
Jul 27, 9:45 PM EDT	HAIL 0.75	Elverson, PA	DIME SIZE HAIL REPORTED.

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
Jul 27, 6:52 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.4 hours before the alert went out and 193 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: 1013 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 1007 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 103 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

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

979 
WUUS51 KPHI 280121
SVRPHI
PAC011-029-280215-
/O.NEW.KPHI.SV.W.0146.140728T0121Z-140728T0215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
921 PM EDT SUN JUL 27 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
  NORTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1015 PM EDT

* AT 918 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR CHURCHTOWN...MOVING EAST AT
  15 MPH. THIS STORM IS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEW MORGAN AROUND 930 PM EDT...
  COATESVILLE AROUND 935 PM EDT...
  ELVERSON AROUND 940 PM EDT...
  GLENMOORE AROUND 945 PM EDT...
  DOWNINGTOWN AROUND 955 PM EDT...
  PUGHTOWN AND CEDARVILLE AROUND 1010 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...MOVE INDOORS TO A
STURDY BUILDING AND STAY AWAY FROM WINDOWS. WHEN IT IS SAFE TO DO
SO...REPORT SEVERE WEATHER TO LOCAL LAW ENFORCEMENT OR TO THE
NATIONAL WEATHER SERVICE.

DOPPLER RADAR HAS INDICATED SOME ROTATION WITHIN THIS STORM. WHILE
NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A TORNADO IS
SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM ON THE LOWEST
FLOOR.

&&

LAT...LON 4025 7570 4025 7569 4024 7569 4024 7565
      4023 7562 3995 7557 3997 7598 4004 7594
      4011 7595 4014 7589 4022 7600
TIME...MOT...LOC 0121Z 260DEG 15KT 4012 7592

$$

IOVINO

1 follow-up statement

408 
WWUS51 KPHI 280145
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
945 PM EDT SUN JUL 27 2014

PAC011-029-280215-
/O.CON.KPHI.SV.W.0146.000000T0000Z-140728T0215Z/
BERKS PA-CHESTER PA-
945 PM EDT SUN JUL 27 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM EDT
FOR NORTHERN CHESTER AND SOUTH CENTRAL BERKS COUNTIES...

AT 942 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE 
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS CENTER OF THE 
STORM WAS LOCATED NEAR ELVERSON...MOVING EAST AT 15 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  PUGHTOWN...CEDARVILLE...SOUTH POTTSTOWN AND 7 MILES NORTH OF
  LIONVILLE BY 1010 PM EDT...
  CHESTER SPRINGS AND KENILWORTH BY 1015 PM EDT...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...MOVE INDOORS TO A
STURDY BUILDING AND STAY AWAY FROM WINDOWS. WHEN IT IS SAFE TO DO
SO...REPORT SEVERE WEATHER TO LOCAL LAW ENFORCEMENT OR TO THE
NATIONAL WEATHER SERVICE.

LAT...LON 4025 7570 4025 7569 4024 7569 4024 7565
      4023 7562 3995 7557 3997 7598 4004 7594
      4011 7595 4014 7589 4022 7600
TIME...MOT...LOC 0145Z 260DEG 15KT 4014 7579

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 8:28 PM EDT	Special Weather Statement	PHI	Berks	62 min
Jul 27, 8:42 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	3 hr
Jul 27, 9:12 PM EDT	Special Weather Statement	PHI	Chester	63 min
Jul 27, 9:43 PM EDT	Flash Flood Warning	PHI	Berks, Chester, Montgomery	4 hr
Jul 27, 10:20 PM EDT	Special Weather Statement	PHI	Chester, Montgomery	55 min
Jul 27, 10:26 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	3 hr
Jul 27, 10:33 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	4 hr
Jul 27, 10:44 PM EDT	Special Weather Statement	PHI	Chester, Delaware	61 min
Jul 27, 10:47 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	43 min
Jul 27, 11:28 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	62 min
Jul 27, 11:32 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	58 min
Jul 28, 12:31 AM EDT	Flash Flood Warning	PHI	Delaware, Montgomery, Philadelphia	3 hr
Jul 28, 12:35 AM EDT	Special Weather Statement	PHI	Bucks, Chester, Delaware, Philadelphia	85 min
Jul 28, 2:58 AM EDT	River Flood Warning	PHI	Chester	8 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2014 Every severe thunderstorm warning in 2014

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.