Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 77, NWS Philadelphia/Mount Holly

August 13, 2018Bucks County, Pennsylvania; Hunterdon County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 2018, 9:16 PM EDT for Bucks County, Pennsylvania; Hunterdon County, New Jersey. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 13, 2018, 9:16 PM EDT (01:16 UTC)
Expired: Aug 13, 2018, 10:00 PM EDT
In force: 44 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 01:17 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.3 hours before the alert went out and 196 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: 399 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 664 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 82 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

763 
WUUS51 KPHI 140116
SVRPHI
NJC019-PAC017-140200-
/O.NEW.KPHI.SV.W.0077.180814T0116Z-180814T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
916 PM EDT MON AUG 13 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Hunterdon County in northwestern New Jersey...
  Northwestern Bucks County in southeastern Pennsylvania...

* Until 1000 PM EDT.

* At 916 PM EDT, a severe thunderstorm was located over Dublin, or 
  22 miles southeast of Allentown, moving northeast at 20 mph. It 
  will not take as much wind to down some trees due to the saturated 
  ground.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Perkasie, Doylestown, Byram, Bedminster, Tinicum, Dublin, Ferndale,
  Frenchtown, Milford, Riegelsville, Stockton, Revere, Ottsville,
  Sergeantsville, Pipersville, Erwinna, Gardenville, Lumberville and
  Sand Brook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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 4030 7511 4040 7532 4060 7519 4063 7514
      4049 7485
TIME...MOT...LOC 0116Z 235DEG 17KT 4036 7518 

HAIL...<.75IN
WIND...60MPH
 
$$

Gorse

2 follow-up statements

814 
WWUS51 KPHI 140145
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
945 PM EDT MON AUG 13 2018

NJC019-PAC017-140200-
/O.CON.KPHI.SV.W.0077.000000T0000Z-180814T0200Z/
Hunterdon NJ-Bucks PA-
945 PM EDT MON AUG 13 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT
FOR SOUTHWESTERN HUNTERDON AND NORTH CENTRAL BUCKS COUNTIES...

At 945 PM EDT, a severe thunderstorm was located over Byram, or 19 
miles southeast of Easton, moving northeast at 20 mph. It will not 
take as much wind to down some trees due to the saturated ground.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Byram, Tinicum, Ferndale, Frenchtown, Milford, Riegelsville,
Stockton, Revere, Ottsville, Sergeantsville, Erwinna, Lumberville and
Sand Brook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4036 7502 4050 7521 4060 7519 4063 7514
      4049 7485
TIME...MOT...LOC 0145Z 235DEG 17KT 4044 7503 

HAIL...<.75IN
WIND...60MPH
 
$$

Gorse

249 
WWUS51 KPHI 140155
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
955 PM EDT MON AUG 13 2018

NJC019-PAC017-140205-
/O.EXP.KPHI.SV.W.0077.000000T0000Z-180814T0200Z/
Hunterdon NJ-Bucks PA-
955 PM EDT MON AUG 13 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN HUNTERDON AND
NORTH CENTRAL BUCKS COUNTIES WILL EXPIRE AT 1000 PM EDT...
                
The storm which prompted the warning is weakening. Therefore, the 
warning will be allowed to expire. However locally gusty winds and 
heavy rain are still possible with this thunderstorm.

LAT...LON 4036 7502 4050 7521 4060 7519 4063 7514
      4049 7485
TIME...MOT...LOC 0155Z 235DEG 17KT 4046 7498 

$$

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 8:13 PM EDT	Special Weather Statement	PHI	Montgomery	32 min
Aug 13, 8:16 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	3 hr
Aug 13, 8:51 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	54 min
Aug 13, 9:00 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	60 min
Aug 14, 12:50 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	4 hr
Aug 14, 3:22 PM EDT	Special Weather Statement	PHI	Lehigh	53 min
Aug 14, 3:58 PM EDT	Special Weather Statement	PHI	Montgomery	47 min
Aug 13, 9:14 PM EDT	Areal Flood Warning	PHI	Ocean	4 hr
Aug 14, 3:24 PM EDT	Special Weather Statement	PHI	Burlington	51 min
Aug 14, 3:36 PM EDT	Special Weather Statement	PHI	Monmouth	39 min
Aug 14, 3:48 PM EDT	Special Weather Statement	PHI	Monmouth	57 min
Aug 14, 4:00 PM EDT	Special Marine Warning	PHI		60 min
Aug 14, 4:45 PM EDT	Special Weather Statement	PHI	Hunterdon, Somerset	45 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2018 Severe Thunderstorm Warnings in New Jersey, 2018 Every severe thunderstorm warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.