Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 11, NWS Philadelphia/Mount Holly

February 25, 20179 counties in Pennsylvania; Hunterdon County, Morris County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Feb 25, 2017, 4:17 PM EST for 9 counties in Pennsylvania; Hunterdon County, Morris County, Warren County, New Jersey. It was in force for 43 min. 20 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: Feb 25, 2017, 4:17 PM EST (21:17 UTC)
Expired: Feb 25, 2017, 5:00 PM EST
In force: 43 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.88 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Morris County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 96 km from the middle of the area, began a volume at 21:19 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
Feb 25, 4:23 PM EST	TSTM WND DMG	Macungie, PA	ROOF BLOWN OFF AN APARTMENT BUILDING. ALL OCCUPANTS OF THE 20 APARTMENTS WERE EVACUATED AND SOUGHT HOUSING WITH FAMILY MEMBERS. NO INJURIES WERE REPORTED. TIME ESTIMATED FROM RADAR.
Feb 25, 4:23 PM EST	TSTM WND DMG	Weisenberg Twp, PA	MULTIPLE POWER POLES DOWN. TIME ESTIMATED FROM RADAR.
Feb 25, 4:25 PM EST	TSTM WND DMG	W Allentown, PA	SEVERAL TREES DOWN IN WEST ALLENTOWN. TIME ESTIMATED FROM RADAR.
Feb 25, 4:25 PM EST	TSTM WND GST 53	2 Nw Zionsville, PA
Feb 25, 4:29 PM EST	TSTM WND GST 56	S Allentown, PA
Feb 25, 4:29 PM EST	TSTM WND GST 56	S Allentown, PA
Feb 25, 4:30 PM EST	TSTM WND DMG	1 Ene Bushkill Center, PA	ALONG A 1.5 MILE STRETCH FROM BUSHKILL CENTER ROAD TO HIGHWAY 33...THERE WERE NUMEROUS TREES... POWER LINES... AND TELEPHONE POLES DOWN. TREES WERE BLOWN DOWN ON TO 4 HOUSES AND ONE BARN. A TRACTOR TRAILOR WAS BLOWN OVER AND MOVED 30 FEET. TIME ESTIMATED FROM
Feb 25, 4:30 PM EST	HAIL 0.75	Allentown, PA
Feb 25, 4:31 PM EST	TSTM WND DMG	Bushkill Twp, PA	SEVERAL TREES AND WIRES DOWN
Feb 25, 4:35 PM EST	TSTM WND DMG	2 Sw Wind Gap, PA	TREES DOWN WITH ONE ON A HOUSE ALONG A PORTION OF SULLIVAN TRAIL. TIME ESTIMATED FROM RADAR.
Feb 25, 4:35 PM EST	TSTM WND DMG	Plainfield Twp, PA	SEVERAL TREES AND WIRES DOWN
Feb 25, 4:38 PM EST	TSTM WND DMG	Belfast, PA	TREES DOWN ONTO WIRES ON SULLIVAN TRAIL ROAD BETWEEN BELFAST ROAD AND CHURCH ROAD. ALL LANES CLOSED. TIME ESTIMATED FROM RADAR.
Feb 25, 4:40 PM EST	TSTM WND DMG	1 Wsw Tatamy, PA	TRAFFIC LIGHTS BLOWN DOWN AT THE TATAMY INTERCHANGE ON ROUTE 33. TIME ESTIMATED FROM RADAR.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	AT JACOBSBURG RD AND PARKLAND DR. TREES DOWN, POWER LINES DOWN, TELEPHONE POLES SNAPPED. 3 HOUSES WITH TREES THROUGH THE ROOFS. BARN DOOR WAS BLOWN OFF THE HINGE.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	TRACTOR TRAILOR BLOWN OVER AND TOSSED 30 FEET ON BUSHKILL CENTER ROAD.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	TREE DOWN ON BARN, RESULTING IN 1 HORSE DEAD ON CREAMERY ROAD.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	TREE ON HOUSE AND FENCE BLOWN OUT ON RENALDI ROAD.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	TREES DOWN ON BELLFAST ROAD AND GOLD MILL ROAD.
Feb 25, 4:50 PM EST	TSTM WND DMG	Bushkill Twp, PA	TREES DOWN ON ROAD, POWER LINES DOWN ON KELLER ROAD.
Feb 25, 4:54 PM EST	TSTM WND GST 55	Blairstown, NJ

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
Feb 25, 1:30 PM EST	Severe Thunderstorm Watch	SPC	6 hr
Feb 25, 2:46 PM EST	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.3 hours before the alert went out and 207 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: 576 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

311 
WUUS51 KPHI 252117
SVRPHI
NJC019-027-041-PAC011-017-029-045-077-089-091-095-101-252200-
/O.NEW.KPHI.SV.W.0011.170225T2117Z-170225T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
417 PM EST SAT FEB 25 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  Southwestern Morris County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  Northeastern Berks County in eastern Pennsylvania...
  Montgomery County in southeastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Bucks County in southeastern Pennsylvania...
  Eastern Chester County in southeastern Pennsylvania...
  Northern Philadelphia County in southeastern Pennsylvania...
  South central Monroe County in northeastern Pennsylvania...
  Northern Delaware County in southeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 500 PM EST

* At 416 PM EST, severe thunderstorms were located along a line
  extending from Claussville to near Topton to Pottstown to near
  Kennett Square, moving northeast at 55 mph.

  HAZARD...60 mph wind gusts and nickel size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Severe thunderstorms will be near,
  Royersford, Trappe, Topton, Bally, Bechtelsville, Ancient Oaks, 
  Claussville, Coffeetown, Gilbertsville and Schnecksville around 
  420 PM EST. 
  Allentown, Emmaus, East Greenville, Schwenksville, Green Lane, 
  Spring Mount and Lionville around 425 PM EST. 
  Westtown, Northampton, Souderton, Hatfield, Lehigh University, 
  Beersville, Cheyney, Gradyville, Geryville and Lionville-Marchwood 
  around 430 PM EST. 
  Bethlehem, Quakertown, Perkasie, Hellertown, Bath, Steuben, Paoli, 
  Newtown Square, Valley Forge and Springtown around 435 PM EST. 
  West Norriton, Forks, Wilson, Bedminster, Nazareth, Dublin, 
  Belfast, West Easton, Tatamy and Riegelsville around 440 PM EST. 
  Easton, Norristown, East Norriton, Conshohocken, Narberth, 
  Tinicum, Pen Argyl, Wind Gap, Alpha and Ferndale around 445 PM 
  EST. 
  Byram, Ambler, Bangor, Harmony, Frenchtown, Milford, East Bangor, 
  Bloomsbury, Stockton and Erwinna around 450 PM EST. 
  Washington, Jenkintown, High Bridge, Belvidere, Rockledge, Oxford, 
  Abington, Glen Gardner, Hampton and Brass Castle around 455 PM 
  EST. 

Other locations impacted by these severe thunderstorms include
Boyertown, Churchville, Pottsgrove, Hokendauqua, Thorndale,
Stockertown, Evansburg, Malvern, West Goshen and Fort Washington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

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.

&&

LAT...LON 4081 7483 4063 7481 4007 7502 3979 7586
      4023 7569 4046 7571 4064 7577 4107 7496
TIME...MOT...LOC 2116Z 241DEG 52KT 4060 7568 4050 7564 4027 7563 3990
7577

TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
 
$$

DRAG

1 follow-up statement

806 
WWUS51 KPHI 252141
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
441 PM EST SAT FEB 25 2017

PAC011-252151-
/O.CAN.KPHI.SV.W.0011.000000T0000Z-170225T2200Z/
Berks PA-
441 PM EST SAT FEB 25 2017

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

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 800 PM EST for
southeastern Pennsylvania. A severe thunderstorm watch also remains
in effect until 900 PM EST for central, northern and northwestern New
Jersey...and eastern, southeastern and northeastern Pennsylvania.

LAT...LON 4081 7483 4063 7481 4007 7502 3982 7578
      4043 7548 4058 7542 4085 7537 4107 7496
TIME...MOT...LOC 2141Z 223DEG 61KT 4092 7527 4080 7524 4053 7529 4003
7550

$$

NJC019-027-041-PAC017-029-045-077-089-091-095-101-252200-
/O.CON.KPHI.SV.W.0011.000000T0000Z-170225T2200Z/
Morris NJ-Hunterdon NJ-Warren NJ-Montgomery PA-Lehigh PA-Bucks PA-
Chester PA-Philadelphia PA-Monroe PA-Delaware PA-Northampton PA-
441 PM EST SAT FEB 25 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EST
FOR SOUTHWESTERN MORRIS...HUNTERDON...WARREN...MONTGOMERY...
SOUTHEASTERN LEHIGH...BUCKS...EASTERN CHESTER...NORTHERN
PHILADELPHIA...SOUTH CENTRAL MONROE...NORTHERN DELAWARE AND
NORTHAMPTON COUNTIES...

At 441 PM EST, severe thunderstorms were located along a line
extending from near Stormville to near Belfast to Pleasant Valley to
Paoli, moving northeast at 70 mph.

HAZARD...60 mph wind gusts and nickel size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

These severe storms will be near...
  Hellertown, Bangor, Pen Argyl, Wind Gap, Ferndale, Belfast, 
  Tatamy, East Bangor, Riegelsville and Springtown around 445 PM 
  EST. 
  Easton, Forks, East Norriton, Wilson, Collegeville, Trappe, 
  Belvidere, Alpha, West Easton and Milford around 450 PM EST. 
  Lansdale, Ambler, Blairstown, Harmony, Hope, Bloomsbury and Great 
  Meadows-Vienna around 455 PM EST. 
  Doylestown, Souderton, Washington, Chalfont, Hatfield, Oxford, 
  Dublin, Glen Gardner, Hampton and Brass Castle around 500 PM EST. 

Other locations impacted by these severe thunderstorms include
Churchville, Stockertown, Evansburg, Malvern, West Goshen, Fort
Washington, Bridgeport, Blue Bell, Maple Glen and Eagleville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

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 occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4081 7483 4063 7481 4007 7502 3982 7578
      4043 7548 4058 7542 4085 7537 4107 7496
TIME...MOT...LOC 2141Z 223DEG 61KT 4092 7527 4080 7524 4053 7529 4003
7550

TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
 
$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 25, 2:22 PM EST	Special Weather Statement	PHI	Lebanon	53 min
Feb 25, 2:47 PM EST	Severe Thunderstorm Warning	PHI	Berks	43 min
Feb 25, 2:55 PM EST	Special Weather Statement	PHI	Carbon	50 min
Feb 25, 3:02 PM EST	Special Weather Statement	PHI	Berks	58 min
Feb 25, 3:19 PM EST	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Northampton	41 min
Feb 25, 3:26 PM EST	Severe Thunderstorm Warning	PHI	Berks, Chester	64 min
Feb 25, 3:57 PM EST	Special Weather Statement	PHI	Lehigh, Montgomery	48 min
Feb 25, 4:04 PM EST	Severe Thunderstorm Warning	PHI	Chester, Delaware	41 min
Feb 25, 4:05 PM EST	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe	40 min
Feb 25, 4:34 PM EST	Special Weather Statement	PHI	Monroe	41 min
Feb 25, 4:40 PM EST	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	50 min
Feb 25, 4:54 PM EST	Severe Thunderstorm Warning	PHI	Bucks, Monroe	51 min
Feb 25, 5:01 PM EST	Special Weather Statement	PHI	Bucks	44 min
Feb 25, 5:17 PM EST	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	43 min
Feb 25, 6:10 PM EST	Special Weather Statement	PHI	Delaware	35 min
Feb 24, 9:50 PM EST	Marine Dense Fog Advisory	PHI		20 hr
Feb 25, 4:24 PM EST	Special Marine Warning	PHI		66 min
Feb 25, 4:59 PM EST	Special Marine Warning	PHI		61 min
Feb 25, 5:23 PM EST	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Cape May, Cumberland, Gloucester, Salem	52 min
Feb 25, 5:38 PM EST	Special Marine Warning	PHI		67 min
Feb 25, 6:04 PM EST	Special Weather Statement	PHI	Middlesex, Monmouth, Ocean	41 min
Feb 25, 6:09 PM EST	Special Marine Warning	PHI		66 min
Feb 25, 6:14 PM EST	Special Weather Statement	PHI	Atlantic	31 min
Feb 25, 6:20 PM EST	Special Marine Warning	PHI		85 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017 Severe Thunderstorm Warnings in New Jersey, 2017 Every severe thunderstorm warning in 2017

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.