When I wrote up the August outlook, I said September looked encouraging for rainfall, and that still appears to be the case. With the increasing El Niño, which I'll show in just a second, we are likely to start seeing the southern branch of the jet stream getting more and more active as we get into fall. I would assume this will come too late for many fall crops.
Latest drought map (August 13th):
Much of the state had tremendous rainfall in June, making it a top 10 wettest for several parts of the state. July started drying out and as expected, August has gone hot and dry statewide. But as most of us know, one extreme can follow another, and while I'm not saying we'll have flooding in 30 days, a change is coming.
Here's the 30 day rainfall outlook - starting now - Sep. 12th:
Model #1:
Model #2:
It looks like in the final week of August the upper high pressure is collapsing fairly quickly as several systems begin to track straight in from the West. Each passing one will likely weaken the "high" even more, so I think we will see things flip fairly quickly here as August comes to a close and we get into September. It may make for an interesting fall harvest season if things turn wet. I do not think September will be exceptionally cool, but it should be much closer to average compared to the blow-torch hot August that we've had so far.
Side note - September is not traditionally a very wet month for Kansas. Average rainfall drops by about an inch for most of the state.
El Nino is impressive:
Just incredible what's happening along the equator in the Pacific. Notice the area of white, south of Hawaii that stretches for thousands of miles. Right now, the area monitored for El Nino is 1.8°C above average and it continues to warm. What's also of interest is the exceptionally cold water that is west of the dateline, southwest of Hawaii. That will also play a role in developing weather patterns as we go into the winter season.
Past El Nino influence on fall weather patterns generally trend toward wetter setups overall. Most recently, 2015-16 was a strong El Nino episode and much of the season & into winter was wet. See the examples below, starting with October, followed by November and December. You will see that October was drier for central and eastern Kansas.
October 2015:
November 2015:
December 2015:
