Happy New Year everybody! As we welcome in 2010, an arctic blast of air will generate some heavy lake-effect snow. Lake Effect Snow Warnings are out for all of our Lakeshore counties through Saturday morning (including Cass), and Lake Effect Snow Advisories are out for Kalamazoo and St. Joseph counties. So how much are we talking about? Take a look at the graphic below. Areas well east of 131 won't see anything but flakes or flurries the next few days. Areas along the lakeshore and south and west of Grand Rapids will see the highest amounts. Through Saturday, some locations in Van Buren and Berrien counties may see 12"-18" of snow, so travel to Chicago is not advised. The Grand Rapids metro area is only expecting to see about 1"-3". Drive safely and a pleasant New Year!
December 2009 Archives
But how are the normals computed? Well, the official "NORMAL" (although I prefer the term "average," since Michigan weather is rarely normal!) snowfall is the average of the totals for a 30-year period, currently 1971-2000. Every decade, those numbers are recalculated, so we'll be due to adjust the averages at the end of 2010.
Where does that put us? I checked the numbers from 1981 to present and found, as you might expect, that recent higher snowfall numbers push our overall average up a few inches, from 72.2" for the season to around 75.5". December, January, and February averages go up, while the fringes of the snow season see numbers drop a bit.
If you take out some of the early-80s seasons with low snow totals, the effect is even greater. From 1989-2009, the average has been about 80.9", with increases in every month except March and April.
It's obvious based on that information that snow totals have trended upward through the last couple of decades. But how much of that is cyclical (there is evidence of ups & downs in such numbers back to the 1950s), and can any of it be attributed to climate change or other factors? That's for us to try to gather data to analyze, and for future meteorologists to decide!
There never seems to be a really good time for a major snowstorm, but during the biggest travel week of the year is especially bad. A low pressure system over Texas, alot of energy in the upper levels of our atmosphere, and plenty of moisture from the Gulf of Mexico will all combine to make some very nasty travel conditions across the Midwest, Northern Plains, Upper Mississippi Valley, and Great Lakes. Places like Kansas, Nebraska, the Dakotas, Minnesota, and western Wisconsin could see 12"-18" of snow by the time this system lifts out of the area. Other states across the Mid-Mississippi Valley will be looking at flooding because of the heavy rain expected. Still more, the Great Lakes is likely going to see a "mix" of various precip...starting with some freezing rain and sleet Thursday afternoon and evening. Along with all of this mess, 20-30 mph winds gusting even higher. Below is a snapshot of watches, warnings, and advisories from the National Weather Service as of Wednesday morning. Notice all the winter storm warnings across the Central/Northern Plains and upper Mississippi Valley. All of West Michigan remains under a "Winter Storm Watch" for Thursday afternoon through Friday afternoon due to the messy mix that will be arriving. If your travel plans allow you to leave early on Christmas Eve, by all means do so. The later the trip is delayed, the more likely it is running into freezing rain and sleet. Drive safely and allow extra time to your destinations...and as always, stay tuned to later forecasts. Have a safe, happy, and healthy Christmas and holiday season!
- Upcoming weather to watch: parts of the Mid-Atlantic are going to get SLAMMED with snow Saturday. The Richmond-Washington D.C.-Baltimore corridor will be under the gun Friday night into Saturday, with snow spreading northeastward from there through the weekend.
A couple of weak systems will slide through the Great Lakes this weekend, with each possibly giving us an inch or two of fresh snow. Some lake-effect or lake-enhanced snow may develop from time to time as well Sunday and Monday.
After a midweek break, medium-range computer models are indicating a more potent system developing and moving into the Great Lakes. However, they're not being very consistent about where exactly it will head, so it's way too early to say for sure whether it will cause travel problems around West Michigan. As we like to say, "Stay tuned for later forecasts!"
- Copenhagen climate talks: As I'm typing this, President Obama and other foreign leaders are still sniping at one another about worldwide greenhouse gas emissions and how their respective nations will cut them over the next few decades. Despite some general agreements, it's unlikely that groundbreaking changes are forthcoming. The international community is always hesitant to impose real deadlines. That creates a very easy return to everyday activity and an eventual changing of the target later down the road, or loopholes that allow nations to avoid the pain that would come with real change. The politicians want to claim victory now, despite the fact that the promises may fall by the wayside later on.
I'm not on board with those who proclaim global doom because of climate change; but if the world decides to tackle this issue, I'd rather leaders do it quickly and efficiently rather than through finger-pointing and rhetoric. Politicians are great, aren't they? Another topic for another day.
- I'm off all next week through Christmas for some much-appreciated family time. Kevin will carry you through the holiday, and I'll be back on Monday the 28th. Until then, thanks for following FOX 17 Morning News and for supporting what we try to do in the weather department. Merry Christmas!
-JS
Snow will gradually spread into West Michigan during the day today, but minimal accumulation by this afternoon's commute. Snow will continue to increase into this evening:
That heavy band of snow will develop and lift northward into central and northern Lower Michigan overnight. South of Grand Rapids, accumulations will be less as a mix of sleet, freezing rain, and rain moves in. The question tonight is where the precipitation remians mostly snow, as those places will see the highest totals through early Wednesday:
You'll notice some wide ranges of numbers there... that's intentional because of the uncertainty associated with the type of precipitation that will fall overnight. Our Future Track computer model brings in much more warm air, and as a result cuts most of those snowfall numbers in half. That's not a likely outcome right now, but be aware that it's possible that the snowfall totals are limited a bit into early Wednesday.
We'll see a bit of a break early in the day Wednesday as the main area of low pressure swings through. But once it does, cold air will rush in, winds will pick up dramatically, and temperatures will drop. That means roads will ice up Wednesday afternoon and evening, with heavy lake-effect snow developing. With wind gusts around 40-50 mph, that will create near-blizzard conditions from along U.S. 131 westward to the lakeshore.
Here is the computer forecast of winds Wednesday night... the red and pink colors indicate wind gusts approaching 50 mph:
Snow and blowing snow will continue Thursday and possibly into Friday too before it really starts to lighten up. To complicate matters further, temperatures in the teens to around 20 for most of that time, which is in the range where road salt and chemical treatments are not as effective. It is likely that many of the lake-effect snowbelt regions along and west of U.S. 131 will end up with snowfall totals around a foot, with additional blowing and drifting, by Friday.
Please be safe over the next couple of days! Check for updated Interactive Alerts here... and updated forecasts here.
As if parts of West Michigan haven't seen enough lake effect snow lately...15" in Marne, 14" in Comstock Park, 12" in Walker and Allendale, and 14" in Coopersville. A major winter storm (still developing in California as of Sunday night) will draw up plenty of Gulf moisture and pull down the coldest air of the season and sweep across the Midwest and Great Lakes. Winds will begin picking up Tuesday afternoon/evening as the precip develops across the area. If the storm system tracks further north and west, then West Michigan will likely see more liquid and mixed precip with less snow. However, a track further south and east means less liquid and mixed precip and alot more snow. Preliminarily, the heaviest snow looks to be from Grand Rapids to the north with about 6"-12" possible. We have the chance to see some rain or mixed precip during the morning hours Wednesday before changing to all snow as a major winter storm system and low pressure track directly over the Great Lakes. Winter storm watches have already been posted for Tuesday and Wednesday from National Weather Service offices in Green Bay, Milwaukee, and Chicago. Winter storm watches are expected to be forthcoming sometime on Monday from the NWS office in Grand Rapids. Our forecast models are indicating that strong west/southwest winds will develop behind this storm. That means more lake effect snow across the heart of our viewing area all the way in to U.S. 131. This is expected to be a brief shot of the coldest air of the season. Highs only in the low 20s with windchills in the single digits. Regardless of which way the low pressure system tracks on Wednesday, heavy lake effect is imminent with
1"-2" snowfall rates per hour and near white out and blizzard conditions (at times) with the strong winds. Get the snowblower ready!
Below is a snapshot from our computer forecast model Tuesday at 7:00 PM. Note the expansive area of wet, heavy snow across the upper Midwest and Great Lakes. As the low briefly wraps some warm air into its core, freezing rain, sleet, and rain are also likely.
Below is another snapshot from our computer forecast model showing Wednesday at 4:00 PM. Note the location of the low, very strong winds behind this system (40-50 MPH), and heavy snow. I would expect a "flash freeze" Wednesday night going into Thursday morning as temps fall from the low/mid 30s into the teens. Then, heavy lake effect snow is likely along and west of U.S. 131 with the coldest air of the season coming across Lake Michigan. Plan accordingly and don't get caught off guard with this system. The possibility exists for 6"-12" of snow with the low, then at least another 12" or more of lake effect snow Thursday, Friday, and slowly tapering off Saturday. Drive safely!
As of midnight Thursday evening, the National Weather Service has upgraded to Winter Storm Warnings for Muskegon, Kent, and Ottawa counties with 6"-10" likely across some locations in those areas. Winter weather advisories are in effect for Allegan and Newaygo counties with 3"-6" possible there. Much lesser amounts 1"-3" elsewhere. This is obviously our first big snowfall of the season, but it will certainly be one to remember. There are essentially three things working together to produce the"perfect first" lake effect event. One, is plenty of energy in the upper levels of the atmosphere rotating through the Great Lakes. Two, enhancement from Lake Michigan. Three, just good old fashioned lake effect where colder air flows over the relatively warmer waters of Lake Michigan, picks up moisture, then deposits it in the form of snow on the lee side of the water. In order to get optimal lake effect, we need temperature differences between the lake and the air about 5,000 feet above the surface of at least 13 degrees. (More is better). We also need a saturated airmass (which we have with all the clouds). Finally, upper level energy just acts as an additional catalyst to create extra lift in order to sustain and enhance the snowfall. All of these things combined has already produced some lightning in Ottawa county around the Hudsonville area, plus one inch snowfall rates per hour.
Below is a snapshot of our latest computer forecast model we use here at FOX 17. It shows the heaviest snow setting up in dark blue and purple across southern Muskegon county, northern Ottawa, and portions of Kent. Other locations are expected to see lesser amounts. Make sure to allow plenty of time in the morning for the commute to work or school, and don't forget to slow things down! For those locations that get little to no snow from this event (Battle Creek/Lansing/I-94 southward, we have more accumulating snow on the way for next week Monday, and again on Wednesday and Thursday with two more systems. Stay tuned to later forecasts!
Lake-effect bands will continue as a rain/snow mix through midday, with a gradual shift inland and transition to all snow by late afternoon and early evening.
An upper-level disturbance is going to swing through tonight and disrupt the pattern a bit, generating a fairly heavy single band of lake-enhanced snowfall this evening and overnight. The biggest question is where that band will set up?
As of early this morning, the heaviest accumulation looked to be down toward I-94... but over time this morning, each computer model has gradually shifted it northward toward Grand Rapids and, now as of 11 AM, the Muskegon area. If that band sits still for a few hours, a narrow zone of 6"+ accumulations are possible, with only 1-3" outside of it. If it swings through the area gradually, the snow will spread out more into a general 2-4" accumulation. There will still be some decent lake-effect possible outside of that main swath, but that disturbance will be the main player.
Here's our latest computer model forecast of regional snowfall through noon Friday:
That dark blue area is the 6"+ zone (near Muskegon, in case you can't see the map outline), and the lightest blue is 2-4" (along and west of US-131 down to Kalamazoo).
Kevin will be updating the forecast tonight at 6:00 and 10:00.
