Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

July 16, 2021Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 16, 2021, 8:14 PM EDT for Montgomery 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: Jul 16, 2021, 8:14 PM EDT (00:14 UTC)
Expired: Jul 16, 2021, 8:45 PM EDT
In force: 31 min
Issued by: NWS Philadelphia/Mount Holly

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 100 km from the middle of the area, began a volume at 00:16 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

Brookhaven, NY (KOKX), launched 00:00Z, 0.2 hours before the alert went out and 220 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: 996 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 1326 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

As transmitted.

381 
WWUS81 KPHI 170014
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
814 PM EDT Fri Jul 16 2021

PAZ060-061-103-105-170045-
Upper Bucks-Lehigh-Western Montgomery-Berks-
814 PM EDT Fri Jul 16 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL BERKS...
SOUTHEASTERN LEHIGH...NORTHWESTERN MONTGOMERY AND NORTHWESTERN BUCKS
COUNTIES...

At 813 PM EDT, a strong thunderstorm was located near Bally, or 16
miles south of Allentown, moving east at 25 mph.

Wind gusts up to 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Quakertown, Perkasie, Souderton, East Greenville, Dublin, Bally,
Bechtelsville, Green Lane, Pleasant Valley, Fricks, Zionsville,
Geryville, Springtown, Gilbertsville, Telford, Sellersville,
Boyertown, Pennsburg, Coopersburg and Red Hill.

This includes Northeast Extension between mile markers 34 and 49.
 
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4040 7568 4056 7536 4054 7533 4057 7528
      4033 7515 4031 7518 4027 7562
TIME...MOT...LOC 0013Z 252DEG 22KT 4036 7555 

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 12:55 PM EDT	Special Weather Statement	PHI	Hunterdon	50 min
Jul 17, 1:05 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer	40 min
Jul 17, 1:31 PM EDT	Areal Flood Advisory	PHI	Hunterdon	97 min
Jul 17, 1:50 PM EDT	Special Marine Warning	PHI		40 min
Jul 17, 1:56 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Somerset, Warren	36 min
Jul 17, 2:02 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	92 min
Jul 17, 2:56 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Somerset	49 min
Jul 17, 3:06 PM EDT	Severe Thunderstorm Warning	PHI	Warren	39 min
Jul 17, 3:09 PM EDT	Tornado Warning	PHI	Middlesex	21 min
Jul 17, 3:38 PM EDT	Areal Flood Advisory	PHI	Middlesex	40 min
Jul 17, 3:51 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex	24 min
Jul 17, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	50 min
Jul 17, 5:13 PM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
Jul 17, 5:19 PM EDT	Tornado Warning	PHI	Hunterdon	14 min
Jul 17, 5:25 PM EDT	Flash Flood Warning	PHI	Hunterdon	6 hr
Jul 17, 5:30 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	19 min
Jul 17, 5:52 PM EDT	Areal Flood Advisory	PHI	Somerset	2 hr
Jul 17, 6:02 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Somerset	43 min
Jul 17, 6:15 PM EDT	Flash Flood Warning	PHI	Morris, Somerset	5 hr
Jul 17, 6:39 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	51 min
Jul 17, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	39 min
Jul 17, 6:59 PM EDT	Small Craft Advisory	PHI		7 hr
Jul 17, 7:01 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset	44 min
Jul 17, 7:12 PM EDT	Areal Flood Advisory	PHI	Mercer, Somerset	3 hr
Jul 17, 7:26 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	49 min
Jul 16, 8:41 PM EDT	Special Weather Statement	PHI	Bucks	34 min
Jul 16, 9:07 PM EDT	Special Weather Statement	PHI	Lehigh	23 min
Jul 16, 9:29 PM EDT	Special Weather Statement	PHI	Lehigh	31 min
Jul 16, 10:21 PM EDT	Special Weather Statement	PHI	Lehigh	24 min
Jul 17, 2:30 PM EDT	Special Weather Statement	PHI	Berks	45 min
Jul 17, 2:36 PM EDT	Severe Thunderstorm Warning	PHI	Berks	39 min
Jul 17, 7:36 PM EDT	Special Weather Statement	PHI	Carbon	54 min
Jul 17, 7:36 PM EDT	Special Weather Statement	PHI	Kent	39 min
Jul 17, 7:59 PM EDT	Severe Thunderstorm Warning	PHI	Kent	46 min
Jul 17, 5:09 PM EDT	Special Weather Statement	PHI	Kent	51 min
Jul 17, 5:54 PM EDT	Special Weather Statement	PHI	Kent, Queen Anne's	36 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.