Tornado

What can you say about a month that began with a swarm of tornadoes, finished with flooding rain, and in between, featured record heat, wildfires, and increasing drought concerns? Best to say that it was an odd one! Fitting this theme, the statewide average temperature of 55.4° was 3.9° above the 1991–2020 normal. This ranks as the third warmest April on record (since 1895) only behind 2017 and 2010 for top honors. April was the fifth month of the past ten ranking in the top 10, joining July (#7), August (#1), January (#1), and February (#5). The first four months of 2023 come in as the warmest start of the year on record with an average of 44.4°. This exceeds the previous record of 44.2° in 2012, with seven of the 10 warmest January–April periods (1895–present) occurring since 2002. The average April maximum temperature across NJ was 67.4° (+4.7°, 3rd warmest) and the average minimum was 43.4° (+3.1°, 5th warmest). Northern counties averaged 53.5° in April (+3.6°, 5th warmest), southern counties 56.6° (+4.0, 2nd warmest), and the coastal zone 55.8° (+4.1°, 2nd warmest).

April precipitation averaged 5.84” across New Jersey. This was 2.14” above normal, ranking as the 10th wettest on record. It was the wettest April since 2007 and second wettest since 1983. All but scattered areas in the northwest received above-normal precipitation, the greatest amounts falling near the Atlantic and Delaware Bay coasts. Northern counties averaged 5.55” (+1.65”, 26th wettest), southern counties 6.04” (+2.49”, 7th wettest), and the coastal zone 5.94” (+2.39”, 10th wettest). It is important to note that these totals and those for individual stations in the next section, do not include heavy rain that fell after standard early morning observation times at CoCoRaHS and National Weather Service Cooperative stations on April 30th. These rains were reported in morning observations on May 1st, thus will be included in May totals.

Post tropical storm Ida moved across the Garden State during the afternoon of September 1st into the early hours of the 2nd. It brought with it torrential rainfall, leading to flash and river flooding that took the lives of approximately 30 individuals and the rescue of countless more from raging waters. Additionally, it brought three tornadoes to southwestern and central areas, including the first EF-3 twister to strike New Jersey in 31 years. There were only minor injuries and no deaths from the tornadoes.

Ida developed in the Caribbean, being named a tropical storm on August 26th. From there, it moved northwestward, attaining hurricane status on the 27th as it passed over extreme western Cuba and moved into the Gulf of Mexico. It maintained a steady course as it strengthened into a major category 4 hurricane, making landfall in Louisiana on the 29th with sustained one-minute wind speeds as high as 150 mph. Once inland, winds diminished rather quickly but rainfall associated with the tempest remained heavy as the storm began to curve toward the northeast. This track remained quite steady as the storm weakened to a tropical depression on the 30th and became an extratropical low-pressure system as it approached the central Appalachians. On September 1st, Ida’s remnants merged with an advancing cold front as the system entered the Mid-Atlantic and crossed New Jersey before moving into southeast New England on the 2nd.

With 565 incorporated communities in New Jersey, one would think that the odds of multiple significant weather events specific to any one of them within a month would be exceedingly rare. Yet July 2019 brought such a duel scenario to not one but two NJ townships. Mt. Laurel (Burlington County) was visited by two tornadoes, while one rain gauge in Stafford Township (Ocean) caught 5.00” in two separate 24 hour periods. More specifics are provided later in this report. The good news is that, despite damage occurring in each of the four events, there were no fatalities nor reported injuries.

The month as a whole was a wet one, averaging 6.15” across the state. This is 1.58” above the 1981–2010 mean and ranks as the 20th wettest since 1895. Northern counties were wettest, averaging 7.20” or some 2.45” above normal and ranking 16th wettest. The south averaged 5.61”, which is 1.12” above normal and ranks 29th wettest.

Ten of the past 12 months and 15 of the past 18 months have received above-average precipitation across the state. While the 12 months ending in January this year ranks as wettest (66.61”) of 1484 such intervals dating back to 1895, the past 12 month period ending in July comes in second place with 65.74”, just ahead of the 12 months ending in June (65.50”).

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.