Over the weekend we flipped the switch to summer in a big way. Temperatures were not all the bad, mid to upper 80s, but humidity was the worst it had been in nearly 2 months. As you can see below the dew point in Cedar Rapids Sunday reached 77, the 3rd highest of the summer and the highest since the first week of July.
Tuesday won't be much better as dew points in much of the central Midwest are again headed for the mid 70s.
Precipitable water vapor (pwat's) are way up there. Note the max of 2.36" in NE Iowa. A widespread swath of 2 or more inches covers the heart of my local area.
These pwat's are at levels that are 200% above normal. The extreme amount of moisture means any storms that get going in that type of environment are likely to be heavy rain producers.
As a cold front enters the region late Tuesday it will become the catalyst for strong storms and heavy rain. CAPE (convective available potential energy) is shown reaching high levels of 3-4,000 J/kg. That's a potentially explosive and unstable air mass.
As of Monday night, the Storm Prediction Center has much of my area in a slight risk of severe weather.
Behind the cold front much cooler and drier air arrives for the middle of the week. The GFS has most areas into the 60s by Wednesday evening.
Dew points by Thursday morning have fallen into the low 50s. That's a good 25 degrees lower than recent days and a far more comfortable air mass.
No matter how you slice it, there's a lot of weather on the table the next 24 hours. Should be fun to watch it all unfold. Roll weather...TS