Heat Advisory Vs. Excessive Heat Warning?

Question

I live in Interior Southeast Va. and Heat Index Values have been over 110F for the past 4 days and it will continue for the next 2 days, why has the NWS decided to go with an heat advisory rather than an excessive heat warning? Heat Advisory Criteria is Heat Index Values between 105F-109F and Excessive Heat Index Warning is above 110F. Whats going on here?

Answer 1

The person who issued the advisories probably was not thinking correctly. Some meteorologists will make such decisions from time to time if they feel that their decision is appropriate.

Answer 2

Hello,

First of all, I'm feeling your pain, I live in Newport News. We hit 100* today. I'm not feeling the love from the weather this year.

Ok, to answer your question we meteorologists will basically take the temperatures from the moment of most intense heating (usually 11 AM-1 PM) and monitor temperatures from then on until about 5 PM. Now the temperatures forcasted for these times will be averaged out and then we will put our advisories out.

You have to understand, we may hit our high temperature for only a few minutes and then something as insignificant as a cloud could lower the temperature substantially.

So in layman terms, we use averages of temps and Heat Indices in order to put out our warnings.