Friday, December 6, 2013 6:07 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
"Life in a Northern Town"
Wind Chill Advisory Continues Until Noon Saturday
The full truth of the arctic came raining down on Minnesota yesterday. As is typical of a cold outbreak, skies cleared out, so there was plenty of sunshine (arctic is really a cold desert). The new fallen snow took its effect, reflecting nearly 90% of the sun's energy back to space, so temperatures began at Wednesday night around 10 degrees (see NWS: Last 72 hours of St. Cloud Observations), fell to near zero by late morning, hovered there for most of the afternoon, then resumed its plunge after dark, so yesterday's low was last evening as readings dropped below zero for the first time this season (on the average, St. Cloud has 42.7 such nights).
The blowing snow, when the sun was low in the sky, produced colorful sundogs and haloes in the early morning yesterday. The sunlight shining through some of the blowing snow, bends and in some cases breaks into its colors, producing these sundogs.
Temperatures have continued to fall slowly through the minus single digits overnight (see NWS: Last 72 hours of St. Cloud Observations). The northwest winds aren't as strong as yesterday pre-dawn and early morning, when they reached 35 MPH in a gust at 2:24 AM, but have remained in the 10-15 MPH category for most of the night. That is producing wind chill on the NWS
wind chill chart generally in the minus 20's in central Minnesota (see NWS
Minnesota Hourly Weather Round-Up) with a few -30s reported at Staples, Glenwood, and Wadena. There are also readings in the minus 30s in eastern Montana and North Dakota on the UNISYS hourly wind chill chart. At wind chills of -35, the exposure period is only 10 minutes.
That's why the National Weather Service has a wind chill advisory for most of Minnesota through 9 AM this morning and again for tonight into midday tomorrow. In the St. Cloud area, this advisory continues all day today and through tomorrow noon.
(On the other hand, I walked into SCSU around 4 AM--thanks no DSL service--and the -7 temperature with the -24 wind chill didn't bother me that much. That may be more related to the extra blubber I may have put on in preparation for this cold season).
Keep in mind that these temperatures are too cold for salt to melt ice, so there will continue to be slippery spots on the roads, probably into next week. When temperatures stay below zero, black ice could also form. See the MnDOT Minnesota Travel Information map (slow loading version) or faster loading version for the latest conditions. Also, pack a cold weather survival kit in your car (see bottom of NWS Sioux Falls Arctic Air Outbreak page)
Cold Hard Facts Through Next Week
In case you notice that the part of my forecast dealing with the end of the week through early next week hasn't changed much, you're right. We're well entrenched in the cold steering wind pattern (see water vapor loop from College
of DuPage Satellite and Radar Menu). In this case, there is straight north-to-south movement right on the West Coast, which has produced a hard freeze in the big growing areas of the California Central Valley and the Sonora Desert near the Salton Sea. It's also dropping a decent amount of snow on the Ohio River Valley today (4-8 inches) and producing a major ice storm from Arkansas and Texas to Tennessee, Kentucky, and southern Ohio today. There will be huge numbers of customers losing power as 1 1/2-3 inches in ice has already been reported from the Dallas-Fort Worth area through southeastern Oklahoma, most of Arkansas, and southern Missouri.
For us, we will be relatively storm-free for the next week, but we will see this cold high over Nebraska (see NWS
HPC Latest North American zoom-in surface map) hang around through tomorrow and the next one in northern Alberta swoop in for the first half of next week. (see NWS HPC 0-7 day forecast map loop) With the high moving closer to us during the next 24 hours, the winds will ease off, but any stirring with these cold temperatures (highs only around zero at best today and tomorrow; lows in the minus teens to perhaps minus 20 early tomorrow morning) will produce wind chills in the -35 to -20 range. That's why the wind chill advisory will continue until midday tomorrow.
It's not unusual to have highs at zero or colder during an arctic outbreak in St. Cloud (the average is 4.3 days per cold season), but we haven't had a cold season with at least that many sub-zero highs since 2008-2009.
Chance of Light Snow Sunday and Sunday Night
We will see a slight warming tomorrow night into Sunday as a new West Coast storm, which will dump a lot of snow on Oregon, northern California and Utah today and tomorrow, moves into the Southern Plains by Sunday, then tracks to the Great Lakes by Monday. We will be on the far northern fringe of this storm, so there will be very little moisture available. However, with such cold air over us (I still expect highs to be no better than the lower teens on Sunday), it doesn't take much moisture to squeeze out an inch or two of very fluffy snow. So, we could end up with as much as 1-3 inches of snow from Sunday into Sunday night.
That next high pushes in after this storm goes by, so we will have another blast of cold air. Yes, it looks like the leading edge will come with a lot of wind, so expect temperatures to begin Monday around 5 degrees, fall to around zero and hover there for most of the day. With the northwest winds at 15-25 MPH, there will be blowing and drifting of the snow pack and wind chills getting down into the minus 20's once again Monday and in the -35 to -20 range Monday night. Don't expect the next shot of cold air to loosen its grip on Minnesota until at least next Thursday. We'll have to see if we have a night with calm winds that could have temperatures make a run at the -20s. This is fairly routine for an arctic outbreak (the average is 5 days per cold season), but St. Cloud hasn't had a low of -20 since Feb. 10, 2011.
Wrap-Up Of Early Week Snow: Two Harbors Wins
All of the reports are in from the December 2-4 snowfall across Minnesota. In central Minnesota, a station near Hillman reported 9.2 inches, but that was dwarfed by the 1 1/2 to three feet seen from Moose Lake and the Duluth area up the North Shore. Duluth ended up with 23.3 inches, the 6th highest storm total snowfall, but the golden shovel goes to the cooperative observer northwest of Two Harbors who saw 35.3 inches this week. Beaver Bay saw 34.5 inches.
You can see the effect of this storm on the snow cover across the Northern Plains during the last two weeks.
Climatology of First, Continuous Snow
So, St. Cloud is now under snow cover for the fourth straight day. With these cold temperatures, that snow won't leave any time in the next week plus. St. Cloud's average of nearly three months of consecutive days with a snow cover (86 days on average) has begun about a week early (average is around December 10). Last winter's 120 straight days with at least an inch on the ground (and 140 days total) began on December 8.
The November 2013 and Fall 2013 St. Cloud weather summary is now available. Yes, it was cold (about a degree and a half colder than average), but it's one of the few (3) cold Novembers since 1996.
See Forecast Below
Wind Chill Advisory Continues Through Noon Saturday
Friday 12/6: Sunny, still bitingly breezy, and even more January-like. High: between -4 and +2. Winds: WNW 10-20 MPH. Wind chill: between -35 and -20 in the morning, between -25 and -15 during the afternoon. Chance of measurable snowfall: 0%
Friday Night: Clear, but still a biting breeze, and very cold. Low: between -20 and -15. Winds: W 5-12 MPH. Wind chill: between -35 and -20. Chance of measurable snowfall: 0%.
Saturday 12/7: Sunny, less windy, but continued January-like. High: between -4 and +2. Winds: W 5-10 MPH. Morning wind chill: between -35 and -20. Chance of measurable snowfall: 10%
End of "Reasonable" Forecast Certainty
Saturday Night: Clear evening, clouding up late at night, and not quite as cold. Low: between -12 and -7 evening, rising to near zero by morning. Winds: light SE. Wind chill: between -22 and -10. Chance of measurable snowfall: 10%.
For Entertainment Purposes Only.
Sunday 12/8: Cloudy with a chance of light snow developing and not quite as cold. High: between 10 and 15. Winds: SW 5-15 MPH. Chance of measurable snowfall: 40%.
Sunday Night: Cloudy with light snow or flurries continuing until midnight, partial clearing, with increasing wind late. Between a dusting and 3 inches of new snow could fall between early Sunday and midnight Sunday night. Low: in the teens evening, falling to near +5 by morning. Winds: SW 5-15 MPH, turning to WNW 15-25 MPH late at night. Wind chill: between -22 and -10 by morning. Chance of measurable snowfall: 40%.
Monday 12/9: Right back to the deep freeze with dangerous wind chills. Temperatures steady near zero. Winds: NW 15-25 MPH. Wind chill: between -25 and -15. Chance of measurable snowfall: 10%
Monday Night: Mostly cloudy with perhaps a few flurries, windy, and continued cold. Low: between -5 and 0. Winds: NW 10-20 MPH. Wind chill: between -30 and -15. Chance of measurable snowfall: 20%.
Tuesday 12/10: Do you really want to know? Highs: near zero. Winds: NW 10-20 MPH. Wind chills between -30 and -15. Chance of measurable snowfall: 10%.
Tuesday Night: Clear, but still a biting breeze, and very cold. Low: between -15 and -10. Winds: W 5-15 MPH. Wind chill: between -35 and -20. Chance of measurable snowfall: 0%.
Wednesday 12/11: Sunny, less windy, but continued January-like. High: between -5 and 0. Winds: W 5-15 MPH. Morning wind chill: between -35 and -20. Chance of measurable snowfall: 10%
Extended: Start of warm-up on Thursday, but could be a low in the minus -20s on Wednesday night.
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 8 Tuesday through Thursday, 6 Thursday night and Friday, 5 Friday night and Saturday, 3 Saturday night, 2 Sunday.
Yesterday's High: 10°F (set at midnight Wednesday night); Yesterday's Daytime High: 4°F; Overnight Low (through 5 AM): -7°F
24-Hour Precipitation: St. Cloud Prison: None; SCSU Precipitation: None
Normal Temperatures for December 6 - High: 28°F;
Next Update: Monday, December 9 8:00 AM
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!
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go to the Earth and Atmospheric Sciences Department home page.