Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 62, NWS Philadelphia/Mount Holly

August 1, 20185 counties in Pennsylvania; Hunterdon County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 1, 2018, 10:40 PM EDT for 5 counties in Pennsylvania; Hunterdon County, Warren County, New Jersey. It was in force for 37 min. 5 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
Aug 1, 2018, 10:40 PM EDT (02:40 UTC)
Expired
Aug 1, 2018, 11:17 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

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

The radar

The Philadelphia radar (KDIX), 85 km from the middle of the area, began a volume at 02:41 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

TimeReportWhereRemark
Aug 1, 10:41 PM EDTTSTM WND DMGEmmaus, PAMULTIPLE REPORTS OF TREES DOWN INCLUDING SOME DOWN ON CARS AND A HOUSE. TIME ESTIMATED FROM RADAR.
Aug 1, 10:42 PM EDTTSTM WND DMGSalisbury Twp, PANUMEROUS TREES AND WIRES REPORTED DOWN.
Aug 1, 10:45 PM EDTTSTM WND DMGUpper Saucon Twp, PANUMEROUS REPORTS OF TREES AND WIRES DOWN.
Aug 1, 10:50 PM EDTTSTM WND DMG2 N Hellertown, PALARGE TREE DOWN
Aug 1, 10:54 PM EDTTSTM WND DMG2 N Lower Saucon, PATREE DOWN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 2.7 hours before the alert went out and 190 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-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2018-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 986 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2018-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
986 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
816 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.9
Supercell composite
6.6

Open this sounding in Storm Lab

The text

As transmitted.

167 
WUUS51 KPHI 020240
SVRPHI
NJC019-041-PAC011-017-077-091-095-020330-
/O.NEW.KPHI.SV.W.0062.180802T0240Z-180802T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1040 PM EDT WED AUG 1 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Hunterdon County in northwestern New Jersey...
  Southwestern Warren County in northwestern New Jersey...
  East central Berks County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Eastern Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 1130 PM EDT.

* At 1039 PM EDT, severe thunderstorms were located along a line
  extending from Kunkletown to Allentown to near Bally, moving east
  at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton,
  Quakertown, Perkasie, Doylestown, Byram, Wilson, Bedminster,
  Washington, Hellertown, Nazareth, Tinicum, High Bridge, East
  Greenville, Clinton and Bath.

People attending Warren County Farmers Fair should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4082 7489 4056 7489 4034 7491 4034 7494
      4032 7492 4031 7496 4034 7566 4080 7558
TIME...MOT...LOC 0239Z 269DEG 33KT 4083 7546 4059 7549 4038 7556 

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

Fitzsimmons
2 follow-up statements
485 
WWUS51 KPHI 020303
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1103 PM EDT WED AUG 1 2018

PAC011-077-091-020312-
/O.CAN.KPHI.SV.W.0062.000000T0000Z-180802T0330Z/
Berks PA-Montgomery PA-Lehigh PA-
1103 PM EDT WED AUG 1 2018

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL BERKS...
NORTHWESTERN MONTGOMERY AND EASTERN LEHIGH COUNTIES IS CANCELLED...

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

LAT...LON 4050 7489 4038 7491 4037 7541 4038 7541
      4053 7535 4054 7533 4055 7535 4080 7529
      4081 7526 4081 7520 4082 7489
TIME...MOT...LOC 0302Z 259DEG 36KT 4080 7519 4058 7521 4037 7528 

$$

NJC019-041-PAC017-095-020330-
/O.CON.KPHI.SV.W.0062.000000T0000Z-180802T0330Z/
Hunterdon NJ-Warren NJ-Bucks PA-Northampton PA-
1103 PM EDT WED AUG 1 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM EDT
FOR CENTRAL HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN BUCKS AND
SOUTHEASTERN NORTHAMPTON COUNTIES...

At 1102 PM EDT, severe thunderstorms were located along a line
extending from near Harmony to Riegelsville to Perkasie, moving east
at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Easton, Bethlehem, Forks, Quakertown, Perkasie, Byram, Wilson,
Bedminster, Washington, Hellertown, Nazareth, Tinicum, High Bridge,
Clinton, Harmony, Oxford, Alpha, Dublin, Glen Gardner and Ferndale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4050 7489 4038 7491 4037 7541 4038 7541
      4053 7535 4054 7533 4055 7535 4080 7529
      4081 7526 4081 7520 4082 7489
TIME...MOT...LOC 0302Z 259DEG 36KT 4080 7519 4058 7521 4037 7528 

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

Fitzsimmons
076 
WWUS51 KPHI 020317
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1117 PM EDT WED AUG 1 2018

NJC019-041-PAC017-095-020326-
/O.CAN.KPHI.SV.W.0062.000000T0000Z-180802T0330Z/
Hunterdon NJ-Warren NJ-Bucks PA-Northampton PA-
1117 PM EDT WED AUG 1 2018

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL HUNTERDON...
SOUTHWESTERN WARREN...NORTHWESTERN BUCKS AND SOUTHEASTERN NORTHAMPTON
COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.

LAT...LON 4050 7489 4038 7491 4037 7541 4038 7541
      4053 7535 4054 7533 4055 7535 4080 7529
      4081 7526 4081 7520 4082 7489
TIME...MOT...LOC 0314Z 269DEG 33KT 4080 7503 4058 7505 4037 7512 

$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 8:59 PM EDTSpecial Weather StatementPHIBerks61 min
Aug 1, 9:54 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh66 min
Aug 1, 11:35 PM EDTSevere Thunderstorm WarningPHIChester, Delaware20 min
Aug 2, 3:31 AM EDTFlash Flood WatchPHIBerks, Carbon, Lehigh, Monroe, Northampton55 hr
Aug 2, 1:50 PM EDTSpecial Weather StatementPHILehigh25 min
Aug 2, 2:19 PM EDTSpecial Weather StatementPHINorthampton41 min
Aug 2, 1:41 PM EDTSpecial Weather StatementPHIBurlington34 min
Aug 2, 2:09 PM EDTSpecial Weather StatementPHIMonmouth36 min
Aug 2, 3:41 PM EDTSpecial Weather StatementPHIMorris34 min
Aug 2, 6:02 PM EDTSpecial Marine WarningPHI58 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2018Severe Thunderstorm Warnings in New Jersey, 2018Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.