Evening Snow

The snow is beginning to wind down as it continues to move to the east.  Please continue to use caution this evening as roads may remain slick.

5:45pm Orfordville, Rock Co - 0.3" Snow

7:00pm - Newark, Rock Co - 1.0"  Snow

Weekend Low Still Trending North

Morning and afternoon runs continued to show a more northerly track with our weekend low passing through northern Illinois Saturday afternoon and into Michigan by Saturday night.  If this trend continues, the chances of a significant snow across the Stateline would likely be reduced as warm air would keep a mix going early Saturday before changing to snow by Saturday evening.  The top image on the left shows the probability for at least four inches of snow while the bottom is for eight.  With this more northerly track, if this were to actually pan out, the heavy snow would be shifted through Wisconsin.  A slight deviation further to the south, however, would bring that heavy snow band down.  Winter Storm Watches have basically been issued for the entire state of Wisconsin, northern Iowa and southern Minnesota in anticipation for this more northerly track.  If the next couple model runs continue to come in with this northerly track, we'll trend down our snowfall totals and increase the chance of rain at the onset Saturday afternoon.

Weekend Weather Update

Wow!  What a difference a day makes!  Yesterday nearly all of our weather forecast models had jumped on the southern track bandwagon with our weekend system and now this morning they have trended further north, way north.  The top image was Wednesday morning's GFS run and had the low moving through the lower Mississippi River Valley Saturday afternoon.  The early morning runs have now trended the low right through Northern Illinois/Southern Wisconsin.  The reason for such an inconsistency - this storm isn't even onshore yet!

A more southerly track would have likely yielded a heavier snow accumulation across parts of the area.  With this more northerly track, there is a greater potential for warm air to initially get wrapped into it which would likely keep a mix going at the onset before changing over to snow Saturday night.  If we were to see a mix, snowfall amounts would be reduced and the heaviest of snowfall would likely occur to the north and northwest of the WTVO forecast area.

One thing that has been very consistent through this whole week is the polar arctic air expected to surge in quickly by Saturday night.  Winds are expected to increase through the night into Sunday with temperatures falling into the middle single digits by Sunday evening.  Winds will be gusty dropping wind chills by Monday morning well below zero!!

Be sure to stay with us throughout the afternoon and into tomorrow morning as we continue to get new data in.  Anyone with travel interests should continue to monitor the forecast.

One...Two Punch

A Winter Weather Advisory is in effect from 3pm to midnight tonight for Rock and Walworth Counties in southern Wisconsin.  A clipper system will move along the U.S/Canadian border drawing in moisture throughout the Stateline.  As it does a few flurries may be possible later this morning, but snow will likely move in during the afternoon and evening.  Anywhere between 1"- 3" will be possible with locations further north of the Stateline closer to the 3" mark.  Once this one passes another system will quickly move in this weekend and could give someone across the Great Lakes a significant amount of snowfall by Sunday morning.

Snow Cover Contributing to Cold Air Outbreaks

One contributing factor to the next cold air outbreak will be the extent of snow cover across the US and Canada. It's only the first part of December, but already much of the northern US and nearly all of Canada have a good snowpack going (see image at right, courtesy of Intellicast). Currently, snow is covering the ground as far south as central Illinois, eastern Kentucky, and the mountains of North Carolina. This snow reflects sunlight back into space, and insulates the relatively warm ground from the cold air moving southward. The coming blast of cold air early next week will invade much of the eastern US -- including interior sections of south Florida where the mercury will plunge below freezing!  --TS

Another Arctic Blast Follows Snow

We've talked a good deal about the coming snow this weekend, and the amount of snow we'll see based on the track of the low pressure system coming our way on Saturday. But we're also looking at an even colder blast of air making headlines behind this low on Sunday into early next week. By Monday and Tuesday morning, we could be looking at our first widespread sub-zero readings so far this year!  --TS

Lastest on the Weekend Weather

With each new day and model run we are starting to get a little better handle on what's going to happen this weekend.  Are we certain...no!  But things are starting to come together a little better than before.  There were a couple things I wanted to talk about to kind of give you an idea of just what we are looking at.

First, this storm is still off shore and isn't expected to come onshore until the next day or so.  As it does begin to move into the Pacific Northwest we will be able to get a better data sample that will then feed into our weather models.  This will help narrow down the potential track.  Secondly - the one model (the ECMWF) which was taking a more northerly track with the low has now jumped on board with it's latest run and pushed the low south.  This is more in line with our other models.  The current track, as of this morning, took the low through southern Missouri and southern Illinois and then strengthened it by Saturday night into the Ohio River Valley.  With this current track the possibility would be there for the heaviest of the snow to miss us to the south.  We would still end up with some (it's still way too early to even talk about totals) but we just might not see a significant amount.  Now I want to stress that any deviation from this track either north or south will play a role in what we get for this weekend.

A clipper system is expected to move north of the Stateline Thursday afternoon into the evening.  Now I'm fairly certain that the associated snow with this will likely not add too much to the current snow we have on the ground or even extend it further south.  But what we will be looking at is just where the baroclinic zone sets up after this clipper system Thursday.  With this weekend storm quickly coming in on the heals of the first one we might not have enough time to get the cold air to settle in.  That could possibly trend a further northward track.  However, the jetstream does dig out through the lower Mississippi and Ohio River Valleys and this would help drive the low.  Looking at how quickly the low will strengthen, there is the chance that it might not really gain strength until it reaches the lower Ohio River Valley which would be a big snow for places like Ohio and Pennsylvania and not so much for us.

Bottom line is this, I do expect some snow for us beginning Saturday afternoon and lasting into Sunday.  The million dollar question, though, is just how much.  As I mentioned before we should really start to get a better picture once we head into Thursday morning.