There was something not quite right about the severe weather outbreak that tore across the Midwest late Tuesday and into Wednesday.
At least 24 tornado reports were recorded with more than 162 high wind reports and more than 200 hail reports, and while this wouldn’t be a strange occurrence for a weather pattern in March or April, it happened at the end of February.
This is not normal.
On a typical last night of February in Chicago, snow would be in the air, or at least on the ground. But not this year. In a city where for the first time in 146 years of record-keeping there was no snow on the ground at all in January or February, the skies lit up with streaks of lightning on Tuesday night.
The tornadoes have killed at least three, with the town of Perryville, Missouri particularly hard hit. More severe weather is taking shape on Wednesday, with the Mid-Atlantic states in the crosshairs for severe thunderstorms with damaging winds and heavy rain.
The storms developed in a juicy airmass with unusually warm temperatures, high amounts of moisture and winds that helped prompt supercell storms that have rotating updrafts.
The severe thunderstorms have been striking during a period of record-shattering warmth that has spread across the U.S. east of the Rockies, with the earliest-ever start of spring observed in some areas.
Many cities in the U.S. had their warmest February on record. During that month, thousands of warm temperature records were set or tied, compared to just a few hundred cold temperature records. The ratio of daily record highs to daily record lows for the month is nearly 54 to 1, while monthly record highs outnumbered monthly record lows by an even more staggering ratio of 408 to 1.
In Washington, D.C., which was hit with severe storms on Wednesday after seeing the thermometer shoot up to a record 80 degrees, the National Park Service is expecting what could be the earliest cherry blossom peak bloom on record, sometime between March 14 to 17.
How rare is a Midwest tornado outbreak in late February?
The severe weather outbreak on Tuesday and Wednesday, during which time at least 24 tornado reports were recorded along with 243 high wind reports, was unusual for striking so far north so early in the year. (The actual number of tornadoes that touched down is yet to be determined.)
The heaviest storm damage occurred in the vicinity of Perryville Missouri, which is about 65 miles south of St. Louis. Tornadoes also caused damage in several locations in Illinois.
The storms seem to be yet another sign of this wacky winter, which has brought only glancing blows of cold air and heavy snow to the northern tier of the U.S., interspersed with periods of record high temperatures.
In fact, the severe weather put an exclamation point at the end of what meteorologists consider to be the three winter months, which are December, January and February.
Severe weather is not common so far north at this time of year, but it is not rare, either, tornado experts said. Harold Brooks, a senior research scientist at the National Severe Storms Laboratory, said the most recent example of a similar storm outbreak occurred from Feb. 28 through March 2, 2012.
In an email, Brooks cited two significant tornadoes that occurred during that outbreak, one in Harrisburg, Illinois, and the other in Henryville, Indiana.
Patrick Marsh, a meteorologist at the Storm Prediction Center in Norman, Oklahoma, cited several tornado outbreaks that occurred this far to the north during early to mid-March, including in Missouri and Illinois.
He said there is some evidence of increasing variability of tornadoes when it comes to getting off to an early or a late start on tornado season, which typically occurs during spring, but it’s difficult to tie this to a cause such as global warming since tornadoes are so rare to begin with.
As human-caused global warming continues, there may be a shift in the seasonality and geographic scope of tornado-prone areas, but this has not become clear in tornado data or climate model projections yet. Part of the problem facing scientists trying to detect such changes is that tornadoes are rare phenomena, making pulling out statistical trends from the background noise quite difficult.
At the end of the day, the severe weather outbreak, which is coming on the heels of record warm weather, is another example of weather being weird. But it’s not necessarily a sign of climate change. At least not yet.
One factor that some meteorologists are monitoring closely for clues about the upcoming peak of the tornado season is the presence of unusually warm ocean temperatures in the Gulf of Mexico and western Atlantic Ocean, which could feed more moisture into storm systems and cause bigger tornado outbreaks in the coming weeks.