Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 109, NWS Philadelphia/Mount Holly

July 18, 20165 counties in Pennsylvania; Hunterdon County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 18, 2016, 2:51 PM EDT for 5 counties in Pennsylvania; Hunterdon County, New Jersey. It was in force for 39 min. 15 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 18, 2016, 2:51 PM EDT (18:51 UTC)
Expired: Jul 18, 2016, 3:30 PM EDT
In force: 39 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 18:51 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 18, 2:58 PM EDT	TSTM WND DMG	Orefield, PA	TREES AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jul 18, 3:00 PM EDT	TSTM WND DMG	Breinigsville, PA	WHEAT CROP DAMAGED. TIME ESTIMATED FROM RADAR.
Jul 18, 3:02 PM EDT	TSTM WND DMG	Trexlertown, PA	TREES DOWN ONTO WIRES. TIME ESTIMATED FROM RADAR.
Jul 18, 3:05 PM EDT	TSTM WND DMG	Allentown, PA	400 POUND A/C UNITS WERE KNOCKING OFF THEIR MOUNTING AND ONTO THEIR SIDE. THIS OCCURRED ON THE TOP OF THE EMERGENCY MANAGEMENT BUILDING... 10 STORIES UP.
Jul 18, 3:05 PM EDT	TSTM WND DMG	Allentown, PA	SOME VERY LARGE TREE LIMBS TORN OFF NEAR 13TH STREET AND CONGRESS AVENUE... SOME BLOCKING ROADS.
Jul 18, 3:05 PM EDT	TSTM WND DMG	South Whitehall Twp, PA	TREES DOWN.
Jul 18, 3:05 PM EDT	TSTM WND DMG	Whitehall Twp, PA	TREES DOWN.
Jul 18, 3:05 PM EDT	TSTM WND GST 56	Allentown, PA	7TH AND HAMILTON IN THE CITY OF ALLENTOWN.
Jul 18, 3:07 PM EDT	TSTM WND DMG	Allentown, PA	LARGE TREE LIMB DOWN ONTO A CAR ON 22ND STREET BREAKING THE BACK WINDOW.
Jul 18, 3:08 PM EDT	TSTM WND DMG	S Allentown, PA	TREES DOWN
Jul 18, 3:08 PM EDT	TSTM WND GST 62	S Allentown, PA	MEASURED AT 308 AND AT 309 PM.
Jul 18, 3:08 PM EDT	TSTM WND GST 62	S Allentown, PA	MEASURED AT 308 AND AT 309 PM...SOME TREES DOWN
Jul 18, 3:10 PM EDT	TSTM WND GST 56	Allentown, PA	7TH AND HAMILTON IN THE CITY OF ALLENTOWN.
Jul 18, 3:14 PM EDT	TSTM WND DMG	S Allentown, PA	TREES DOWN
Jul 18, 3:15 PM EDT	HAIL 0.25	Macungie, PA

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 18, 12:05 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 18, 1:42 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.9 hours before the alert went out and 208 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: 1 J/kg
Mixed-layer CIN: -127 J/kg
Mixed-layer LCL: 1554 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

455 
WUUS51 KPHI 181851
SVRPHI
NJC019-PAC011-017-077-091-095-181930-
/O.NEW.KPHI.SV.W.0109.160718T1851Z-160718T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
251 PM EDT MON JUL 18 2016

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN HUNTERDON COUNTY IN NORTHWESTERN NEW JERSEY...
  SOUTHWESTERN NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  EASTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  NORTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  NORTHWESTERN BUCKS COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  NORTH CENTRAL MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 330 PM EDT

* AT 250 PM EDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR ANCIENT
  OAKS... OR NEAR ALLENTOWN...MOVING SOUTHEAST AT 50 MPH.

  HAZARD...60 MPH WIND GUSTS AND NICKEL SIZE HAIL. 

  SOURCE...RADAR INDICATED. 

  IMPACT...EXPECT DAMAGE TO ROOFS...SIDING...AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  ALLENTOWN...BETHLEHEM...LANSDALE...EMMAUS...NORTHAMPTON...
  QUAKERTOWN...PERKASIE...SOUDERTON...BEDMINSTER...HELLERTOWN...
  CHALFONT...TINICUM...HATFIELD...EAST GREENVILLE...DUBLIN...
  FERNDALE...FRENCHTOWN...MILFORD...RIEGELSVILLE AND PLEASANT VALLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

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 4071 7553 4062 7519 4061 7520 4059 7519
      4061 7516 4056 7495 4022 7528 4053 7570
TIME...MOT...LOC 1850Z 296DEG 44KT 4058 7556 

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

PO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 12:58 PM EDT	Special Weather Statement	PHI	Carbon	62 min
Jul 18, 1:48 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	57 min
Jul 18, 1:52 PM EDT	Special Weather Statement	PHI	Chester	38 min
Jul 18, 2:28 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Northampton	47 min
Jul 18, 3:17 PM EDT	Special Weather Statement	PHI	Delaware, Montgomery, Philadelphia	43 min
Jul 18, 3:25 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	50 min
Jul 18, 3:41 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	49 min
Jul 18, 4:04 PM EDT	Special Weather Statement	PHI	Philadelphia	56 min
Jul 18, 4:04 AM EDT	Small Craft Advisory	PHI		12 hr
Jul 18, 2:42 PM EDT	Special Weather Statement	PHI	Sussex	63 min
Jul 18, 4:07 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Morris, Somerset	38 min
Jul 18, 4:14 PM EDT	Severe Thunderstorm Warning	PHI	Salem	46 min
Jul 18, 4:15 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	2 hr
Jul 18, 4:37 PM EDT	Severe Thunderstorm Warning	PHI	Salem	38 min
Jul 18, 4:47 PM EDT	Special Marine Warning	PHI		88 min
Jul 18, 4:47 PM EDT	Special Weather Statement	PHI	Burlington, Camden	43 min
Jul 18, 5:00 PM EDT	Special Marine Warning	PHI		60 min
Jul 18, 5:07 PM EDT	Special Marine Warning	PHI		83 min
Jul 18, 5:22 PM EDT	Special Weather Statement	PHI	Cumberland, Salem	53 min
Jul 18, 5:49 PM EDT	Special Marine Warning	PHI		116 min
Jul 18, 5:51 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	24 min
Jul 18, 6:05 PM EDT	Special Marine Warning	PHI		85 min
Jul 18, 6:23 PM EDT	Special Marine Warning	PHI		97 min
Jul 18, 7:43 PM EDT	Special Weather Statement	PHI	Sussex	47 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2016 Severe Thunderstorm Warnings in New Jersey, 2016 Every severe thunderstorm warning in 2016

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.