Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 50, NWS Philadelphia/Mount Holly

July 4, 2018Berks County, Lehigh County, Northampton County, Pennsylvania; Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 4, 2018, 3:40 PM EDT for Berks County, Lehigh County, Northampton County, Pennsylvania; Warren County, New Jersey. It was in force for 50 min. 2 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 4, 2018, 3:40 PM EDT (19:40 UTC)
Expired
Jul 4, 2018, 4:30 PM EDT
In force
50 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Warren County, NJ, Berks County, PA, Lehigh County, PA, Northampton County, PA

What was reported inside it

TimeReportWhereRemark
Jul 4, 3:50 PM EDTTSTM WND DMGEaston, PASEVERAL REPORTS OF TREES DOWN IN EASTON...INCLUDING ON NORTH DELAWARE DRIVE...RIVER ROAD...AND ON FRUTCHEY HILL ROAD. TIME ESTIMATED FROM RADAR.
Jul 4, 3:55 PM EDTTSTM WND DMGCrossroads, PANUMEROUS REPORTS OF TREES AND WIRES DOWN ACROSS THE AREA. TIME ESTIMATED FROM RADAR

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 12:00Z, 7.7 hours before the alert went out and 223 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 12:00Z on 2018-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 145 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 12:00Z on 2018-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939Sfc1 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
145 J/kg
Mixed-layer CIN
-205 J/kg
Mixed-layer LCL
1091 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

383 
WUUS51 KPHI 041940
SVRPHI
NJC041-PAC011-077-095-042030-
/O.NEW.KPHI.SV.W.0050.180704T1940Z-180704T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
340 PM EDT WED JUL 4 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Warren County in northwestern New Jersey...
  Northeastern Berks County in eastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 430 PM EDT.

* At 339 PM EDT, severe thunderstorms were located along a line
  extending from Harmony to near Lenhartsville, moving west at 5 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Wilson,
  Hellertown, Nazareth, Bangor, Kutztown, Slatington, Pen Argyl, Wind
  Gap, Bath, Belvidere, Harmony, Alpha, Walnutport and Topton.

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 4065 7598 4070 7583 4077 7570 4081 7554
      4083 7538 4086 7529 4092 7522 4096 7510
      4069 7503 4059 7518 4061 7520 4052 7536
      4045 7570 4059 7601
TIME...MOT...LOC 1939Z 075DEG 6KT 4075 7513 4059 7581 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS
2 follow-up statements
050 
WWUS51 KPHI 042012
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
412 PM EDT WED JUL 4 2018

NJC041-PAC011-077-095-042030-
/O.CON.KPHI.SV.W.0050.000000T0000Z-180704T2030Z/
Warren NJ-Berks PA-Lehigh PA-Northampton PA-
412 PM EDT WED JUL 4 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHWESTERN WARREN...NORTHEASTERN BERKS...LEHIGH AND NORTHAMPTON
COUNTIES...

At 411 PM EDT, severe thunderstorms were located along a line
extending from near Harmony to Lenhartsville, moving west at 5 mph.

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

SOURCE...Radar indicated. Several reports of wind damage have been 
         received from Northampton County.

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

Locations impacted include...
Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Wilson,
Hellertown, Nazareth, Kutztown, Slatington, Wind Gap, Bath,
Walnutport, Topton, Belfast, West Easton, Tatamy, Riegelsville and
Steuben.

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.

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

&&

LAT...LON 4065 7598 4070 7583 4077 7570 4081 7554
      4083 7538 4086 7529 4077 7517 4059 7518
      4061 7520 4052 7536 4045 7570 4059 7601
TIME...MOT...LOC 2011Z 075DEG 6KT 4074 7519 4058 7587 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS
610 
WWUS51 KPHI 042026
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
426 PM EDT WED JUL 4 2018

NJC041-PAC011-077-095-042035-
/O.EXP.KPHI.SV.W.0050.000000T0000Z-180704T2030Z/
Warren NJ-Berks PA-Lehigh PA-Northampton PA-
426 PM EDT WED JUL 4 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WARREN...
NORTHEASTERN BERKS...LEHIGH AND NORTHAMPTON COUNTIES WILL EXPIRE AT
430 PM EDT...
            
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 will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
in Mount Holly NJ.

LAT...LON 4065 7598 4070 7583 4077 7570 4081 7554
      4083 7538 4086 7529 4077 7517 4059 7518
      4061 7520 4052 7536 4045 7570 4059 7601
TIME...MOT...LOC 2025Z 075DEG 6KT 4074 7521 4057 7589 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 9:33 AM EDTAreal Flood AdvisoryPHICarbon, Monroe98 min
Jul 4, 2:55 PM EDTSpecial Weather StatementPHILehigh35 min
Jul 4, 3:09 PM EDTAreal Flood AdvisoryPHILehigh, Northampton4 hr
Jul 4, 3:22 PM EDTFlash Flood WarningPHILehigh, Northampton4 hr
Jul 4, 3:32 PM EDTSpecial Weather StatementPHILehigh, Northampton28 min
Jul 4, 3:56 PM EDTSpecial Weather StatementPHILebanon34 min
Jul 4, 3:59 PM EDTAreal Flood AdvisoryPHILehigh, Northampton4 hr
Jul 4, 4:20 PM EDTSpecial Weather StatementPHICarbon25 min
Jul 4, 4:25 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh4 hr
Jul 4, 4:28 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton4 hr
Jul 4, 4:28 PM EDTSpecial Weather StatementPHILehigh, Northampton32 min
Jul 4, 4:34 PM EDTSpecial Weather StatementPHIBerks56 min
Jul 4, 4:56 PM EDTSpecial Weather StatementPHICarbon49 min
Jul 4, 5:46 PM EDTSpecial Weather StatementPHIBerks29 min
Jul 4, 6:13 PM EDTSpecial Weather StatementPHIBucks, Montgomery32 min
Jul 4, 6:15 PM EDTSpecial Weather StatementPHIBerks45 min
Jul 4, 6:20 PM EDTFlash Flood WarningPHIBerks4 hr
Jul 4, 6:32 PM EDTSpecial Weather StatementPHIChester28 min
Jul 4, 7:00 PM EDTSpecial Weather StatementPHIDelaware, Montgomery, Philadelphia30 min
Jul 4, 7:07 PM EDTSpecial Weather StatementPHILebanon23 min
Jul 4, 7:13 PM EDTAreal Flood AdvisoryPHILehigh, Northampton3 hr
Jul 4, 7:18 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery, Philadelphia3 hr
Jul 4, 7:32 PM EDTSpecial Weather StatementPHIMontgomery43 min
Jul 4, 9:35 AM EDTAreal Flood AdvisoryPHISussex100 min
Jul 4, 12:15 PM EDTAreal Flood AdvisoryPHISussex4 hr
Jul 4, 12:53 PM EDTSpecial Weather StatementPHISussex22 min
Jul 4, 1:11 PM EDTSpecial Weather StatementPHISussex34 min
Jul 4, 1:22 PM EDTAreal Flood AdvisoryPHIMorris, Sussex3 hr
Jul 4, 1:44 PM EDTSpecial Weather StatementPHISussex31 min
Jul 4, 1:48 PM EDTSpecial Weather StatementPHIWarren27 min
Jul 4, 1:57 PM EDTSevere Thunderstorm WarningPHIMorris, Warren48 min
Jul 4, 2:02 PM EDTSpecial Weather StatementPHISussex28 min
Jul 4, 2:15 PM EDTAreal Flood AdvisoryPHIWarren3 hr
Jul 4, 2:18 PM EDTSpecial Weather StatementPHIWarren27 min
Jul 4, 2:31 PM EDTSpecial Weather StatementPHIWarren44 min
Jul 4, 2:48 PM EDTAreal Flood AdvisoryPHIMorris3 hr
Jul 4, 3:12 PM EDTSpecial Weather StatementPHIWarren33 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.