Today's Weather Discussion: Winter Takes Hold
Winter has certainly made its presence felt today! Snow lovers got their wish as much of the region east of the Mississippi River received the first accumulating snow of the season. If you would like to check out the snow totals from around the region, click here to view the latest snowfall totals from the Paducah National Weather Service. The totals I've seen generally range from 1-3", with a few 4" totals in Southern IL. While this storm has led to some travel difficulties and uncomfortable conditions around the Local 6 area, it has been a dangerous and historic storm for parts of the upper Midwest. No place felt the wrath of this system more than Minneapolis, MN, where over 15 inches of snow fell. All of that snow proved to be too much for the roof of the Metrodome, home of the NFL's Minnesota Vikings. The roof collapsed under the weight of the snow early this morning, providing some incredible video that you can see by clicking here.
Before we move on to the upcoming forecast, a quick word on the forecasting methods with today's snowfall. This event provided an example of a situation where it pays to stay on top of the forecast as things evolve during the life of a storm system. If you have listened to our forecasts over the past few days, you'll recall hearing "little to no accumulation" a couple of days ago, and a forecast of 1/2"-1" on Saturday morning. At the time, the forecast models we look at were all in pretty good agreement on those amounts, and so that was the logical forecast to make. As I mentioned a day or two ago, our area usually picks up most of our significant snowfalls when an area of surface low pressure moves from the southern Plains, taps into Gulf moisture, and tracks about 100-150 miles south through the TN valley. This system was much farther north, sending a surface low through Iowa, northern IL, and toward the Great Lakes....not the typical location for accumulating snowfall for us. What happened with this storm system is that because the surface low was very strong, it was able to wrap moisture around the back side of the low and into a secondary "upper-level" low that developed to the SW of the surface low, and tracked just to our north. This created our snowfall today. Normally, any precipitation associated with an upper-level low is quite light, since most of the available moisture in a system is found to the east, or ahead of the surface low. This storm was an exception in that the forecast models never really caught on to how deep the surface and upper lows would become. Finally, by Saturday afternoon, models started to catch up and figure out what was going on, and we were able to ramp up our snowfall forecast accordingly. Especially during the winter, storm systems are constantly evolving, and it's important to be aware of the very latest forecast to see what has changed over the past few hours.
Alright, onto what to expect over the next several days. Winter appears to have taken hold in a big way, as we'll be in a deep freeze for the next couple of days. With a good snowpack in place, temperatures will get even colder than forecast models have suggested. NW winds will continue to make things quite miserable too, blowing from 15-25 mph tonight and tomorrow, with an occasional gust to 30-35 mph. Here's what we're going to have to deal with:
Tonight: Lows from 7-12.....wind chills as cold as -5 to -10.
Monday: Highs from 17-22....wind chills from zero to 10 above.
Monday Night: Lows from 6-11.....light wind, little wind chill effect.
With these temperatures, driving conditions are going to deteriorate tonight and tomorrow morning....and again Monday night. The salt used by road crews becomes ineffective at temperatures below 18 degrees.....so any wet or slushy roads will refreeze tonight. This will result in some slick roadways tonight. In addition to that, blowing snow will drift across previously cleared roadways. Bottom line, be sure to leave plenty of extra time for travel, take it slow, and allow lots of extra room to stop or turn.
Now onto the really fun stuff.....more wintry weather appears to be possible as we look to the middle of the week. An area of low pressure is expected to develop over the central Plains by Wednesday. While a shallow pool of freezing air stays in place here at the surface, a warm advection pattern will bring moisture and a layer of milder air up over the top of us. This may lead to the development of some light freezing rain on Wednesay, and possibly a mixed bag of precip early Thursday. Here's a look at a forecasting tool called "Bufkit" that we sometimes use to analyze precip types and amounts:Notice the red bars in the middle? That is the model indicating freezing rain. Here is the good news....for now, this does not look like it will produce much precip.....today's forecasts are only indicating about 0.1" of freezing rain. Here's the bad news.....it only takes a tiny bit of freezing rain to make things really slick.....and this may turn out to be one of those "light icing" events that creates some big travel concerns. We're still a few days away from this system, so expect the forecast to be tweaked over the next couple days. Stay tuned for updates.