It's been hot this summer, but not this hot. We are bracing for highs in the low to mid 90s into the weekend. The heat plus oppressive humidity will be a dangerous combination as the heat index surges into the triple digits.
A big heat dome will stretch from the Great Plains to the Mid-Atlantic, and the Commonwealth will be stuck right in the middle. An upper-level high is situated across the Southwest. Sinking air is associated with an upper-level ridge. As the air continues to sink it warms in the process and generates hotter conditions at the surface. Areas directly under the highs should expect the worst of the heat. This week it will be the Plains and parts of the Midwest where highs are expected to climb into the triple digits, without the added humidity factored in.
In anticipation of this intense heat and humidity, excessive heat warnings and heat advisories have been posted. The Bluegrass and areas to the west will be under an excessive heat warning until Sunday evening. The remainder of the LEX 18 viewing will be under a heat advisory.
The difference between a heat advisory and an excessive heat warning comes down it how hot it will feel and for how long. The criteria for each of these heat alerts varies from region-to-region across the country. For Lexington, a heat advisory will be issued if the maximum heat index will be 105° or higher for at least two hours. An excessive heat warning will be posted if the heat index climbs above 110° AND the minimum heat index remains around 75° over a 48-hour period.
As a reminder take it easy in this heat. Be sure to stay hydrated by drinking plenty of water. Avoid caffeine and alcohol. If you're working or playing outside, spend some time in the shade, even better take a break in the AC. The heat can put more stress on the young, the elder, and your pets. Be sure to check on them and make sure they are keeping cool.