Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

July 29, 2021Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 29, 2021, 6:21 PM EDT for Bucks County, Pennsylvania. It was in force for 24 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 29, 2021, 6:21 PM EDT (22:21 UTC)
Expired: Jul 29, 2021, 6:45 PM EDT
In force: 24 min
Issued by: NWS Philadelphia/Mount Holly

County Bucks County, PA

The radar

The Philadelphia radar (KDIX), 69 km from the middle of the area, began a volume at 22:21 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.

What was reported inside it

Time	Report	Where	Remark
Jul 29, 6:49 PM EDT	FUNNEL CLOUD	Willow Grove, PA	ROTATING WALL CLOUD OBSERVED NEAR WILLOW GROVE, PA. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.4 hours before the alert went out and 205 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: 54 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 823 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

457 
WWUS81 KPHI 292221
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
621 PM EDT Thu Jul 29 2021

PAZ071-103-104-106-292245-
Lower Bucks-Eastern Montgomery-Western Montgomery-Philadelphia-
621 PM EDT Thu Jul 29 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL MONTGOMERY...
SOUTHEASTERN BUCKS AND NORTHEASTERN PHILADELPHIA COUNTIES...

At 621 PM EDT, a strong thunderstorm was located over Lansdale, or 15
miles north of Philadelphia, moving east at 35 mph.

Wind gusts up to 45 mph and pea size hail are possible with this 
storm.

Locations impacted include...
Philadelphia, Bensalem, Lansdale, East Norriton, Hatboro, Ambler,
Chalfont, Hatfield, Newtown, Abington, Langhorne, Bryn Athyn,
Ivyland, Feasterville-Trevose, Willow Grove, Northeast Philadelphia,
Feasterville, Richboro, Langhorn and Horsham.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 339 and 353.
 Northeast Extension between mile markers 24 and 29.
 Interstate 95 in Pennsylvania near mile marker 36.

If outdoors, consider seeking shelter inside a building.

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.

A Tornado Watch remains in effect until 900 PM EDT for southeastern
Pennsylvania.

LAT...LON 4007 7494 4017 7536 4028 7533 4028 7526
      4026 7522 4029 7519 4030 7488
TIME...MOT...LOC 2221Z 277DEG 31KT 4022 7525 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 3:33 AM EDT	Small Craft Advisory	PHI		20 hr
Jul 29, 1:33 PM EDT	Special Marine Warning	PHI		42 min
Jul 29, 2:53 PM EDT	Special Marine Warning	PHI		100 min
Jul 29, 4:26 PM EDT	Special Weather Statement	PHI	Morris	34 min
Jul 29, 4:30 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	45 min
Jul 29, 4:57 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Sussex, Warren	3 hr
Jul 29, 5:01 PM EDT	Special Weather Statement	PHI	Morris	29 min
Jul 29, 5:03 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	42 min
Jul 29, 5:08 PM EDT	Tornado Warning	PHI	Hunterdon	37 min
Jul 29, 5:27 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Morris, Somerset	3 hr
Jul 29, 5:32 PM EDT	Flash Flood Warning	PHI	Warren	2 hr
Jul 29, 5:32 PM EDT	Tornado Warning	PHI	Hunterdon	28 min
Jul 29, 5:51 PM EDT	Tornado Warning Tornado observedConsiderable damage threat	PHI	Hunterdon, Mercer	24 min
Jul 29, 5:58 PM EDT	Flash Flood Warning	PHI	Hunterdon, Mercer, Somerset	3 hr
Jul 29, 6:06 PM EDT	Tornado Warning Considerable damage threat	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth	39 min
Jul 29, 6:44 PM EDT	Tornado Warning	PHI	Mercer, Monmouth, Ocean	46 min
Jul 29, 6:45 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer	45 min
Jul 29, 6:56 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Monmouth, Ocean, Somerset	4 hr
Jul 29, 7:07 PM EDT	Tornado Warning	PHI	Burlington	23 min
Jul 29, 7:12 PM EDT	Flash Flood Warning	PHI	Burlington	4 hr
Jul 29, 7:18 PM EDT	Tornado Warning	PHI	Mercer, Middlesex, Monmouth, Ocean	27 min
Jul 29, 7:25 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Monmouth, Ocean	50 min
Jul 29, 7:28 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	47 min
Jul 29, 7:52 PM EDT	Special Marine Warning	PHI		113 min
Jul 29, 3:48 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Northampton	42 min
Jul 29, 4:03 PM EDT	Tornado Warning	PHI	Berks, Lehigh, Northampton	27 min
Jul 29, 4:27 PM EDT	Tornado Warning	PHI	Lehigh, Northampton	16 min
Jul 29, 4:46 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh, Northampton	3 hr
Jul 29, 4:56 PM EDT	Tornado Warning	PHI	Bucks, Lehigh, Northampton	34 min
Jul 29, 1:37 PM EDT	Special Weather Statement	PHI	Sussex	38 min
Jul 29, 2:38 PM EDT	Special Weather Statement	PHI	Sussex	37 min
Jul 29, 2:43 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	62 min
Jul 29, 3:02 PM EDT	Tornado Warning	PHI	Sussex	43 min
Jul 29, 11:35 AM EDT	Special Weather Statement	PHI	Talbot	55 min
Jul 29, 11:48 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Talbot	45 min
Jul 29, 12:12 PM EDT	Areal Flood Advisory	PHI	Caroline, Talbot	84 min
Jul 29, 5:59 PM EDT	Special Weather Statement	PHI	Queen Anne's	31 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.