Heat Wave This Week.

Sunday, June 24th 2012, 9:45 am
By: News On 6

The heat wave that is building over the state will dominate our weather for much of the coming week, but there is lots of uncertainty regarding how the end of the week will play out. The reason for the uncertainty is TS Debby which has formed in the Gulf of Mexico. Debby is currently drifting around with no well defined steering currents to force it one way or the other. As a result, depending on which computer model one looks at, Debby will either be heading for the lower Texas coast, the Florida coast, or somewhere in between. This is illustrated by the scatter plot map on the right. Needless to say, that is a very low confidence scenario and has implications for us as well.

One thing that is certain, we will have the hottest weather we have had so far this year. In fact, the high of 97 yesterday was the hottest so far and we expect to see triple digits in many locations starting today and for at least the next several days. The exception will be where the rain footprint from last Thursday's rains will hold temperatures down several degrees. However, those same areas will also have somewhat higher dew point temperatures so a bit of a trade off there as the heat index will also be somewhat higher.

In general, look for daytime highs to be at or slightly above 100 at least through Friday of this coming week. Overnight lows will be generally in the low-mid 70s through the period as well. Relative humidity values will be dropping off to near 30% during the hottest part of the day, so heat index values will generally be 3-5 degrees above the actual air temperature. If the dew point temperature should make it into the upper 60s to near 70, that will really make the heat index soar, but right now that does not appear to be the case.

We will also have light southerly winds for much of the coming week which will not provide much in the way of a cooling breeze and may also lead to air quality issues. Together with only a few fair weather cumulus clouds, this all adds up to an extended period of much above normal temperatures, or what we refer to as a heat wave.

A couple of things should combine to provide at least a bit of a break by the coming weekend. One scenario involves TS Debby mentioned above. One of the computer solutions brings Debby our direction which would obviously imply more cloud cover and increasing changes of rain by the weekend. Not going to bite on that just yet, but even if that does not materialize, some of the other computer solutions are still showing a weakness in the ridge aloft that is over the state. That would also allow for more clouds and at least the possibility for a few showers. So, have trended temperatures down a bit by the weekend and introduced at least a very slight chance for rain. Obviously, this is a low confidence situation, so those numbers may change significantly over the next few days as better data becomes available.

In the meantime, stay tuned and check back for updates.