Good afternoon, before getting to the impacts that the remnants of Alberto will bring, let’s take a look at where Alberto is currently. As of this typing, Alberto is located about 25 miles northwest of Birmingham or about 417 miles south-southwest of Indianapolis. Alberto is moving to the north at 12 mph and maximum sustained winds are near 30 mph. Alberto is currently producing heavy rainfall across northwest and central Alabama.
Alberto will continue to move north to north-northwest through the rest of today into tonight and will move through the Tennessee Valley through the day and move into the Ohio Valley during the day on Wednesday as Alberto will begin to turn to the northeast. Some of the most outer rainbands will move through southern Indiana this afternoon and evening and the core of Alberto’s remnants will move across the state during the day on Wednesday. The area that have the potential of seeing the heaviest rainfall will be on the north side of the storm. The core of Alberto will be affecting the southwest counties Wednesday morning and spread into the Indy area by lunchtime and northern counties by the early evening hours. Futurecast radar will show the evolution and movement of Alberto and will run from 2 pm this afternoon through midnight Thursday.
In addition to the heavy rainfall potential on Wednesday, there is the potential for severe weather as well. There is a marginal risk of severe storm for the northeast half of Indiana, where isolated tornadoes and damaging winds will be the primary threat. As the core of Alberto moves across the state, areas that will be in the northeast quadrant will be under the highest potential of seeing severe storms.
Finally, how much rain will fall, here is a couple of models that show what will fall, the first model is an in-house model that I think is under doing the total rainfall as this model is showing less than an inch of rainfall through midnight Thursday. Again, I think that this model is under doing the amount of rainfall that could fall.
Next is the NAM 3km model rainfall potential through 2 am Thursday. This models is a bit closer to my thinking with widespread areas in excess of an inch across the state, with pockets of 2 to 3 inch rainfall totals.
Finally a look at the GFS, rainfall totals again looking a bit lower than my thinking of rainfall will eventually end up being. GFS for much of the state is showing an inch or less through 2 am Thursday.
So my thoughts for rainfall. I think that western Indiana will see the highest rainfall totals between 1 and 2 inches, with isolated totals of 3 to 3 1/2 inches possible. Eastern Indiana will likely see closer to 1/2 to an inch of rainfall, with isolated totals of up to 2 inches. Flash flooding will be possible as this final graphic shows, that there is a marginal to slight risk of excessive rainfall for southern Indiana this evening and tonight. A slight risk for excessive rainfall for the entire state on Wednesday, flash flooding will be possible and flash flood watches are already posted for far southern Indiana counties and we will see if watches will be expanded north. Stay weather aware on Wednesday.