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Central U.S. braces for dangerous blast of winds amid record warmth

Winds could gust over 60 mph from New Mexico to the Great Lakes while temperatures rise 30 to 40 degrees above normal

Wind gust forecast from the National Weather Service, as of midday Tuesday. (weatherbell.com)

For a second week in a row, large parts of the central United States are staring down record high temperatures, followed by a blast of extremely turbulent weather. This time, rather than a tornado outbreak, a widespread zone will see roaring winds up to 80 mph.

The “large-scale high wind event,” according to the National Weather Service, “may cause damage from the central Rockies into the Plains and Mississippi Valley on Wednesday.”

While the strong winds may be short-lived, the zone from New Mexico to the Great Lakes could see pockets of damage and scattered to widespread power outages. Both Denver and Des Moines are among cities where winds may gust over 60 mph Wednesday. In the Southern and Central Plains, dry, windy conditions present a top-tier fire threat.

While an outbreak of twisters is not expected, severe thunderstorms with damaging winds and isolated tornado activity cannot be ruled out in parts of the Midwest on Wednesday, particularly in Iowa and southern Minnesota.

Ahead of the storminess, some areas will see temperatures swell 30 to as much as 40 degrees above normal. But the cold front ushering in the powerful winds means the exceptional warmth will be relatively short-lived.

The record-breaking tornadoes that swept the United States, by the numbers

Scores of record high temperatures ahead of the wind storm

Unusually mild weather is already surging into the Southern Plains, where a number of record highs may fall Tuesday; this is the calm before the storm.

The warmth will peak in the central United States on Wednesday, from Texas to Wisconsin, when dozens of record highs are threatened. Record-high temperatures near 80 are forecast for Denver, with the mid-70s around Oklahoma City and 60s to near 70 into the Upper Midwest. Chicago is forecast to hit 65, topping its previous record of 64, while Des Moines could reach 70, obliterating its previous record of 59.

High temperatures of 20 degrees or more above normal are set to cover much of Nebraska, Oklahoma, Kansas, Iowa, Missouri, Illinois, Wisconsin and portions of surrounding areas. In Iowa, at the core of the warmth, temperatures may be 35 or even 40 degrees above normal.

On Thursday, the warmth is pushed east along the advancing cold front. Records are likely to fall in parts of the Mid-Atlantic and Northeast, with highs into the 60s, as well as portions of the Gulf Coast region, with highs in the 70s and 80s.

This is the third record-setting pulse of warmth this December in the Lower 48 states. Through the second week of the month — using a more expansive list of observation sites — preliminary numbers indicate at least 3,069 record highs have occurred, compared with just 14 record lows. Human-induced climate change is increasing the likelihood of such warm weather.

The wind storm and fire threat

As the storm system, which is bringing tremendous amounts of snow and rain to the West, ejects from the Rockies into the Plains on Wednesday, it will drag a cold front along with it, clashing with the record-setting warmth. This will incite a wind storm.

Alex Lamers, a forecaster at the National Weather Service, tweeted that computer model forecasts are “absolutely screaming rare high wind event” into Thursday. High wind warnings stretch from Southern California to Wisconsin, with the strongest winds expected Wednesday from eastern Colorado to Iowa.

These wind warnings could certainly be extended northeast Wednesday night, as well. Gusts of 50 to 60 mph may continue into the Great Lakes and, ultimately, Canada.

High winds combined with extremely dry conditions will create a top-tier fire threat in the Southern and Central Plains, with the Weather Service anticipating “a volatile fire weather day” Wednesday.

The Weather Service has declared “extremely critical” fire weather in the Texas and Oklahoma panhandles and over large portions of western Kansas. Sustained winds may approach 45 mph in these areas, with gusts near and past 70 mph possible.

The Weather Service office in Amarillo, Tex., wrote that “wind gusts may approach historic levels for the month of December,” even noting the possibility of 80 mph gusts.

To the west, in the mountains of Colorado, wind gusts of 100 mph or higher are possible; Boulder could see gusts over 75 mph, with some models showing 100 mph gusts possible.

In addition to the fire and wind damage risk from high winds, areas of blowing dust may reduce visibilities to near zero, creating hazardous driving conditions.

In the Southern and Central Plains, the windiest conditions are expected late Wednesday morning and afternoon, with gusty conditions shifting northeast after that time.

Although the storm system triggering this wind storm is quite powerful, its fast movement and inability to tap into much moisture from the Gulf Mexico may limit its ability to trigger widespread severe thunderstorms and tornadoes. However, the Weather Service’s Storm Prediction Center predicts some risk of severe storms from southern Minnesota, through Iowa and into western Missouri, northeast Oklahoma and northwest Arkansas.

“Damaging wind gusts and a couple of tornadoes will be possible,” the Storm Prediction Center wrote.

A volatile weather pattern keeps repeating but could soon break down

The pattern over the country this week is not too unlike the last, when temperatures rose to record levels in the eastern half of the Lower 48 before a storm blasted across the country. This kind of pattern is often a hallmark of La Niña winters.

There are, however, some hints that the pattern will break down some later this month, perhaps drawing more widespread chilly air into the Lower 48 states. The recurrent heat dome over the Southeast, responsible for the pulses of warmth, should get squashed south for a time, opening the door for some chillier episodes over the northern tier and Northeast.

Although colder air may eventually pour into the Lower 48 states, the very volatile pattern seen in recent weeks could return at times this winter, as is typical during La Niña.

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