Changeable, To Say the Least: December and Annual 2008 Overview

Dr. David A. Robinson
New Jersey State Climatologist
Center for Environmental Prediction, School of Environmental and Biological Sciences/NJAES, Rutgers University
January 2, 2009

December Recap

The last month of 2008 certainly exemplified the old adage: "If you don't like the present weather just wait a short while and conditions are sure to change." New Jersey residents endured a month of warmth, cold, flooding rain, snow, ice and an abundance of wind. The northern third even got to experience a white Christmas (an inch or more of snow on the ground).

When all was said and done, December was the 5th wettest of the past 114. The 6.77" average is 3.07" above normal. It is interesting to note that the ten wettest Decembers fell within 9 different decades (see table below), including a representative from each decade since the 1930s! All of the state was wet (the precipitation totals include rainfall and melted sleet and snow), with the coastal counties receiving the most liquid and the southwest the least. Lavallette (Ocean County) topped all observing stations with 10.42", with Wall Township (Monmouth) receiving 9.78" and Lower Township (Cape May) 9.38". Bridgeton (Cumberland, 4.51"), Merchantville (Camden, 5.78") and Washington Township (Mercer, 6.10") had some of the lower totals.

Rank Year Precip
1 1996 7.96"
2 1973 7.29"
3 1969 7.21"
4 1983 7.08"
5 2008 6.77"
6 1901 6.68"
7 1902 6.61"
8 1948 6.39"
9 1957 6.33"
10 1936 6.26"

The month started wet, as a November 30 rain event came to an end. Given that many observers for the National Weather Service (NWS) and all for the NJ Community Collaborative Rain, Hail and Snow Network report precipitation close to 7AM each day, the post-7 a.m. November 30th totals of from 0.50" to 1.50" around NJ are included in December 1 counts, thus helped make this month a wet one. This has been the NWS practice for some time, thus it doesn't place much of an asterisk, if any, on the near-record December 2008 total.

The major rain event of the month occurred from the morning of the 10th until the dawn on the 12th. Totals of 3-4" were common throughout the state, with as much as 5.05" at Lavallette (Ocean) and 4.81" in Lower Township (Cape May). Significant icing of trees and power lines occurred above elevations of 1300' in the Highlands of northern central NJ. This led to extended power outages for more than 1,000 homes. The heavy rain caused considerable highway flooding, along with light to borderline-moderate flooding on streams and rivers. As a result, a number of roads and bridges were closed on the 12th, with some rivers cresting at levels not seen since the major April 2007 flood.

Five low pressure systems impacted NJ during the last half of December. Each brought some form of winter weather to at least a portion of the state. The event on the 16th-17th brought 0.50-1.00" of rain and melted snow/sleet to most of the state. Early rain on the 16th turned to snow and sleet and totaled 1-3" between approximately Routes 1 and 80 (Whitehouse, Hunterdon County: 3.0"). Lesser amounts fell to the north and little or no ice accumulated to the south.

The largest snow event of the month followed on the 19th, with Greenwood Lake and West Milford (Passaic) receiving 10". Amounts of 5-7" were common north of Route 78 and tapered down to less than an inch south of Route 195. Close to an inch of rain and melted snow/sleet fell in the northern two thirds of the state, with about a half inch in the southern third. Considerable travel delays occurred on the icy roads and especially at Newark Airport.

More snow, sleet and some freezing rain visited the northern half of NJ on the 21st. Snowfall exceeded 4" in the northern Highlands, but was more commonly 1-3" north of Route 80. The precipitation was all rain south of Route 1 in central NJ. Monmouth County received about 1" of liquid, but lesser amounts fell elsewhere.

Christmas Eve began with freezing rain icing many roads in central and northern NJ, resulting in several accidents on what was a light commuting morning. As temperatures warmed, just plain rain continued to fall and a significant portion of the snow cover in central and northern areas melted. Still, despite the early Christmas warmth and close to an inch of rain in northwestern NJ (rainfall gradually diminished to less than 0.10" in the far southeast), snow covered remained on the ground north of Route 78 on the morning of the 25th.

Even warmer weather on the 28th eliminated snow cover throughout the state, though a light covering returned to close the year. The 31st saw 1-3" of wind-whipped snow fall north of Route 80 (3.2" in Ridgewood and Westwood, Bergen County topped the totals). Again, areas in the southern half of the state saw little snow. This was the case time and again during the last half of the month. Monthly snow totals ranged from as little as a few tenths of an inch to an inch at best south of Route 195 (for instance 0.2" at Folsom, Atlantic and 1.0" at Moorestown, Camden) to 15.0" at Wantage (Sussex). Some other totals include 1.5" Howell (Monmouth), 3.2" Lawrence Township (Mercer), 4.4" North Brunswick (Middlesex), 6.6" Greenwich Township (Hunterdon), 10.1" Parsippany (Morris), 11.0" Tenafly (Bergen), and 12.4" Hawthorne (Passaic).

Temperatures swung at times wildly across the state during December. However, when all days were averaged together, the month only came in 1.4° above the long-term average. The 36.8° mean made for the 31st warmest December on record. Daily maxima exceeded 60° at more than one location in the state on 7 days. All but the northwest and immediate coast were in the 60s on the 10th (68° at Hammonton, Atlantic and Howell, Monmouth), with the 60° mark exceeded in the south on the 11th-12th. The 15th was the warmest day, with Howell reaching 70° and Holmdel (Monmouth) and Eastampton (Burlington) at 69°. Within 24 hours, snow would be falling in central and northern NJ!

A burst of warm air invaded NJ on Christmas Eve, with temperatures maxing out in the 60s late in the evening and early Christmas morning in much of the state. Only the northwestern corner stayed in the upper 40s. Despite there not being much sun, warm winds sent temperatures back into the 60s on the 28th. Toms River (Ocean) and Woodbine (Cape May) reached 69°, with only the northwest staying in the mid to upper 50s.

Excessive cold was not too plentiful during the month, however there was one notable cold spell on the 22nd and 23rd that saw the temperature drop to 1° at High Point on the 22nd and the same value at Walpack on the 23rd. The maximum at High Point on the 22nd was 16°, while elsewhere in the state only a few Cape May County stations exceeded the freezing point. Most of the state was in the single digits and teens on each of these mornings.

Given the frequently-changing conditions and storms of December 2008, it is not surprising that there was many a windy day. Wind gusts exceeded 40 mph at one or more locations on 14 days. The table below reports some of the peak gusts on these days (not all reports above 40 mph). Tragically, the strong wind early on Christmas morning cost the lives of two travelers on the Garden State Parkway in Brookdale (Essex) when a tree fell onto their car.

December Station (county) and speed (mph)
1 Atlantic City Marina (Atlantic): 40
7 High Point (Sussex): 54; Harvey Cedars (Ocean): 48
10 Atlantic City Marina: 41
11 Atlantic City Marina: 47
12 Wantage (Sussex): 51; Bivalve (Cumberland): 49
15 Wantage: 45
19 Harvey Cedars: 44
21 Point Pleasant (Ocean): 46
22 High Point: 48
24 Atlantic City Marina: 50
25 Atlantic City Marina: 45; High Point: 44
28 Berkeley Township (Ocean) & Point Pleasant: 41
30 High Point: 54
31 Wantage: 63; High Point: 60; Harvey Cedars & Atlantic City Marina: 54

2008 Recap

As has been seen in many a year of late, temperatures in 2008 averaged above normal. The preliminary statewide value of 54.0° is 1.3° above the 1971-2000 mean. Eight months experienced above-average temperatures, with April, June and July falling into the top 10 since 1895. Only 8 of the past 114 years have been warmer (table). Six of the warmest 14 years have occurred in just the past 8 years, and 10 of the top 15 since 1990.

Rank Year Annual Avg
1 1998 55.6°
2 2006 55.4°
3 1949 54.8°
4 2002 54.8°
5 1990 54.7°
6 1991 54.6°
7 1999 54.4°
8 1953 54.2°
9 2008 54.0°
10 1973 54.0°
11 2001 54.0°
12 1931 53.9°
13 2005 53.9°
14 2007 53.9°
15 1959 53.7°

The preliminary annual precipitation total is 48.00". This is 0.80" above normal, and ranks as the 39th wettest since 1895. Seven months received below-average precipitation, however the 5 wet months pulled the year to its above-average status, as December was the 5th wettest and February the 9th wettest.

Monthly and seasonally specific information can be found in previous narratives; however several events and intervals are worth noting. Thanks in part to the influence of a major La Niña event in the tropical Pacific, snowfall during the winter of 2007/08 was well below average, except in the higher elevations where it was just cold enough for snow. Overall, winter was the 16th warmest and 18th wettest. Summer proved to be the 7th warmest and 19th driest on record, with an abundance of excellent beach weekends. Tropical storm Hanna crossed the state on September 6th, bringing gusts exceeding 40 mph to the coast and over 5" of rain to portions of northern NJ. The flooding from a storm in the second week of December exceeded that from Hanna, though was generally minor in nature. An unusual October snow storm brought over 10" of the white stuff to higher elevations in the northwest and western central regions. Over 80,000 customers lost electric service as a result of falling leafed trees.

It is difficult to gather complete information concerning deaths and injuries caused either directly or indirectly by weather. Surely, there were a number of such occurrences associated with automobile accidents. Lightning killed a beachgoer at Sandy Hook on July 27, and injured others that day at several coastal locations. Falling trees killed two individuals on June 10, one on November 15 and two on December 25. Reports of 4 individuals losing their lives in rip tides came in over the course of the summer.

For those seeking more detailed information on hourly, daily and monthly conditions, please visit the following Office of the NJ State Climatologist's websites:

NJ Weather and Climate Network
NJ Community Collaborative Rain, Hail and Snow Network
NJ Snow Event Reports

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