New Jersey, 1999

Winter Weather in New Jersey, December 20, 1999

December 20, 1999 · NWS PHI · 4 events in 4 counties and zones

A high pressure system that moved across the northern Middle Atlantic States and New England on the weekend of the 18th and 19th pumped in a cold, dry air mass into the region. On the 19th, a weak low pressure system developed along the South Carolina coast and pumped moisture northward into the region.

Where it happened

Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
4

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PHI wrote it up.

A high pressure system that moved across the northern Middle Atlantic States and New England on the weekend of the 18th and 19th pumped in a cold, dry air mass into the region. On the 19th, a weak low pressure system developed along the South Carolina coast and pumped moisture northward into the region. While the air aloft was warm enough for precipitation to fall as rain, temperatures near the ground were still below freezing. As precipitation spread north across Northwest New Jersey between 3 a.m. and 6 a.m. EST on Monday the 20th, it began as light freezing rain. The cold air tenaciously held on and took the better part of the morning for readings to get entirely above the freezing mark in Hunterdon, Morris and Warren Counties and into the middle of the afternoon for Sussex County. Nearly a quarter of an inch of ice accrued in some of the valleys of Sussex County before the change to plain rain occurred. Driving and walking on untreated surfaces were treacherous.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 winter weather. Local standard time, as filed.

Winter Weather, Hunterdon

When
December 20, 3:00 AM EST to 9:00 AM EST
Where
Hunterdon forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.567, -74.912 (the zone’s center; the record gives no point)

Winter Weather, Warren

When
December 20, 4:00 AM EST to 10:00 AM EST
Where
Warren forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.857, -74.997 (the zone’s center; the record gives no point)

Winter Weather, Morris

When
December 20, 5:00 AM EST to 10:00 AM EST
Where
Morris forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.862, -74.544 (the zone’s center; the record gives no point)

Winter Weather, Sussex

When
December 20, 6:00 AM EST to 2:00 PM EST
Where
Sussex forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
41.140, -74.690 (the zone’s center; the record gives no point)

What these are

Winter Weather
Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in New Jersey in 1999Every state in 1999This day in weather historyWarnings in New Jersey, December 1999

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 5720543, 5720546, 5720544, 5720545.