As the Gulf Coast begins to recover from Isaac's lashing of wind and rain, we are preparing to see what is left of the tropical system as it approaches eastern Oklahoma. Isaac is already making his approach known in our region this afternoon. The first effect: the wind. Gusts over 30mph have already been clocked in southeastern Oklahoma. The second effect: the clouds. Isaac's outer bands are starting to spread into the state and will overtake all of Green Country later tonight. The final (and most anticipated) effect: the rain. How much we see all depends on Isaac's track.
Compared to coastal Louisiana and Mississippi, Isaac will be just a ghost of the storm it once was as it heads north. The National Hurricane Center puts the official track of the Tropical Depression through western Arkansas before making an eastward turn. Some computer models still bring it as far west as east-central Oklahoma so there is still room for the forecast to change. However, as it stands now, the heaviest rain will fall well into Arkansas, generally on the eastern side of the circulation. Tulsa and surrounding areas will be on the western fringe of things. Still, all of the computer models swing bands of rain and a few thunderstorms out to near I-35 as Isaac makes its closest approach. Rainfall from tropical systems tends to add up quicker than other systems we see because of the rich moisture content found in the warm-core low. Hopefully that will work to our benefit with extreme drought conditions persisting in the region.
The bottom line – Friday will be wet at times with breezy conditions and cooler temperatures. I don't expect the whole day to be a washout, but if you do have plans to head outdoors to a football game or elsewhere, prepare for rain and wind. We may only see half an inch of rain around Tulsa, but if Isaac adjusts a little further westward, it could be a more significant soaking. Either way, it'll be a nice break from the summer heat!
Some lingering showers and thunderstorms remain possible on Saturday as Isaac slides out to the northeast, but the coverage will be less. Isaac's exit will lead to a hot and dry Labor Day weekend. Depending on how much (or little) rain we see, temperatures may approach the century-mark by Labor Day. Summer-like weather won't end there, but it does appear a cold front may try to slide toward us by mid to late next week.
For what it's worth, meteorological summer ends Friday. As we know in Oklahoma, we don't often see more permanent relief from the heat till about half-way through September. Tropical season, on the other hand, is just now reaching its peak. We already have our L-named system in the Atlantic (Leslie). We're at a near-record pace for the number of tropical systems. We only see the direct effects of these systems once every couple of years so we are experiencing the very active Tropical season as well.