Changes in September
August is finishing up on a hot note in many areas. The heat is likely going to continue into the first week of September before cooler temperatures arrive and the start to the end of summer will commence.
The first shot of cooler air will move into the Midwest, Corn Belt and east after September 7th. This will bring relief to the areas who have experienced some very hot weather over the past week to ten days. There should also be some welcome rain to the above mentioned areas as temperatures cool some. The period of September 7th through September 17th will be much cooler for the nation east of the Rockies. West of the Rockies expect summer to hold on for a bit longer.
One of the big question marks for September is whether or not we will have an early season frost/freeze, especially in the upper Midwest and Corn Belt where crops will need as many warm days as possible to reach full development. The first wave of cooler temperatures between September 7th through September 17th will likely not be cold enough to cause any early season frost/freeze conditions.
However, for the last ten days of September we will likely see the first real push of significantly cooler air into the USA of season. This shot of colder air will likely impact the Rockies and northern plains first then will spread south and east into the plains, Midwest and Corn Belt by the last week or so of September. This time frame will be one to watch carefully for the threat of colder temperatures that may send temperatures downward to frost levels in some areas of the northern plains and Rockies.
When it comes to expected precipitation, odds are good that precipitation amounts in many areas will be close to normal with perhaps some areas of the Rockies and Desert Southwest having above normal precipitation in September.
Another big question mark is tropical activity. As well all know it has been a very quiet hurricane season, that should change in September and into early October as there will likely be a brief, but busy period of tropical activity for the Gulf Coast and east coast in September.