Alert archive / Pennsylvania / Snow Squall Warnings in 2019

Snow Squall Warning 4, NWS Philadelphia/Mount Holly

February 13, 20195 counties in Pennsylvania; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this snow squall warning at Feb 13, 2019, 12:37 PM EST for 5 counties in Pennsylvania; 4 counties in New Jersey. It was in force for 53 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 13, 2019, 12:37 PM EST (17:37 UTC)
Expired
Feb 13, 2019, 1:30 PM EST
In force
53 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Morris County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 97 km from the middle of the area, began a volume at 17:36 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, 5.6 hours before the alert went out and 179 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 2019-02-13Temperature 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 2019-02-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -312 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
414 m above ground
0-6 km bulk shear
104 kt
0-1 km storm-relative helicity
-312 m²/s²
0-3 km storm-relative helicity
-20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

654 
WWUS51 KPHI 131741
SQWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Mount Holly NJ
1237 PM EST Wed Feb 13 2019

NJC019-027-037-041-PAC011-017-077-091-095-131830-
/O.NEW.KPHI.SQ.W.0004.190213T1737Z-190213T1830Z/
Morris NJ-Hunterdon NJ-Sussex NJ-Warren NJ-Berks PA-Montgomery PA-
Lehigh PA-Bucks PA-Northampton PA-
1237 PM EST Wed Feb 13 2019

The National Weather Service in Mount Holly NJ has issued a

* Snow Squall Warning for...
  Morris County in northern New Jersey...
  Northern Hunterdon County in northwestern New Jersey...
  South central Sussex County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  Northeastern Berks County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Southern Northampton County in eastern Pennsylvania...

* Until 130 PM EST.

* At 1237 PM EST, a dangerous snow squall was located along a line
  extending from near Great Meadows-Vienna to near Bethlehem to
  Leesport, moving east at 30 mph.

  HAZARD...Poor visibility in heavy snow.

  SOURCE...Radar and spotters.

  IMPACT...Dangerous life-threatening travel.

* Visibility reduced to a quarter mile or less has been reported 
  with this snow squall in Northampton and Lehigh counties. 
  Temperatures are above freezing, however they may quickly drop to 
  freezing during the burst of snow resulting in icy conditions on 
  untreated roads.

Locations impacted include...
Allentown, Easton, Morristown, Bethlehem, Dover, Hopatcong, Forks,
Emmaus, Lincoln Park, Northampton, Hackettstown, Quakertown, Boonton,
Wilson, Wharton, Washington, Rockaway, Hellertown, Nazareth and
Morris Plains.

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 4070 7540 4098 7492 4095 7428 4093 7428
      4075 7455 4073 7471 4064 7473 4058 7481
      4031 7549 4045 7614
TIME...MOT...LOC 1737Z 277DEG 24KT 4092 7490 4064 7532 4046 7595 

$$

Gorse
1 follow-up statement
983 
WWUS51 KPHI 131804
SQWPHI

Snow Squall Warning
National Weather Service Mount Holly NJ
103 PM EST Wed Feb 13 2019

NJC019-027-037-041-PAC011-017-077-091-095-131830-
/O.CON.KPHI.SQ.W.0004.000000T0000Z-190213T1830Z/
Morris NJ-Hunterdon NJ-Sussex NJ-Warren NJ-Berks PA-Montgomery PA-
Lehigh PA-Bucks PA-Northampton PA-
103 PM EST Wed Feb 13 2019

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 130 PM EST FOR
MORRIS...NORTHERN HUNTERDON...SOUTH CENTRAL SUSSEX...SOUTHERN
WARREN...EAST CENTRAL BERKS...NORTHWESTERN MONTGOMERY...SOUTHEASTERN
LEHIGH...NORTHWESTERN BUCKS AND SOUTH CENTRAL NORTHAMPTON COUNTIES...

At 103 PM EST, a dangerous snow squall was located along a line
extending from Wharton to near Bloomsbury to near Bally, moving east
at 35 mph.

HAZARD...Poor visibility in heavy snow.

SOURCE...Radar indicated.

IMPACT...Dangerous life-threatening travel.

Visibility reduced to a quarter mile or less has been reported with 
this snow squall earlier in Northampton and Lehigh counties. 
Temperatures are above freezing, however they may quickly drop to 
freezing in some areas during the burst of snow resulting in icy 
conditions on untreated roads.

Locations impacted include...
Morristown, Dover, Hopatcong, Emmaus, Lincoln Park, Hackettstown,
Quakertown, Boonton, Wharton, Washington, Rockaway, Hellertown,
Morris Plains, Mount Arlington, Mendham, Mountain Lakes, High Bridge,
Stanhope, Netcong and East Greenville.

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 4064 7519 4097 7478 4095 7428 4093 7428
      4075 7455 4073 7471 4064 7473 4058 7481
      4031 7549 4042 7579
TIME...MOT...LOC 1803Z 274DEG 28KT 4091 7458 4063 7500 4045 7563 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 13, 2:52 PM ESTSpecial Weather StatementPHIBucks38 min
Feb 13, 1:22 PM ESTSpecial Weather StatementPHIHunterdon, Middlesex, Morris, Somerset23 min
Feb 13, 3:28 PM ESTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset32 min
Feb 13, 3:59 PM ESTSpecial Weather StatementPHIMorris, Warren31 min
Feb 13, 4:28 PM ESTSpecial Weather StatementPHIMorris32 min
Feb 13, 6:20 PM ESTSmall Craft AdvisoryPHI15 hr

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.