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Friday, November 20, 2009 4:16 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
Synopsis:
Dense Fog Advisory from St. Cloud North and West Until 8 AM
Then a Sunny Interlude
Lingering moisture from the low clouds of the past day plus early evening clearing has resulted in a patch of dense fog in central and northwestern Minnesota. The dense fog is just on the western edge of the low cloud area on the Colorado
State RAMDIS Western US Fog/Reflectivity Product and has knocked visibility down to 1/4 mile or less at several stations to the north and west of St. Cloud, as you can see on the UCAR
Minnesota surface chart loop. For this reason, Stearns and Benton Counties are on the southern edge of a dense fog advisory until 8 AM.
The fog should slowly give way as drier air with dew points in the 20's slowly works its way into Minnesota. So, we'll have a sunny second half of the day. Look for highs to again hover around 50 degrees.
We will only see some high clouds spill over the Rockies into central Minnesota, as you can see on the College
of DuPage national infrared satellite loop. So, we'll continue to be mainly clear through tomorrow. The drier air and clear skies should allow low temperatures to drop down into the 20's tonight, then rebound back into the lower 50's tomorrow. There will be more of a wind tomorrow out of the south to southeast than we've seen the past few days.
Then, comes the cloudy forecast for Sunday through Tuesday. It's not that I'm sure it will be cloudy; I'm just not sure what will happen. There will be a series of storms, now in the eastern Pacific on the College
of DuPage national 24-hour water vapor loop, that will move across southwestern Canada and into the Northern Plains. The computers agree on this series of storms, but they widely vary on timing and which one will be the strongest.
There's at least agreement on Sunday that there will be a chance of a few rain showers. I don't think it will be a very good chance of rain and I'm not sure whether the best chance will be in the morning or the afternoon. If it comes early, it is possible that we could see some sunshine in the afternoon, as was true yesterday. What is sure is that it won't be a big deal. With the possibility of at least some sun, look for highs to climb into the upper 40's.
But there's all kinds of uncertainty about any Monday or Tuesday storm. The computer forecast I trust the most is trying to focus the best chance of precipitation on Tuesday. This forecast is also holding off on the colder air behind the storm until Wednesday. That would mean that we would tend to see rain, rather than snow from this system. But this whole scenario is so shaky that I can't rule out that some of the precipitation could fall as snow. Please note that this does not mean that I am sure that there will be accumulating snow either. I just can't tell right now.
For now, I'll go with a vague mixed clouds and sun for Monday with a slight chance of a rain shower, then bring in the best chance of rain or snow showers on Tuesday.
It looks a little more reliable that the coolest air of the season could build in for Wednesday and Thursday. That would be good news for travel conditions, since we should dry out, except for a stray flurry. There is all kinds of jumping around about how cold it would be, but a reasonable guess would be highs in the 30's. On Wednesday, that could come with quite a wind, knocking wind chills down to the 20's. That would come as quite a shock to those of us who have been getting used to temperatures 5-15 degrees warmer than normal, as they have been in November. However, we have had days with highs in the 30's, back during the cold and wet October (10-12). And, we're supposed to have highs in the lower 30's and lows in the teens this time of year.
That line-up of West Coast storms has been causing all kinds of problems along the Washington and Oregon coasts. Up to 5 inches of rain and a foot of snow have been reported in parts of northern Washington. The rainfall along the coast has come with wind gusts up to 60 MPH. There's still plenty of rain as you can see on the College
of DuPage US radar loop, but the focus of the heaviest rain will move to Oregon and northern California over the next couple of days. Still, there are high wind warnings along the coasts, a winter storm warning for northern California and the northern Sierra, and avalanche warnings in the Washington Cascades (since the area with snowfall will now warm up).
The best threat of flooding, however, will be from the strong thunderstorms that have developed over the Texas coast, as you can see on the College
of DuPage US radar loop and the College
of DuPage national infrared satellite loop. Severe weather doesn't appear to be likely, but heavy rain of up to 5 inches is possible today, as you can see on the NWS HPC excessive rainfall outlook and the NWS HPC daily rainfall forecast. This storm affecting Texas, seen as the counterclockwise circulation on the College
of DuPage national 24-hour water vapor loop, will move slowly along the southern US, staying well to our south and keeping the most moisture away from any storm affecting us.
Yeah, We Were at Record Warm Pace, But It's Hard to Keep it Up
Low temperatures stayed up the past two nights, so the November St. Cloud average temperature has steadied at 40.7°F, 9.0°F warmer than normal. That would still be good for second place among the warmest Novembers in St. Cloud records if it holds through the end of the month. If we return to near normal readings next week, it will be difficult to hang on to one of the 10 warmest Novembers.
The National Weather Service has a nice year-at-a-glance graph of St. Cloud conditions on its St. Cloud climate web page.
Review of Winter Hazards Awareness Week in Minnesota
You can still look at the material from winter hazards awareness week, including the daily topics of winter weather advisories and warnings, a review of outdoor weather safety, rules for winter fire safety, how to keep an eye on indoor air quality, and automobile safety in both storms and cold conditions.
You can also go to the NWS Winter Safety Page for the latest advisories of winter-type weather. Still, it doesn't fit this week's weather well.
Links:
Surface
Satellite
Radar
Current Watches/Warnings
Road Reports
Climate
Drought
Forecast: Friday: Areas of dense fog with visibility under a quarter mile until 8 AM. Then, slow clearing and continued mild. High: between 46 and 52. Winds: NW 5-10 MPH. Chance of measurable rainfall: 0%.
Friday Night: Mostly clear with areas of dense fog again and cooler. Low: between 22 and 26. Winds: light SE. Chance of measurable rainfall: 0%.
Saturday: Partly to mostly sunny, turning breezy, and a shade warmer. High: between 50 and 55. Winds: SE 8-15 MPH. Chance of measurable rainfall: 0%.
Saturday Night: Clouding up with some fog and drizzle possible, breezy, and milder. Low: between 38 and 43. Winds: S 5-10 MPH. Chance of measurable rainfall: 10%.
Sunday: Lots of clouds with a chance of a few rain showers and not quite as warm. High: between 44 and 48. Winds: S 10-20 MPH, shifting to SW. Chance of measurable rainfall: 20%.
End of "Reasonable" Forecast Certainty
Sunday Night: Partial clearing, breezy, and still mild. Low: between 30 and 35. Winds: SE 10-20 MPH. Chance of measurable rainfall: 10%.
Monday: Mixed clouds and sun, perhaps a chance of a rain shower. High: between 44 and 48. Winds: SE 10-20 MPH. Chance of measurable rainfall: 20%.
For Entertainment Purposes Only.
Your Weather May (and Probably Will) Vary
Monday Night: Cloudy with a chance of rain showers. Low: between 32 and 37. Winds: E 10-20 MPH. Chance of measurable rainfall: 30%.
Tuesday: Cloudy with a chance of some rain or snow showers. High: between 40 and 45. Winds: NE 10-20 MPH. Chance of measurable rainfall: 30%.
Extended: Turning much closer to normal temperatures (highs in the 30's) Wednesday and Thursday???
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 7 Friday through Saturday, 6 Saturday night and Sunday, 5 Sunday night, 4 Monday, 2 Monday night through Thursday.
Yesterday's High: 49°F; Overnight Low (through 4 AM): 34°F
St. Cloud Precipitation Last 24 Hours: None
Growing Season Rainfall (April 1-Nov 19): 21.13 inches, Normal St. Cloud Growing Season Rainfall: 23.13 inches
Normal Temperatures for November 20 - High: 34°F; Low: 18°F
Next Update: Monday 6:00 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 temporary home page.
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