Keep the umbrella handy today. We have a weak cold front moving across the state, and it will trigger some minor precipitation. Right now we have no reason to deviate from our thoughts of a few hundredths to .3”, but we honestly think most of the state will be in the lower half of that range. There just is not a lot of moisture to work with here. However, clouds will be around all day, and will not break up until after midnight tonight.
Dry weather is back behind the front for tomorrow through the weekend. Most of the state will see that dry weather continue the 4 day on Monday. However, we still see some precipitation threats over far northern Indiana Monday morning and midday, as the northern low of our big system lifts north and east, dragging a warm front through IL, WI, and MI. Temps will moderate through the weekend and should be nicely above normal Monday, even in areas where it rains. Clouds will be a big part of the forecast Monday north of US 24, and rains will be limited to the northernmost 2 tiers of counties that morning.
Strong southwest flow pumps plenty of moisture into the second southern low. That circulation and the associated cold front blast through overnight Monday night and Tuesday. We continue to look for our best rains in this period, with .25”-.75” over about 70% of the state. The highest chances for thunderstorms are likely going to stay west of the state, with the front passing overnight Monday night. That means we are not timing things out in a way to see the biggest energy flows into any thunderstorms here. So, we like these rain totals, and do not think we will have to raise them due to thunderstorm fears. Still, it is a prospect we are watching closely.
Clouds break up Tuesday night, and we should be dry for the balance of the week, Wednesday through Friday. We expect Canadian high pressure to nose into the western Corn Belt, and while we never really fall under the influence of that high, we see it blocking any moisture or systems coming in from the west and northwest. Overall, we only see 2 systems in the next 10 days – what we see today, and then early next week. The map above shows combined rain potential over the next 10 days.
No significant change in the extended forecast period this morning, except to push back our next system just a bit – about 12-18 hours or so. We now have a weak upper-level circulation moving into the great lakes closer to the 10th, but it has a potential of only a few hundredths to a tenth or two. The rest of the period looks mostly dry, but colder. Northwest flow will keep temps closer to and below normal as we move toward mid-month.