There's more rain in sight over the next 12-24 hours, and by some model estimates, quite a bit of it! As is typically the case, there's a large spread in the precipitation forecasts generated by a suite of five computer models examined Thursday afternoon. The range varies from the 0.20" forecast from the European Center for Medium-Range Weather Forecast model to the robust 1.57" output from Environment Canada's GEM forecast model!
Generally speaking, we tend to throw out the extremes, rather preferring to blend all solutions into an ensemble average. The average rainfall output from the five models resulted in a respectable 0.76" tally. Using a quarter-inch buffer on either side, it seams reasonable that the Stateline is due for a 0.50" to 1.00" rainfall event Friday, with the heaviest rains to come before 7:00PM.
Such rains like the ones due in Friday would continue the positive momentum that has taken place in recent weeks with our current drought situation. Isaac's remnants, and the bountiful rains produced downstate as a result made some huge headway in the effort to relieve the Land of Lincoln from the current drought! There's been little or no change when it comes to the Abnormally Dry or Moderate Drought categories, but significant changes can be reported for the more severe categories! Just 56.3% of the state falls into the Severe Drought category, down from a whopping 94% last week. In the Extreme Drought classification, even more significant progress was made over the past 7 days, as we fell from 69.6% all the way down to just 7% this week! And we're happy to report that for the first time in weeks, there is not a single inch of the state in Exceptional Drought!
What's interesting is that when this drought first began, it progressed from South to North... Areas downstate were those first to see the Extreme Drought conditions, while further North, we were among the last to be put into that classification! But given the fact that Isaac's prolific rains fell generally to our South, we're now the only part of Illinois to be still in that Extreme Drought category. It's a testament to the fact that rainfall's still VERY MUCH needed here, and on a regular basis as we head into the upcoming Autumn season.