Heat wave has potential to be season’s worst

On Sunday, NOAA projects peak heat indices exceeding 100 degrees from southern Louisiana to the Canadian border, with a large area of 105-115 values in the upper Midwest. (NOAA)

Private sector forecasters, the media and the government are united in the forecasts for dangerous heat and are spreading the word.

On Facebook this morning, the National Weather Service wrote:

The stage is being set for a massive heat wave to develop into next week as a large area of high pressure is anticipated to circulate hot and humid air over much of the central and eastern U.S. Maximum heat index values of at least 100°F are likely across much of this area by the middle of next week, with heat index values in excess of 110°F possible over portions of these areas.

Minneapolis Star Tribune meteorologist Paul Douglas blogged:

The projected Heat Index on Sunday is forecast to be in the 105-115 range from central and southern Minnesota southward to the Gulf coast. The risk of heat exhaustion and heat stroke will be significant across the central third of the USA, especially Sunday/Monday of next week.

By Tuesday, NOAA projects peak heat indices exceeding 100 degrees spreading to the Southeast and mid-Atlantic with the upper Midwest still scorching with 105-115 values.

Instead of a break from the heat, it now looks like it will get considerably worse with the high temperatures spreading from the Rockies to the East Coast and into Canada. The NOAA GFS model is indicating temps. over 40°C (104°F) in Manitoba early next week. The very high humidity( from wet ground) in the Southeast will mean heat indexes near 115 or higher again.

Chicago broadcast Meteorologist Tom Skilling wrote:

The summer’s most prolonged period of heat looms over the coming weekend and next week

And AccuWeather’s Joe Lundberg cautioned:

I’m saying that it may well get lethal on the Plains and in the Midwest this weekend into next week. We’re talking temperatures near or even above 100, especially in places like St. Louis, Kansas City, Omaha, Rapid City, and Des Moines. It may get close in Minneapolis and Chicago for a day or two. And eventually later in the week, like Friday and Saturday, we can probably toss in Washington, D.C., Richmond, Philadelphia, and New York, maybe even Boston.

Maximum heat index values forecast by NOAA’s Hydrometeorological Prediction Center Sunday through Wednesday:

Oklahoma City102106105102
Kansas City107107108106
Des Moines109111107106
Washington, D.C.8896101103
New York87929696

Here’s the bottom line:

* Computer models are consistent in forecasting the development of a huge heat ridge over the Midwest this weekend

* That heat ridge is forecast to gradually spread east early next week reaching the Southeast and mid-Atlantic - but the core of the heat should remain over the Midwest through mid-week

By Thursday, the GFS model projects 5 p.m. air temperatures will be over 95 (pink shade) over a huge area of the central and eastern U.S.

* This heat wave has the potential to be long duration in northern Midwest cities like Chicago and Minneapolis, presenting a serious risk for heat-related illness and even fatalities.

Watch the video below (second half, starting around 5:30) where I discuss the upcoming heat wave.