Tuesday, March 26, 2019  4:10 AM

Brief Bounce Back to Balmy Temperatures

Cooled Back to Average Yesterday

Slightly cooler air moved into Minnesota yesterday, so high temperatures were limited to the lower half of the 40's (see 3-day loop of high temperatures from NWS/University of Albany), despite a good supply of sunshine. Over the past few days, the snow pack has almost completely disappeared in southern and southeastern Minnesota (see NWS NOHRSC snow depth map), but the main change over the past 5 days has been the disappearance of the dark blue (over 20 inches) across much of the Red River Valley. Still, in the current cycle of daytime temperatures above freezing and overnight temperatures below freezing (see 7-day graph of St. Cloud surface temperatures from MesoWest), the flow of the melt water into streams and rivers is as modest as possible given all of the snow to get rid off.

40's Today, 50's and Perhaps 60 Tomorrow

Today and tomorrow, milder air will again try to work its way into Minnesota, this time from the bare ground areas of Kansas and Oklahoma, where highs were in the upper 50's and lower 60's yesterday (see the 3-day loop of high temperatures from NWS/University of Albany). Again, there will be a struggle to push out the leftover cold air and some of the sun's heat will be lost to melting snow. But, with less snow on the ground to begin and a better chance of a strong south wind today and tomorrow, we should see temperatures make it well up into the 40's today and have a strong chance to top 50 degrees tomorrow. Some areas of southern Minnesota will definitely see highs in the 60's and there may be a few temperatures close to 60 in central Minnesota. That south wind will help us heat up more than we did last Saturday.

There will be more clouds around today than we saw yesterday as there is some moisture trapped in the low level cold air to our west (see Shortwave Albedo from Colorado State slider menu).

More Persistent Cool Weather to Take Over Second Half of Week

However, during the second half of the week, the northwest-to-southeast flow that is pulling cold air into eastern Canada and the Northeast (see North American Mid-tropospheric water vapor loop from Colorado State slider menu) will get going across the Canadian Prairie Provinces. This will route much colder air into Minnesota (you can see the blue, colder than average air move southward from the Arctic Coast by tomorrow and some of that air will reach Minnesota by Thursday (see 850 mb Northern Hemisphere temperature map from Kyle Griffin Global Forecast maps). This first surge will simply knock temperatures back to more seasonable levels. Highs will remain in the 40's on Thursday with perhaps a shot at 50 on Friday. A secondary surge of cold air will move from Hudson Bay into Minnesota over the weekend. The computer forecasts disagree about how cold this air will be with the European Centre projection colder than the US version. That could knock high temperatures down into the 30s over the weekend at the very least. Throw in a biting north wind and wind chills will be in the teens to start each day. Still, this air is colder than average only for the season and will be nothing like the cold air we had seen earlier during the winter.

The second surge of cold air will likely keep a Plains storm, that will break off from the giant rotating whirlpool of death (sort of) seen over the northeastern Pacific (see Pacific Mid-tropospheric water vapor loop from Colorado State slider menu) and move into the Central US. The US computer forecast brings the possibility of cold rain and perhaps even snow to parts of Iowa on Friday, but that would be the northern limit of the precipitation. If the European forecast is more accurate, the rain and snow would be held even further to the south. This is bad news for the flooded areas of Nebraska, southern Iowa, and Missouri, but will keep the snow melt progress as modest as possible.

We will likely alternate between near average and cooler than average temperatures well into next week.

Flooding Update

In addition to the flood warnings over central and southern Minnesota, the midweek surge of mild weather is expected to produce flooded fields in the southern portion of the Red River Valley, but the slow warm up and lack of rain in the next week will help to keep this gradual.

The major Minnesota River flooding has now closed the Hwy. 41 bridge over the Minnesota River between Chaska and Shakopee (see MnDOT Minnesota road conditions). Also, Hwy. 22 crossing the Horseshoe Chain of Lakes south of Richmond has water on the road. The flooding is still expected to slowly increase as the week goes on. The Sauk River continues to be out of its banks with some surges as ice jams temporarily push water levels higher. The Mississippi River is now out of its banks at Fort Ripley and will climb into Wilson Park and other low-lying areas in the St. Cloud area later this week. Ice jams could make the flooding worse.

There are also road closures scattered in Wisconsin, and Iowa, including both I-29 and I-680 near the Missouri River in the Omaha/Council Bluffs areas. There are no closures listed in South Dakota or North Dakota yet, but the active melting will increase the threat.

Latest 50 Degree High? Nearly a Month Later Than Now

Meanwhile, St. Cloud is about 10 days late for its average date of the first 50 degree high. That's usually around the 13th of March. Last year, which was another late snow and warm-up year, we didn't see 50 degrees until April 19, within a week of the latest date for the first 50 degree high. We will have a good shot at that threshold tomorrow.

Confidence Level: "The Bulb on That Hard-To-Reach Light in the Foyer Will Burn Out"

Tuesday 3/26/2019: Not quite as sunny as yesterday, breezy, and continued seasonably mild. High: between 44 and 48. Winds: SW 8-15 MPH. Chance of measurable rainfall: 10%.

Tuesday Night: Cloudy, breezy, and milder. Perhaps some areas of fog. Low: between 35 and 40. Winds: S 8-15 MPH. Chance of measurable rainfall: 20%.

Wednesday 3/27/2019: Morning clouds, afternoon sun, breezy, and even warmer. A slight chance of a late day rain shower. High: between 57 and 63. Winds: SW 10-20 MPH, shifting to NW late. Chance of measurable rainfall: 20%.

Confidence Level: "Every Time I Try to Put in a New Bulb, the Light Fixture Will Try to Detach From the Ceiling"

Wednesday Night: Cloudy with a slight chance of an evening shower, breezy, and cooler. Low: between 32 and 38. Winds: NW 10-20 MPH. Chance of measurable rainfall: 10%.

Thursday 3/28/2019: Sunny, breezy, and not as warm. High: between 44 and 48. Winds: NW 10-25 MPH. Chance of measurable rainfall: 10%.

Confidence Level: "The Only Way I'll Be Able to Change the Bulb and Hold the Fixture in Place Will Be to Yell At It

Thursday Night: Partly clear, light winds, and cooler. Low: between 25 and 30. Winds: NE 5-10 MPH. Chance of measurable snowfall: 10%.

Friday 3/29/2019: Mostly sunny and continued seasonable for late March. High: between 45 and 50. Winds: NW 10-20 MPH. Chance of measurable snowfall: 10%.

Friday Night: Clear, breezy, and cool. Low: between 22 and 28. Winds: N 8-15 MPH. Wind chill in the teens. Chance of measurable snowfall: 10%.

Saturday 3/30/2019: Sunny, breezy, and colder. High: between 35 and 40. Winds: N 10-20 MPH. Chance of measurable snowfall: 10%.

Extended: Cooler than average temperatures during the upcoming weekend.

Forecast Confidence (10 - "The Rabbits Will Thump, Objecting to Me Yelling at the Light Bulb"; 0 - "I Will Be Hosting a DIY Show on Home Repairs"): 8 Monday through Tuesday, 6 Tuesday night and Wednesday, 5 Wednesday night and Thursday, 3 Thursday night and Friday, 2 Weekend.

Yesterday's High: 42°F; Overnight Low (through 4 AM Tuesday): 20°F
St. Cloud Airport Total Storm Precipitation (through 4 AM Tuesday): None; SCSU Precipitation (through 4 AM Tuesday): None

Next Update: Wednesday, March 27, 2019 8 AM (limited updates this week)

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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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