Alert archive / Pennsylvania / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

August 7, 2018Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 7, 2018, 6:21 PM EDT for Lehigh County, Pennsylvania. It was in force for 54 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 7, 2018, 6:21 PM EDT (22:21 UTC)
Expired: Aug 7, 2018, 7:15 PM EDT
In force: 54 min
Issued by: NWS Philadelphia/Mount Holly

County Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 108 km from the middle of the area, began a volume at 22:21 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 12:00Z, 10.4 hours before the alert went out and 218 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: 1115 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 982 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -26 m²/s²
0-3 km storm-relative helicity: 2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

945 
WWUS81 KPHI 072221
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
621 PM EDT TUE AUG 7 2018

PAZ061-062-105-072315-
Upper Bucks-Lehigh-Northampton-
621 PM EDT TUE AUG 7 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN LEHIGH...
NORTHWESTERN BUCKS AND SOUTHERN NORTHAMPTON COUNTIES...

At 620 PM EDT, a strong thunderstorm was located over Emmaus and 
Allentown, moving east at 15 mph.

Winds up to 40 mph and half inch hail are possible with this storm.

Locations that may be impacted include...

Allentown, Easton, Bethlehem, Emmaus, Quakertown, Hellertown, 
Riegelsville, Glendon, Pleasant Valley, Zionsville, Springtown, Old 
Orchard, Lehigh University, Catasauqua, Fountain Hill, Freemansburg, 
Coopersburg, Richlandtown, Fullerton and Hokendauqua.

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

Frequent 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 4065 7551 4066 7519 4040 7523 4045 7553
      4046 7555
TIME...MOT...LOC 2220Z 278DEG 11KT 4054 7548 

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 12:19 PM EDT	Heat Advisory	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 6 more	6 hr
Aug 7, 2:24 PM EDT	Areal Flood Advisory	PHI	Sussex	78 min
Aug 7, 3:31 PM EDT	Heat Advisory	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 4 more	26 hr
Aug 7, 4:27 PM EDT	Special Weather Statement	PHI	Sussex	48 min
Aug 7, 5:07 PM EDT	Special Weather Statement	PHI	Sussex	53 min
Aug 7, 5:46 PM EDT	Special Weather Statement	PHI	Morris, Sussex	59 min
Aug 7, 4:07 PM EDT	Special Weather Statement	PHI	Monroe	38 min
Aug 7, 4:44 PM EDT	Special Weather Statement	PHI	Monroe	61 min
Aug 7, 4:48 PM EDT	Special Weather Statement	PHI	Lehigh	57 min
Aug 7, 5:32 PM EDT	Special Weather Statement	PHI	Berks	58 min
Aug 7, 5:41 PM EDT	Special Weather Statement	PHI	Lehigh	49 min
Aug 7, 6:25 PM EDT	Special Weather Statement	PHI	Berks	65 min
Aug 7, 2:13 PM EDT	Special Weather Statement	PHI	Sussex	47 min
Aug 7, 4:50 PM EDT	Special Weather Statement	PHI	Kent	55 min

Nearby

Special Weather Statements in Pennsylvania, 2018 Every special weather statement 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.