Alert archive / Pennsylvania / Snow Squall Warnings in 2018

Snow Squall Warning 2, NWS Philadelphia/Mount Holly

November 21, 2018Carbon County, Monroe County, Northampton County, Pennsylvania; Morris County, Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this snow squall warning at Nov 21, 2018, 5:28 PM EST for Carbon County, Monroe County, Northampton County, Pennsylvania; Morris County, Sussex County, Warren County, New Jersey. It was in force for 62 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
Nov 21, 2018, 5:28 PM EST (22:28 UTC)
Expired
Nov 21, 2018, 6:30 PM EST
In force
62 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 115 km from the middle of the area, began a volume at 22:31 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, 10.5 hours before the alert went out and 166 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 2018-11-21Temperature 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 2018-11-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.1939587897Sfc1 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
1210 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

948 
WWUS51 KPHI 212230
SQWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Mount Holly NJ
528 PM EST Wed Nov 21 2018

NJC027-037-041-PAC025-089-095-212330-
/O.NEW.KPHI.SQ.W.0002.181121T2228Z-181121T2330Z/
Morris NJ-Sussex NJ-Warren NJ-Carbon PA-Monroe PA-Northampton PA-
528 PM EST Wed Nov 21 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 630 PM EST.

* At 528 PM EST, a dangerous snow squall was located along a line
  extending from Monsey to Poughkeepsie--Newburgh to near Lake Mohawk
  to near Blairstown to near Columbia to near White Haven, moving
  southeast at 30 mph.

  HAZARD...Extremely poor visibility in heavy snow. Wind gusts up to 
           30 mph.

  SOURCE...Radar indicated.

  IMPACT...Dangerous life-threatening travel.

* This will impact the Interstate 80 corridor, with temperatures 
  quickly dropping to near freezing with the burst of snow. Traffic 
  cameras in the Poconos showed a rapid snow accumulation on the 
  roads, therefore the greatest impacts will be where the 
  temperatures drop to near freezing.

Locations impacted include...
Morristown, Newton, Lehighton, Dover, Madison, Hopatcong, Florham
Park, East Hanover, Lincoln Park, Kinnelon, East Stroudsburg,
Hackettstown, Boonton, Butler, Wharton, Rockaway, Blairstown, Morris
Plains, Palmerton and Bangor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4091 7433 4083 7433 4077 7437 4076 7474
      4077 7486 4078 7488 4077 7491 4081 7588
      4091 7599 4101 7573 4107 7577 4102 7521
      4105 7499 4112 7475 4112 7447 4104 7450
      4105 7445 4102 7443 4100 7430 4090 7427
TIME...MOT...LOC 2228Z 321DEG 26KT 4113 7406 4109 7435 4104 7470 4100
7493 4093 7515 4101 7579

$$

Gorse
2 follow-up statements
063 
WWUS51 KPHI 212309
SQWPHI

Snow Squall Warning
National Weather Service Mount Holly NJ
607 PM EST Wed Nov 21 2018

NJC037-212317-
/O.CAN.KPHI.SQ.W.0002.000000T0000Z-181121T2330Z/
Sussex NJ-
607 PM EST Wed Nov 21 2018

...THE SNOW SQUALL WARNING FOR SOUTHERN SUSSEX 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.

LAT...LON 4090 7427 4090 7433 4083 7433 4077 7437
      4076 7474 4077 7486 4078 7488 4077 7491
      4081 7588 4091 7599 4088 7519 4091 7472
      4090 7471 4091 7467 4094 7428
TIME...MOT...LOC 2307Z 321DEG 26KT 4092 7384 4088 7412 4083 7447 4079
7470 4072 7492 4080 7556

$$

NJC027-041-PAC025-089-095-212330-
/O.CON.KPHI.SQ.W.0002.000000T0000Z-181121T2330Z/
Morris NJ-Warren NJ-Carbon PA-Monroe PA-Northampton PA-
607 PM EST Wed Nov 21 2018

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 630 PM EST FOR
CENTRAL MORRIS...CENTRAL WARREN...SOUTHERN CARBON...SOUTH CENTRAL
MONROE AND NORTHERN NORTHAMPTON COUNTIES...

At 607 PM EST, a dangerous snow squall was located along a line
extending from Bronxville to Passaic to Morris Plains to Chester to
Glen Gardner to Danielsville, moving southeast at 30 mph.

HAZARD...Extremely poor visibility heavy snow. Wind gusts up to 30 
         mph.

SOURCE...Radar indicated.

IMPACT...Dangerous life-threatening travel.

The greatest impacts will be where the temperatures drop to near 
freezing associated with a burst of snow.

Locations impacted include...
Morristown, Lehighton, Dover, Madison, Florham Park, East Hanover,
Lincoln Park, Hackettstown, Boonton, Wharton, Rockaway, Morris
Plains, Palmerton, Bangor, Mount Arlington, Mendham, Jim Thorpe,
Mountain Lakes, Stanhope and Pen Argyl.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4090 7427 4090 7433 4083 7433 4077 7437
      4076 7474 4077 7486 4078 7488 4077 7491
      4081 7588 4091 7599 4088 7519 4091 7472
      4090 7471 4091 7467 4094 7428
TIME...MOT...LOC 2307Z 321DEG 26KT 4092 7384 4088 7412 4083 7447 4079
7470 4072 7492 4080 7556

$$

Gorse
762 
WWUS51 KPHI 212323
SQWPHI

Snow Squall Warning
National Weather Service Mount Holly NJ
623 PM EST Wed Nov 21 2018

NJC027-041-PAC025-089-095-212333-
/O.EXP.KPHI.SQ.W.0002.000000T0000Z-181121T2330Z/
Morris NJ-Warren NJ-Carbon PA-Monroe PA-Northampton PA-
623 PM EST Wed Nov 21 2018

...THE SNOW SQUALL WARNING FOR CENTRAL MORRIS...CENTRAL WARREN...
SOUTHERN CARBON...SOUTH CENTRAL MONROE AND NORTHERN NORTHAMPTON
COUNTIES WILL EXPIRE AT 630 PM EST...

The snow squall which prompted the warning continues to exit the 
area. Therefore, the snow squall warning will be allowed to expire.

LAT...LON 4090 7427 4090 7433 4083 7433 4077 7437
      4076 7474 4077 7486 4078 7488 4077 7491
      4081 7588 4091 7599 4088 7519 4091 7472
      4090 7471 4091 7467 4094 7428
TIME...MOT...LOC 2323Z 321DEG 26KT 4085 7376 4081 7404 4076 7439 4072
7462 4065 7484 4073 7548

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 21, 4:24 PM ESTSnow Squall WarningPHICarbon, Monroe66 min
Nov 21, 6:22 PM ESTSpecial Weather StatementPHINorthampton53 min

Nearby

Snow Squall Warnings in Pennsylvania, 2018Snow Squall Warnings in New Jersey, 2018Every snow squall warning in 2018

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.