This might be a good week to enjoy some tea or hot cocoa, as last week’s pattern of above average temperatures changes to below average this week. Highs through midweek are expected to be fairly consistent from day to day, only reaching up into the mid to upper-30s, Monday-Thursday. For reference, temperatures on average this time of year sit in the mid-40s. The temperatures aren’t the only wintry feature of this week’s forecast, with some chances for snow showers expected this week as well. The greatest chances of snow for the first half of the week look to be Tuesday evening through Wednesday, although, models are inconsistent with exactly where in the region snow is expected to be.
At the high range, our area of the state looks like it may see as much as 1-2 inches of snow spread between Tuesday and Thursday. Although, uncertainty regarding exact positioning of snow this far out in the forecast period and warm ground temperatures may keep grassy areas green into mid-week. With overnight lows dipping down below freezing and possibly into the upper-20s throughout this week, soon our ground temperatures may be giving a different story. With timing of any snowfall possibly beginning during the evening commute Tuesday through into the rest of the week, even during light accumulations, remember to “drive slow in ice and snow”, as this may end up being the first real measurable snow of the season here in our area. Tuesday night looks to be the period of gustiest winds through mid-week, with some gusts up to 20 MPH possible. Thursday night into Friday, this cool pattern continues to make its presence known as a cold front passes through our area dropping our temperatures even further. Lake effect snow chances continue into this weekend with highs in the 20s and lows in the teens currently favored.
Cold Continues Beyond the 7-Day
It’s been warm for quite some time this fall with plenty of 60s and 70s lasting all the way through the first third of November. That pattern has now changed and temperatures look to be running well below normal this weekend and into at least the beginning of the week leading up to Thanksgiving. Computer model data is cold, but it continues to trend even colder with each passing day. This idea makes since because it fits well with the negative EPO pattern being off the charts and the position of the Polar Vortex situated on our side of the globe.
Given these anomalies, this advertises highs in the 20s this weekend and during the days leading up to Thanksgiving. Lows would be in the teens if not single digits if conditions become right on the smaller scale. Plenty of snow chances are on the table as well, although details on specifics and amounts are always unclear until we get closer to any given potential accumulating snow event. The bottom line is, the large scale, synoptic pattern supports well below normal temperatures, which means cold and, as a result, snow this time of year.
What is a -EPO pattern you ask? Well, simply put, a negative EPO pattern refers to ridging ongoing over Alaska, which leads to troughing across much of the United States. This means warmer than normal temperatures in Alaska and colder than normal temperatures across much of the United States. As you might notice in the image above, the blue and purple colors are covering nearly the entire U.S., which is indicating below normal temperatures. The dark purple over the Great Lakes and Upper Midwest show well below normal temperatures of 15-20+ degrees. For reference, our normal highs in mid-November are in the mid-40s here in central MI, so that is why highs may only be in the 20s this weekend and potentially early next week as well.
What about the Polar Vortex? It is a real meteorological term that refers to the arctic cold air that usually stays near the arctic. However, it is possible for it to become displaced and move to lower latitudes, rather than only staying at the north pole. When this happens, it makes it easier for the Jetstream to tap into bitter cold air and drag it even further south into the mid-latitudes, which is where the United States is located. As the cold air becomes transported from the north pole to the United States, it does become modified and not nearly as cold as it was when it left the arctic, so we don’t experience exactly what it was at the north pole, but it is still a source of very cold air for us to tap into and bring south into the U.S. when the synoptic pattern becomes favorable to do so. Combine this source of arctic air with the negative EPO pattern discussed previously and you end up with a very cold weather forecast.
Winter Weather Watches, Warnings, and Advisories:
We hear them frequently…Watches, Warnings, and Advisories. But what do they mean? What is the difference between a winter weather advisory and a winter storm warning? What about a watch? Let’s discuss that here:
First, we’ll discuss what a “WATCH” means. Anytime a weather alert is labeled as a “watch,” whether it be a Severe Thunderstorm Watch, a Winter Storm Watch, or some other form of “watch,” it means that the weather conditions being discussed are possible. The details haven’t been ironed out specifically yet, but there is a threat for some serious impacts based on what the forecast is showing, so this “watch” provides an early heads up that something may be coming and you are encouraged to check later forecasts as more details become available.
Second, we’ll talk about the “ADVISORY” and “WARNING” at the same time. This is because both of these terms are used to communicate that the hazard being discussed is EXPECTED. The only difference is that the Warning is more impactful than the Advisory. Typically, during an advisory, weather conditions make daily routines, such as driving to work, more inconvenient than normal. You’ll likely need more time to reach your destination. You’ll still probably be able to do what you want to do, but it will take more time. In some instances, the inconvenience may require you to change your plans. Furthermore, during a warning, conditions will be so severely impacted that plans will need to be changed or cancelled, except for emergency situations. This is because daily routines will become extremely difficult to potentially impossible given the weather conditions.
Since we are moving into the winter season, here are the most common alerts we can expect to see this winter should weather conditions warrant them. These definitions are not perfect and the use of them depends on the situation, but these do provide general insight.
Winter Storm Watch: Typically issued when 6” or more of snow is possible based on the current forecast. This is used as an early alert to let you know about the potential for significant winter weather impacts. When the forecast becomes more certain, it will either be cancelled or upgraded to a Winter Storm Warning or a Winter Weather Advisory.
Winter Storm Warning: Typically issued for 6” or more of snow. Overall, significant winter weather impacts are expected that will make driving dangerous or impossible. In some cases, there can be less than 6” of snow if there is ice that will make things equally as dangerous.
Winter Weather Advisory: Typically issued for anywhere between 2 and 6 inches of snow. If there is blowing snow or ice, an advisory may also be issued to account for the inconvenient travel conditions, regardless of the amount of snow. This can be issued for any combination of wintry weather precipitation that will cause impacts and make travel conditions inconvenient and slow.
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 November 14th between 1991 and 2020 and calculate the average of all 30 values, the result would be 46. Therefore, the normal high for today is 46°. Record high and low temperature data goes back to 1895. Sunrise and sunset data is also provided. All information is valid for Mount Pleasant.
Normal High/Low: 46°/31°
Record High: 70° 1909
Record Low: 13° 2019
Normal High/Low: 46°/31°
Record High: 68° 1953
Record Low: 2° 1959
Normal High/Low: 45°/31°
Record High: 69° 1990
Record Low: 2° 1933
Normal High/Low: 45°/30°
Record High: 69° 1953
Record Low: 3° 1959
Normal High/Low: 45°/30°
Record High: 68° 1958
Record Low: 11° 1924
Normal High/Low: 44°/30°
Record High: 70° 1941
Record Low: 10° 1989
Normal High/Low: 44°/30°
Record High: 67° 1953
Record Low: 13° 1951
Mid-Mitten Weather View’s Mission is to serve people by providing timely information to help keep you safe and make decisions based on the weather. We are passionate about educating both our forecasters and our followers about how weather forecasting works and how we can be best prepared when impactful weather threatens. Our team consists of both CMU alumni degreed meteorologists and current student forecasters from the University. For daily updates, we welcome you to check out our Facebook Page! We look forward to catching you back here next week for another weekly 7-Day forecast update.
-Weather Forecast by CMU Student Forecasters Isaac Cleland and John Jones