Alert archive / New Jersey / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

September 15, 2021Hunterdon County, Morris County, New Jersey; Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 15, 2021, 7:36 PM EDT for Hunterdon County, Morris County, New Jersey; Montgomery County, Pennsylvania. It was in force for 24 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
Sep 15, 2021, 7:36 PM EDT (23:36 UTC)
Expired
Sep 15, 2021, 8:00 PM EDT
In force
24 min
Issued by
NWS Philadelphia/Mount Holly
Hail
0.00 in
Wind
40

Counties Hunterdon County, NJ, Morris County, NJ, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 104 km from the middle of the area, began a volume at 23:38 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, 11.6 hours before the alert went out and 153 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2021-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1879 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2021-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1879 J/kg
Mixed-layer CIN
-36 J/kg
Mixed-layer LCL
623 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.9
Supercell composite
4.6

Open this sounding in Storm Lab

The text

As transmitted.

541 
WWUS81 KPHI 152336
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
736 PM EDT Wed Sep 15 2021
 
NJZ001-007>010-PAZ060-061-101-103>105-160000-
Hunterdon NJ-Morris NJ-Sussex NJ-Somerset NJ-Warren NJ-
Upper Bucks PA-Lehigh PA-Eastern Montgomery PA-Western Montgomery PA-
Western Chester PA-Berks PA-
736 PM EDT Wed Sep 15 2021

...Gusty winds will impact portions of Hunterdon, Morris, 
southeastern Sussex, southern Warren, northwestern Somerset, 
southeastern Berks, southeastern Lehigh, northwestern Montgomery, 
northwestern Bucks and northeastern Chester Counties through 800 PM 
EDT...

At 734 PM EDT, Doppler radar was tracking an outflow boundary ahead 
of an area of thunderstorms along a line extending from Upper 
Greenwood Lake to near Pleasant Valley to near Birdsboro. Movement 
was east at 50 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

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

Locations impacted include...
Morristown, Pottstown, Dover, Phoenixville, Lansdale, Hopatcong,
Lincoln Park, Kinnelon, Hackettstown, Quakertown, Perkasie, Byram,
Boonton, Butler, Souderton, Bedminster, Wharton, Washington, Rockaway
and Morris Plains.

This includes the following highways...
 Northeast Extension between mile markers 28 and 46.
 Interstate 78 in New Jersey between mile markers 2 and 28.
 Interstate 80 in New Jersey between mile markers 21 and 46.
 Interstate 287 in New Jersey between mile markers 31 and 33, and
between mile markers 36 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

These gusty winds will occur well ahead of any rain or lightning. 

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northwestern New Jersey...and eastern Pennsylvania.

&&

LAT...LON 4120 7436 4109 7450 4104 7450 4105 7445
      4103 7442 4100 7430 4097 7428 4092 7428
      4091 7434 4085 7437 4014 7544 4017 7591
      4054 7534 4060 7520 4064 7519 4122 7439
TIME...MOT...LOC 2334Z 263DEG 43KT 4118 7438 4071 7502 4023 7577 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 3:25 AM EDTSmall Craft AdvisoryPHI21 hr
Sep 15, 5:31 PM EDTSpecial Weather StatementPHIMonroe29 min
Sep 15, 6:29 PM EDTSpecial Weather StatementPHILebanon31 min
Sep 15, 6:48 PM EDTSpecial Weather StatementPHIBerks27 min
Sep 15, 7:08 PM EDTSevere Thunderstorm WarningPHIBerks37 min
Sep 15, 7:17 PM EDTSpecial Weather StatementPHILehigh28 min

Nearby

Special Weather Statements in New Jersey, 2021Special Weather Statements in Pennsylvania, 2021Every 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.