COMPLEX WINTER STORM ON THE TABLE...
While some important details are yet to be resolved, confidence continues to grow that a significant storm will bring a wide variety of weather to the nations mid-section Friday night and especially later Saturday and Saturday night.
This system could pack a real punch and be quite disruptive to parts of my region and the surrounding area. No doubt it is going to be a challenge to forecast in terms of precipitation types, amounts, and the location of the heaviest snow. After some doubt earlier Wednesday about how the storm storm would evolve, now all models agree in principle on the general trends.
Due to their recent consistency I am leaning heavily on the EURO and 12K NAM in their overall handling of the track and precipitation shield. Both models have been staunch in taking a closed upper air low right over Quincy this weekend and that is the sweet spot for heavy snow, especially Saturday night.
There also looks to be two potential periods of precipitation. The first round in some areas could start as rain and then transitions to freezing rain, sleet. especially southeast of a line from Cedar Rapids to Dubuque. This initial wave of precip eventually mixes with or changes to snow before it moves out by Saturday morning.The best chances for a couple inches of slushy accumulation Friday night appears to be NW of a line from Iowa City and on to Freeport, Illinois. From that line southeast to the Quad Cities mixed precipitation is more likely with rain changing to freezing rain or sleet and perhaps some snow before ending. A few models show up to a 1/2" of freezing rain or sleet near the Quad Cities. This part of the forecast, especially the icing is very hard to call and much lower in confidence at this time
Accumulated freezing rain on the EURO