Alert archive / Pennsylvania / Snow Squall Warnings in 2019

Snow Squall Warning 10, NWS Philadelphia/Mount Holly

December 19, 2019Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, New Jersey

NWS Philadelphia/Mount Holly issued this snow squall warning at Dec 19, 2019, 12:09 AM EST for Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, New Jersey. 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 19, 2019, 12:09 AM EST (05:09 UTC)
Expired
Dec 19, 2019, 12:45 AM EST
In force
36 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Burlington County, NJ, Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 37 km from the middle of the area, began a volume at 05:10 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 00:00Z, 5.2 hours before the alert went out and 191 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 00:00Z on 2019-12-19Temperature 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 00:00Z on 2019-12-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -100 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
995 m above ground
0-6 km bulk shear
94 kt
0-1 km storm-relative helicity
-100 m²/s²
0-3 km storm-relative helicity
-67 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

147 
WWUS51 KPHI 190511
SQWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Mount Holly NJ
1209 AM EST Thu Dec 19 2019

NJC005-PAC017-091-101-190545-
/O.NEW.KPHI.SQ.W.0010.191219T0509Z-191219T0545Z/
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
1209 AM EST Thu Dec 19 2019

The National Weather Service in Mount Holly NJ has issued a

* Snow Squall Warning for...
  Northern Burlington County in southern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southeastern Bucks County in southeastern Pennsylvania...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until 1245 AM EST.

* At 1209 AM EST, a dangerous snow squall was located along a line
  extending from near Ambler to Florence, moving southeast at 35 mph.

  HAZARD...Poor visibility in snow and blowing snow. Wind gusts up 
           to 30 mph.

  SOURCE...Radar and webcams.

  IMPACT...Expect hazardous road conditions.

* This includes the following highways...
   Interstate 295 in New Jersey between mile markers 40 and 56.
   Interstate 95 in Pennsylvania between mile markers 31 and 40.
   New Jersey Turnpike between exits 5 and 7A.
   Pennsylvania Turnpike between exits 351 and 353.

Locations impacted include...
Philadelphia, Bensalem, Willingboro, Lumberton, Florence, Burlington,
Bristol, Mount Holly, Riverside, Beverly, Rockledge, Tullytown,
Abington, Pemberton, Bryn Athyn, Wrightstown, Feasterville-Trevose,
Florence-Roebling, Northeast Philadelphia and Jacksonville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3989 7484 4002 7454 4018 7478 4013 7514
TIME...MOT...LOC 0509Z 316DEG 28KT 4021 7522 4009 7479 

$$

Gorse
1 follow-up statement
619 
WWUS51 KPHI 190535
SQWPHI

Snow Squall Warning
National Weather Service Mount Holly NJ
1235 AM EST Thu Dec 19 2019

NJC005-PAC017-091-101-190545-
/O.EXP.KPHI.SQ.W.0010.000000T0000Z-191219T0545Z/
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
1235 AM EST Thu Dec 19 2019

...THE SNOW SQUALL WARNING FOR NORTHERN BURLINGTON...SOUTHEASTERN
MONTGOMERY...SOUTHEASTERN BUCKS AND NORTHEASTERN PHILADELPHIA
COUNTIES WILL EXPIRE AT 1245 AM EST...

The snow squall which prompted the warning has weakened. Therefore,
the snow squall warning will be allowed to expire.

LAT...LON 3989 7484 4002 7454 4018 7478 4013 7514
TIME...MOT...LOC 0535Z 316DEG 28KT 4007 7504 3995 7462 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 18, 11:49 PM ESTSnow Squall WarningPHIBucks, Montgomery, Philadelphia26 min
Dec 19, 6:07 AM ESTSmall Craft AdvisoryPHI12 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.