JANUARY 10, 2004 FROM DROUGHT TO DELUGE Dr. David A. Robinson New Jersey State Climatologist Rutgers University It was just over 12 months ago that I last attended a drought meeting at the NJ Department of Environmental Protection. New Jersey had just experienced a wet fall, thus the water experts in the room were confident that for the time being thoughts of ongoing drought could be put aside. It had taken some time for our confidence to grow, as we were not far removed from the record dry fall 2001-winter 2002 period. Spring 2002 was wet enough to provide a reprieve from serious water concerns, but a hot, dry summer left us wondering if spring 2002 had only been a brief respite within an ongoing period of intermittent acute drought that dated back to 1998. However, by the end of 2002, 12-month precipitation totals were running close to the long-term mean, and other hydrological indicators such as stream flow, ground water and reservoir storage were at or above seasonal norms. Recent years reminded us that drought has been and will continue to be of critical concern to residents of the Garden State. However the past several decades have been among the wettest in the past century. The 1971-2000 annual mean precipitation (rain and melted snow) across NJ of 47.19" is almost 2.5" greater than the 1895-2002 mean of 44.73". 2003 was the 5th wettest calendar year since 1895. Following are a few pertinent observations regarding recent statewide precipitation. The past few months of data are not yet available from all of the three dozen stations, thus some values are preliminary: - 57.47" of precipitation fell in 2003. This is 10.28" above the 1971-2000 average. - Precipitation was relatively well distributed throughout 2003. - June 2003 rainfall totaled 8.61" (4.82" above average), one of three months more than 2.00" above average (February was +2.03”, December was +2.12”). - Four months were 0.50”-2.00” above average. - Only January was more than 1.00” below average. - 33.06” fell from June to November 2003. Only 1% of the six-month intervals since 1895 have been wetter. - 9.79" fell during the six months ending in February 2002, making this the driest of any six month period on record. 2003 challenged but failed to exceed the calendar year record maximum of 59.98" set in 1996 (table 1). Despite this, a top ten finish is quite a reversal from the 4th driest year (35.66") experienced in 2001! When will New Jersey be threatened again by drought? An accurate prediction would certainly be useful to those whose livelihoods are severely impacted by persistent dry weather or to those who manage NJ water supplies. However, beyond a season, where a modicum of predictive skill can be achieved, such predictions will likely elude us for years to come. Suffice it to say that even in this overall wet era in New Jersey, drought is certain to return intermittently. This behooves us to closely monitor and use our precious water resources wisely, even as our precipitation gauges currently "overflow". You are invited to monitor the latest conditions by visiting the Office of the NJ State Climatologist web site (http://climate.rutgers.edu/stateclim). Here you may link to our ongoing "NJ DroughtWatch" page or find the latest NJ weather conditions on our NJ Weather and Climate Network (NJWxNet) page. Precip. Year 59.98 1996 58.85 1975 58.33 1983 57.56 1972 57.47 2003 56.60 1979 55.56 1989 55.08 1903 54.73 1902 54.50 1952 Table 1. Ten wettest calendar years observed in New Jersey since statewide records began in 1895. Precipitation (rain and melted snow measured in inches) totals are averaged from approximate three dozen stations distributed throughout the Garden State and weighted spatially. The 2003 total is considered preliminary until all reports are received, processed and quality controlled.