A Wet One for the Record Books
April 2007 Climate Summary
New Jersey State Climatologist
Center for Environmental Prediction, Cook College/NJAES, Rutgers University
May 7, 2007
April 2007 will go into the record book as New Jersey's wettest fourth month of the year in 113 years of statewide records. The 9.03" of precipitation is well above the monthly average of 3.93". Only 1983, with 8.91", rivals this past month for the top spot. The third wettest, April 1973 with 6.64", sits far behind.
Since 1895, only 14 other months (out of 1348) saw more rain fall across NJ. Once all stations have reported, should the average rise just 0.11", this month will jump to 10th greatest. In fact, only 5 previous months have received more than an inch more than April 2007. Making this month's total all the more impressive is the tendency for wetter months to occur during the warm season (July-September). Outside of these three warm months, only October 1903 (9.13"), January 1979 (9.09"), November 1972 (9.06") and October 2005 (the largest total of any month, with 11.98") saw more precipitation fall on the Garden State than this past April.
In the temperature department, the 48.7° average for April was 1.8° below the 1971-2000 mean. This ranked 35th coolest, but was the lowest average since 1992 and the third coolest in the past 32 years. Until above normal temperatures arrived on 9 of the last 11 days of the month, a decidedly March feel was in the air.
The month began with a few mild days, but by the 4th a cool regime set in that would not relinquish its grip until the 20th. A cold rain, with some snow and sleet in the mix at some locations, fell on the 4th. One of the coldest April weeks in years followed. This centered on Easter Sunday the 8th, when scattered snow flurries and squalls fell in spots and afternoon temperatures were colder than on Christmas Day 2006.
Temperatures moderated a bit the next week, but were still below average. The major story however was rain and more rain. Over an inch fell in many locations on the 12th, but that was only a minor precursor to the largest April rain event on record in the Garden State. Beginning in the early hours of Sunday the 15th, moderate to heavy rain fell for approximately the next 36 hours. By the time the storm came to an end, most rivers across the state were out of their banks. Coastal areas escaped with no more than several inches. However throughout the remainder of the state totals exceeded 4". Portions of central, northeast and northwest NJ measured 6-8", with a few reports as much as an inch higher (click here for a map of observed rainfall totals). New Brunswick received 6.43" of its 7.82" storm total in a 24 hour period, making this the 3rd wettest day on record (since 1912) at this station. Only August days in 1911 and 1971 exceeded this total.
As a result of the heavy rain falling on already wet ground, a number of rivers reached record or near record levels. For instance, the flood of record occurred on the Hackensack River, and some gauging stations in the Raritan basin reached levels that have only been surpassed in the past century by the flooding from Floyd in 1999. Also of note with this storm were exceedingly low pressures. The NJWxNet station at Sea Girt came in with a 28.58" reading, the lowest noted across the state. While rain fell in the north during the early hours of the 16th, the ground was briefly covered by snow in some southern reaches, as cold air rushed in as the intense storm slowly headed away.
Calm followed the storm, with a preview of early summer on the 22nd and 23rd, where away from the chilly coast and somewhat cooler hills, temperatures reached the low to mid 80s. As if not enough rain had already fallen, another storm on the 27th dumped over 2" in some areas, again bringing rivers such as the Millstone in the central portion of the state to bank full. As trees began a rapid late leafing out, April concluded with afternoon temperatures in the 70s to a few low 80s.
The May flowers should be enormous this year!
Past Climate Summaries