Not a lot of big changes to mention with the new forecast package this afternoon. A major winter storm is still pegged to impact the region beginning early Monday morning and continuing into Tuesday morning. Deep and unseasonably high will overspread the state along the low pressure system, and this will assist in yielding significant snow and ice accumulations across the area with snowfall rates of one-to-two inches likely. Total snowfall accumulations have increased slightly as confidence increases with seven-to-nine inches expected across much of western Iowa.

These totals may still be a bit undercut with the possibility of a nine-to-eleven or even ten-to-twelve inch area being considered across some of northwestern Iowa where the accumulations will be heavier. Nonetheless, with this heavy, wet snow being combined with 20-25 MPH winds (gusting to 40 MPH), dangerous travel impacts can be assumed across much of the area with near-blizzard, completely snow covered roads (potentially combined with ice in central Iowa). Power outages are also possible with trees and powerlines, covered with the heavy, wet snow aforementioned, being blown down by strong winds expected.

Farther southeast, ice is the bigger concern. A quarter-to-half inch of ice is possible across much of southeastern Iowa with locally higher amounts. This will create very dangerous traveling conditions and power outages can be expected with ice accretion on trees and powerlines causing them to potentially fall. Light-to-moderate snowfall accumulations will also be possible here, on top of the ice accumulation, which will create beyond hazardous travel in these areas.

The National Weather Service has upgraded the Winter Storm Watch to a Winter Storm Warning for nearly the entire state, with the exception of Lyon county. I wouldn’t be surprised to see the southeastern counties transitioned from the Winter Storm Warning to an Ice Storm Warning or Freezing Rain Advisory as ice is the main threat there. Nonetheless, these alerts will go in effect at various times (sometime late tonight) and remain through early Tuesday morning.

Here is the original post for a little bit more in-depth information: http://www.iawx.net/2015/12/27/significant-winter-storm-pegged-to-impact-area-late-sunday-through-monday/

Stay tuned to the Iowa Weather Network throughout the event for the latest information!