Make no mistake about it, the start of the weekend is is going to be a washout. Not only will it be wet, it'll be windy and cold and just plain coyote ugly. Here's the culprit, a deepening 987mb surface low that travels from St. Louis to near Chicago.
Divergence aloft and strong vertical lift, combined with ample moisture will generate a broad swath of moderate to heavy rain that's aimed at much of my area starting early Saturday morning. Models are in good agreement that the strong trowel (deformation band) is focused along the Mississippi. That allows rainfall of 1-2 inches to fall in most spots with some areas along a line from Burlington through the Quad Cities and on to Mt. Carroll with as much as 3 inches. The lightest amounts of 1/2 to 1 inch are expected NW of a line from Cedar Rapids to northwest of Dubuque. Here's what the latest models are suggesting for totals.
The 12K NAM
The deepening low and tightening pressure gradient means winds are going to rev up out of the northeast. Gusts of 35-40 mph are anticipated. The 3k NAM and EURO depict 10 meter gusts (just above the surface) of 48 mph.
Throw the wind and the rain into temperatures in the 40s and 50s and you have yourself a perfectly lousy day. The EURO has this for temperatures late Saturday.
The track of the storm appears to be far enough into Illinois that the threat of low CAPE high shear strong storms should end up east of my area. Even there the concern is conditional on how much heating and destabilization can take place. SPC shows this for its severe thunderstorm risk area at the time of this post.
You can see the whole thing event coming together in this GOES 16 satellite image from Friday night.
Sunday with the storm inching east lingering showers will spin out of Iowa in the morning but may linger in my Illinois counties well into the afternoon. That should allow temperatures to be warmer in my western counties in Iowa where there may be some breaks or at least thinning of the clouds. The GFS shows the issue clearly with late day readings that look like this.
Another surge of cold air quickly rotates into the mean trough Monday and remains intact all of next week. The GFS ensembles show this for high temperatures next week and well beyond (out to April 25th). Normal highs are in the low to mid 60s and not a single day is out of 50s. Since this is an ensemble showing the average of all the extremes, there are days in here where readings don't get out of the 40s. I could see a couple dogs like that if overcast conditions were to prevail.
In general, after the weekend most of next week sees little in the way of precipitation. However, there's plenty of cold air aloft to generate some spotty light showers. Again, I have to mention the possibility of a few wet snowflakes mixing in during the colder times of the day. This is the EURO ensemble snowfall forecast. Some of its 51 members see that potential. I think the potential of any accumulating snow is low but the fact we are even mentioning it in mid-April is not a good thing.
Sorry for all the bad news but I will end with this positive note, if todays storm was a month or so earlier its track is ideal for heavy snow in my area. All that rain we'll see could have been a whole lot of snow. A cold rain's not pretty but at least you don't have to shovel it. Stay warm and dry and by all means, roll weather...TS