GLAD THAT'S BEHIND US...

Last week at this time I was promoting a a multi-day rainfall event that I felt had the potential to be quite significant with most areas seeing 2-5 inches of rain, locally more (7" plus) in the heaviest band. Models did a good job showing the excessive rain potential but struggled until midweek to determine where the heaviest amounts would occur.

As it turned out, the stationary boundary (ring of fire) laid out over southern Iowa into central Illinois and Indiana from Tuesday to Sunday. That position put my counties south of I-80 in the bullseye for numerous rounds of thunderstorms, many with torrential rainfall. Over that 6 day period rains over 10 inches ended up falling in the area. The 10 inch amounts were focused near Wapello in Louisa Co. Iowa. Further north of I-80, amounts were more in the 1-3 inch range with some spots in the far north near Dubuque seeing totals closer to 1/2 inch. Take a look.

6-10 inch rains in August are a bit rare coming in as high as 10 times more than normal during that period. These are the departures.

Here's a tighter perspective of some of the heavier rains August 9th-16th.

These are the associated departures

Fortunately, the pattern that delivered the excessive rain and humidity is breaking down. Totals in the coming week are generally expected to be 1/2 inch or less. A few local spots could be higher where the strongest thunderstorm or updrafts form. The next round of showers and storms arrives Tuesday. It appears remnants of of that activity will drift into the area during the morning, especially the north. By then they are weaking and should eventually fizzle out later in the morning. More important, is the fact there will be debris clouds that will hinder heating. How much is the big question at this point in time? Current indications are that highs in most areas will remain in the range of 75 to 80 keeping instability moderate at best. What instability develops in the afternoon will drive a potential secondary line of showers and storms later in the day. Guidance is inconsistent on how widespread the storms will be, but at least scattered activity is likely to redevelop late in the afternoon. The 3k NAM simulated radar shows them forming around 5pm. in the north.

As I mentioned models are varied on amounts. The EURO is the most aggressive with rain amounts.

The GFS noticeably lower.

The National Blend of models is somewhat in the middle and may be more in line with reality.

Due to potential clouds the severe threat seems much lower than a couple of days ago. SPC has dropped the slight level 2 risk to a marginal level one. Hopefully that works out.

After the system passes comfortable temperatures in the range of 76 to 82 are expected through the weekend. There is a chance of showers and storms sometime Friday, but rainfall looks to be light with the system on the progressive side.

That's where we stand for now. Have a terrific Tuesday and roll weather...TS