Alert archive / Pennsylvania / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

August 4, 2017Carbon County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 4, 2017, 11:49 PM EDT for Carbon County, Lehigh County, Pennsylvania. It was in force for 56 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 4, 2017, 11:49 PM EDT (03:49 UTC)
Expired
Aug 5, 2017, 12:45 AM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly

Counties Carbon County, PA, Lehigh County, PA

The radar

The Binghamton radar (KBGM), 146 km from the middle of the area, began a volume at 03:52 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, 3.8 hours before the alert went out and 235 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 2017-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 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 2017-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 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
425 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
695 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

918 
WWUS81 KPHI 050349
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1149 PM EDT FRI AUG 4 2017

PAZ054-061-062-050445-
Lehigh-Northampton-Carbon-
1149 PM EDT FRI AUG 4 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN LEHIGH...
CARBON AND WEST CENTRAL NORTHAMPTON COUNTIES...

At 1148 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Sheppton to McKeansburg to near
Shoemakersville. Movement was northeast at 25 mph.

Winds up to 40 mph are possible with these storms.

These storms will be near...
  New Mahoning around 1220 AM EDT. 
  Nesquehoning, Weatherly and Wanamakers around 1225 AM EDT. 
  Lehighton around 1230 AM EDT. 
  Jim Thorpe around 1235 AM EDT. 
  Palmerton, Slatington, Walnutport and New Tripoli around 1240 AM 
  EDT. 
  Beltzville State Park, Jordan Valley, Schnecksville, Neffs, 
  Claussville, Penn Forest Reservoir, Emerald, Coffeetown and 
  Christmans around 1245 AM EDT. 

Other locations impacted by these storms include Beaver Meadows,
Coplay, Hokendauqua, Summit Hill, Bowmanstown, Trachsville,
Weissport, Parryville, North Catasauqua and Weissport East.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

Cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4109 7560 4100 7551 4098 7550 4095 7557
      4082 7548 4082 7542 4070 7539 4056 7571
      4068 7589 4074 7576 4083 7590 4091 7599
      4101 7573 4105 7577 4109 7577 4113 7567
TIME...MOT...LOC 0348Z 235DEG 21KT 4087 7611 4069 7600 4049 7605 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 1:42 AM EDTSpecial Weather StatementPHIHunterdon, Warren48 min
Aug 5, 3:32 AM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester, Mercer, Middlesex58 min
Aug 5, 4:15 AM EDTSpecial Weather StatementPHIMiddlesex, Monmouth45 min
Aug 5, 4:42 AM EDTSpecial Marine WarningPHI63 min
Aug 5, 3:24 PM EDTSmall Craft AdvisoryPHI12 hr
Aug 4, 11:36 PM EDTSevere Thunderstorm WarningPHIBerks69 min
Aug 5, 12:10 AM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery51 min
Aug 5, 1:59 AM EDTSpecial Weather StatementPHIChester, Montgomery46 min
Aug 5, 2:38 AM EDTSpecial Weather StatementPHIChester52 min
Aug 5, 2:41 AM EDTSpecial Weather StatementPHIBucks, Montgomery, Philadelphia49 min

Nearby

Special Weather Statements in Pennsylvania, 2017Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.