Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

February 18, 20217 counties in New Jersey; 8 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Feb 18, 2021, 12:06 PM EST for 7 counties in New Jersey; 8 counties in Pennsylvania. It was in force for 54 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
Feb 18, 2021, 12:06 PM EST (17:06 UTC)
Expired
Feb 18, 2021, 1:00 PM EST
In force
54 min
Issued by
NWS Philadelphia/Mount Holly

Counties Burlington County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Somerset County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 50 km from the middle of the area, began a volume at 17:08 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, 5.1 hours before the alert went out and 189 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 2021-02-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1468 m above ground
0-6 km bulk shear
82 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
406 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

524 
WWUS81 KPHI 181706
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1206 PM EST Thu Feb 18 2021

DEZ001-NJZ007>010-012>020-026-027-PAZ060>062-070-071-101>106-181800-
New Castle-Salem-Camden-Coastal Ocean-Mercer-Northwestern
Burlington-Ocean-Southeastern Burlington-Morris-Hunterdon-Eastern
Monmouth-Western Monmouth-Somerset-Middlesex-Warren-Gloucester-Lower
Bucks-Lehigh-Eastern Montgomery-Northampton-Upper Bucks-Western
Montgomery-Delaware-Eastern Chester-Western
Chester-Philadelphia-Berks-
1206 PM EST Thu Feb 18 2021

...AN AREA OF HEAVY SNOW WILL AFFECT NORTHERN NEW CASTLE...OCEAN...
NORTHWESTERN CAMDEN...SOUTHWESTERN WARREN...MERCER...SOMERSET...
NORTHWESTERN SALEM...SOUTHERN MORRIS...HUNTERDON...NORTHWESTERN
GLOUCESTER...BURLINGTON...MONMOUTH...MIDDLESEX...MONTGOMERY...EASTERN
BERKS...SOUTHEASTERN LEHIGH...BUCKS...CHESTER...PHILADELPHIA...
SOUTHERN NORTHAMPTON AND DELAWARE COUNTIES...

At 1205 PM EST, an area of heavy snow was located along a line
extending from Coatesville to near Bivalve. 

Snowfall rates of around an inch and a half per hour will be common 
within this band. Given temperatures in the 20s and the cold ground, 
road conditions will rapidly deteriorate. In addition, the 
visibility will be reduced to one quarter of a mile within the heavy 
snow.

Be prepared for snow covered roads. Slow down and allow extra time 
when traveling.

Locations impacted include...
Philadelphia, Toms River, Reading, Trenton, Camden, Wilmington, New
Brunswick, Perth Amboy, Newark, Long Branch, Easton, West Chester,
Asbury Park, Somerville, Gloucester City, Sandy Hook, Somerset,
Edison, Lakewood and Bethlehem.

This includes the following highways...
 New Jersey Turnpike between exits 1 and 13.
 Pennsylvania Turnpike between mile markers 296 and 359.
 Northeast Extension between mile markers 21 and 60.
 Interstate 95 in Pennsylvania between mile markers 0 and 40.
 Interstate 95 in Delaware between mile markers 0 and 23.
 Interstate 76 in Pennsylvania between mile markers 327 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 78 in Pennsylvania between mile markers 47 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 43.
 Interstate 195 in New Jersey between mile markers 0 and 34.
 Interstate 295 in New Jersey between mile markers 0 and 76.
 Interstate 287 in New Jersey between mile markers 0 and 31.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 676 in New Jersey between mile markers 0 and 4.
 Interstate 476 in Pennsylvania between mile markers 0 and 19.
 Interstate 176 in Pennsylvania between mile markers 1 and 11.
 Garden State Parkway between mile markers 75 and 134.

Conditions can deteriorate rapidly in winter weather situations. Be 
prepared for snow or ice covered roads. Slow down and allow extra 
time when traveling.

LAT...LON 4001 7397 3979 7431 3985 7495 3960 7561
      3963 7579 3972 7579 3972 7613 3987 7599
      4011 7594 4014 7588 4034 7618 4082 7522
      4074 7437 4060 7446 4060 7421 4047 7427
      4041 7398 4048 7402 4047 7400 4043 7397
TIME...MOT...LOC 1705Z 233DEG 49KT 3999 7583 3916 7503 

$$

BAH

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 18, 5:46 AM ESTSpecial Weather StatementPHIMercer89 min
Feb 18, 5:58 AM ESTSpecial Weather StatementPHIMonmouth77 min
Feb 18, 7:24 AM ESTSpecial Weather StatementPHIMercer, Middlesex, Monmouth51 min
Feb 18, 8:24 AM ESTSpecial Weather StatementPHIMercer, Middlesex, Monmouth66 min
Feb 18, 10:43 AM ESTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset62 min

Nearby

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