A mixture of rain and snow showers is likely today and Tuesday. High temperatures of 40 to 45 will prevent any daytime accumulation, but it is likely that the first snowflakes of the season will be flying. It is also possible to see some graupel mixing in with the rain drops. Nighttime lows should stay just above freezing, so notable accumulations are not expected overnight either. Most of the snow will melt on contact with any ground or elevated surface, however, any brief and localized heavier bursts of snow could allow brief sticking on grassy surfaces before it quickly melts away. Travel impacts are unlikely due to the warm ground. There is no doubt that this is some early season snowfall activity, which is occurring because of a strong upper-level low pressure system that is bringing in temperatures 15° or more below normal for this time of year. Therefore, the daytime is certainly chilly, but I think the good news is temperatures do not drop below freezing, so icy conditions are unlikely and we don’t see a hard freeze. So far, the lowest temperature in Mount Pleasant this fall was an overnight low of 31°, so we have yet to see lows in the 20s and none are currently forecast.
Don’t like mid-October snow? No worries! A warming trend is due in late this week and especially into the weekend. There is no escaping the wind, though. It will be breezy nearly all week. The first half of the week will be a cold wind from the north that results in lake effect rain and snow and the second half of the week will be a warm wind that brings in much warmer temperatures. While Wednesday and Thursday continue to see cloud cover, we expect skies to clear out as we head into Friday and Saturday, which means sunshine arrives with the milder air! Highs should return to near 50 on Thursday before climbing to near 60 on Friday. A moderately-strong Low Pressure system developing over the Rockies combined with a moderately-strong High Pressure just off the U.S. east coast will place mid-Michigan right in between where strong southwest winds will occur, so high temperatures approaching 70 degrees next weekend is a good bet. If we extended the 7-day out further into early next week, there will likely be some rain as the low pressure approaches, but in the meantime, next weekend looks dry, warm, and breezy right now. Here is a look at the next 7-days:
What is Graupel?
Last Thursday, we saw some small hail and graupel mixing in with rain across mid-Michigan. Temperatures were near 50, though, so how was this occurring and what was it? Interestingly, the air a few thousand feet aloft was much colder than what we were experiencing at the ground. In fact, it was below freezing. This means that rain and snow were forming in the clouds and falling to the ground as precipitation. Precipitation is anything that falls from the clouds to the ground, which includes rain, snow, freezing rain, sleet, graupel, and more. As the snowflakes and raindrops were in the air falling toward the ground, the snowflakes began to melt as the air became warmer, while also colliding with other raindrops and snowflakes. As a result, rather than snowflakes reaching the ground, partially melted snowflakes that had collided with super-cooled water droplets were reaching the ground in the form of white, opaque, soft pellets. Unlike hail, graupel is not ice, so it is soft and easy to break apart. That being said, there was also some small hail occurring, which formed in a similar way that it would during a summer thunderstorm. With a similar setup today and tomorrow as highs reach the low to mid-40s with much colder air aloft, we could see more mixing of rain, snow, and graupel.
Mt. Pleasant Almanac for This Week:
Almanac Information is a way to look at normal and record high and low temperatures for this time of year. The normal temperatures are based on the 30-year average high and low for that date between 1991 and 2020. For example, if you take the high temperature for every October 17th between 1991 and 2020 and calculate the average of all 30 values, the result would be 60. Therefore, the normal high for today is 60°. Record high and low temperature data goes back to 1895. Sunrise and sunset data is also provided. All information is valid for Mount Pleasant.
October 17th
Normal High/Low: 60°/40°
Record High: 88° 1938
Record Low: 20° 1902
Sunrise: 7:56AM
Sunset: 6:52PM
October 18th
Normal High/Low: 59°/40°
Record High: 84° 1950
Record Low: 18° 1896
Sunrise: 6:51AM
Sunset: 7:02PM
October 19th
Normal High/Low: 59°/40°
Record High: 81° 1920
Record Low: 21° 1901
Sunrise: 7:58AM
Sunset: 6:49PM
October 20th
Normal High/Low: 58°/39°
Record High: 80° 1953
Record Low: 21° 1902
Sunrise: 8:00AM
Sunset: 6:48PM
October 21st
Normal High/Low: 58°/39°
Record High: 83° 1953
Record Low: 18° 1907
Sunrise: 8:01AM
Sunset: 6:46PM
October 22nd
Normal High/Low: 57°/39°
Record High: 81° 1953
Record Low: 21° 1930
Sunrise: 8:02AM
Sunset: 6:44PM
October 23rd
Normal High/Low: 57°/38°
Record High: 82° 1963
Record Low: 22° 1969
Sunrise: 8:03AM
Sunset: 6:43PM
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-Weather Forecast by CMU Student Forecaster Isaac Cleland