Archive: October, 2010
When the rains started last week, Philadelphia's precipitation total for the previous 30 days was under a third of normal. Through yesterday, it was 178 percent of normal, thanks to that 5-plus inch soaking. The hefty rain totals also evidently were widespread, the only exception being near the Shore. Using data from a variety of stations throughout the counties, as of yesterday, precipitation for the last 30 days was about double normal in Bucks County, and well over twice normal in Chester, Delaware and Montgomery Counties, according to the government's Middle Atlantic River Forecast Center. The mainland Jersey figures weren't quite as hefty, but still well over. In Burlington, it was 164 percent of normal; 167, in Camden, and 189, in Gloucester. All that said, a drought watch remains in effect for all of New Jersey and for Chester and Delaware Counties, and a drought warning stays posted for Philly and Bucks and Montgomery Counties. Showers are in the forecast into Wednesday night, however, the rain amounts won't be of the deluge variety, maybe a half inch to an inch, total. So far today, the airport total is well under a quarter-inch.
The pre-season predictions were ominous, as were the in-season updates. The consensus was that this had the potential to be one of the most-destructive hurricane seasons on record. Warm Atlantic, cool Pacific, favorable environment --everything was aligned. So what has happened? With the season well past its climatological peak, not a single hurricane has made landfall on U.S. shores. That certainly ranks as a surprise, but it would be unfair to declare that all the forecasts have been busts. First, the season isn't over yet. It doesn't end until Nov. 30. More on that below. Secondly, in terms of the raw numbers of named storms, the forecasts haven't been far off. The National Oceanic and Atmospheric Administration, Colorado State University, Accu-Weather, WSI Corp., and Tropical Storm Risk all predicted well above-average numbers of named storms, those with winds of 39 m.p.h. or better, and hurricanes, with winds of at least 74 m.p.h. Accu-Weather, for example, called for 16 to 18 named storms and 10 or 11 hurricanes, with five of those major, having winds of 131 m.p.h. or more. NOAA cast a far-broader net, calling for a range of 14 to 23 named storms, 8 to 14 hurricanes, and 3 to 7 of those major. So where do we stand? As of today, the government has identified 14 named storms in the Atlantic Basin, seven of which became hurricanes, and five of those major. Given what's left of the season, those numbers would be in the forecast ballparks, or at least in the stadium parking lots. One point worth mentioning is that NOAA had said that reaching the upper end of its forecast would depend on whether La Nina, a widespread cooling of the equatorial Pacific took hold. It has, and it has come on strongly. In its weekly update today, the government's Climate Prediction Center reports that temperatures in the key measuring zone are better than 3 degrees below normal as La Nina intensifies. It would take quite an active late season to bump up the named-storm numbers into the 20s to reach that upper end, but it isn't out of the question. In 2005, the year of Katrina, 10 named storms developed after Oct. 1, including the destructive and underrated Wilma. Back in 1887, long before satellite and plane reconnaissance, nine tropical storms formed. In 2007, seven storms formed, and five of those became hurricanes. We will keep watch and match the individual forecasts for named storms and hurricanes with the semi-final numbers later this month.
To the west and north of Philadelphia, rain amounts came in even higher than the scary forecasts, but rain was not much of an issue at the Shore.
Rain totals generally were under 2 inches near the coast, said Valerie Meola at the National Weather Service office in Mount Holly, and only about an inch was measured in the last 24 hours in Atlantic City.
The reason: The complex storm system that exploited the leftovers of Tropical Storm Nicole took a slightly more westerly track than anticipated.
The two-day rain totals didn't quite approach the levels of Floyd, in 1999, but the final tallies resembled snow accumulations and did break two long-standing records in Philadelphia.
The 2.99 inches that fell overnight broke the old record of 1.79 for an Oct. 1 set back in 1902. Remember, this is the dry season around here.
Yesterday's 2.41 topped the 2.38 standard set in 1900, bringing the two-day total to 5.30 at Philadelphia International Airport. Floyd is in the clubhouse at 6.98, 6.63 of that one one day, Sept. 16.
The region's waterways are still processing the mass quantities of tropical moisture they ingested, and some of the major ones remain above flood stage.
The National Weather Service reports that the Neshaminy Creek, at Langhorne, and the Brandywine, at Chadds Ford, have just past their crests and are starting to go down.
The Neshaminy was at 10.25 feet, or 1.25 above flood stage, and the Brandywine at 13.1, 4.1 above the flood level.