The heat is building into Hampton Roads today. The heat wave is on for a large section of the country. Highs will be in the 90s and 100s for more than half of the United States:
So today we start what I’d call hot temperatures. Highs will be in the low/mid 90s. The average highs area in the mid 80s. The good news is that it is still pretty dry outside. Dewpoints in the entire region are in the 50s. That is pretty comfortable:
That factor can make a big difference. The heat index will either be near or even below the high temperatures for the day. That’s right! The heat index can be below the air temperature. In fact that’s what happens a lot out West. Basically it means that the air is so dry that a very small amount of evaporation will cool you off greatly, and make you feel cooler than it actually is. There will be a lot of sunshine though, and so sitting in the sun for a while will counteract that cooling. We’ll have a light southwest breeze at 5-10mph.
Tomorrow the heat will build in stronger from the west. Highs will rise to the upper 90s with a few 100s around. The heat index will be up to 105. I put our high up to 100 on Saturday, and I think we’ll be in the upper 90s on Sunday. I do think a few storms will try to sneak in from the north Sunday as well. That leads to a bit of a nerdy subject concerning the heat. Typically you get a heat wave like this when there is a strong upper level ridge (A hill like shape in the jetstream). That will help to create a lot of sinking air and strong high pressure. However, in this case the ridge will be more flat, and the center of the high will be more towards Alabama. So most of our heating will come from the hot air blowing in from the west (warm air advection). Plus, there will also be some downloping winds off of the mountains which will aid in heating. This weather pattern also means that a few storms may try to sneak in on a couple of days. Especially on Sunday. There will be some cooling in the Ohio Valley where some of the stronger storms will form. A few of those may try to push southeast. This will have to be monitored over the weekend into Monday. Overall, the forecast is dry, but stay tuned for updates. The 90s are expected to last through the middle of next week.
There are several stories that are tied to the heat in the U.S. The first one by far is the wildfires out west. They are creating a really bad fire season especially in Colorado this Summer. Also, we may be looking at some major crop losses across the U.S. heartland. There are conditions that are similar to the drought of 1988. This will have a huge impact on corn and food prices. The drought is tough in many parts of the country. Moderate drought is affecting at least part of 40 U.S. states.
The once-tropical system “Debby” brought some drought relief to Florida and southern Georgia, but it is now well out to sea. It is now just a disorganized area of low pressure that is riding east along an old frontal boundary.
Meteorologist: Jeremy Wheeler