#ILwx Zones 3/4 – VERY warm again today, multiple rain chances next 72 hours, STRONG storm risk Wed-Thurs, Frost potential Friday AM? Kirk.

Home / Uncategorized / #ILwx Zones 3/4 – VERY warm again today, multiple rain chances next 72 hours, STRONG storm risk Wed-Thurs, Frost potential Friday AM? Kirk.

Key Points – Tuesday, October 18, 2016 – mid next week


Good Tuesday morning and thanks for checking out the latest Zones 3/4 forecast update! First things first, it’s very unseasonably warm out right now…the average high for most areas in Illinois this time of year is in the mid to lower 60s…and currently every station is reporting 70°F or above!

(Current temps)


(Temp anomaly map…the reds showing most places are 20°F above normal!)


On and off clouds are expected today, with highs in the lower 70s in northern IL to the lower 80s in the south. 

(Cloud cover loop)


(Today’s high temps)


We have a cold front that’ll pass through portions of Zone 3 today, as noted here via our windfield!

(Cold front today)


Showers and maybe a few storms will pass NW to SE across southern Zone 4 to Zone 3 today by mid-afternoon. These look to continue southward into this evening along a skinny line, bringing around a 30-40% coverage as it passes.

(Today’s shower risk)


Wednesday’s shower/storm risk will form off of a stationary front that will lift from the south to the north. 

(Stationary front Wed-Thurs)


These will start across Zone 3 and move north to southern Zone 4…the heaviest looks to come very early Thursday morning.

(Thursday early morning heavy showers)


Some of these showers could be strong and heavy…capable of producing localized flash flooding, small hail and strong winds. Here’s the risk area for Wednesday into Thursday.

(Strong/heavy storm risk area)


The NAM forecast models puts nearly 2.0″ down in portions of Zone 3 in the next 72 hours. Right now, 0.5-1.5″ is not out of the question, with localized higher amounts possible where thunderstorms pop up.

(NAM 72 hour rainfall totals)


Storms look to exit the area east by Thursday evening, ushering in much cooler, drier weather Friday. We even have some forecast models that indicate the return of the 30s by Friday morning daybreak…especially across the NW portions of Zone 4. Right now our confidence is average on frost potential…but it’s not off the table by any means. Highs Friday will likely be in the low to mid 50s across Zone 4 with the mid to upper 50s expected across Zone 3.

(Friday AM temps)


Right now we have average to low confidence on showers moving through Zone 4 on Saturday morning, as mentioned in yesterday’s Zone 3/4 forecast. It is still worth the mention of potential showers, but right now we need more accurate data to asses better timing and location of those showers.

(Saturday AM showers)


High pressure will work in on the back half of the weekend, with the return of the 60s and 70s expected with plentiful sunshine and dry weather. The Euro has our next potential big system moving through mid-next week around Wednesday that we are eyeing more than a week out…so keep an eye on upcoming forecasts in regards to more details on this.

(Storm risk mid-next week)


7-day rainfall totals reveal the heavier rain totals across portions of Zone 3, mainly coming in the next 72 hours along the cold/stationary fronts. Localized 2.0″+ are now out of the question in heavier storms.

(7-day rainfall totals)


Thanks for checking out today’s Zone 3/4 update, check back this afternoon and in the coming days for more detailed updates on rain chances over the next week!


Today’s Video (time):

Confidence and Risk:

  • We have high confidence that today will remain very unseasonably warm…with temps 15-20°F above normal expected
  • We have above average confidence in a shower chance moving NW to SE across mainly Zone 3 this afternoon and this evening along a cold front
  • We have high confidence in heavy storms lifting north off of a stationary front coming Wednesday into Thursday, with the potential right now for small hail and strong winds. Localized 2.0″ not out of the question
  • We have average to above average confidence that Friday will see below normal temps, and potential some 30s across the northern portions of Zone 4
  • We have low confidence in Saturday morning showers across Zone 4
  • We have above average confidence in high pressure setting in the back half of the weekend, bring seansonable temps and plentiful sunshine

Related Posts