Dry weather continues today and tomorrow, and temperatures warm up from the seasonal readings we saw over the weekend. Sunshine will dominate today and tomorrow, helping to fuel the warming again. This will continue to be excellent for harvest.
Things start to change up a little bit at midweek. We have a significant front working out of the plains and into the Corn Belt this week, and it looks to try and move into Indiana the second part of the week. This is where things get a little interesting, though, as some models are trying to bring in action already first thing Wednesday. Likely what we will be looking at here is a pseudo-warm front that will be attempting to lift through ahead of the cold frontal boundary arrival. The question is: “is there enough energy and moisture with that little warm wave to actually trigger some precipitation”. At this point, we think that we need to at least be on the lookout for something through the first part of Wednesday over the northern half of the state. South of I-70 we see nothing. Moisture totals will be minor…a few hundredths to at most a quarter of an inch, but with clouds building and a front lurking, it is a little bit of a gamble to leave the forecast completely dry. That being said, we think that moisture chances are much higher and rain is actually likely statewide the following day on Thursday.
Thursday, the actual cold front arrives, and we see good moisture through the state. In fact, statewide coverage will be pushing 90%, with rain totals of at least .25”-.75”. There is a threat of thunderstorms overnight Thursday night. Another question mark revolves around how long the rains linger. Some models again are stringing the rains out to include the first half of Friday. We are not there yet. WE think this front sweeps through strong and has a good clearing line behind it. This front does not look like one that wants to linger unless it is stalling and dying over the region…and it does not fit that description at the moment. Thunderstorms overnight may push some rain totals, particularly over northern Indiana, to well over an inch combined for the second half of the week.
WE look for drying weather Friday and Saturday, although we admit that clouds will be a formidable foe for those days and may limit outright drying. A better way to put it may be “no new precipitation” those days. A secondary front arrives for Sunday, bringing another .25”-.5” over about 75% of the state. This, combined with the rains for the second part of this week, will lead to our first significant slowing in harvest progress over the state, as cumulative rain totals will be over 1-1.5” over at least 60% of the state. We expect a multi-day delay in harvest over about 80% of the state. However, behind the Sunday system, we do string together dry days Monday through at least Thursday of next week, so even a multi-day delay will not last an exceptionally long period of time. The map above shows potential cumulative rainfall over the state through Sunday, which would include both of the aforementioned systems.
In the extended forecast period, we see strong upper-level high pressure in control through early the 14th, keeping the sunshine, blue sky and good drying in over the entire state. Later the 14th into the 15th, we have a system moving in out of the western corn belt that can trigger a few hundredths to perhaps a quarter inch of rain. A much more impressive storm complex works towards us for the 16th. This system has a strong low and ample moisture circulating with it. It could bring us half to 1.5” rains over 80% of the state. However, this is far out in the extended period, and we have plenty of time to see this thing modify, or even change course. But it is a system we need to watch.
Overall, temperatures through the rest of the 2-week window, right on through mid-October look to be normal to above normal. We do not see any significant below normal temperatures headed our way. Even dramatic moves behind fronts only return our temps to seasonal levels, and they do not produce any kind of cold snap. Normal first frost dates for the region dance around October 10th. We do not see any significant frost threat until well after that date at this time.