Alert archive / Pennsylvania / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

August 3, 2018Delaware County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 3, 2018, 5:45 PM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 60 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, 2018, 5:45 PM EDT (21:45 UTC)
Expired
Aug 3, 2018, 6:45 PM EDT
In force
60 min
Issued by
NWS Philadelphia/Mount Holly

Counties Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 64 km from the middle of the area, began a volume at 21:46 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, 9.8 hours before the alert went out and 215 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 2018-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1132 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 2018-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
1132 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
732 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted.

258 
WWUS81 KPHI 032145
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
545 PM EDT FRI AUG 3 2018

DEZ001-NJZ016>018-PAZ070-071-102>104-032245-
New Castle-Salem-Camden-Gloucester-Eastern Montgomery-Western
Montgomery-Delaware-Eastern Chester-Philadelphia-
545 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN NEW CASTLE...
NORTHWESTERN SALEM...NORTHWESTERN CAMDEN...NORTHWESTERN GLOUCESTER...
SOUTHEASTERN MONTGOMERY...SOUTHEASTERN CHESTER...PHILADELPHIA AND
DELAWARE COUNTIES...

At 544 PM EDT, a strong thunderstorm was located over Arden, or 7
miles northeast of Wilmington, moving northeast at 20 mph.

Winds up to 40 mph are possible with this storm.

Locations impacted include...
Philadelphia, Camden, Wilmington, Norristown, Chester, Lansdale, West
Norriton, East Norriton, Yeadon, Westtown, Carneys Point,
Conshohocken, Palmyra, Folcroft, Ambler, Swarthmore, Paulsboro, Penns
Grove, Jenkintown and Narberth.

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 4027 7533 4008 7496 4006 7498 4005 7498
      4002 7501 4002 7504 3999 7506 4000 7504
      3999 7503 3967 7543 3982 7565
TIME...MOT...LOC 2144Z 220DEG 17KT 3982 7545 

$$

Meola

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 9:35 PM EDTSpecial Weather StatementPHISomerset25 min
Aug 2, 10:05 PM EDTSpecial Weather StatementPHIMorris, Somerset55 min
Aug 3, 11:47 AM EDTSpecial Marine WarningPHI88 min
Aug 3, 12:17 PM EDTSpecial Weather StatementPHICape May43 min
Aug 3, 12:37 PM EDTSpecial Weather StatementPHICamden, Gloucester38 min
Aug 3, 12:52 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland21 min
Aug 3, 1:01 PM EDTSpecial Weather StatementPHIHunterdon44 min
Aug 3, 1:14 PM EDTSpecial Weather StatementPHIMercer46 min
Aug 3, 1:27 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Somerset48 min
Aug 3, 1:42 PM EDTSpecial Weather StatementPHIHunterdon, Morris, Sussex, Warren63 min
Aug 3, 2:00 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Somerset30 min
Aug 3, 2:37 PM EDTSpecial Weather StatementPHIMorris, Sussex38 min
Aug 3, 2:54 PM EDTSpecial Marine WarningPHI20 min
Aug 3, 3:33 PM EDTSpecial Weather StatementPHICamden, Gloucester, Salem57 min
Aug 3, 4:31 PM EDTSpecial Weather StatementPHISalem59 min
Aug 3, 4:45 PM EDTSpecial Weather StatementPHIWarren60 min
Aug 3, 5:25 PM EDTSpecial Weather StatementPHIMonmouth, Ocean50 min
Aug 3, 5:27 PM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester63 min
Aug 3, 6:52 PM EDTSpecial Weather StatementPHISussex, Warren113 min
Aug 3, 7:56 PM EDTAreal Flood AdvisoryPHISussex, Warren4 hr
Aug 3, 3:42 PM EDTSpecial Weather StatementPHILehigh, Northampton63 min
Aug 3, 7:37 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh4 hr
Aug 3, 3:29 PM EDTSpecial Weather StatementPHISussex46 min

Nearby

Special Weather Statements in Pennsylvania, 2018Every 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.