Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

October 16, 2021Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Oct 16, 2021, 2:44 PM EDT for Chester County, Pennsylvania. It was in force for 61 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 16, 2021, 2:44 PM EDT (18:44 UTC)
Expired: Oct 16, 2021, 3:45 PM EDT
In force: 61 min
Issued by: NWS Philadelphia/Mount Holly
Hail: 0.00 in
Wind: 40

County Chester County, PA

The radar

The Dover AFB radar (KDOX), 127 km from the middle of the area, began a volume at 18:45 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, 6.7 hours before the alert went out and 167 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1259 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 141 m²/s²
0-3 km storm-relative helicity: 192 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

647 
WWUS81 KPHI 161844
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
244 PM EDT Sat Oct 16 2021
 
PAZ101-102-161945-
Western Chester PA-Eastern Chester PA-
244 PM EDT Sat Oct 16 2021

...Strong thunderstorms will impact portions of Chester County
through 345 PM EDT...

At 243 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near New Morgan to near Mount Vernon. Movement
was northeast at 30 mph.

HAZARD...Wind gusts up to 45 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
Coatesville, Downingtown, Kennett Square, Oxford, Parkesburg, West
Grove, Honey Brook, Elverson, Homeville, Glen Roy, Cochranville,
Pughtown, Mount Vernon, Marshallton, Lionville-Marchwood, Glenmoore,
Chester Springs, Lionville, Ladenberg and Kemblesville.

This includes Pennsylvania Turnpike between mile markers 300 and 316.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 3974 7612 3973 7610 3976 7606 3983 7604
      3987 7599 3995 7600 4004 7593 4011 7594
      4019 7579 4021 7556 4020 7558 4019 7556
      3983 7566 3977 7575 3972 7578 3972 7613
      3973 7613
TIME...MOT...LOC 1843Z 237DEG 27KT 4024 7591 3983 7606 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 16, 10:35 AM EDT	Coastal Flood Statement	PHI	Ocean	2 hr
Oct 16, 3:22 PM EDT	Special Marine Warning	PHI		113 min
Oct 16, 3:31 PM EDT	Severe Thunderstorm Warning	PHI	Salem	18 min
Oct 16, 3:41 PM EDT	Special Weather Statement	PHI	Hunterdon, Sussex, Warren	49 min
Oct 16, 4:02 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	43 min
Oct 16, 4:18 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 1 more	57 min
Oct 16, 5:10 PM EDT	Special Marine Warning	PHI		95 min
Oct 16, 5:29 PM EDT	Special Marine Warning	PHI		91 min
Oct 16, 6:09 PM EDT	Special Marine Warning	PHI		66 min
Oct 16, 6:52 PM EDT	Coastal Flood Statement	PHI	Ocean	4 hr
Oct 16, 1:39 PM EDT	Special Weather Statement	PHI	Berks	51 min
Oct 16, 2:32 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	58 min
Oct 16, 3:40 PM EDT	Special Weather Statement	PHI	New Castle	50 min

Nearby

Special Weather Statements in Pennsylvania, 2021 Every 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.