Model Snowfall Potential
Here are a few different model solutions for the upcoming storm system on Tuesday. Keep in mind that it's still pretty early and the ground is quite warm, so much of this would melt on contact. At any rate, I think this will be our first decent chance of accumulating snow across the state. Stay tuned.
Fall Color Update
Typical Peak Color
According to the MN DNR, here is the typical peak of fall color across state. Note that fall colors typically peak across the international border mid to late September, which is only a few weeks away. Meanwhile, peak color in the Twin Cities metro generally isn't until around MEA Weekend.
What Causes Fall Color?
The following information is from the MN DNR via Joe Zeleznik, Extension Forester, North Dakota State University. 2007. Fall Colors of North Dakota. Pages 15-16 in North Dakota Climate Bulletin.
"What Causes Fall Color? The Chemicals! Four main groups of biochemicals are responsible for the various yellows, oranges, reds and browns that we see in the fall:"
"Each has its own color and chemistry. As the amount of these chemicals vary, they will cause subtle variations in color from one leaf to the next, or even from tree to tree. "
"The green color that we see on most plant leaves throughout the spring and summer is caused by a pigment called chlorophyll. Chlorophyll is one of several pigments that gather energy from sunlight in the process of photosynthesis. Chlorophyll absorbs both the blue and the red wavelengths from sunlight, and reflects the green wavelengths. Nitrogen is one of the main components of chlorophyll. As our days shorten and temperatures get cooler, chlorophyll is broken down faster than it's produced. The majority of the nitrogen migrates back to the twigs, where it is stored for next year's new growth. As chlorophyll breaks down, the carotenoids are revealed."
"Many of the yellows and oranges we see in nature are the result of carotenoid compounds. They are what make carrots orange! Carotenoids play a minor role in photosynthesis—they are present throughout the growing season, but are only revealed when chlorophyll breaks down. You are more likely to see brilliant colors when the fall weather has warm, sunny days with cool nights between 32° and 45 °F. Look at a leaf that has been grown in the shade, and you may notice it is a duller color than leaves that grew in the full sun, even on the same plant."
"The reds and purples you see in the fall are caused by anthocyanins, which are what you get when sugars combine with compounds called anthocyanidins. Many things affect the exact color produced by anthocyanins, including the pH (acidity or alkalinity) of the cell sap in the leaves. With an acid pH, anthocyanins are often red; with a more alkaline pH they turn purple-to-blue. Because anthocyanins need sugar for their creation, weather that favors photosynthesis (sugar production) is essential. Bright, sunny fall days produce the best colors. Very little photosynthesis occurs on cloudy days, and rain can actually leach the anthocyanins and carotenoids out from the leaves. Different combinations of anthocyanins and carotenoids can result in there being yellow, orange and red leaves all on the same tree at the same time. The exact color a tree produces will vary from year to year. Some people believe they can force a more brilliant red color by adding acid-forming fertilizers to the tree, especially aluminum sulfate. This method may sound like it should work, but there is no scientific evidence to support it."
"In many forests, oak trees don't add much to the collage of fall colors. They often just turn brown, thanks to a group of compounds called tannins. Tannins are revealed when both chlorophyll and carotenoids break down in the leaves. Some oaks do produce a light red or pink color in the fall, but our native bur oak does not."
(Image below courtesy MNDNR via Park Staff at Mille Lacs Kathio State Park)
How Does Weather Affect Fall Color?
The following information is from the MN DNR via Val Cervenka, DNR Forest Health Specialist.
"Here's why fall colors vary from year to year and place to place:
Weather is most critical in determining the colors displayed each fall.
Colors are best when high quality foliage - a product of a warm, moist summer is exposed to sunny, cool fall days.
Light frosts may also help, but hard freezes can ruin the display.
Physiological stresses placed on trees can impact fall colors.
Cool, we summers can cause premature displays of color.
A mild summer drought may actually increase the display, but severe drought usually dulls colors noticeably. In some cases, foliage may die early and turn straw-colored due to a lack of water.
The slightest changes in weather in September - too warm, too cold, too wet, too dry - can slow color change or cause trees to drop leaves before they change color.
Becuase it is too dry to produce the vibrant reds, yellows, and orages, a severe summer drought will create a landscape filled with the subtler colors of tans, bronzes and auburns."
(Image courtesy MN DNR via Park Naturalist at Fort Snelling State Park)
Minnesota Crop Update
The information below comes from the MN USDA...
Sunday Meteograms for Minneapolis
Here's the forecast for Sunday, which shows chilly sunshine continuing for much of the day. High temps will be lucky to reach 40F. A brisk WNW breeze will make it feel even cooler
Sunday Weather Outlook
High temps on Sunday will only warm into the 30s and 40s across the state, which will be nearly -10F to -20F below average for this time of the year. Bundle up!!
Extended Temperature Outlook For Minneapolis
The week ahead will be extremely chilly for the 2nd half of October. Interestingly, there will be a could of chances for snow. This first system will be on Tuesday and the second will be here on Thursday.
Extended Temperature Outlook For Minneapolis
The extended outlook through the end of October shows some pretty chilly temps. It definitely looks like late Fall weather with highs only warming into the 30s and 40s. We might even see temps only warming into the 20s later this month.
Average First 1" Snowfall at MSP
The first 1" of snow typically happens around the 3rd or 4th week is November. The lastest first 1" of snow didn't fall in the metro until January 1st, back in 2005!
Feels Like November. More Snow Chances
By Todd Nelson, filling in for Douglas.
I don't know about you, but I am suffering from a serious case of weather whiplash. A couple of weeks ago we were dealing with near record warmth and tinkering with the A/C dial, now we're scrambling to find Long Johns and getting snow threats from local meteorologists, what gives?
October can be an interesting month, no question. The extremes have ranged from record 90 degree highs in the Twin Cities metro in 1997 to an historic Halloween Blizzard in 1991.
With that said, our weather is highly dependent on the position of the jet stream or upper level winds. Earlier this month, that river of air was positioned well north of us, which allowed dry and well above average temps to settle in for several days. Since then, the jet stream has become more "zonal" and is sitting over the northern tier of the nation. This has allowed cooler and more active weather to follow.
Another storm system blows into town on Tuesday with the potential of thunderstorms in southern MN and snow possible in northern MN. Talk about weather whiplash.
SUNDAY: Chilly sunshine. Winds: W 5-15. High: 42.
SUNDAY NIGHT: Partly cloudy and quite chilly. Winds: W 5. Low: 28.
MONDAY: More clouds. Light rain/snow mix late. Winds: SSE 5-10. High: 41.
TUESDAY: Rain snow likely. Slushly accumulations possible. Winds: SSE 5-10. Wake-up: 29. High: 42.
WEDNESDAY: Some sun early. Rain develops at night. Winds: WSW 5-10. Wake-up: 31. High: 46.
THURSDAY: Rain & thunder south. Snowy mix north. Winds: NNW 10-20. Wake-up: 38. High: 48.
FRIDAY: Chilly sunshine returns. Winds: NNW 5-15. Wake-up: 32. High: 44.
SATURDAY: Light rain/snow showers possible. Winds: ENE 10-15. Wake-up: 25. High: 43.
This Day in Weather History
1950: Record high temperatures are set across the area as highs reached the mid to upper 80s. Minneapolis and Farmington saw highs of 87 degrees Fahrenheit, while Albert Lea reached 86 degrees.
1916: A blizzard impacts Minnesota. A sharp temperature drop begins as well; Hallock drops from the 60s to 2 above by the 20th.
Average High/Low for Minneapolis
Average High: 57F (Record: 87F set in 1950)
Average Low: 39F (Record: 18F set in 1972)
Record Rainfall: 1.05" set in 1979
Record Snowfall: 1.3" set in 1976
Sunrise/Sunset Times for Minneapolis
Hours of Daylight: ~10 hours & 49 minutes
Daylight LOST since yesterday: ~ 3 minutes & 00 seconds
Daylight LOST since Summer Solstice (June 20th): ~ 4 hour & 48 minutes
Moon Phase for October 18th at Midnight
2.5 Days Since New Moon
What's in the Night Sky?
"The closest new moon of the year was October 16, 2020, at which time the moon was transitioning out of the morning sky and into the evening sky. On October 17, some people might spot the young moon’s rebirth at day’s end. If you do see it, the moon will be low in the west, in the glow of sunset. Be forewarned … this young, pale, fragile crescent after sunset October 17 will be a challenge to spot, even with binoculars, especially from Northern Hemisphere locations. It’s hard to spot a young moon that’s less than a day old (less than 24 hours after new moon), especially in the autumn. If you want to try your luck on October 17, be sure to find an unobstructed horizon in the direction of sunset. Find a hilltop if you can. Bring along your binoculars! Southern Hemisphere viewers will have an easier time spotting the young moon on October 17 than those of us north of Earth’s equator. That’s because it’s spring now in the Southern Hemisphere, and springtime young moons are the easiest to see. From everywhere worldwide, the young moon will appear as a fatter crescent, farther from the sunset and easier to spot, on the evenings of October 18, 19 and 20. Day by day, a wider lunar crescent will appear higher up at sunset and will stay out longer after sundown."
(Image Credit: EarthSky.org)
National Forecast Map For Sunday
The National Forecast on Sunday looks somewhat active across the northern tier of the nation and the central US. Temps will be running well below average across the northern tier of the nation, which will be cold enough for chances of snow.
National Weather Outlook
Here's the national weather outlook through the rest of the weekend and into early next week. Note that weather will continue to remain quite active across the Upper Midwest with multiple shots of rain and snow.
Delta Rains Move Northeast; Heavy Precipitation in the Northwest.
Here's the 7-day preciptation outlook across the nation, which shows some fairly heavy amounts across the Great Lakes Region and the Ohio River Valley. There alway appears to be decent amounts across the Northwest.
National Snowfall Potential
The national snow over the next several days suggests areas of decent snowfall potential as we enter the back half of October.
Ongoing Wildfires in the Western US
Take a look at how many ongoing wildfires there are across the Western US. Of course it has been extremely hot and dry as of late, but recent thunderstorms have resulted in hundreds of new fires since last week. Cal Fire reports that:
"Today Over 8,000 firefighters remain on the frontlines of 20 wildfires across the state, 12 of which remain major incidents. Yesterday, firefighters across the State responded to 38 new wildfires, and despite Red Flag Warning conditions in many areas, all were quickly contained. A Red Flag Warning for critical fire weather continues today in much of the North State for gusty winds and low humidity. Warm and dry conditions persist throughout the State, continuing the elevated fire threat. Temperatures are expected to cool slightly with some humidity increase over the next couple of days, but conditions will generally remain dry with no precipitation forecast for the next week. Since the beginning of the year, there have been over 8,500 wildfires that have burned well over 4.1 million acres in California. To date, the total number of fatalities statewide is 31 and more than 9,200 structures have been destroyed."
The tropics aren't dead yet. There are still a couple of areas that the NHC is monitoring. Will this be the most active Tropical Season on record? Stay tuned!!
Secondary Spike in Mid October?
While the peak of the Atlantic Hurricane Season is behind us (September 10th), there is usually a secondary spikes that happens around mid October. Things are rather quiet in the Atlantic now, but don't let your guard down, things could still get interesting. Stay tuned...
No More Regular Alphabet Names
It has been an active season so far as we've used up all 21 names that NOAA's NHC set for the year. Interestingly, Tropical Storm Arthur developed back in mid May, more than 4 months ago! Since then, we've had a total of 9 huricanes!
We're Into the Greek Alphabet - First Time Since 2005
Not only did we use up all 21 names in the list above, but we've entered the Greek Alphabet, which is only the 2nd time in recorded history that we've done that and the first time since 2005. Delta became the 25th named storm and the 9th hurricane of the 2020 Atlantic Hurricane Season.