Alert archive / Pennsylvania / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

July 28, 2017Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 28, 2017, 8:29 PM EDT for Berks County, Pennsylvania. It was in force for 46 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: Jul 28, 2017, 8:29 PM EDT (00:29 UTC)
Expired: Jul 28, 2017, 9:15 PM EDT
In force: 46 min
Issued by: NWS Philadelphia/Mount Holly

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 149 km from the middle of the area, began a volume at 00:29 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, 0.5 hours before the alert went out and 190 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: 83 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 676 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

388 
WWUS81 KPHI 290029
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
829 PM EDT FRI JUL 28 2017

PAZ060-101-103-290115-
Western Montgomery-Western Chester-Berks-
829 PM EDT FRI JUL 28 2017

...A LINE OF SHOWERS WILL AFFECT CENTRAL BERKS...WEST CENTRAL
MONTGOMERY AND NORTHWESTERN CHESTER COUNTIES...

At 828 PM EDT, radar indicated a cluster of showers and 
thunderstorms were located along a line extending from near 
Fredericksburg to Wyomissing to near Pottstown.
Movement was west at 15 mph.

Heavy rainfall is occurring with these showers and thunderstorms... 
and may cause ponding on roadways and poor drainage areas. Do not 
drive your vehicle through flooded roadways.

Ocasional lightning is occuring. Lightning can strike 15 miles away 
from a thunderstorm. If you see lightning or hear thunder seek a 
safe shelter inside a building or vehicle.

Locations impacted include...
Reading, Pottstown, Wyomissing, Birdsboro, Sinking Spring,
Laureldale, Womelsdorf, Wernersville, Newmanstown, Adamstown, Honey
Brook, Elverson, Bernville, Strausstown, New Morgan, Spring Ridge,
Fairview Hgts, Cedarville, Gilbertsville and Stowe.

LAT...LON 4052 7634 4052 7625 4053 7620 4038 7590
      4029 7550 3999 7597 4004 7593 4011 7594
      4014 7588 4032 7617 4036 7621 4037 7623
      4049 7643
TIME...MOT...LOC 0028Z 077DEG 12KT 4047 7640 4032 7599 4026 7568 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:52 PM EDT	Rip Current Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	23 hr
Jul 28, 10:25 PM EDT	Special Marine Warning	PHI		65 min
Jul 28, 11:13 PM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland, Gloucester, Salem	4 hr
Jul 29, 1:10 AM EDT	Flash Flood Warning	PHI	Atlantic, Cumberland, Gloucester, Salem	4 hr
Jul 29, 3:03 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more	4 hr
Jul 29, 4:14 AM EDT	Special Marine Warning	PHI		61 min
Jul 29, 5:08 AM EDT	Special Marine Warning	PHI		52 min
Jul 29, 5:13 AM EDT	Flash Flood Warning	PHI	Cape May	3 hr
Jul 29, 6:48 AM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May	117 min
Jul 28, 8:48 PM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Jul 28, 9:25 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Jul 29, 1:38 AM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	4 hr
Jul 29, 2:17 AM EDT	Special Weather Statement	PHI	Talbot	28 min
Jul 29, 5:30 AM EDT	Areal Flood Advisory	PHI	Caroline	2 hr
Jul 28, 8:48 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr
Jul 28, 10:17 PM EDT	Special Weather Statement	PHI	Sussex	28 min

Nearby

Special Weather Statements in Pennsylvania, 2017 Every special weather statement in 2017

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.