It’s been an eventful week on the weather front, so let’s highlight a few points.
What started out as a very quiet first quarter of the year as regards the number of tornadoes has become much more active since mid-April. There have been several widespread, damaging and deadly outbreaks, especially over the last ten days or so.
In addition, the storms over the past weekend (May 9 and 10) included extremely high rainfall rates in some areas which led to flash flooding and necessitated swift water rescues. Some of the rescues were broadcast live by television stations in Dallas and retransmitted to the entire country via The Weather Channel.
And if that wasn’t enough, a late season snowstorm on the same weekend buried parts of the Rocky Mountains into the Dakotas. The heavy, wet snow damaged buildings and had to be shoveled out of Coors Field before the Colorado Rockies could host their Sunday afternoon game against the Los Angeles Dodgers.
And to top it all off, Tropical Storm Ana, brought gusty winds and copious amounts of rain to the Southeast.
The Climate Prediction Center recently issued its 90-day outlook for temperature and precipitation for the U.S. It also updated the drought monitor tool.
In general the outlook calls for the next three months to feature above normal temperatures in the western third of the country and in the far southeastern states. Alaska and the Pacific Northwest will also be warmer than usual. Below normal temperatures are confined to much of Texas and areas of adjoining states. Most of the country will see an equal chance for above or below normal temperatures.
Much of the nation may experience above normal precipitation from the southeast through the gulf states to the western plains and Rockies along with a good portion of Alaska. The above normal rainfall may bring drought relief to Texas and the four corners area. The Great Lakes states will see below normal precipitation and the potential of a developing drought. Lake levels and fire danger may be impacted.
The drought monitor shows little change in the near term for the hardest hit areas of the west, parts of Texas, and parts of the Dakotas, Minnesota and Wisconsin. Over the 90 day period of the outlook, the drought may ease in Texas and areas northwest of there. However, drought conditions may expand in the Great Lakes. Unfortunately, little or no relief is seen for California. Just this week water use restrictions of from 8% to 36% were enacted for some municipalities.
On this Tax Day edition of Weather Wednesday, we’ll revisit last week’s tornado outbreak in Illinois. Statewide, 11 tornadoes have been confirmed in the April 9th event. The earliest, which caused very little damage, was reported just northwest of Peoria in the afternoon hours. By early evening, strong thunderstorms were crossing far northern Illinois and eventually spawned the first EF-4 tornadoes ever reported in DeKalb and Ogle Counties (records kept since 1950) and the strongest tornado in the National Weather Service Chicago Office County Warning Area since an EF-5 devastated Plainfield, in the southwest suburbs, in 1990.
Two people were killed in the unincorporated town of Fairdale where nearly every structure, more than 70 in all counting outbuildings, was either damaged or destroyed. 22 injuries were reported in the outbreak. The tornadoes eventually approached the far western suburbs of Chicago but missed three population centers near their path. Damage was widely scattered in a multi-county area.
This outbreak was well forecast and there is general agreement there was plenty of warning. The Storm Prediction Center (SPC), as it did with the EF-3 and 4 tornadoes in Illinois on November 17, 2013, mentioned possibly tornadic storms at least four days in advance.
The National Weather Service Chicago Office updated their summary of the tornadoes just this morning. This is one of the most complete such documents I’ve ever read and includes some of the few satellite images of a tornado’s path I’ve ever seen. Read it all the way to the bottom and you’ll see the SPC guidance in the week leading up to the storms.
A couple of these tornadoes were extremely well documented via video (note: Strong language toward end) and live streaming and some of the visuals of the rotating wall clouds were just about textbook. The low sun angle contributed how well the tornadoes were captured.
There was also a significant side issue involving a motorist by the name of Sam Smith who was shooting video. That footage was widely shown on television and the driver was taken to task for getting too close to the storm, even if accidentally. (There are now licensing issues with the video so we won’t link to it here. However, it is widely available on You Tube.)
There were a couple of takeaways from his experience which are good reminders to all of us who may encounter storms. First, if a funnel cloud or tornado does not appear to be moving, it is either headed straight for the observer or dead away from the observer. To be safe, get out of that area immediately by driving at right angles to the storm. Second, this motorist backed up to take shelter in his vehicle under a bridge. Although many people have done that and survived, experts say that is a bad idea because wind speed may actually be amplified as it is compressed into that confined space. There have been fatalities of people under overpasses.