Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 37, NWS Philadelphia/Mount Holly

May 27, 20144 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 27, 2014, 5:08 PM EDT for 4 counties in Pennsylvania. It was in force for 67 min. 4 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: May 27, 2014, 5:08 PM EDT (21:08 UTC)
Expired: May 27, 2014, 6:15 PM EDT
In force: 67 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), 117 km from the middle of the area, began a volume at 21:08 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
May 27, 5:15 PM EDT	TSTM WND DMG	Pottsgrove, PA	WIDESPREAD TREES AND WIRES DOWN. TIME ESTIMATED FROM RADAR
May 27, 5:30 PM EDT	TSTM WND GST 54	Skippack, PA
May 27, 5:45 PM EDT	TSTM WND DMG	Radnor Twp, PA	A TREE IS DOWN
May 27, 5:45 PM EDT	TSTM WND DMG	Radnor Twp, PA	TREES ARE DOWN. SEPTA OUTBOUND TRAINS TERMAINATING AT RADNOR DUE TO DOWN TREE AND WIRES NEAR THE COUNTY LINE. UPDATED FROM PREVIOUS REPORT.

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
May 27, 2:13 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.1 hours before the alert went out and 68 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1885 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 94 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.

373 
WUUS51 KPHI 272108
SVRPHI
PAC011-029-045-091-272215-
/O.NEW.KPHI.SV.W.0037.140527T2108Z-140527T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
508 PM EDT TUE MAY 27 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  SOUTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  WESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 615 PM EDT

* AT 505 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS. THESE SEVERE STORMS EXTENDED FROM
  READING TO CHURCHTOWN TO PARADISE...MOVING SOUTHEAST AT 30 MPH.
  THESE STORMS ARE CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
  60 MPH. 

* SEVERE THUNDERSTORMS WILL BE NEAR...
  HONEY BROOK AND NEW MORGAN AROUND 515 PM EDT...
  ELVERSON AND BIRDSBORO AROUND 520 PM EDT...
  PARKESBURG AND GLENMOORE AROUND 525 PM EDT...
  COATESVILLE AND COCHRANVILLE AROUND 530 PM EDT...
  CEDARVILLE AND POTTSTOWN AROUND 535 PM EDT...
  LIONVILLE AND DOWNINGTOWN AROUND 540 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.

VERY HEAVY RAIN WILL ALSO OCCUR WITH THIS LINE OF SEVERE
THUNDERSTORMS...WHICH COULD FLOOD LOW LYING AREAS QUICKLY AND COVER
ROADS WITH WATER. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE
ROAD.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
TUESDAY EVENING FOR NORTHEASTERN MARYLAND AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4004 7594 4011 7595 4014 7589 4022 7600
      4027 7577 4037 7568 4013 7522 3983 7548
      3984 7562 3982 7567 3977 7575 3989 7600
      3997 7600
TIME...MOT...LOC 2108Z 300DEG 27KT 4031 7591 4016 7592
          4001 7609

$$

FORECASTER: HEAVENER

2 follow-up statements

352 
WWUS51 KPHI 272148
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
548 PM EDT TUE MAY 27 2014

PAC011-272158-
/O.CAN.KPHI.SV.W.0037.000000T0000Z-140527T2215Z/
BERKS PA-
548 PM EDT TUE MAY 27 2014

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS COUNTY IS
CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
TUESDAY EVENING FOR NORTHEASTERN MARYLAND AND EASTERN PENNSYLVANIA. A
SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL MIDNIGHT EDT
WEDNESDAY MORNING FOR DELAWARE AND SOUTHERN NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.

LAT...LON 4033 7561 4013 7523 3983 7548 3984 7562
      3977 7575 3988 7597
TIME...MOT...LOC 2148Z 300DEG 27KT 4016 7557 4001 7558
          3986 7575

$$

PAC029-045-091-272215-
/O.CON.KPHI.SV.W.0037.000000T0000Z-140527T2215Z/
MONTGOMERY PA-DELAWARE PA-CHESTER PA-
548 PM EDT TUE MAY 27 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR CHESTER...WESTERN DELAWARE AND SOUTHWESTERN MONTGOMERY
COUNTIES...

AT 547 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM SPRING CITY TO EXTON TO TOUGHKENAMON...OR ALONG A LINE
EXTENDING FROM 14 MILES NORTH OF WEST CHESTER TO WEST CHESTER TO 11
MILES SOUTHWEST OF WEST CHESTER...MOVING SOUTHEAST AT 30 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  COLLEGEVILLE...TRAPPE...WEST GOSHEN AND PHOENIXVILLE BY 555 PM
  EDT...
  EAGLEVILLE...EVANSBURG...PAOLI AND CHESTERBROOK BY 600 PM EDT...
  AUDUBON AND TROOPER BY 605 PM EDT...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
TUESDAY EVENING FOR NORTHEASTERN MARYLAND AND EASTERN PENNSYLVANIA. A
SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL MIDNIGHT EDT
WEDNESDAY MORNING FOR DELAWARE AND SOUTHERN NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.

LAT...LON 4033 7561 4013 7523 3983 7548 3984 7562
      3977 7575 3988 7597
TIME...MOT...LOC 2148Z 300DEG 27KT 4016 7557 4001 7558
          3986 7575

$$

HEAVENER

679 
WWUS51 KPHI 272202
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
602 PM EDT TUE MAY 27 2014

PAC029-045-091-272215-
/O.CON.KPHI.SV.W.0037.000000T0000Z-140527T2215Z/
MONTGOMERY PA-DELAWARE PA-CHESTER PA-
602 PM EDT TUE MAY 27 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR EASTERN CHESTER...WESTERN DELAWARE AND CENTRAL MONTGOMERY
COUNTIES...

AT 600 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM VALLEY FORGE TO GRADYVILLE TO
KENNETT SQUARE...OR ALONG A LINE EXTENDING FROM 13 MILES NORTHEAST OF
WEST CHESTER TO 7 MILES EAST OF WEST CHESTER TO 9 MILES NORTHWEST OF 
WILMINGTON...MOVING EAST-SOUTHEAST AT 30 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  TROUT LAKE...KING OF PRUSSIA...BRIDGEPORT AND NORRISTOWN BY 610 PM
  EDT...
  WEST CONSHOHOCKEN...CONSHOHOCKEN...PLYMOUTH MEETING AND 7 MILES
  SOUTHWEST OF BLUE BELL BY 615 PM EDT...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
TUESDAY EVENING FOR NORTHEASTERN MARYLAND AND EASTERN PENNSYLVANIA. A
SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL MIDNIGHT EDT
WEDNESDAY MORNING FOR DELAWARE AND SOUTHERN NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.

LAT...LON 4025 7545 4013 7523 3983 7548 3984 7562
      3977 7575 3982 7585
TIME...MOT...LOC 2202Z 300DEG 27KT 4011 7545 3996 7546
          3981 7563

$$

HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
May 27, 4:33 PM EDT	Special Weather Statement	PHI	Berks	57 min
May 27, 4:47 PM EDT	Severe Thunderstorm Warning	PHI	Berks	43 min
May 27, 5:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	66 min
May 27, 5:52 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	53 min
May 27, 6:19 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	3 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.