ST. LOUIS, MO (KPLR) – It is a real challenge to keep the forecast for this winter storm event simple enough to understand, yet, with enough detail to satisfy the viewer’s desire for information and need alert the public. But, I will give it my best shot.
Everything is pretty much on track with my previous forecasts for this event. Some key points:
- This is NOT an epic storm as some in the social media world have described it.
- This IS a solid mid-range ice storm by STL standards and will have some pretty decent impacts on the region for a couple of days…but we can handle this St. Louis!
- This is a multi-day event that will bring several waves of icy weather to the region starting Friday and lasting through Sunday. However, it will not be raining (or sleeting) all the time. It comes in waves that may last for several hours each time. Between the waves of “heavier precip” we will still have freezing drizzle or just plain drizzle depending on your location and temperature.
- The greatest impacts can be broken down geographically into the three zones I have drawn on the graphic below. Please refer to the map and know where you live to get an idea of what to expect. Here is the breakdown by zone.
ZONE 1: Precip begins early Friday morning. It may start briefly as sleet but then kicks to freezing rain quickly. The most substantial freezing rain will come Friday morning into early Friday afternoon. By late Friday afternoon the band of precipitation will have lifted northeast of this region. In addition, temperatures will have rebounded back to just slightly above freezing by late in the day. This means the greatest impact in the region will be during the day Friday. Total sleet accumulation: trace. Total freezing rain: up to 1/3” of glaze ice…maybe a touch more in a few spots. That’s enough to cause some problems for sure. After Friday evening… it appears everything will be liquid in Zone 1.
ZONE 2: Precip begins between 10am and 2pm (around midday). I expect there will be some sleet Friday afternoon with up to ½” of sleet possible in some spots…before the change to freezing rain occurs late Friday afternoon. Periods of freezing rain will continue Friday afternoon into Friday night and Saturday morning. There should be a lull for a while Saturday afternoon before another round of freezing rain develops Saturday night into Sunday morning. When all is added up, the weekend total for glaze ice should range from ¼” to 1/3” in Zone #2 by midday Sunday.
ZONE 3: Precip will be slow to reach Zone #3 Friday…and it is possible only very light sleet falls up here Friday..if anything at all. A better chance for some freezing rain will come late Friday night and on-and-off through Saturday into Sunday. Total glaze ice in Zone #3 will be ¼” to 1/3”.
Despite the expected ice loading of trees and power lines, major large scale power outages are not expected. That is because winds remain fairly light..generally less than 15 mph. By contrast, in 2006, we had frequent gusts to 40 mph which resulted in massive tree and power line damage.
Despite the very mild air earlier in the week, the return to winter cold will be enough to chill road surfaces back to near or below freezing. This means untreated surfaces will become icy…especially bridges, overpasses, on/off ramps, parking lots and sidewalks…but even main roads will be a problem…especially if we get some sleet on the front end.