Hang on tight or get smacked. Temperatures are about to rush to levels last seen in mid-July and then crash down to the kind of chill in the pipeline come October, all in the course of a few days.

A few spots locally could witness a 50-degree swing in temperatures.

Here’s Wednesday’s high temperature forecast, courtesy the high resolution NAM model:

High temperature forecast Wednesday from high resolution NAM model (WeatherBell.com)

The brown hues suggest the mercury will reach 93-96 in the D.C. metro region, probably falling just short of the summer’s hottest reading of 97 (from July 17) and the record high for the date of 98 (from 1983). But it will still be plenty hot. Factoring in the humidity, it will feel like 100 in the afternoon.

After another day near or crossing the 90-degree threshold Thursday, the bottom begins to fall out. Friday’s highs fail to reach 80. Then, on Friday night, temperatures really tank.

Look at the low temperatures forecast Saturday morning by the GFS model:

Saturday morning’s low temperatures as simulated by the GFS model (WeatherBell.com)

Yes, those are 40s across the D.C. area. And, if you look west, there are 20s in the mountains of West Virginia and 30s in western Maryland. Amazing.

Here are the high temperatures forecast by the GFS model Saturday afternoon:

Saturday afternoon high temperatures as simulated by the GFS model (WeatherBell.com)

Much of the region is stuck in the 60s Saturday if this simulation is correct. That’s more typical of late October. The model might be a little too aggressive with the chill, but I doubt we get much higher than the low 70s.

Andrew Freedman, former CWG contributor who now writes for Climate Central, came up with a term for this kind of wild thermal ride: “weather whiplash”.

“[W]eather whiplash” is an ailment that strikes during/after an unusually rapid transition from one season to the next, such as when a workweek starts out with temperatures in the low 40s Fahrenheit and winds up in the 80s to near 90, thereby transitioning from winter to summer in a few short days, and vice versa. Cases of weather whiplash usually involve skipping an in-between season, like spring or fall, and transitioning immediately to either summer or winter.

Weather whiplash may cause a general sense of unease, and an overpowering urge to talk about the weather with total strangers in line at the ATM. Rare but more serious complications include forgetting one’s inhibitions, which can lead to major mistakes such as riding a bike shirtless despite the beer belly gained during the winter, and forgetting about work, school and family responsibilities in favor of enjoying the new season that has suddenly appeared.

The incoming jolt of weather whiplash is sure to invigorate fans of fall. But for those who enjoy outdoor dining as opposed to curling up next to an indoor fire, it’s a painful blow.