Friday, May 22, 2015 2:59 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
Not a Complete Weekend Washout
Even though St. Cloud managed its third straight day without measurable rainfall yesterday and will make it four in a row today for the first time since the end of April, another storm threatens to produce rain for a good chunk of the weekend. Unlike last weekend, however, it does not appear that we will see continuous rain throughout the weekend.
Likely Dry Today and Much of Tomorrow
Yesterday was St. Cloud's first high in the 70's (see Yesterday's
High Temperature Map from NWS/SUNY-Albany) since Sunday and we will add today and possibly tomorrow to that streak. There are still enough clear skies ahead of the next developing storm system, now moving into Colorado (see infrared loop from College
of DuPage Satellite and Radar Menu) to allow temperatures to climb from morning lows in the 40's (see NWS
Aviation Center Minnesota map) to the middle 70's this afternoon.
As noted yesterday, this storm is actually broken into several pieces. The water vapor loop from College
of DuPage Satellite and Radar Menu shows the prominent first system in Colorado, but there's another counterclockwise circulation pushing into southern California, one that moved southwestward from the Oregon coast back into the eastern Pacific, and another over British Columbia. Each of these smaller systems will tend to weaken as they try to push northeastward into the Plains. So, there will be holes in the potential showers and thunderstorms, especially this far north.
Some Showers Saturday Night
We will at least see an increase in clouds late tonight as the warmer and more sticky air begins to pump over the drier air near the ground. However, I think we will stay mostly rain-free tonight and through much of tomorrow. With the clouds, lows will be kept to near 50 tonight and the high clouds will knock high temperatures down to around 70 degrees tomorrow. Scattered showers and thunderstorms will move into southern Minnesota tomorrow afternoon and possibly brush our area before dark. The warm front from this system will stay in Iowa through tomorrow night. We will have a 50-50 chance of rain or showers tomorrow night as storms develop along the front and push northward. Still, I don't expect the dousing we saw last Saturday and Sunday through this Sunday morning.
Best Chance of Rain Sunday Afternoon and Night, Monday Afternoon
I now think our best chance of showers and thunderstorms will be from Sunday afternoon until Sunday midnight and again on Monday. That will be the time when the most organized storm in the western US traffic jam will push into Minnesota. So, we could see yet another half inch of rain during this time. The air this storm will work with won't be quite as sticky as last weekend's warm air mass, so I don't see much of a threat for severe thunderstorms.
As was the case early this week, improvement will be painfully slow. We will see a lot of clouds on Monday with some scattered showers, especially in the afternoon, but I don't see an all day washout. Sun will be hard to come by Sunday and Monday, so highs will be stuck in the 60's. At least, that's not the 40's.
Definitely Not 40's on the Back of This Storm
On Tuesday, we will take another small step towards drying out. There will be quite a few clouds around, but I am hoping to see some sun. I can't rule out some scattered afternoon showers. Since the air behind this storm won't be anything like what we had early this week, Tuesday's highs will return to the 70's. The drying out should continue through the middle of the week with a chance for 80-degree highs to return.
This series of storms could produce some severe thunderstorms in the southern and central Plains over the weekend, but the weaker individual low pressure systems make for a less prominent threat of severe weather than last weekend. So, the main problem will be more heavy rain over waterlogged portions of Kansas, Oklahoma, and Texas.
Yesterday's US Drought Monitor did drop much of Minnesota out of the drought category, replacing the rating with just abnormally dry conditions. The drought classification still holds for much of west central, northwest, and parts of northeast Minnesota. I'm not sure I understand why (most of the climate sites in the Red River Valley and International Falls now have well above average rainfall for 2015. Only Duluth is still considerably above average. So, I think that drought map is making mountains out of mole hills.
See Forecast Below
Friday 5/22: Sunny, light winds, and continued seasonably warm. High: between 72 and 76. Winds: S 5-15 MPH. Chance of measurable rainfall: 0%.
Friday Night: Partly clear, breezy, and not quite as cool. Low: between 47 and 52. Winds: SE 5-10 MPH. Chance of measurable rainfall: 10%.
Saturday 5/23: Thickening clouds and not quite as warm. A chance of afternoon rain showers. High: between 68 and 72. Winds: SE 5-15 MPH. Chance of measurable rainfall: 30%.
Saturday Night: Cloudy with a good chance of rain or showers. Milder. Low: between 52 and 56. Winds: SE 8-15 MPH. Chance of measurable rainfall: 50%.
End of "Reasonable" Forecast Certainty
Sunday 5/24: Mostly cloudy. Perhaps a morning rain shower. Showers and thunderstorms likely in the afternoon. Breezy, and cool. High: between 64 and 68. Winds: SE 10-20 MPH. Chance of measurable rainfall: 40% in the morning, 80% in the afternoon.
Sunday Night: Steady rain tapers off to occasional showers or drizzle during the evening. Maybe some fog late. Low: between 54 and 58. Winds: E 5-15 MPH. Chance of measurable rainfall: 80%.
Monday 5/25: Continued cloudy with occasional rain showers. Maybe some afternoon drying. Still cool. High: between 65 and 70. Winds: E 8-15 MPH in the morning, SW 10-20 MPH in the afternoon. Chance of measurable rainfall: 60% in the morning, 30% in the afternoon.
Monday Night: Partial clearing, but still mild. Low: between 54 and 58. Winds: SW 5-10 MPH. Chance of measurable rainfall: 10%.
For Entertainment Purposes Only.
Tuesday 5/26: Morning sun, afternoon clouds, maybe a spotty shower or thunderstorm late. Warmer. High: between 74 and 78. Winds: NW 10-20 MPH. Chance of measurable rainfall: 30%.
Extended: Drying out Wednesday. Highs near 80. Even warmer late next week??
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 8 Friday, 6 Friday night through Saturday night, 5 Sunday and Sunday night, 4 Monday and Monday night, 3 Tuesday.
Yesterday's High: 71°F; Overnight Low (through 3 AM): 42°F
St. Cloud Airport 24-Hour Precipitation: None; SCSU Precipitation (Through 3 AM Friday): None
Normal Temperatures for May 22 - High: 71°F;
Next Update: Monday, May 25, 2015 8:00 AM (or as needed)
Ground and Air Travel
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.