#ILwx Zones 3/4 – Increased shower coverage into the weekend, clearing out late weekend, warm-up next week, strong storms mid-week? Kirk.

Key Points – Friday, September 30, 2016 – mid next week


Good Friday morning, I hope you all have had a wonderful week thus far! We have a lot to cover today, and I would like to first start it off by checking out the latest radar loop…you can see we continue to have “waves” or bands of rainfall swirling around our upper level low generally from east to west across our Zones. Cold-air funnels, small hail, some lightning, localized heavy rains and some gusty winds are all possible today, as well. Similar threats continue into Saturday.

(Latest radar loop)


To get a better visual of where our upper level low is located this morning, here’s a quick glance at our latest water vapor loop from a regional perspective, where our low is situated right over IN.

(Regional radar loop)


Our HRRR forecast looks to be handling today’s weather fairly well this morning so far, here’s how things are shaping up around the 8amCDT hour. This morning we will have around a 30% coverage of showers, so fairly scattered and isolated in nature. 

(Simulated radar ~8amCDT)


Moving to the noon hour, we can see that the majority of both Zones 4 and 3 have a scattered chance for showers at around 30-40% coverage.

(Simulated radar around noon)


We have a little bit more coverage of showers around the 4pmCDT timeframe, I would call it 40-50% here across both Zones…localized 0.50″ or a higher could fall out of some of these storms moving east to west.

(Simulated radar around 4pmCDT)


Things get a little heavier around the 7pmCDT hour, especially across the eastern portions of Zones 4 and 3 as seen below. Some of these storms could contain heavy rainfall, gusty winds, small hail, lightning and even a possible cold-air funnel. These will continue to move in the general east to west direction. Our coverage will be around 40%.

(Simulated radar around 7pmCDT)


Overnight, we will have continued rain coverage moving east to west around 40-50% across both Zones…some of these showers will continue heavier rains as well.

(Overnight rainfall coverage)


Saturday morning will see similar rain coverage across the Zones moving into the early afternoon hours…around 50% coverage is expected. The low pressure will finally start to pick up and move east Saturday evening into Sunday, moving rain chances more eastward towards the IL/IN border and beyond as it does so. We still expect around 40-50% rainfall coverage most of Saturday. 

(Saturday morning rainfall coverage…could be 50-60% at times)


Sunday we will see a progressive clearing out throughout much of the day as our upper level low moves off to the east…we should see a sunny sunset by Sunday evening as well!

(Clearer skies Sunday evening…the lighter colors represent cloud coverage)


Overall, we expect around another inch or slightly higher rainfall totals near the IL/IN border through Sunday evening, around 0.25-0.50″ in the central portions of the Zones, and around 0.10-0.25 for folks across the more western portions.

(Rainfall totals through Sunday evening)


We expect a clearing out for a few days early next week…meanwhile, we are still watching for the potential for strong storms to move through sometime next Thursday. Our models are still in a slight disagreement on timing of when this cold front will move through and with intensity, so right now our confidence is about average with this event. Stay tuned as this will need additional fine-tuning. 

(Strong storm threat next Thursday)


Overall, as we have mentioned throughout the week, next week will see above average temperatures across the Zones, with highs nearing 80 by mid-week.

(Above average temps next week)


Today’s Video (6min):

Confidence and Risk:

  • We have high confidence of continued showers through Sunday morning across both Zones
  • We have above average confidence on around an inch or slightly higher rainfall totals for folks near the IL/IN border…decreased totals west
  • We have above average confidence that we start clearing out Sunday and into early next week…lots of sunshine returns to the forecast!
  • We have average confidence of a strong storm threat mid to late next week that needs more fine-tuning
  • We have high confidence that next week we see highs that are above average across the Zones

Thanks for checking out Friday’s Zones forecast, stay tuned in the coming days for more updates on shower coverage this weekend and next week’s potential strong storms!