Alert archive / Pennsylvania / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

October 15, 2018Delaware County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Oct 15, 2018, 10:55 PM EDT for Delaware County, Philadelphia County, Pennsylvania. It was in force for 35 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
Oct 15, 2018, 10:55 PM EDT (02:55 UTC)
Expired
Oct 15, 2018, 11:30 PM EDT
In force
35 min
Issued by
NWS Philadelphia/Mount Holly

Counties Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 78 km from the middle of the area, began a volume at 02:59 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.9 hours before the alert went out and 217 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, Washington/Dulle, VA at 00:00Z on 2018-10-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Washington/Dulle, VA at 00:00Z on 2018-10-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 225 square meters per square second.1939587897117Sfc1 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
16 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
1083 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
225 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

539 
WWUS81 KPHI 160255
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1055 PM EDT MON OCT 15 2018

NJZ015-018-019-PAZ070-071-102>104-106-160330-
Northwestern Burlington-Camden-Mercer-Lower Bucks-Eastern
Montgomery-Western Montgomery-Delaware-Eastern Chester-Philadelphia-
1055 PM EDT MON OCT 15 2018

...A LINE OF SHOWERS WILL AFFECT NORTHWESTERN CAMDEN...SOUTH CENTRAL
MERCER...NORTHWESTERN BURLINGTON...SOUTHEASTERN MONTGOMERY...
SOUTHEASTERN BUCKS...EAST CENTRAL CHESTER...PHILADELPHIA AND CENTRAL
DELAWARE COUNTIES...

At 1055 PM EDT, radar indicated showers were located along a line
extending from East Norriton to West Chester. Movement was east at 45
mph.

Winds up to 40 mph are possible with these showers.

Locations impacted include...
Philadelphia, Trenton, Camden, West Chester, Gloucester City,
Bensalem, Norristown, West Norriton, East Norriton, Yeadon, Westtown,
Bristol, Riverside, Conshohocken, Palmyra, Hatboro, Folcroft, Ambler,
Swarthmore and Jenkintown.

LAT...LON 3988 7515 3993 7571 4008 7553 4010 7546
      4013 7547 4021 7537 4022 7468
TIME...MOT...LOC 0255Z 266DEG 40KT 4015 7533 3995 7564 

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 15, 11:19 PM EDTSpecial Weather StatementPHIMercer, Middlesex, Monmouth56 min
Oct 15, 11:39 PM EDTSpecial Weather StatementPHISalem36 min
Oct 15, 11:41 PM EDTSpecial Marine WarningPHI94 min
Oct 16, 12:01 AM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester, Ocean, Salem44 min
Oct 16, 12:41 AM EDTSpecial Weather StatementPHIAtlantic, Cape May, Cumberland, Ocean49 min
Oct 16, 1:22 AM EDTSpecial Weather StatementPHICape May38 min
Oct 16, 3:58 PM EDTGale WarningPHI40 hr
Oct 16, 3:58 PM EDTSmall Craft AdvisoryPHI24 hr
Oct 16, 1:05 AM EDTSpecial Weather StatementPHIKent, Sussex40 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.