The Heat Will Finally Break
by Cody Matz
July 24, 2012 8:09 PM
After what has felt like forever, temperatures will finally begin to cool Wednesday. Now, it’s not going to be an instantaneous fix, but over the course of a couple days, humidity levels will drop and so will the temperatures. In fact, some areas could be below average by Friday. But it has been an exhausting few weeks with temperatures climbing to the triple digits upwards of a dozen times in some areas. Not to mention, high temperatures have been at or above average for over a month in spots. Now the time has finally come for our pattern to shift a little bit allowing cooler weather into the region.
But its been incredibly hot. The images below are the average temperatures so far for the month of July for select locations. It also shows how many degrees above or below average at that location.
You can see for yourself that temperatures have been extremely warm. The average temperature is 5 to 10 degrees above normal. For places like Mitchell, Sioux Falls, and Worthington, this could be one of the warmest July’s on record. Keep in mind though that there is another week or so of the month left, and with temperatures falling a bit, these numbers will fall too. But I would expect most areas to be between 4 and 8 degrees above average by the time July has concluded.
In most cases, when you talk about the heat of this season, its not that its hot. I mean lets face reality it gets hot every summer. But what really makes it so unbearable is how long it has been hot. The streak for above average high temperatures continues to grow now surpassing 30 days in a couple of cities. And even though the temperatures are falling through the end of the week, some of these streaks may continue right into August.
Accompanying the warm temperatures has been the lack of rainfall. Everyone is experiencing dry or extremely dry conditions, as precipitation has been less then a quarter of normal in most areas. In fact, it’s been so dry that Sioux Falls could have the driest summer ever recorded.
As of Tuesday evening, Sioux Falls has seen just three quarters of an inch of rain from June 1st, barely 10 percent of the average rainfall for that time frame. It’s so bad that the city has to receive nearly 3 additional inches of rain by September 1st just to surpass the old record for the summer.
The good news is the heat must come to an end at some point, and it looks like relief is in sight. 2 cold fronts will be pushing through the Upper Midwest through Thursday which will result in a 10-25 degree drop in temperatures and a significant drop in humidity. For this to fully sink in, let me show you our cool down how meteorologists see it. The first image below are the 850mb temperatures (the temperatures at about 5000 feet) seen across the area Tuesday afternoon. Plenty of reds and pinks on that map indicating lots of very warm air.
The second image is the forecasted 850mb temperatures for Friday afternoon.
A pretty big difference right? These forecasting models are showing a nearly 30 degree drop in temperatures 5000 feet above the surface which translates into a significant drop in temperatures for us at the surface as well.
All I can say is enjoy the cool down while it lasts because if history has told us anything, the heat will likely return before too long.