Winter Storm (Dec. 18) Update #1

Winter Storm Watches still are to remain in effect until later tonight where they will likely be changed over to some type of winter storm warning, whether it be for snow, or sleet/freezing rain. This mornings computer models came into a little better agreement on the placement of significant freezing rain and sleet. However, the overall location of the heaviest precipitation was still somewhat varied in mainly the east/west location. For a quick overview, models are still expecting a low pressure system to develop off of the lee of the Rockies on Thursday and quickly move into the central plains by Thursday night. The low track is expected to be through northern Missouri and into central Illinois, thus putting Iowa into the favorable area for continued precipitation. Rapid moisture return ahead of the system (up to 3 times the climatological average), along with warmer temperatures will allow for significant QPF amounts. This system is fast-moving, thus precipitation may begin Thursday afternoon over the state and may exit the state completely by Noon on Friday. For a graphical depiction of what is expected, please view the graphic below:



Yes, the image is hard to read... It has to be to put in all of the different precipitation types and amounts that are expected with this storm. Essentially the blue circle represents areas where more than 4 inches of snow is possible; the yellow represents up to an inch or more of sleet; and the red indicates areas where more than a tenth of an inch of freezing rain is possible. Enjoy this weather!