Wednesday, September 17, 2014 6:30 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
Cold Air Sliding Right On By
We Made It
The average temperature for September 16 and 17 is 70 degrees and, for the first time in a week, St. Cloud got there, despite the chilly start. We have a good chance of getting back there today. We are starting off with some faint low clouds (see infrared loop from College
of DuPage Satellite and Radar Menu), which have kept overnight temperatures in the 50's in much of Minnesota (see UCAR
Minnesota surface chart loop). There is a strong cold front (see NWS
HPC Latest North American zoom-in surface map) associated with the band of clouds near the Rainy River (see infrared loop from College
of DuPage Satellite and Radar Menu). That front will edge into Minnesota during today (see NWS HPC Short-Range forecast map), but we will only be sideswiped by the cold air associated with it as it heads to eastern Canada and New England. So, we should have a good chance at another high in the lower half of the 70's today. The only change you'll notice from the front is a shift to a light north wind.
We will get slightly deeper into the cooler air tomorrow, so highs will take a baby step backwards to the upper 60's to near 70.
Storm Potential Increasing From Thursday Night Into Early Weekend
There will be a low pressure system moving along the Canadian border and into Minnesota by Saturday (see NWS HPC Short-Range forecast map). At first, this system will try to pump warmer air from the south over the cooler air near the ground, so we will see clouds on the increase on Thursday night. There could be a few scattered showers or thunderstorms late Thursday night into the first part of Friday. We will break out into the warmer and much more humid air on Friday. I'm not so sure that we will be able to break out into sunshine Friday afternoon, so I've dropped my Friday high temperatures back a few degrees into the middle or perhaps upper 70's. Dew points well up in the 60's will make it feel quite uncomfortable. We'll have a shot at showers and thunderstorms from late Friday into Friday evening as the cold front tries to push through.
An upper-level low behind the cold front will move into Minnesota on Saturday. That system will bring some cooler air aloft. Combine that with still significant moisture at the ground and it will produce scattered showers and perhaps a thunderstorm Saturday afternoon. That actually may be our best chance for rainfall through the next week. Highs will remain in the middle 70's and it will still feel humid.
Next Cool-Off: Sunday Through Tuesday
Eventually, the pattern across North America with cool air surges moving southward out of Canada and into the Eastern US will repeat itself. In the weekend cool push, we will catch more of the cooler air than we will the next two days. So, look for highs to back off into the 60's on Sunday and only a few degrees above 60 on Monday. At this point, it appears that there will be enough lingering moisture to keep low temperatures from dropping any cooler than the 40's, so there doesn't appear to be a threat of the next frost into early next week. I'll be watching that potential.
Overall, the long-range pattern looks like it will repeat with moderation towards mid-week, then another chunk of Canadian air trying to push south and east by late next week. The details of how cool it could get are uncertain, but a trend seems to be emerging.
Flooding in Arizona, New Mexico Deserts Due to Odile
You can now see the complete circulation of Tropical Storm Odile from its center in the northern Gulf of California to the moisture spread into Arizona and New Mexico on the infrared loop from College
of DuPage Satellite and Radar Menu). Here's a better look. Top winds are down to 50 MPH and the winds are expected to die down more as it moves ashore in extreme northwestern Mexico today. Winds blowing through the Gulf of California could cause flooding problems along the north shore of the Gulf of Calfornia today. In the US, the main problem will be the potential for high rainfall in Arizona and New Mexico. Some of the forecast rainfall totals amount to half (or more) of the average rainfall for the entire year. So, there is concern for the potential of major flooding in Arizona and New Mexico. Flash flood watches are out, covering Las Vegas, Phoenix, southern New Mexico, and El Paso, Texas. If some of the rain could actually reach west Texas, it would help to ease some of the drought conditions there. do at least some gooTop winds are down to 65 MPH and the storm will slowly weaken. However, the area of rain will continue to approach the Southwest Deserts, starting to produce major rainfall by mid-week. Whileany moderate rainfall over the deserts will lead to more flooding problems.
There is now another eastern Pacific Tropical Storm: Polo. This system is expected to strengthen into a hurricane and head parallel to the west coast of Mexico. It could also affect the southern portion of Baja California, but may veer off. And, it doesn't appear it will be able to either get as strong as Odile or maintain its strength for as long.
In the central Atlantic, Edouard did have top winds of 115 MPH around midday yesterday, but has since weakened a bit. The storm is now headed northeastward and well out to sea..On the forecast path, it will be a problem for shipping and something to dodge for Trans-Atlantic flights from South America, but that will about do it.
See Forecast Below
Ground and Air Travel
Wednesday 9/17: Mostly sunny, light winds, and continued warm. High: between 70 and 75. Winds: light W shifting to N 5-10 MPH in the afternoon. Chance of measurable rainfall: 10%.
Wednesday Night: Clouding up and a shade cooler. Low: between 40 and 45. Winds: E 5-10 MPH. Chance of measurable rainfall: 10%.
Thursday 9/18: Early clouds, then becoming partly sunny, breezy, with seasonable temperatures again. High: between 67 and 72. Winds: SE 10-15 MPH. Chance of measurable rainfall: 10%.
Thursday Night: Cloudy with a chance of a few scattered showers and thunderstorms, breezy, and milder. Low: between 52 and 56. Winds: SE 8-15 MPH. Chance of measurable rainfall: 30%.
Friday 9/19: A chance of an early shower or thunderstorm, then some afternoon sunny breaks, breezy, warmer, and uncomfortably humid. High: between 74 and 78. Winds: SW 10-20 MPH. Chance of measurable rainfall: 30%.
End of "Reasonable" Forecast Certainty
Friday Night: Cloudy with a good chance of showers and thunderstorms. Warm and sticky. Low: between 62 and 68. Winds: becoming W 8-15 MPH. Chance of measurable rainfall: 50%.
Saturday 9/20: Partly sunny, still warm and humid, with a chance of occasional afternoon showers. High: between 72 and 77. Winds: W 10-20 MPH. Chance of measurable rainfall: 50%.
Saturday Night: Showers ending evening, then partial clearing, breezy, and turning less humid. Low: between 50 and 55. Winds: NW 8-15 MPH. Chance of measurable rainfall: 30%.
Sunday 9/21: Morning sun, mixed clouds and sun in the afternoon with a slight chance of a shower. A bit cooler. High: between 64 and 68. Winds: NW 8-15 MPH. Chance of measurable rainfall: 20%.
For Entertainment Purposes Only.
Sunday Night: Mostly clear and cooler. Low: between 44 and 48. Winds: NW 5-10 MPH. Chance of measurable rainfall: 10%.
Monday 9/22: Morning sun, mixed clouds and sun in the afternoon. High: between 60 and 65. Winds: NW 8-15 MPH. Chance of measurable rainfall: 10%.
Extended: Continued on the cool side Tuesday. Moderating trend later in the week.
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 8 Wednesday, 7 Wednesday night and Thursday, 6 Thursday night and Friday, 5 Friday night and Saturday, 4 Saturday night and Sunday, 3 Sunday night and Monday.
Yesterday's High: 70°F; Overnight Low (through 3 AM): 54°F
St. Cloud Airport Rainfall (Since 7 AM Monday): None; SCSU Rainfall (Since 7 AM Monday): None
Normal Temperatures for September 17 - High: 70°F;
Next Update: Thursday, September 18, 2014 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!
Are you interested in studying meteorology? If so,
go to the Earth and Atmospheric Sciences Department home page.