#ILwx Zones 3/4 – Active next 10 days, diminishing warmth the remainder of the week, late wknd system with “wintry” potential…details here! K.

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Key Points – Tuesday, November 29, 2016 – next week

Synopsis: Showers have since pushed out of our area well to the east, partly sunny skies expected today with spotty showers possible as a small disturbance moves through…accumulations will be minimal. Temperatures take a dive the remainder of the week in the 40s to even areas to the north seeing highs in the 30s by late week/weekend…increasing clouds move into the area later today for the remainder of the week as well. Still targeting a system to move through late weekend/early next week that has wintry potential for both Zones 3/4. This system is all dependent on the cold-air supply, if we get more warm air to work in it cuts down the snowfall accumulations, if we get more cold air to work in on the backside the more likely the precipitation is to fall as snow. Confidence is low right now on the specifics, we need more time and better data to make a better forecast. Another system moves through mid to late next week that we’ve been targeting, especially in the winter threat assessment blog that we need to be watching very intently for snowfall potential. Long-range update later this afternoon that covers more information on that.

A few showers possible as we progress into the day…20-30% coverage at best and not lasting more than 20-30 minutes. Clouds increase on Wednesday bringing as well as our next chance for a rain/snow mix works into the forecast Wednesday afternoon/evening into the overnight with the focus on northern Zone 4 locations (eastern Iowa, Rockford to Chicago). Snowfall accumulations are not expected at this time.


Next system moves into the Zones Sunday into Monday, the big question is the precipitation-type and accumulations…we need better data for a more accurate forecast.


Our next system of interest comes mid to late next week where we have growing confidence that we will have a lot more cold air to work with. Confidence is also growing that someone in the Midwest next week gets snowfall, it all depends on the cold-air supply, the colder the air is in these systems the more like we have snow vs rain.


The new European weeklies came in last night with a favorable pattern as we usher in December, here’s a look at temperatures over the next 32 days…the takeaway is it’s not a warm signal…we don’t need a colder than normal December to bring above normal snowfall, but the colder air makes it easier to forecast snow vs rain.


Here’s a brief look a precipitation over the next 32 days…the focus is on an active Ohio Valley track.


Confidence and Risk:

  • Average to above average of a spotty showers possible across Zones 3/4 today…minimal accumulations expected
  • High confidence the remainder of the weekend is much cooler, with many locations in Zone 4 below normal for highs as well
  • Below average confidence in our system late weekend into early next as to precipitation-type and totals…need better data
  • Increasing confidence in our system mid to late next week bring wintry potential to Illinois locations
  • Increasing confidence of a growing trend of cool to colder temperatures as we head into December as well as a favorable storm track

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