DES MOINES — This is Winter Weather Awareness Day as Iowans are encouraged to start planning for the cold weather that’s coming and brush up on terminology we’ll hear in forecasts for the next several months.
National Weather Service meteorologist Chad Hahn says some Iowa communities have already had early snows in recent weeks and there’s certainly much more to come. “We know that the season of change is upon us,” Hahn says, “so the more that we can start thinking about it, start to transition our brains from summertime thunderstorm safety and preparedness to wintertime, the better prepared we’ll be.”
Hahn says Iowans need to know the difference between a watch and a warning. “A Winter Storm Watch is when we have the expectations of an event in the offing, and its certainty and the location and specifics aren’t quite clear yet,” Hahn says. “Whenever it gets in the short term, we would upgrade to a Winter Storm Warning. The certainty is there, the details are more clear and we want folks to change plans or make different decisions.”
Iowans will also be hearing about Winter Weather Advisories which involve events that motorists should be able to navigate through safely if they simply slow down and make themselves aware of their surroundings. “The DOT has made it very clear that 75% of crashes occur with events of two inches or less of snow,” Hahn says. “So even though it’s a winter weather advisory, and maybe it’s more of a nuisance level, folks tend to take those less serious and we really want to address that as we go through this winter.”
Forecasters say it appears the La Nina weather pattern will continue into the season ahead, for the third winter in a row. “Typically, those conditions would be set up more favorable for colder-than-normal conditions, the tip of the odds towards a colder winter ahead,” Hahn says, “but when we look for precipitation trends from those La Ninas, we don’t see a real good signal across the Midwest here.”
We still have about six weeks of fall ahead, as winter arrives on December 21st.