Alert archive / New Jersey / Dense Fog Advisories in 2025

Dense Fog Advisory 3, NWS Philadelphia/Mount Holly

February 13, 202511 counties in New Jersey; Chester County, Delaware County, Philadelphia County, Pennsylvania; Kent County, New Castle County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this dense fog advisory at Feb 13, 2025, 9:23 AM EST for 11 counties in New Jersey; Chester County, Delaware County, Philadelphia County, Pennsylvania; Kent County, New Castle County, Sussex County, Delaware. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Feb 13, 2025, 9:23 AM EST (14:23 UTC)
Expired: Feb 13, 2025, 12:00 PM EST
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly

Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 57 km from the middle of the area, began a volume at 14:26 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 2.4 hours before the alert went out and 223 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 416 m above ground
0-6 km bulk shear: 91 kt
0-1 km storm-relative helicity: 482 m²/s²
0-3 km storm-relative helicity: 532 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this dense fog advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this dense fog advisory went out at Feb 13, 6:45 AM EST, 2 hours 38 minutes earlier.

Area forecast discussion, Feb 13, 6:45 AM EST, 2 hours 38 minutes before

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In the hours before

Local storm report, Feb 13, 4:30 AM EST, 4 hours 53 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
430 AM EST Thu Feb 13 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0424 AM     Snow             4 WSW Wantage Twp       41.22N 74.68W
02/13/2025  M0.2 Inch        Sussex             NJ   Trained Spotter

            Snow and sleet.

&&

Gorse

Local storm report, Feb 13, 4:33 AM EST, 4 hours 50 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
433 AM EST Thu Feb 13 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0424 AM     Freezing Rain    4 WSW Wantage Twp       41.22N 74.68W
02/13/2025  E0.05 Inch       Sussex             NJ   Trained Spotter

            Light glaze of ice. Heavy freezing drizzle
            occurring at the time of report.

&&

Gorse

Local storm report, Feb 13, 4:42 AM EST, 4 hours 41 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
442 AM EST Thu Feb 13 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 AM     Freezing Rain    Pocono Mountains Munici 41.14N 75.38W
02/13/2025  M0.43 Inch       Monroe             PA   ASOS

            Combination of freezing rain and freezing
            fog.

0100 AM     Freezing Rain    Lehigh Valley Internati 40.65N 75.44W
02/13/2025  M0.06 Inch       Lehigh             PA   ASOS

0100 AM     Freezing Rain    Reading Regional Airpor 40.38N 75.96W
02/13/2025  M0.01 Inch       Berks              PA   ASOS

&&

Gorse

Local storm report, Feb 13, 4:47 AM EST, 4 hours 36 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
447 AM EST Thu Feb 13 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 AM     Freezing Rain    Pottstown Municipal Air 40.26N 75.67W
02/13/2025  M0.03 Inch       Montgomery         PA   ASOS

&&

Gorse

Local storm report, Feb 13, 4:49 AM EST, 4 hours 34 minutes before

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
449 AM EST Thu Feb 13 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 AM     Freezing Rain    Doylestown Airport      40.33N 75.12W
02/13/2025  M0.01 Inch       Bucks              PA   ASOS

&&

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 12, 9:25 PM EST	Coastal Flood Advisory	PHI	Middlesex, Monmouth	14 hr
Feb 13, 12:04 AM EST	Marine Dense Fog Advisory	PHI		12 hr
Feb 13, 4:35 PM EST	Wind Advisory	PHI	Berks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more	5 hr

Nearby

Dense Fog Advisories in New Jersey, 2025 Dense Fog Advisories in Pennsylvania, 2025 Dense Fog Advisories in Delaware, 2025 Every dense fog advisory in 2025

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.