Wednesday, December 17, 2014 2:29 AM
Prepared by Bob Weisman
Professor of Earth and Atmospheric Sciences
Saint Cloud State University
Earth and Atmospheric Sciences Department
Saint Cloud and Vicinity Forecast
Welcome Back to December
Clear Skies...At The Wrong Time
We are rapidly approaching the December solstice, the day in the Northern Hemisphere with the fewest hours of daylight. It will take place on Sunday at 5:03 PM. On that day, there will be only 8 hours and 43 minutes of daylight. However, with all the low clouds and fog we've been seeing, even 8 hours of sunshine would sound good. And prospects for at least some sunshine today and tomorrow have improved.
For the first time since 4 AM last Tuesday, breaks in the low clouds developed last evening in St. Cloud (see NWS: Last 72 hours of St. Cloud Observations). There is a relatively large swath of clear skies in the eastern Dakotas into southwestern and south central Minnesota (see Colorado
State RAMDIS Western US Fog/Reflectivity Product). There are still clouds in northern Minnesota, associated with the second of the low pressure systems that pushed right over Minnesota from the northwest yesterday (see water vapor loop from College
of DuPage Satellite and Radar Menu). There isn't much moisture with this low, so it did little more than squeeze out a few flurries. That low is expected to move northeastward today, so we could end up seeing our first sunshine since Saturday the 6th later today.
Where skies have cleared, temperatures have dropped into the single digits above zero, which is 40-45 degrees colder than they were at this time Monday (see NWS Aviation Center Minnesota map). Still, lows in the plus single digits and highs in the 20's are average for mid-December. There are some light winds blowing, but they are nothing like the northwest winds that still gusted to 25-30 MPH yesterday morning. However, the light winds with temperatures in the plus single digits are creating wind chills in the minus single digits where temperatures have fallen below 10 (see NWS
Minnesota Hourly Weather Round-Up).
Seasonable Temperatures With a Shot at Sunshine(!!) Today and Tomorrow
We will have a good chance of seeing some sunshine during the daylight hours today. There will still be some cloudy periods and perhaps an occasional snow flurry until we get rid of this low pressure system over us. Highs will be in the middle 20's, a couple of degrees milder than yesterday.
Milder With Cloudy Periods Over the Weekend
Minnesota will be dodging patches of clouds throughout the rest of the week. A fast moving west-to-east flow (see water vapor loop from College
of DuPage Satellite and Radar Menu) will continue to push the main storm track from the West Coast through the Central and Southern Plains to the Northeast. There will be a series of weaker systems pushing along the US-Canadian border, but little moisture will be able to get far enough north to feed these systems. So, I don't see any system being able to produce the precipitation amounts we saw on Monday. Instead, we will have cloudy periods with a few flurries, mainly from Friday into the weekend.. At this point, I don't see thick enough clouds to produce anything except flurries. There may be the risk of some areas of fog and perhaps some spotty drizzle, but it's too early to be sure. Temperatures will moderate from highs in the 20's through Friday to above freezing over the weekend.
Thawing to Disappear Next Week??
There are now some strong indications that this relatively mild weather will come to an end next week. Much of the mild period was fueled by very warm low temperatures, but 8 of the 9 days between December 7 and Monday had temperatures more than 10 degrees above the average. While this has been going on, really cold air has been trapped in northern Canada with temperatures in the minus 20's and minus 30's on some of the northern Canadian islands (see NWS
HPC Latest North American zoom-in surface map). High pressure is expected to develop over the weekend off the Calfornia coast. This has the potential to turn our upper-level winds to north to northwest, giving a path for that colder air to come in.
Yes, there's a strong Central US in the computer forecasts for December 24 to 25. The current forecasts would give Minnesota a shot at seeing some significant snowfall and would potential cause problems in the flight hubs of Chicago and Detroit. However, it's only a 9 day forecast, far too early to get alarmed yet.
See Forecast Below
Ground and Air Travel
Wednesday 12/17: Mixture of clouds and actual sunshine, a chance of an occasional flurry, not as windy and seasonably cold. High: between 23 and 27. Winds: NW 5-10 MPH. Chance of measurable snowfall: 10%.
Wednesday Night: Partial clearing, light winds, and cold. Low: between 7 and 13. Winds: light E-SE. Chance of measurable snowfall: 10%.
Thursday 12/18: Some sunshine through high clouds, light winds, and continued seasonably cold. High: between 24 and 28. Winds: SE 5 MPH. Chance of measurable snowfall: 10%.
Thursday Night: Increasing clouds with a chance of flurries late, and not as cold. Low: between 16 and 22. Winds: SE 5 MPH. Chance of measurable snowfall: 10%.
Friday 12/19: Mostly cloudy, breezy, and seasonably mild. A chance of a few flurries. High: between 25 and 30. Winds: S 5-10 MPH. Chance of measurable snowfall: 20%.
End of "Reasonable" Forecast Certainty
Friday Night: Cloudy and milder with a chance of flurries. Temperatures holding between 25 and 30. Winds: SE 5-10 MPH. Chance of measurable snowfall: 20%.
Saturday 12/20: Cloudy with a chance of flurries and milder. High: between 32 and 36. Winds: SE 5-10 MPH. Chance of measurable snowfall: 20%.
Saturday Night: Cloudy, breezy, and milder. Some flurries or some patchy fog. Low: between 25 and 30. Winds: SE 8-15 MPH. Chance of measurable snowfall: 20%.
Sunday 12/21: Sunshine through high clouds, breezy, and continued mild. High: between 32 and 36. Winds: S 8-15 MPH. Chance of measurable snowfall: 20%.
For Entertainment Purposes Only.
Extended: Chance of snow Monday??? A colder period begins next week????
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 8 Wednesday through Thursday, 6 Thursday night and Friday, 5 Friday night and Saturday, 3 Saturday night and Sunday, 2 Monday, -10 on Potential Christmas Eve/Day Snowstorm(!!!)
Yesterday's High: 24°F (set at midnight- 1 AM Monday Night); Yesterday's Daytime High: 21°F; Overnight Low (through 2 AM): 11°F
St. Cloud Airport Precipitation: Trace/0.1 inch snow; SCSU Precipitation (Through 2 AM Wednesday): TBA
Normal Temperatures for December 17 - High: 24°F;
Next Update: Thursday, December 18, 2014 8:00 AM (or as needed)
Let me know what you think about this forecast and discussion by emailing SCSU
meteorology professor Bob Weisman. Please note that I make the forecast, not the weather!
Are you interested in studying meteorology? If so,
go to the Earth and Atmospheric Sciences Department home page.