With Rains like These, Who Needs Hurricanes? August 13, 2016

WeatherUnderground:

A devastating flood event was unfolding over southeast Louisiana on Friday, and conditions may get worse yet, as an extremely slow-moving center of low pressure is dumping colossal amounts of rain on the region. This sprawling, “stacked” low is carrying more water vapor than many tropical cyclones, and its slow motion is leading to persistent rains that could add up to all-time record totals in some places. Multi-sensor analyses indicate that several areas in southeast Louisiana and southermost Mississippi racked up more than 6” of rain from 7:00 am CDT Thursday, August 11, to 7:00 am Friday (see Figure 1). More than 10” of rain was analyzed just northeast of Baton Rouge, the hardest-hit area thus far. In the 24 hours from 2:00 pm CDT Thursday to 2:00 pm Friday, Baton Rouge Metropolitan Airport recorded a preliminary total of 8.49” of rain. Since records began in 1892, the city’s largest calendar day total is 11.99” (set on April 14, 1967), and the largest two-day calendar total is 14.03” (June 6-7, 2001). Given the very slow motion of the stacked low, these all-time records are conceivably within reach. A cooperative observer in Livingston, LA, reported 17.09” of rain from midnight to 3:00 pm CDT Friday. The state’s official 24-hour record is 22 inches, reported near Hackberry on August 28-29, 1962.

So since around 10pm last night Grangeville on the Amite River has risen around 22 ft & still going up fast. #LAwx pic.twitter.com/pwkp1Ik7bL — Christopher Bannan (@ulmwxr) August 12, 2016

Pacific Standard:

Although 2015 saw a Northern Hemisphere record for major hurricanes, Cat 3 and above. Still we hear climate deniers talking about a “hurricane drought”. Only for those who look beyond the Dogpatch County line.

ThinkProgress:

You may have seen a headline in recent weeks that asserted “The U.S. coast is in an unprecedented hurricane drought” (Washington Post) or “U.S. experiencing record hurricane drought” (USA Today). In fact, the major “hurricane drought” in these stories is so arbitrary and frankly irrelevant to the lives of most Americans living along the coast as to render it beyond misleading. A journal article published over two months ago — aptly titled “The Arbitrary Definition of the Current Atlantic Major Hurricane Landfall Drought” — pointed out: From a societal context, human and financial losses matter most, and Irene [2011; $8 billion (U.S. dollars)] and Sandy (2012; $88 billion) occurred during the current drought. D’oh! We could get hit by a Sandy every year — heck, every month — for the entire century and still be in this so-called drought! How is that possible? Well, the primary “drought” people are talking about (yes, there is more than one) is, as the Post put it “A major hurricane hasn’t hit the U.S. Gulf or East Coast in more than a decade…. The streak has reached 3,937 days, longer than any previous drought by nearly two years.” But wait, you say, Sandy and Irene were both Category 3 hurricanes — and Ike (2008) was a Category 4 — and the definition of a “major hurricane” is a Category 3, 4, or 5 hurricane. True, say the drought-ists, but the semantic drought we’re talking about is a drought in hurricanes that were major when they made land-fall! But wait, you say, Sandy was the second costliest hurricane in U.S. history (after Katrina), and “truly astounding in its size and power,” as hurricane Hunter and meteorologist Dr. Jeff Masters has explained. It had a “larger area of tropical storm-force winds” than any hurricane on record, and “At landfall, Sandy’s tropical storm-force winds spanned 943 miles of the the U.S. coast”: At its peak size, twenty hours before landfall, Sandy had tropical storm-force winds that covered an area nearly one-fifth the area of the contiguous United States…. Sandy’s area of ocean with twelve-foot seas peaked at 1.4 million square miles — nearly one-half the area of the contiguous United States, or 1% of Earth’s total ocean area. Most incredibly, ten hours before landfall, the total energy of Sandy’s winds of tropical storm-force [was] the highest value for any Atlantic hurricane since at least 1969. This is 2.7 times higher than Katrina’s peak energy, and is equivalent to five Hiroshima-sized atomic bombs.