Alert archive / Pennsylvania / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

August 3, 2017Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 3, 2017, 8:11 PM EDT for Lehigh County, Pennsylvania. It was in force for 49 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 3, 2017, 8:11 PM EDT (00:11 UTC)
Expired
Aug 3, 2017, 9:00 PM EDT
In force
49 min
Issued by
NWS Philadelphia/Mount Holly

County Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 126 km from the middle of the area, began a volume at 00:11 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, 0.2 hours before the alert went out and 231 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 2017-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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 2017-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.193958Sfc1 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
87 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
937 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

322 
WWUS81 KPHI 040011
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
811 PM EDT THU AUG 3 2017

PAZ054-061-062-040100-
Lehigh-Northampton-Carbon-
811 PM EDT THU AUG 3 2017

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL LEHIGH...SOUTHEASTERN
CARBON AND WEST CENTRAL NORTHAMPTON COUNTIES...

At 810 PM EDT, a strong thunderstorm was located over Claussville, or
8 miles west of Allentown, moving northeast at 5 mph.

Winds up to 50 mph and dime size hail are possible with this storm.

Locations impacted include...
Allentown, Bethlehem, Northampton, Palmerton, Slatington, Walnutport,
Steuben, Neffs, Coffeetown, Berlinsville, Jordan Valley, Ancient
Oaks, Beersville, Emerald, Schnecksville, Claussville, Catasauqua,
Coplay, North Catasauqua and Alburtis.

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

LAT...LON 4051 7559 4062 7578 4084 7563 4068 7535
TIME...MOT...LOC 0010Z 217DEG 6KT 4063 7563 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 8:02 PM EDTSpecial Weather StatementPHIWarren43 min
Aug 3, 9:11 PM EDTAreal Flood WarningPHIBurlington4 hr
Aug 3, 9:20 PM EDTAreal Flood AdvisoryPHISussex, Warren3 hr
Aug 4, 3:41 PM EDTSmall Craft AdvisoryPHI9 hr
Aug 3, 8:01 PM EDTSpecial Weather StatementPHIBerks44 min
Aug 3, 8:29 PM EDTSevere Thunderstorm WarningPHILehigh, Northampton46 min
Aug 3, 8:35 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Northampton4 hr
Aug 3, 8:54 PM EDTSpecial Weather StatementPHIBerks51 min
Aug 3, 9:29 PM EDTSpecial Weather StatementPHILehigh, Northampton46 min
Aug 4, 1:25 PM EDTSpecial Weather StatementPHIBerks65 min
Aug 4, 2:49 PM EDTAreal Flood AdvisoryPHIBerks116 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.