On Wednesday, a destructive, dangerous and historic December day is ahead, with all possible weather hazards including strong, long-trajectory tornadoes, high winds and explosive forest fires.
About 100 million people were under some sort of weather alert stretching from the west coast to the Great Lakes.
As of Wednesday morning, 9 million people were exposed to severe storms in parts of the Central Plains and the Upper Midwest. The main risks were to be destructive winds above 75 mph, followed by the threat of long track tornadoes and heavy tornadoes.
Two factors increase the level of danger: storms after dark and the speed of storms.
For cities like Kansas City, Missouri; Des Moines, Iowa; and Minneapolis, the storms were expected to arrive after sunset. Night tornadoes are more than twice as likely to cause deaths.
On top of that, the storms are expected to move at a speed of 80 mph. This means that those on the path should prepare now as the storms will approach quickly.
Wednesday’s storm and tornado threat was the highest winter risk in 20 years and simply unheard of in mid-December. In fact, Minnesota did not experience any confirmed tornadoes during the month of December dating back to 1950.
The national meteorological service has never issued a tornado watch or warning during the month of December.
There are 4 to 8 inches of snow on the ground beneath much of Wednesday’s tornado threat. The rare overlap in tornado risk over deep snow cover leaves meteorologists wondering how snow cover could limit or increase tornado potential.
This rare tornado threat in December follows the historic tornado outbreak that struck Friday.
While the risk of severe thunderstorms and tornadoes could be the most lethal and deadly, the risk of damaging winds will be the most prevalent.
About 89 million people were under wind alert Wednesday stretching from eastern Arizona to upstate New York. This should be a rare wind event for both the ferocity of the expected winds and the widespread nature of the event.
Until Wednesday evening, winds could be gusting 60 to 80 mph for areas under wind warnings. Widespread power outages are expected.
Denver and surrounding areas are expected to generate gusts of up to 100 mph.
The strong winds will act as the match for the wildfire risk on Wednesday where 10 million people are under red flag warnings across the central plains. Record high temperatures in the 1970s and 1980s combined with low humidity will create the right conditions for forest fires.
The extremely critical wildfire risk in place for parts of Texas, Oklahoma and Kansas is the highest wildfire risk issued during the month of December since 1999.
Highs 20 to 40 degrees above average on Wednesday will bring more than 40 record highs across the Plains and Upper Midwest. All-time records could be jeopardized for places like Kansas City and Des Moines. Other places that could set records on Wednesday include Austin, Texas; Wichita, Kansas; Little Rock, Arkansas; Minneapolis; Chicago; Madison, Wisconsin; and Milwaukee.
On Thursday, another 30 records will be possible further east in parts of the Great Lakes and the northeast, including places like Boston; Buffalo, New York; Syracuse, New York; New York City; and Providence, Rhode Island.