St. Cloud, MN Weather Forecast

Storm 1 - Mostly Producing Ice Early This Morning and That Will Continue for a While (6 of 10 Confidence)

The area of precipitation moved into central and southern Minnesota yesterday afternoon (see College of DuPage north central US radar loop) and has persisted overnight night. Temperatures were initially above freezing yesterday afternoon (upper 30's and even lower 40's before the precipitation began; see yesterday's 4 PM CDT NWS WPC North America zoom-in map), but the dew points were primarily in the middle to upper 20's. This meant that the early precipitation would be evaporated by the low-level air, cooling the air close to the ground. The air temperatures at 10,000 feet above the ground are climbing above freezing (see the right hand black line, temperature, nudge 0ºC near 750 mb on the 7 PM CDT Chanhassen upper air report from Wyoming Weather Web). The warm air aloft means that all of the precipitation has changed to liquid form during the late evening with the St. Cloud area having about an inch and a half of snow as of midnight.

To our south, evening temperatures were above freezing and the precipitation was falling as rain, but the low-level cooling supply by falling rain has knocked the early morning temperatures back to near freezing. Temperatures have to get to 32 degrees or colder to allow ice accumulation (a little milder will allow the accumulation on bridges). This is where the greatest potential for ice accumulation will be from the early morning hours until midday (set precipitation type to freezing rain and time tab to 00 UTC Fri, 7 PM CDT Thurs, on the NWS WPC probabilistic winter precipitation guidance).So, the National Weather Service has a Winter Storm Warning through noon today for the Minnesota River Valley through New Ulm, Mankato, and Redwood Falls into the Twin Cities.

In central Minnesota, we will see more precipitation with some light ice accumulation through the morning, but the precipitation is getting more showery in Iowa, so we may not have continuous freezing rain. The temperature will also have a chance to creep above freezing, especially if the precipitation lets up. Still, travel conditions, especially during the morning, will be icy in any area with untreated surfaces. This could spread to secondary roads as long as the ice keeps falling.

The main snow area has been in northeastern South Dakota and eastern North Dakota. This narrow area where temperatures aloft are cold enough to produce a mixed bag of wet snow, sleet, and freezing rain will have the best chance to see between 2 and 5 inches of snow, mainly during the day today (set precipitation type to snow and time tab to 06 UTC, 1 AM CDT, Fri on the NWS WPC probabilistic winter precipitation guidance).

You can trace the advance of Storm 1 using:

• ground reports map (NWS Aviation Weather Center METAR map)
• text ground reports (NWS Minnesota hourly weather round-up)
• radar (College of DuPage north central US radar loop)
• Minnesota road reports (from MnDOT)
• Winter Weather Advisory in effect (National Weather Service)
  • Winter Storm Warning for primarily ice Minnesota River Valley to Twin Cities
• Precipitation Reports from NWS
  • Snow Reports (after 6 AM)
  • Ice Accumulation Reports (after 6 AM)

Storm 2: Rain or Ice Late Friday-Friday Night (Lighter Central Minnesota Amounts??) 4 of 10 Confidence

And, we still have storm 2 to deal with from Friday afternoon until Saturday. There will be less cold air aloft to work with in central and southern Minnesota. I think the main precipitation type in south central, east central, and southeastern Minnesota will be rain with thunderstorms quite possible (severe weather threat to the south; see NWS Storm Prediction Center Day 2 convective outlook).

But, I still see the bulk of the rain being steered northeastward, limiting the heaviest precipitation to the Twin Cities, south central, and southeastern Minnesota.

Underneath the upper air low on the northwestern flank of the storm, there is the potential for a moderate snow accumulation (between 4 and 8 inches; set tab to 12 UTC, 7 AM CDT, Sat. on the NWS WPC probabilistic winter precipitation guidance). The upper air low will track across central or northern Minnesota during the day on Saturday, so a piece of northwestern and north central Minnesota will have a shot at between 2 and 5 inches of snow (set tab to 00 UTC Sun., 7 PM CDT Sat., on the NWS WPC probabilistic winter precipitation guidance).

So, I think St. Cloud, Alexandria, Willmar, and even Little Falls and Brainerd could see some light ice or rain on Friday night (set precipitation type to freezing rain, and set tab to 12 UTC, 7 AM CDT, Sat. on the NWS WPC probabilistic winter precipitation guidance), then occasional wet snow showers on Saturday (possibility of at least an inch a bit to our north on the NWS WPC probabilistic winter precipitation guidance). I could see a brief coating of snow accumulating during the heaviest snow showers, since temperatures would be held to the 32-34 degree range, but I think the snow would begin melting as soon as it lets up, since our temperatures should be able to make it into the middle 30's.

Melting to Begin, But Still Cool Until Early Next Week

Beyond Saturday, slightly milder temperatures would mean that temperatures should climb above freezing each day, so any snow or ice will melt rather quickly. However, there will be a lot of clouds as pockets of cold air aloft move through. And the winds will remain strong. With temperatures likely to remain colder than the early April averages (highs only in the upper 30's to lower 40's), some moisture in the air, and the persistent wind, it will still feel miserable. There are no more storms on tap through Tuesday, but the forecast gets uncertain beyond then.