Winter Storm: Dec. 1-2 -- Update #3

Winter Storm Watches are still the only issuances that have been made by the NWS thus far, don't expect any of them to change over until tomorrow afternoon when areas of KS and possibly NE may see the upgrade as the storm begins to affect them by early Saturday. Early Saturday morning is when we will likely see a majority of the warnings come out, likely ranging from heavy snow warnings in SD/MN to winter storm warnings and freezing rain advisories over portions of IA/MO and areas to the northeast.

The afternoon runs of the WRF & GFS became a little closer together, timing is still an issue as the GFS is more progressive. Currently belief is that the WRF, although an outlier with the other models may actually have the best idea of what is occurring near the surface; due to the model resolution. Both are fairly similar in total precip amounts over the plains states as of the 18z runs. The 00z run (tonights) of the WRF has just came in and it has kept fairly consistent on most grounds, it actually increased the total precip amounts over NE/IA/MN. No substantial differences in its' temperatures at the different levels between the runs either. Will have to wait and see how the GFS handles things with its' 00z run.

Ended up not having a lot of time for a detailed forecast, but here is my quickcast for this weekend in Iowa. Both the WRF & GFS are fairly warm now over the state of Iowa, giving way to a mix of snow, freezing rain and even general rain showers. Areas of extreme northern Iowa look to receive the heaviest snow amounts, but likely only in the 4-7" rain at the maximum. They will likely see some sleet and freezing rain by Saturday evening, thus hampering the snowfall totals. Much of the rest of Iowa may see snow beginning on Saturday, but by evening have freezing rain or rain falling as temperatures continue to rise just above the surface. Some areas in extreme southern Iowa may get away with mainly freezing rain and rain, snow being the least prominent precip type.

The forecast is still going to be quite tricky, as the strength of warm air advection just above the surface is crucial to what type of precip is going to fall. The exact path of the low pressure system is also going to have some affect, a more southerly track than currently forecasted will bring more snow to northern Iowa as not as much warm air is likely. I'll likely get one more quick forecast in tomorrow afternoon, likely with updates on what types of warnings/advisories are going to be issued for the state.