Alert archive / Pennsylvania / Snow Squall Warnings in 2019

Snow Squall Warning 6, NWS Philadelphia/Mount Holly

December 18, 2019Morris County, Sussex County, Warren County, New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this snow squall warning at Dec 18, 2019, 2:23 PM EST for Morris County, Sussex County, Warren County, New Jersey; 4 counties in Pennsylvania. It was in force for 67 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, 2:23 PM EST (19:23 UTC)
Expired
Dec 18, 2019, 3:30 PM EST
In force
67 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Morris County, NJ, Sussex County, NJ, Warren County, NJ, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 137 km from the middle of the area, began a volume at 19:25 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, 7.4 hours before the alert went out and 187 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.

523 
WWUS51 KPHI 181924
SQWPHI

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

NJC027-037-041-PAC025-077-089-095-182030-
/O.NEW.KPHI.SQ.W.0006.191218T1923Z-191218T2030Z/
Morris NJ-Sussex NJ-Warren NJ-Lehigh PA-Carbon PA-Monroe PA-
Northampton PA-
223 PM EST Wed Dec 18 2019

The National Weather Service in Mount Holly NJ has issued a

* Snow Squall Warning for...
  Northwestern Morris County in northern New Jersey...
  Sussex County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  North central Lehigh County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  Monroe County in northeastern Pennsylvania...
  Northern Northampton County in eastern Pennsylvania...

* Until 330 PM EST.

* At 223 PM EST, a dangerous snow squall was located along a line
  extending from High Point to near Crandon Lakes to near Long Pond
  to near Blakeslee to near Drums, moving south at 25 mph.

  HAZARD...Poor visibility in 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...
   Interstate 80 in New Jersey between mile markers 0 and 28.
   Interstate 80 in Pennsylvania between mile markers 278 and 314.
   Northeast Extension between exits A74 and A95.
   Interstate 380 in Pennsylvania between mile markers 0 and 13.

Locations impacted include...
Port Jervis, Newton, Lehighton, Montague, Mount Pocono, Hopatcong,
East Stroudsburg, Hackettstown, Tobyhanna, Blairstown, Palmerton,
Bangor, Mount Arlington, Franklin, Jim Thorpe, Slatington, Stanhope,
Pen Argyl, Nesquehoning and Hamburg.

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 4120 7437 4110 7449 4104 7450 4103 7443
      4089 7467 4080 7501 4076 7542 4070 7570
      4091 7599 4101 7573 4109 7577 4112 7564
      4123 7554 4125 7513 4115 7515 4114 7509
      4108 7503 4116 7490 4128 7483 4136 7470
TIME...MOT...LOC 1923Z 007DEG 22KT 4132 7465 4115 7490 4107 7540 4108
7567 4106 7605

$$

NC
1 follow-up statement
842 
WWUS51 KPHI 182011
SQWPHI

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

PAC077-182016-
/O.CAN.KPHI.SQ.W.0006.000000T0000Z-191218T2030Z/
Lehigh PA-
306 PM EST Wed Dec 18 2019

...THE SNOW SQUALL WARNING FOR NORTH CENTRAL LEHIGH COUNTY IS
CANCELLED...

The snow squall which prompted the warning has moved out of the 
warned area. Therefore, the snow squall warning has been cancelled. 
Some light snow will still be possible this afternoon.

LAT...LON 4120 7437 4110 7449 4104 7450 4103 7443
      4089 7467 4080 7501 4076 7543 4073 7556
      4089 7567 4094 7573 4109 7575 4112 7564
      4115 7525 4114 7512 4108 7503 4114 7480
      4115 7463 4124 7447
TIME...MOT...LOC 2006Z 007DEG 22KT 4107 7469 4090 7494 4082 7544 4083
7571 4081 7609

$$

NJC027-037-041-PAC025-089-095-182030-
/O.CON.KPHI.SQ.W.0006.000000T0000Z-191218T2030Z/
Morris NJ-Sussex NJ-Warren NJ-Carbon PA-Monroe PA-Northampton PA-
306 PM EST Wed Dec 18 2019

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 330 PM EST FOR
NORTHWESTERN MORRIS...SOUTHERN SUSSEX...WARREN...EASTERN CARBON...
MONROE AND NORTHERN NORTHAMPTON COUNTIES...

At 306 PM EST, a dangerous snow squall was located along a line
extending from near Newton to Hope to near Kunkletown to Lehighton to
Grier City-Park Crest, moving south at 25 mph.

HAZARD...Poor visibility in 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...
 Interstate 80 in New Jersey between mile markers 0 and 28.
 Interstate 80 in Pennsylvania between mile markers 279 and 314.
 Northeast Extension between exits A87 and A95.
 Interstate 380 in Pennsylvania between mile markers 0 and 4.

Locations impacted include...
Newton, Mount Pocono, Hopatcong, East Stroudsburg, Hackettstown,
Blairstown, Palmerton, Bangor, Mount Arlington, Franklin, Stanhope,
Pen Argyl, Hamburg, Netcong, Wind Gap, Belvidere, Oxford, Ogdensburg,
Hope and Belfast.

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 4120 7437 4110 7449 4104 7450 4103 7443
      4089 7467 4080 7501 4076 7543 4073 7556
      4089 7567 4094 7573 4109 7575 4112 7564
      4115 7525 4114 7512 4108 7503 4114 7480
      4115 7463 4124 7447
TIME...MOT...LOC 2006Z 007DEG 22KT 4107 7469 4090 7494 4082 7544 4083
7571 4081 7609

$$

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, 2:44 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, 4:09 PM ESTSnow Squall WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset, Warren36 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 Pennsylvania, 2019Snow Squall Warnings in New Jersey, 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.