The Iowa Storm Center Winter Storm Watch was issued Monday and now the final warning product, this is it. Heavy snowfall rates and gusty winds will be the main threat with this system. The full ISC model suite is below, so read on for the details...
A strong pacific storm system will begin to impact the forecast area later this morning through Thursday morning. This will bring a conveyor belt of ample moisture stretching from northeast Colorado through Nebraska and into west/north Iowa. Temperatures are warm aloft across southwest Iowa this morning which will lead to a window of freezing rain for the southwest and south central zones late this morning and through the afternoon. That threat will diminish as cold air will begin to take over the storm system changing all precipitation over to snow by late this afternoon. So, with that, these zones will have ice accumulations before the snow hits. Further north, snow will start to increase across west and northwest Iowa by this afternoon with the activity expanding east into central and eastern Iowa this evening.
Snowfall rates of 1-3" per hour is expected within the deformation band near and north of the rain/snow line stretching from southwest up through central and into a large portion of northern Iowa between this afternoon and through 12 AM Thursday. Omaha/Council Bluffs metro will be the first to get drilled with snowfall rates of 1-3" per hour from 3 PM through 8 PM. The deformation band with these snow rates will lift north into all northern Iowa after 6 PM this evening. During the storms stay, the wind will gust 25-35 MPH this afternoon through Thursday leading to blowing and drifting of snow. Once you factor in the snow with the wind, visibility will likely be an issue as well especially for the northwest half of the forecast area. Eventually, snow will taper off from west to east by Thursday morning as the system departs by midday Thursday. The forecast radar and model image suite for rain, snow, ice and wind are below.
Alert Map - Today through Thursday morning
WINTER STORM WARNING: Effective this afternoon through Thursday morning. Heavy snowfall rates of 0.5-3" per hour for a time this afternoon/evening through late tonight and moderate to heavy snowfall accumulations. Main impacts from southwest, west central, central and through northern Iowa. Refer to the snow model below for accumulation numbers in your area.
WINTER WEATHER ADVISORY: Effective today through Thursday morning. Heavy snow at times this afternoon through late tonight with snowfall accumulations of 2-6" in the advisory zones. Ice accumulations from south central to southwest Iowa.
Rain Model - Valid Today through late tonight
Snow Model - Valid Today through Thursday morning
Ice Model - Valid Today through this afternoon
Iowa Storm Center Wind Gust Intensity Scale -
Level 6. Damage may occur to buildings and trees. Power outages possible. High Profile Vehicle Roll-Over Likely. Do NOT recommend traveling in this zone.
Level 5. Some trees are broken, building damage possible. High Profile Vehicle Roll-Over Likely. HIGH WIND WARNING CRITERIA
Level 4. Slight damage may occur to trees/buildings. High Profile Vehicle Roll-Over Possible. WIND ADVISORY CRITERIA
Level 3. Small branches may break, walking is difficult.
Level 2. Large trees sway, becoming difficult to walk.
Level 1. Small trees sway, breezy
Forecast Radar - Valid today through Thursday
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