Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

July 21, 2021Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 21, 2021, 1:11 PM EDT for Northampton County, Pennsylvania. It was in force for 34 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 21, 2021, 1:11 PM EDT (17:11 UTC)
Expired: Jul 21, 2021, 1:45 PM EDT
In force: 34 min
Issued by: NWS Philadelphia/Mount Holly

County Northampton County, PA

The radar

The Philadelphia radar (KDIX), 100 km from the middle of the area, began a volume at 17:10 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 12:00Z, 5.2 hours before the alert went out and 202 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: 130 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 1495 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

771 
WWUS81 KPHI 211711
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
111 PM EDT Wed Jul 21 2021

NJZ009-PAZ061-062-105-211745-
Hunterdon-Upper Bucks-Lehigh-Northampton-
111 PM EDT Wed Jul 21 2021

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL HUNTERDON...
SOUTHEASTERN LEHIGH...NORTHWESTERN BUCKS AND SOUTHWESTERN NORTHAMPTON
COUNTIES...

At 111 PM EDT, a strong thunderstorm was located over Allentown,
moving southeast at 25 mph.

Wind gusts up to 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Allentown, Easton, Bethlehem, Emmaus, Northampton, Quakertown,
Bedminster, Hellertown, Dublin, Ferndale, Milford, Riegelsville,
Glendon, Pleasant Valley, Revere, Lehigh University, Ottsville,
Springtown, Old Orchard and Catasauqua.

This includes the following highways...
 Northeast Extension between mile markers 51 and 54.
 Interstate 78 in Pennsylvania between mile markers 56 and 74.

LAT...LON 4064 7519 4062 7519 4061 7520 4059 7519
      4063 7515 4060 7504 4036 7519 4054 7556
      4071 7547
TIME...MOT...LOC 1711Z 295DEG 21KT 4060 7544 

$$

NC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 11:09 AM EDT	Special Weather Statement	PHI	Morris	36 min
Jul 21, 12:41 PM EDT	Special Weather Statement	PHI	Ocean	34 min
Jul 21, 12:46 PM EDT	Special Marine Warning	PHI		89 min
Jul 21, 12:51 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Ocean	39 min
Jul 21, 12:53 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	67 min
Jul 21, 1:28 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic	47 min
Jul 21, 1:43 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	49 min
Jul 21, 2:10 PM EDT	Special Marine Warning	PHI		95 min
Jul 21, 2:13 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	47 min
Jul 21, 2:35 PM EDT	Special Marine Warning	PHI		55 min
Jul 21, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	26 min
Jul 21, 3:04 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	56 min
Jul 21, 3:16 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	44 min
Jul 21, 3:27 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	33 min
Jul 21, 3:43 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	47 min
Jul 21, 3:48 PM EDT	Special Marine Warning	PHI		57 min
Jul 21, 3:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	42 min
Jul 21, 3:57 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Salem	33 min
Jul 21, 4:04 PM EDT	Special Marine Warning	PHI		56 min
Jul 21, 4:17 PM EDT	Special Marine Warning	PHI		58 min
Jul 21, 4:50 PM EDT	Special Marine Warning	PHI		55 min
Jul 21, 5:07 PM EDT	Special Marine Warning	PHI		23 min
Jul 21, 5:09 PM EDT	Special Marine Warning	PHI		66 min
Jul 21, 5:24 PM EDT	Special Marine Warning	PHI		46 min
Jul 21, 5:31 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 21, 5:52 PM EDT	Special Marine Warning	PHI		53 min
Jul 21, 1:08 PM EDT	Special Weather Statement	PHI	Lehigh	37 min
Jul 21, 1:27 PM EDT	Severe Thunderstorm Warning	PHI	Berks	48 min
Jul 21, 2:03 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	42 min
Jul 21, 2:14 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Delaware, Montgomery	19 min
Jul 21, 2:41 PM EDT	Special Weather Statement	PHI	Montgomery	49 min
Jul 21, 2:48 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	42 min
Jul 21, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	38 min
Jul 21, 5:59 PM EDT	Special Weather Statement	PHI	Berks	31 min
Jul 21, 4:50 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	25 min
Jul 21, 3:48 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	26 min
Jul 21, 4:16 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's	44 min
Jul 21, 4:25 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	30 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.