Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

August 18, 2021Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 18, 2021, 9:47 PM EDT for Berks County, Pennsylvania. It was in force for 58 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 18, 2021, 9:47 PM EDT (01:47 UTC)
Expired: Aug 18, 2021, 10:45 PM EDT
In force: 58 min
Issued by: NWS Philadelphia/Mount Holly
Hail: 0.00 in
Wind: 50

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 01:46 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.8 hours before the alert went out and 214 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: 1288 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1100 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 126 m²/s²
0-3 km storm-relative helicity: 171 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 5.9

Open this sounding in Storm Lab

The text

As transmitted.

723 
WWUS81 KPHI 190147
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
947 PM EDT Wed Aug 18 2021
 
PAZ060-190245-
Berks PA-
947 PM EDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of eastern Berks County
through 1045 PM EDT...

At 946 PM EDT, Doppler radar was tracking a strong thunderstorm over
Terre Hill, or near New Holland, moving northeast at 30 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

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

Locations impacted include...
Reading, Wyomissing, Birdsboro, Kutztown, Fleetwood, Sinking Spring,
Laureldale, Wernersville, Topton, Bally, Bechtelsville, Lyons, New
Morgan, Spring Ridge, Gilbertsville, Shillington, West Reading,
Boyertown, Mount Penn and Mohnton.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 296 and 299.
 Interstate 78 in Pennsylvania between mile markers 42 and 44.
 Interstate 176 in Pennsylvania between mile markers 1 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.

A Tornado Watch remains in effect until 1100 PM EDT for eastern and
southeastern Pennsylvania.

&&

LAT...LON 4060 7577 4045 7553 4043 7554 4025 7569
      4014 7587 4029 7611
TIME...MOT...LOC 0146Z 225DEG 28KT 4017 7609 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

$$

Meola

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 11:19 PM EDT	Areal Flood Advisory	PHI	Warren	3 hr
Aug 19, 12:48 AM EDT	Tornado Warning	PHI	Hunterdon	27 min
Aug 19, 1:32 AM EDT	Small Craft Advisory	PHI		5 hr
Aug 19, 2:05 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Morris, Somerset	3 hr
Aug 19, 2:13 AM EDT	Flash Flood Warning	PHI	Burlington, Camden, Mercer	4 hr
Aug 19, 2:33 AM EDT	Tornado Warning	PHI	Morris	27 min
Aug 19, 2:40 AM EDT	Tornado Warning	PHI	Morris	24 min
Aug 19, 3:09 AM EDT	Tornado Warning	PHI	Mercer, Middlesex, Monmouth	36 min
Aug 19, 6:09 AM EDT	Areal Flood Warning	PHI	Mercer	3 hr
Aug 18, 8:53 PM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Aug 18, 9:10 PM EDT	Areal Flood Advisory	PHI	Lehigh, Monroe, Northampton	3 hr
Aug 18, 9:30 PM EDT	Flash Flood Warning	PHI	Berks	2 hr
Aug 18, 9:35 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
Aug 18, 9:45 PM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Aug 18, 10:16 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh	3 hr
Aug 18, 10:44 PM EDT	Flash Flood Warning	PHI	Lehigh, Monroe, Northampton	4 hr
Aug 18, 10:50 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Montgomery	4 hr
Aug 18, 11:19 PM EDT	Special Weather Statement	PHI	Bucks, Chester, Montgomery	41 min
Aug 18, 11:47 PM EDT	Flash Flood Warning	PHI	Chester	2 hr
Aug 19, 12:04 AM EDT	Special Weather Statement	PHI	Bucks, Delaware, Montgomery	71 min
Aug 19, 12:26 AM EDT	Tornado Warning	PHI	Bucks, Montgomery	34 min
Aug 19, 12:31 AM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery	4 hr
Aug 19, 12:44 AM EDT	River Flood Warning	PHI	Chester	5 hr
Aug 19, 12:47 AM EDT	Tornado Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	28 min
Aug 19, 1:14 AM EDT	Special Weather Statement	PHI	Bucks, Delaware, Philadelphia	91 min
Aug 19, 1:30 AM EDT	Flash Flood Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr
Aug 19, 4:33 AM EDT	Areal Flood Warning	PHI	Chester, Delaware	4 hr
Aug 19, 8:50 AM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	3 hr
Aug 19, 10:40 AM EDT	Areal Flood Warning	PHI	Delaware	3 hr
Aug 19, 3:22 PM EDT	Flash Flood Watch	PHI	Kent, Sussex	23 hr

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.