We're starting the day with sunny, clear skies across the Tennessee Valley... except for haze related to Saharan dust that has overspread the area the past few days. Nothing to block the daytime heating though, and as of the 9:00 AM hour, we are already zooming into the mid 80s with heat index values already into the low to mid 90s. The Heat Advisory continues through 7PM this evening for afternoon heat index values near or over 105 degrees for most communities again, and this may be extended into tomorrow as well.
We expect skies to be mostly sunny to partly cloudy through the day, aside from the dust and haze, with afternoon highs once again climbing into the mid and upper 90s. We had earlier added the chance of an isolated shower or storm into the forecast for late this afternoon and the evening hours, but not only does that look to stay much more isolated, but it also looks to stay to the south and east of our viewing area today. As we head into the overnight, temperatures only drop back toward the mid 70s, and then we get ready to do this all over again for Thursday as well.
Storms look to remain isolated on Thursday as well, but we will hold in a 20% chance in case there is a pop-up or two across the area. Rain and storm chances may increase Friday afternoon into Friday night as a weak cold front moves into the area. For now, because of model disagreement and rain chances so far this week underperforming versus model output 24-48+ hrs prior, we are going to hold rain chances no higher than 30%, but we may be revising that upward as more data comes in. That weak frontal boundary doesn't really cool temperatures off much at all, but it does bring in drier air for the weekend, and that drier air will make the lower 90 temperatures much more bearable. That also shifts the upper-level ridge a little west of the area for the weekend, but it parks right back on top of us for next week, and there are indications next week could be even hotter than anything we've seen so far this week. We're still ironing out the details, but don't be shocked if we have afternoon high temps (not heat index values) in the lower triple digits by the middle of next week!