Here's a current picture of the upper level winds or "jetstream" (about 30,000 feet) in our atmosphere. (The areas in blue.)

We call it the jetstream, an area of fast moving air. We usually point out the jetstream in our forecast, because to put it simply, it divides cold Artic air in the North from warm Tropical air in the South. If the jetstream dips this far South, like it is over Arizona right now, temperatures cool! Right now, a ridge, or an area of high pressure in the upper levels of the atmosphere is allowing for a warming of the air in the Southeast. That ridge of high pressure will slowly weaken over the next few days as the trough (or dip in the jetstream) starts moving closer to us. So far, computer models have the ridge "blocking" storms from moving into our region from the north, but allowing Gulf/Tropical moisture back into the picture. Thus, hot & humid days are ahead. A front is expected to move through again and cool us down next weekend. Click on the following link for a more comprehensive explanation of the jetstream.http://www.srh.noaa.gov/jetstream/global/jet.htm

We are watching two areas of low pressure in the Caribbean, one near the Yucatan Peninsula and one in the Central Caribbean Sea. Both have the potential for development.