Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

June 8, 2021Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jun 8, 2021, 3:43 PM EDT for Chester County, Pennsylvania. It was in force for 32 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: Jun 8, 2021, 3:43 PM EDT (19:43 UTC)
Expired: Jun 8, 2021, 4:15 PM EDT
In force: 32 min
Issued by: NWS Philadelphia/Mount Holly

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 112 km from the middle of the area, began a volume at 19:47 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 184 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: 254 J/kg
Mixed-layer CIN: -121 J/kg
Mixed-layer LCL: 1088 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

877 
WWUS81 KPHI 081943
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
343 PM EDT Tue Jun 8 2021

PAZ101>103-082015-
Western Montgomery-Western Chester-Eastern Chester-
343 PM EDT Tue Jun 8 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WEST CENTRAL MONTGOMERY
AND CHESTER COUNTIES...

At 343 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Royersford to near West Grove.
Movement was southeast at 10 mph.

Wind gusts up to 40 mph and pea size hail are possible with these
storms.

Locations impacted include...
West Chester, Pottstown, Phoenixville, Coatesville, Downingtown,
Kennett Square, Collegeville, Oxford, Royersford, Trappe, West Grove,
Cochranville, Pughtown, Marshallton, Lionville-Marchwood, Glenmoore,
Chester Springs, Lionville, Ladenberg and Kemblesville.

This includes Pennsylvania Turnpike between mile markers 306 and 321.
 
If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways. A Flash Flood Warning remains in effect.

LAT...LON 4024 7569 4023 7538 3972 7578 3972 7583
      3978 7600
TIME...MOT...LOC 1943Z 292DEG 9KT 4019 7560 3980 7589 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 8, 1:27 PM EDT	Areal Flood Advisory	PHI	Warren	3 hr
Jun 8, 1:49 PM EDT	Special Weather Statement	PHI	Warren	26 min
Jun 8, 1:54 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex	95 min
Jun 8, 2:19 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer	2 hr
Jun 8, 2:29 PM EDT	Special Weather Statement	PHI	Morris	16 min
Jun 8, 2:48 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset	27 min
Jun 8, 3:13 PM EDT	Special Weather Statement	PHI	Hunterdon, Somerset	32 min
Jun 8, 3:14 PM EDT	Areal Flood Advisory	PHI	Middlesex, Somerset	74 min
Jun 8, 4:12 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth	48 min
Jun 8, 4:14 PM EDT	Special Marine Warning	PHI		91 min
Jun 8, 4:44 PM EDT	Special Weather Statement	PHI	Salem	31 min
Jun 8, 4:47 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	43 min
Jun 8, 4:54 PM EDT	Special Marine Warning	PHI		96 min
Jun 8, 4:56 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Camden, Gloucester	49 min
Jun 8, 4:58 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	47 min
Jun 8, 5:30 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Salem	45 min
Jun 8, 5:43 PM EDT	Special Weather Statement	PHI	Ocean	32 min
Jun 8, 6:01 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Ocean	44 min
Jun 8, 6:22 PM EDT	Special Marine Warning	PHI		83 min
Jun 8, 7:39 PM EDT	Special Marine Warning	PHI		66 min
Jun 8, 7:52 PM EDT	Special Weather Statement	PHI	Cape May	38 min
Jun 8, 11:54 AM EDT	Areal Flood Advisory	PHI	Monroe	2 hr
Jun 8, 12:34 PM EDT	Flash Flood Warning	PHI	Monroe	2 hr
Jun 8, 12:40 PM EDT	Special Weather Statement	PHI	Monroe	35 min
Jun 8, 1:09 PM EDT	Special Weather Statement	PHI	Monroe	21 min
Jun 8, 1:17 PM EDT	Special Weather Statement	PHI	Chester	13 min
Jun 8, 1:18 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	3 hr
Jun 8, 1:24 PM EDT	Special Weather Statement	PHI	Delaware	21 min
Jun 8, 1:35 PM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery	5 hr
Jun 8, 2:07 PM EDT	Special Weather Statement	PHI	Bucks	23 min
Jun 8, 2:43 PM EDT	Special Weather Statement	PHI	Montgomery	32 min
Jun 8, 3:15 PM EDT	Special Weather Statement	PHI	Chester	30 min
Jun 8, 3:21 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	3 hr
Jun 8, 4:20 PM EDT	Special Weather Statement	PHI	Chester	25 min
Jun 8, 4:25 PM EDT	River Flood Warning	PHI	Chester	11 hr
Jun 8, 6:21 PM EDT	Areal Flood Warning	PHI	Chester, Delaware	15 hr
Jun 8, 7:14 PM EDT	River Flood Warning	PHI	Chester, Delaware	18 hr
Jun 8, 7:43 PM EDT	Special Weather Statement	PHI	Sussex	32 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.