drought

As the 10th month of 2019 commenced, attention was on the continuing flash drought conditions across the Garden State. Lawns had gone brown and shallow rooted trees were losing their dull-colored leaves early. By the second week of the month, the US Drought Monitor showed all of NJ to be in either abnormally dry (D0) or moderate drought (D1) status (full disclosure: my recommendations are taken under consideration by the national author of each week’s map). Several rain episodes in the first half of the month, particularly in the north, began to stall any worsening of conditions. However, it wasn’t until the last half that five events deposited an inch or more, three of them with two inches or more, at a number of locations around the state. Thus by month’s end, only portions of southwest, southeast, and central NJ were rated D0, and the remainder, as we like to say, in “D nada.” This turn to storminess didn’t come without consequences. This included localized flash and small stream flooding on occasion, several episodes of strong winds, and some minor to moderate coastal flooding. More on all of this below, but first to further summarize the month. In the precipitation department, the statewide average was 5.79”. This is 1.90” above the 1981–2010 normal and ranks as the 15th wettest dating back to 1895. North Jersey came in with an average of 6.72”, some 2.41” above normal and ranking 10th wettest. In the south, the 5.28” average was 1.65” above normal and ranks as the 20th wettest.

As if the wet month was not newsworthy enough, the statewide monthly temperature of 58.0° tied with two other years as the 9th warmest back to 1895. This is 3.5° above normal, with northern and southern portions coming in at 3.2° and 3.8° above, respectively. The 2nd was arguably the hottest October day on record, thus also the warmest for so late in the season. Meanwhile, several locations experienced the first freeze of the season on the 4th or 5th, with a more widespread frost and freeze on the 19th. Still, the month ended with only 18 of the 63 NJWxNet stations having fallen to the freezing mark.

Even in a rather tranquil month, there are always interesting aspects of New Jersey’s weather and climate that can make for memorable situations. Such was the case during the 11th month of 2017. On the heels of a mild October and first week of November came one of the coldest early-season blasts on record on the 11th. Then the 19th saw some of the strongest winds of the year across the state. Overall, dry conditions by month’s end put the northern Highlands in the D0 (abnormally dry) category on the US Drought Monitor map, threatening to expand further into the state should dry conditions persist.

Rainfall averaged 1.68” across the state. This is 1.93” below the 1981–2010 mean and ranks as the 19th driest November since 1895. It was the driest since 1.30” fell in 2012 and well above the record low 0.54” in 1917. The statewide average temperature of 44.3° tied with 1938 as the 75th coolest (or 49th mildest) on record. The average was 0.9° below the 1981–2010 mean, but 0.8° above the 1895–2017 mean. This demonstrates how New Jersey has warmed in recent decades compared to earlier in the 20th century.

Occasionally there are months that defy a “directional” theme when it comes to the weather and climate conditions experienced across the Garden State. In other words, conditions didn’t lean markedly toward, for example, wet or dry, cold or warm, or calm or stormy. June 2017 was one of those “potpourri” months. There were thunderstorms with drenching rain and even two tornadoes occurred, yet there were stretches of comfortable, dry weather. There was a three-day heat wave, with the temperature going as high as 97°, and some cool nights, with 35° being the coldest observed temperature in the state. When the precipitation was added up, the statewide average came out to 3.34”, which was 0.67” below the 1981–2010 mean of 4.01” and ranks as the 54th driest June of the past 123 years. The statewide average temperature of 70.5° was 0.7° above average. This ranks as the 27th mildest June on record.

Following a March with the first substantially below-average monthly temperature anomaly in NJ in over a year, April brought a return to record warmth last seen in February. With a statewide average of 56.0°, the month was 5.1° above the 1981–2010 mean. This ranked as the warmest April since statewide records commenced in 1895. Five of the top 10 and nine of the top 20 mildest Aprils of the past 123 years have occurred since 2002. With the warmth of January, February, and April hardly balanced by the colder March, this year is off to the 4th warmest start on record. Only January–April averages in 2012, 1998, and 2002 were higher, and five of the eight mildest such intervals in the past 123 years have been since 2002. The 12-month period from May 2016 through April 2017 was the third warmest on record at 55.5°. It was only surpassed by May 2011–April 2012 (56.5°) and 2015–2016 (56.2°). Twelve of the 15 warmest such intervals of the past 123 years have occurred since 1999, the others being in 1931–1932 (#10), 1990–1991 (#11), and 1991–1992 (#14).

The atmosphere was in a progressive mode throughout December, which explains why no particular weather feature lingered in NJ or elsewhere across North America for too long. The seemingly day-to-day changes resulted in the statewide mean temperature of 36.4° being just 1.2° above the 1981–2010 normal. This ranks as the 28th mildest December since statewide records commenced in 1895, a far cry from last year’s record mild conditions. Despite there being seven precipitation events, one of which was mainly a carry over from November 30th, the rapid movement of these systems meant that none deposited prodigious totals in NJ. Thus 3.37” fell, which is 0.48” below average. This ranks as the 55th driest December. Monthly statewide snowfall averaged 2.0”. This is 2.1” below the 1981–2010 average and ranks 45th least snowy. The northern seven counties averaged 5.5”, the central six counties averaged 1.8”, and the eight southern counties 0.2”, all below average.