Hail and water were the most destructive forces at work in U.S. severe weather during April 2016. According to the April 2016 Catastrophe Report
from insurance broker Aon Benfield, two billion-dollar weather disasters hit the U.S. in April: a severe weather outbreak from the Plains to the Southeast on April 10 - 13 that cost at least $2.75 billion and killed one person, and a severe weather outbreak from April 15 - 19 in the Rockies and Plains that cost $1 billion and killed nine. (Note that Aon Benfield includes flash flood damage in its “severe weather” category.) The highly publicized severe weather of April 27 in the Southern Plains failed to make the billion-dollar threshold, although it did generate hundreds of millions in damage.
Heavy rains caused extensive flash flooding across parts of Texas on April 18, killing eight and leading to more than 1,800 water rescues in the greater Houston metropolitan area. The same storm also brought heavy snow and severe thunderstorms from April 15 - 19 to parts of the Rockies and Plains, killing one person. Damage was estimated at $1.0 billion. In this image, we see residents of an apartment complex in the Greenspoint area of north Houston use an air mattress to evacuate their flooded homes on Monday, April 18, 2016. Image credit: AP Photo/David J. Phillip.
Severe thunderstorms caused catastrophic hail damage across parts of the Plains and Southeast from April 10 - 13, killing at least one person and injuring dozens more. The Dallas-Fort Worth and San Antonio metro regions in Texas were the hardest hit, with softball and baseball-sized hail. Damage was estimated at $2.75 billion. In this photo, we see an impressive shelf cloud from a thunderstorm over Royce City, Texas, on April 11, 2016. Image credit: wunderphotographer Gweduc
These events brought the tally of billion-dollar severe weather disasters so far in the U.S. to six. This ties 2016 with 2013 for the third-most billion-dollar severe weather disasters in one year. The record is nine billion-dollar severe weather disasters in 2011, with 2012 in second place with seven, according to NOAA/NCEI.
There was also a $2 billion dollar winter storm in the Eastern U.S. in January, bringing the total number of U.S. billion dollar weather disasters so far in 2016 to seven:
1) Winter Weather, Eastern U.S., 1/21 - 1/24, $2.0 billion, 58 killed
2) Severe Weather, Plains-Southeast U.S., 4/10 - 4/13, $2.75 billion, 1 killed
3) Severe Weather, Rockies-Plains-Southeast-Midwest U.S., 3/22 - 3/25, $1.75 billion, 0 killed
4) Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 3/4 - 3/12, $1.25 billion, 6 killed
5) Severe Weather, Plains-Midwest-Southeast-Northeast U.S., 2/22 - 2/25, $1.2 billion, 10 killed
6) Severe Weather, Plains-Rockies U.S., 4/15 - 4/19, $1 billion, 9 killed
7) Severe Weather, U.S., 3/17 - 3/18, $1.0 billion, 0 killedTornado impacts on the low side this spring
Thus far in 2016, the most destructive and deadly tornadic activity occurred in February with a swarm of early-season twisters, straight-line winds, and large hail across the eastern United States on February 23-24
. The damage toll from the month’s severe weather was expected to top $1 billion, according to Aon Benfield in its February 2016 Catastrophe Report
. Seven tornado-related deaths were recorded by NOAA’s Storm Prediction Center (SPC) on the February 23-24 outbreak. Otherwise, there have been only two killer tornadoes thus far in 2016: an EF2 twister in Manatee County, FL, that took two lives on January 17, and a weak EF0 tornado that killed one person in Houston, TX, during the April 27 outbreak. Seven of this year’s ten deaths have been in manufactured homes.
Through May 8, SPC has tallied a total of 394 preliminary tornado reports. Once this number is “inflation-adjusted” for comparison with earlier decades, when fewer people were looking for tornadoes and reporting them, 2016’s tornado total for the year thus far is lower than about 3 out of 4 years since 1950--although it only takes a single multi-day outbreak to change those numbers significantly. Figure 3
. Killer tornadoes for 2016 thus far. The yellow icon denotes EF1 strength; green, EF2, and blue, EF3. Not shown is the EF0 tornado that produced one fatality in Harris County, TX, on April 27. Image credit: NOAA/SPC
. Figure 4
. WU depiction of NOAA/SPC’s convective outlook, showing the severe-weather risk areas as of mid-morning Monday for Monday
, May 9 and 10, 2016. This weekend’s severe weather and the outlook going forward
An upper-level storm sweeping from the western U.S into the Plains over the past weekend brought plenty of dynamics to trigger severe thunderstorms. However, moisture return from the Gulf of Mexico was relatively slow and anemic, which kept the severe weather relatively limited. Several highly visible twisters occurred in association with two supercell storms over the high plains of far northeast Colorado on Saturday
, with five injuries reported. The strongest tornado, with a preliminary rating of EF2
, damaged several homes and businesses along its eight-mile path north of the town of Wray. About a dozen tornadoes struck on Sunday
along a dry line stretching from Nebraska to Oklahoma, with no major damage reported. Figure 5.
The spectacular EF2 tornado that struck just north of Wray, Colorado, on Saturday, May 7, 2016. Image credit: Bob Smith/Tempest Tours, used with permission.
More severe weather is possible as the upper-level storm system lumbers eastward Monday and Tuesday. SPC has placed a large swath from southern Iowa to northeast Texas under a slight risk (Figure 4), with an enhanced-risk area including Little Rock, AR, and Texarkana, TX. Remnant clouds and storms from Sunday night will complicate Monday’s setup, but upper-level cold air will favor very large hail over eastern OK and northeast TX. Late Tuesday, a mesoscale convective system of MCS (a large cluster of strong thunderstorms, often extending through the night) may develop near the mid-Mississippi Valley and race eastward through the Ohio Valley, with a repeat possible in the same general area on Wednesday evening. MCSs can produce damaging straight-line winds and large hail. Northwest upper-level flow should predominate later in the week, quashing the odds of any widespread severe weather until next week at the earliest.
WU contributor Lee Grenci has an interesting new post
discussing the extremely dry air that fed the catastrophic spread of the Fort McMurray wildfire on Wednesday, May 4.
Bob Henson and Jeff Masters