Isaac...Some Questions Regarding Rainfall

A lot of numbers have been thrown around by various sources regarding the potential for heavy rainfall across Arkansas as a result of Isaac, but radar trends this morning show that some spots in Central Arkansas may not wind up with very much at all. Last night, I noted that very dry mid level air was wrapping back into the circulation of Isaac. Below is the water vapor imagery from around 10 PM Thursday night.

The brown area represents very dry air, with the blue areas indicating higher moisture content in the atmosphere. Dry air was quickly wrapping around the Western side of the circulation. The effects of that dry air are quite evident in looking at Isaac's radar presentation this morning. Most of the rain near the center has vanished, with the heavier rains now well East of the Center.

The center as of 10 AM was located near the white dot over Central Louisiana. Note how there is very little in the way of any significant within about 50 miles of the center. Some rain remains East of the center, with a large curved band of heavy rain and thunderstorms located nearly 150 miles East of the Center. The white dots indicate the forecast track of the center, showing the center moving across West Central Arkansas. Given this track, it would appear likely the heaviest rains would be most likely over EASTERN Arkansas, possibly even East of the Mississippi River. Rainfall amounts near the center line track do not appear to be significant, with many spots receiving an inch of less across Northern Louisiana. We will have to watch for rain filling back into the center later today and tonight, but with the dry air wrapping into the circulation that appears questionable at best.
Most of the severe weather with the system has been associated with the outer band located near the Mississippi/Alabama border. Given the expected track, it is likely the highest tornado potential will remain East of Central Arkansas through tonight.