Alert archive / New Jersey / Snow Squall Warnings in 2019

Snow Squall Warning 8, NWS Philadelphia/Mount Holly

December 18, 20196 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this snow squall warning at Dec 18, 2019, 4:09 PM EST for 6 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 36 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
Dec 18, 2019, 4:09 PM EST (21:09 UTC)
Expired
Dec 18, 2019, 4:45 PM EST
In force
36 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 90 km from the middle of the area, began a volume at 21:09 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, 9.2 hours before the alert went out and 155 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 2019-12-18Temperature 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 2019-12-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -352 square meters per square second.1939587897117136156175Sfc1 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
868 m above ground
0-6 km bulk shear
119 kt
0-1 km storm-relative helicity
-352 m²/s²
0-3 km storm-relative helicity
-46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

520 
WWUS51 KPHI 182109
SQWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Mount Holly NJ
409 PM EST Wed Dec 18 2019

NJC019-021-023-027-035-041-PAC017-182145-
/O.NEW.KPHI.SQ.W.0008.191218T2109Z-191218T2145Z/
Hunterdon NJ-Morris NJ-Warren NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
Bucks PA-
409 PM EST Wed Dec 18 2019

The National Weather Service in Mount Holly NJ has issued a

* Snow Squall Warning for...
  Hunterdon County in northwestern New Jersey...
  Morris County in northern New Jersey...
  Warren County in northwestern New Jersey...
  North central Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Northern Middlesex County in northern New Jersey...
  North central Bucks County in southeastern Pennsylvania...

* Until 445 PM EST.

* At 409 PM EST, a dangerous snow squall was located along a line
  extending from Harrison to Pen Argyl, moving south at 15 mph.

  HAZARD...Heavy snow and blowing snow. Wind gusts up to 30 mph.

  SOURCE...Radar and webcams.

  IMPACT...Dangerous life-threatening travel.

* This includes the following highways...
   Garden State Parkway between mile markers 122 and 134.
   Interstate 287 in New Jersey between mile markers 0 and 48.
   Interstate 78 in New Jersey between mile markers 0 and 42.
   Interstate 80 in New Jersey between mile markers 5 and 24, and
  between mile markers 26 and 47.
   New Jersey Turnpike between exits 10 and 13.

Locations impacted include...
New Brunswick, Perth Amboy, Morristown, Somerville, Somerset, Edison,
East Brunswick, Bridgewater, Sayreville, North Brunswick, Carteret,
Dover, Madison, Hopatcong, Middlesex, Florham Park, East Hanover,
Bound Brook, Manville and Hackettstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Reduce your speed and turn on headlights! During snow squalls, the
visibility may suddenly drop to near zero in whiteout conditions.

Slow Down! Rapid changes in visibility and road conditions are
expected with this dangerous snow squall. Be alert for sudden
whiteout conditions.

&&

LAT...LON 4060 7421 4050 7428 4044 7423 4038 7514
      4059 7524 4062 7519 4075 7519 4080 7510
      4085 7510 4086 7505 4095 7511 4094 7480
      4090 7471 4094 7464 4093 7429 4089 7434
      4075 7436 4067 7446 4065 7441 4060 7446
TIME...MOT...LOC 2109Z 348DEG 11KT 4075 7417 4087 7528 

$$

NC
1 follow-up statement
571 
WWUS51 KPHI 182145
SQWPHI

Snow Squall Warning
National Weather Service Mount Holly NJ
444 PM EST Wed Dec 18 2019

NJC019-021-023-027-035-041-PAC017-182154-
/O.EXP.KPHI.SQ.W.0008.000000T0000Z-191218T2145Z/
Hunterdon NJ-Morris NJ-Warren NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
Bucks PA-
444 PM EST Wed Dec 18 2019

...THE SNOW SQUALL WARNING FOR HUNTERDON...MORRIS...WARREN...NORTH
CENTRAL MERCER...SOMERSET...NORTHERN MIDDLESEX AND NORTH CENTRAL
BUCKS COUNTIES WILL EXPIRE AT 445 PM EST...

The snow squall which prompted the warning has weakened. Therefore, 
the snow squall warning will be allowed to expire. Some light snow 
may remain in the warning area temporarily reducing visibilities 
under 1 mile.

LAT...LON 4060 7421 4050 7428 4044 7423 4038 7514
      4059 7524 4062 7519 4075 7519 4080 7510
      4085 7510 4086 7505 4095 7511 4094 7480
      4090 7471 4094 7464 4093 7429 4089 7434
      4075 7436 4067 7446 4065 7441 4060 7446
TIME...MOT...LOC 2144Z 348DEG 11KT 4066 7414 4078 7525 

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 18, 1:29 PM ESTSnow Squall WarningPHISussex, Warren61 min
Dec 18, 2:23 PM ESTSnow Squall WarningPHIMorris, Sussex, Warren67 min
Dec 18, 2:44 PM ESTSpecial Weather StatementPHICamden, Gloucester46 min
Dec 18, 3:02 PM ESTSnow Squall WarningPHIMiddlesex, Monmouth, Morris, Somerset43 min
Dec 18, 3:29 PM ESTSpecial Weather StatementPHIHunterdon, Somerset, Warren46 min
Dec 18, 3:44 PM ESTSpecial Weather StatementPHIHunterdon, Morris, Somerset, Warren46 min
Dec 18, 4:44 PM ESTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset61 min
Dec 18, 5:12 PM ESTSpecial Weather StatementPHIBurlington, Camden, Ocean93 min

Nearby

Snow Squall Warnings in New Jersey, 2019Snow Squall Warnings in Pennsylvania, 2019Every snow squall warning in 2019

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.