Cold air intrusion before spring equinox with temperatures 15 to 25 degrees below average
March 17, 2023
15-25 degrees below avg
Cold air intrusion before spring equinox
A large bubble of wintry cold air is settling over the U.S. for astronomical winter’s final weekend. Many will need to hold off on the gardening before the cold air moves away.
A strong upper-level low-pressure trough is dumping cold air into much of the U.S. over the next couple of days. High temperatures will be 15 to 25 degrees below normal for this time of year, keeping many indoors and snuggled up before the spring equinox.
Bismarck, N.D., for example, is only making it to eight degrees today. Eight! The usual March high temperatures are in the mid-to-upper 30s for southern North Dakota, making today very abnormal for residents. Saturday will be slightly warmer here, but only in the mid-teens. Big coats and layers will still be needed.
The north isn’t the only spot where temperatures are much below average this weekend. Saturday high temperatures in San Antonio, Texas, will only be in the upper 30s. Average highs this time of year are usually in the mid-70s!
This cold air is coming from northern Canada. At the upper levels of the atmosphere, a low-pressure trough allows for the cold air to spill into the U.S. Since the air mass is cold and dense, high-pressure forms at the surface. While this means many will get more quiet weather, it also means it will be quite cool.
Not to be outdone, the intrusion of this late-to-the-party cold air mass will also allow winds to kick up. Winds across much of the northern Plains and Upper Midwest will be gusting into the 40 mph range today, with the Ohio Valley, Mid-Atlantic, and Northeast being added to the windy mix by Saturday and Sunday.
Ushering this cold weather bubble is a strong border to border storm system bringing heavy rainfall, snow, and severe weather east of the Mississippi today. As this storm system shifts out on Saturday, the cold air will replace it, putting residents back in their big coats.
But since it is St. Patrick’s day, let’s focus on the more ‘lucky’ weather. Just in time for the spring equinox on Monday, temperatures will slowly begin returning to the more mild, spring style. It will be a slow return to warmer weather but keep an eye on your local forecast to see the temperatures slowly rise.