Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

August 27, 2021Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 27, 2021, 3:44 PM EDT for Delaware County, Pennsylvania. It was in force for 31 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 27, 2021, 3:44 PM EDT (19:44 UTC)
Expired
Aug 27, 2021, 4:15 PM EDT
In force
31 min
Issued by
NWS Philadelphia/Mount Holly
Hail
0.25 in
Wind
40

County Delaware County, PA

The radar

The Philadelphia radar (KDIX), 91 km from the middle of the area, began a volume at 19:48 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 12:00Z, 7.7 hours before the alert went out and 192 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 12:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 780 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 12:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
780 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

962 
WWUS81 KPHI 271944
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
344 PM EDT Fri Aug 27 2021
 
DEZ001-NJZ016-017-272015-
New Castle DE-Salem NJ-Gloucester NJ-
344 PM EDT Fri Aug 27 2021

...A strong thunderstorm will impact portions of northeastern New
Castle, northwestern Salem and west central Gloucester Counties
through 415 PM EDT...

At 344 PM EDT, Doppler radar was tracking a strong thunderstorm over
Arden, or near Wilmington. This storm was nearly stationary.

HAZARD...Wind gusts up to 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Wilmington, Pennsville, Carneys Point, New Castle, Penns Grove,
Arden, Beckett, Delaware Memorial Bridge, Talleyville, Marcus Hook,
Bellefonte, Ardentown, Ardencroft, Edgemoor and Claymont.

This includes the following highways...
 Interstate 95 in Pennsylvania near mile marker 0.
 Interstate 95 in Delaware between mile markers 16 and 23.
 Interstate 295 in New Jersey near mile marker 0, and between mile
markers 4 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

Torrential rainfall is also occurring with this storm and may lead to
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 3983 7549 3982 7544 3980 7541 3983 7537
      3974 7534 3967 7555 3983 7555
TIME...MOT...LOC 1944Z 342DEG 3KT 3978 7547 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 1:33 PM EDTAreal Flood AdvisoryPHIBurlington, Camden83 min
Aug 27, 2:18 PM EDTSmall Craft AdvisoryPHI44 hr
Aug 27, 2:28 PM EDTSpecial Weather StatementPHIAtlantic47 min
Aug 27, 2:33 PM EDTAreal Flood AdvisoryPHIWarren109 min
Aug 27, 2:37 PM EDTSevere Thunderstorm WarningPHIOcean38 min
Aug 27, 2:38 PM EDTSevere Thunderstorm WarningPHIWarren35 min
Aug 27, 2:59 PM EDTSevere Thunderstorm WarningPHIOcean46 min
Aug 27, 3:07 PM EDTSevere Thunderstorm WarningPHIWarren24 min
Aug 27, 3:16 PM EDTSpecial Weather StatementPHIBurlington44 min
Aug 27, 3:30 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean45 min
Aug 27, 3:38 PM EDTSpecial Weather StatementPHICamden52 min
Aug 27, 3:45 PM EDTSpecial Weather StatementPHIOcean30 min
Aug 27, 3:54 PM EDTSpecial Weather StatementPHIAtlantic51 min
Aug 27, 3:59 PM EDTSpecial Weather StatementPHIOcean46 min
Aug 27, 4:06 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester39 min
Aug 27, 4:37 PM EDTAreal Flood AdvisoryPHIGloucester106 min
Aug 27, 4:46 PM EDTSpecial Marine WarningPHI43 min
Aug 27, 4:56 PM EDTSpecial Weather StatementPHIAtlantic34 min
Aug 27, 5:02 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cumberland29 min
Aug 27, 5:09 PM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland2 hr
Aug 27, 5:21 PM EDTSpecial Weather StatementPHIMiddlesex39 min
Aug 27, 5:29 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset3 hr
Aug 27, 5:44 PM EDTFlash Flood WarningPHIMiddlesex4 hr
Aug 27, 6:52 PM EDTAreal Flood AdvisoryPHISalem98 min
Aug 27, 1:20 PM EDTAreal Flood AdvisoryPHICarbon, Monroe2 hr
Aug 27, 1:36 PM EDTSpecial Weather StatementPHIMonroe24 min
Aug 27, 1:52 PM EDTSevere Thunderstorm WarningPHIChester53 min
Aug 27, 2:12 PM EDTSpecial Weather StatementPHINorthampton33 min
Aug 27, 2:18 PM EDTAreal Flood AdvisoryPHIChester93 min
Aug 27, 2:32 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe, Northampton28 min
Aug 27, 2:42 PM EDTSevere Thunderstorm WarningPHIChester14 min
Aug 27, 6:29 PM EDTAreal Flood AdvisoryPHIBerks3 hr
Aug 27, 6:41 PM EDTSpecial Weather StatementPHIBerks34 min
Aug 27, 7:17 PM EDTFlash Flood WarningPHIBerks3 hr
Aug 27, 3:48 PM EDTAreal Flood AdvisoryPHINew Castle102 min
Aug 27, 5:11 PM EDTAreal Flood AdvisoryPHINew Castle3 hr
Aug 27, 5:39 PM EDTSpecial Weather StatementPHINew Castle36 min
Aug 27, 6:10 PM EDTAreal Flood AdvisoryPHINew Castle2 hr
Aug 27, 7:10 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's, Talbot65 min
Aug 27, 7:37 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's34 min

Nearby

Special Weather Statements in Pennsylvania, 2021Every special weather statement in 2021

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.