MAJOR NOR'EASTER BLIZZARD POSSIBLE TUESDAY

Here is the latest European model take on the system. The GFS and NAM concentrate the heaviest snow from Boston to Maine, but the Euro has a historic event 3 days from now! While this part of the system will not impact the Midwest, the nation's travel system will ripple delays throughout. Be sure to share with your east coast friends!
This is part of the same energy that will bring a couple inches of snow to the Midwest Saturday night and Sunday.  The forecasted snow amounts are plotted for you below, this comes off the RUC model, which has had a good handle on the system as it developed in southern Canada before crossing into the United States early today. A general 1-3" will fall, with 4" in very isolated locations within the wide band of snow.

Accumulating Snow Sunday

The return of accumulating snow comes back Sunday.  A wide swath of 1-3" will fall Sunday, with the potential of a narrower band of 2-4", maybe 5" in the heaviest locations. Models are having problems pinning down where this may occur, so we have not included in our snow map. As the events draws closer, we will tweak and add details to the map on the left.  The latest trends have been pushing the accumulating snow further south. Stay tuned for more updates throughout the next couple days.

Saskatchewan Screamer to Impact the Midwest Sunday

Current indications are continuing to support an active "clipper-like" pattern to hold across the Midwest over the next week. A weak system will bring light snow showers to Minnesota and Wisconsin Friday into Saturday, but the heaver action comes in again for Sunday.  The above map shows two somewhat consistent models and their take on the snow maker for Sunday.  The trend has been to place the heaviest band of snow more northeast with every model run, something will will need to watch. The trends and data support around 0.3" of precipitation in the heaviest band, and lesser amounts away from the deformation zone.  With such a cold air mass in place, this could translate into a max of 5"/6" of light fluffy snow, with a 18:1 ratio. We are expecting a wide band of 1-3" of snow on Sunday, and the potential of 3-5" in a narrow band of winter weather advisory-like snow. Be sure to stay tune for the latest trends and an eventual snow map on this low pressure system.

Clipper #1, in a Series of Clipper System to Hit the Midwest

A series of quick hitting storm systems coming in from Canada will bring light snow to the Midwest over the next 10 days. The first system comes in tonight and drops around an inch of snow for central and east central Wisconsin.  System number two comes in a little stronger tomorrow for North Dakota and southern Minnesota. The pattern will set up as a northwest to southeast flow, with near average high temperatures across the Midwest. This will allow for more rounds of very light snow in the Midwest, nothing major, but slick road conditions will occur as the light and fluffy snow blankets the ground.

Snow and Dangerous Ice Accumulation Sunday Night

A storm system will bring a large area of precipitation Sunday night into Monday.  The largest concern will be accumulating ice across the Ohio River Valley. An ice storm warning has been issued for the Indianapolis Metro. Current indication are that 0.2"-0.3" of ice will accumulating on surfaces below freezing, including untreated roadways, in the outlined darker pink. This storm has the potential to bring widespread power outages and school cancellations. Outside of central Indiana, winter weather advisories have been issued for areas near or north of the Ohio River for a light glaze of ice.  Meanwhile areas further north will see accumulating snow on the order of a few inches, nothing these areas cannot handle, but it will still impact travel. Be sure to take it slow and monitor the forecast if you plan to travel over the next 12-24 hours in these areas.

Warm and January Thaw on the Way!

After a week of extreme cold and gusty winds associated with wind chill advisories and warnings for much of the week, the tide will turn in terms of temperature by late next week. The map on the left are the forecasted high temperatures for next Saturday using a model blend. Much of the Midwest will be above freezing by next weekend, and with the sun shinning over several days, those piles of snow and snow covered driveways will see some relief, along with your heating bill! The warmth looks to stick around through the following week.

On the right is the 6-10 day temperature outlook from the National Weather Service's Climate Prediction Center.  It clearly shows much of the country, with the Midwest at the epicenter, will be at or above normal high temperatures. The jet stream will push north and winds will shift to a more zonal direction. This west to east flow will create adiabatic warming over the Rocky Mountains. As the air is forced up over a mountain and then forced down, parcels of air will see an increase in pressure but maintain their thermodynamic properties and warm as they sink.  This warmth will manifest itself eastward, into the Midwest and much of the country by the weekend. Below is a map showing just how much above average will get to. Enjoy the warm up!

Accumulating Snow Thursday

A quick hitting clipper will drop several inches of snow across the Great Lakes. Temperatures and wind chills will continue to be in the dangerous category today. With the air being so cold, the snow that falls will be very light and fluffy, and will blow around through the evening and overnight. Travel will be affected in areas that see accumulating snow, as roads treated with salt, with not be affected.   A reinforcing shot of cold air will follow this system, before a warm up by next week.

Accumulating Snow to Return Saturday, in a couple rounds

Major snow droughts in December in areas such as Iowa and Wisconsin will see some relief this weekend. Several inches of snow will blanket areas of brown, barren land by Sunday morning. An area of low pressure currently dumping heavy amounts of snow in the higher elevations of Arizona will makes its trek northeastward over the next few days into parts of the Midwest. As the surface low pressure deepens over northern Illinois, a narrow band of nearly a half of a foot of snow will set up on the northwest side of the track. Currently, models are hinting that the band will set up from central Iowa through northern parts of Lower Michigan, where lake enhancement should provide an amplification in snow totals. Furthermore, eastern Wisconsin could see an inch or two more than surroundings areas as winds will be blowing westerly off the relatively warmer waters of Lake Michigan for a period of time.  This feature will create steep and unstable lapse rates, which may allow for some convection, or thunder in such areas, assuming the dynamics works out as modeled.

It appears there will be two rounds of precipitation that will affect the same areas, but are still associated with the same surface low pressure minimum.  Vorticity (on the right) is basically a measure of spin in the atmosphere, and the more of it, the more upward motion seen in an area, which will then increase the rate at which precipitation falls and accumulates. The first part of the system will move through Saturday morning, and could create some quick hitting snows, but much of this energy will be in the warm, or rainy part of the storm. The more prolonged area of vorticity, "2" will pass through Iowa and Wisconsin by Saturday and will bring with it the bulk of the snow during this time. The exact location of highest values of vorticity will determine who sees the heaviest snow. We will also need to watch where the rain/snow line and thunderstorms set up. The pivoting thunderstorms into cold air can be a tell tale sign off highest snow rates. The NAM model on the left is the northern-most solution, but it brings rain into southern Wisconsin, which will certainly dampen snow totals. The transition line from rain to snow looks to be a quick one, meaning ice accumulation does not look to be much of an issue as vertical profiles through the storm have minimal inversions to create ideal icing conditions.  Meanwhile, another weakening storm system will dump a quick hitting light fluffy snow near the Canada/US border.  This system will pull the stronger cyclone to the north. However, with temperatures so cold, the snow will pile up quickly, as reflected by our snow map below:

Accumulating Snow Likely by the Weekend, Cold to Follow

An area of low pressure will create travel problems in the Midwest by the weekend.  Widespread accumulating snow is increasingly likely as new model runs come in to our weather center. Coincidentally, it appears we will yet again have two pieces of energy coming together over the Midwest to amplify snow totals across the area.
The southern stream will have more moisture to work with, as Gulf air is deposited into the expanding area of cold air to the northwest. Specific accumulations are still unclear, but an area of 3-6" or more would be a good bet at this point.  Snow totals with the northern stream may be on a similar scale, as the snow will be light and fluffy and have the ability to accumulate quickly. Pockets of air below will become trapped within the snowpack, allowing for more beefy totals. Below are two computer model projections of total snow, both are relatively very similar.

As the are of low pressure departs, very cold air will be ushered in from Canada.  Winds will shift to the northwest and open the flood gates of cold Canadian air directly into the Midwest by Sunday. Look for highs to be well below normal, as winter shows its full face by next week.  Below are the temperature anomalies compared to average forecasted off the GFS model.

Winter Storm to Unleassh Widespread Cold Air this Weekend

The next best shot for accumulating snow in the Midwest will come in late this week into the weekend. A rapidly deepening area of low pressure will track through the Midwest Friday into Saturday and interact with a northern stream Alberta Clipper.  Accumulating snow is possible in parts of the Midwest this weekend.  We will look more into the set up early this evening with a post explained the cold and models differences. Until then.

Several Inches of Snow Friday Night into Saturday

A storm system pushing in from the southwest will bring several inches of snow to parts of the area tonight. Winter weather advisories have been posted for the areas seeing the heaviest snow.  It looks like a swath of around 2-3" will pile up before the storm departs, with up to 4", maybe 5" especially in northern Wisconsin, as the system deepens it mean sea level pressure. Areas further south will see most rain than snow, the cut off from accumulating snow to rain will be sharp. A closer look below:

Update: Christmas Eve Winter Storm

Here is the latest: The storm has now began to form over the southern Gulf Coast. It looks to take a track through the Ohio River Valley and lower Michigan, dumping moderate snow on the back side of the system. Unfortunately, models and National Weather Service offices for that matter, are having a tough time forecasting the exact track and impacts. One question is whether or not thunderstorms will take away from available moisture in the cold sector of the system.
Below is our best forecast for the area of snow Christmas Eve.  Winter weather advisories and winter storm watches have been posted in Illinois and Lower Michigan. This is a highly irregular storm system, the origin of development and fact that the Midwest is still waiting for another storm to clear, has created problems in the numerical models. We will make tweaks as needed to the forecast.

Potential Christmas Eve Winter Storm to Strike Midwest with Heavy Snow

The threat of a high impact winter storm is on the rise.  A narrow swath of heavy snow is looking more and more likely, but the exact location is not certain.  This is one of the more complicated winter storm set ups in recent years.  Some models are only putting down a couple inches, while other more consistent ones are putting down 6"+ across parts of the Midwest.  The differences deal with the effects of the northern stream (This Storm).  How much phasing or how far northwest can this system pull in system #2 and how rapidly can it deepen before exiting into Canada.  The storm #2 is still off shore of the Pacific Ocean and has yet to be sampled by on shore weather stations. Once this happens and storm #1 has moved out, confidence will become very high, until then we speculate on the forecast...

We have been talking about this storm for nearly a week now, at two days out the models are coming together but still have their differences!  It appears to be a battle of the High Resolution models vs the lower resolution models. The resolution of model deals with the grid size of the data being put into the model. For example the GFS has a grid size of 27km x 27km while the hi res is 13km x 13km. The trend in both solutions has been to the west, but the high resolution runs have been consistently bringing the area of low pressure up from the Mississippi River Valley and passing it over Lake Michigan, with heavy snow on the back size (Illinois and Wisconsin). Below is the highest amount of snow forecasted by all the models, the 4km 18z NAM, Showing very heavy snow, this is one possible solution:

The above model run is the hi-res NAM, the operational NAM has the system pushing through Michigan, which would leave Illinios and Wisconsin dry. This has been quite the forecast challange. For further inspection, below is the difference in the GFS runs during the afternoon model runs.

One major thing to note, the swath of heavy snow has been much more consistent in the hi-res models, does this mean its more likely? Maybe. This storm has the potential to surprise a lot of people, including local TV stations! We will certainly continue to watch and let you know what we know.  Before we leave, here are the latest thoughts and tidbits to leave with:

• The possibility of a winter storm affecting the Midwest is above 70%
• The Hi-Res models have been very consistent in forecasting heavy snow
• Illinois and Eastern Wisconsin have the best shot at over a half foot of snow
• The trend has been to the west
• We will update throughout the next couple days, here and at our Facebook Page, be sure to give us a 'like'

Additional note: One thing to look for in winter storms is where the thunderstorms and convection parameters set up, the Hi-Res NAM show thunderstorms wrapping into the cold air, and changing over to heavy snow...this will tend to amplify the snow totals in such areas.  Here is a snapshot of the change over to snow:

Christmas Winter Storm Likely! Models having Difficulties

Models are all over the place with the Christmas Winter Storm.  The trend has been to the west, which is common with such a complex and strong area of low pressure.  The afternoon will be spent sifting through the latest date and model outputs. We are working on a more formal post on this system that will be posted early this evening, be sure to check back. You will not want to miss this one!

Pre-Christmas Blanket of Snow for Parts of the Midwest

The northern stream of a large piece of energy will dump several inches of snow in parts of Minnesota, Iowa and Wisconsin.  As moist gulf air streams north into Wisconsin, just enough cold air will be in place to produce accumulating snow. Northern Wisconsin will see the area of largest deformation and consequent moderate snow, 3-5" with an isolated 6" amount is likely. A wintry mix or all rain can be expected points south. A larger winter storm will impact the Midwest Christmas eve! An update will be posted latest today.

'Tis the Season, Winter Storms, Blizzards oh My

A complex and possibly travel crippling area of low pressure will affect the Midwest Christmas Eve into Christmas Day.  The pattern next week will feature two storms, both a which will have a travel impact. However, models continue to be all over the place with the track, timing and extent of the cold air. We are still 4-5 days out, which is on the edge of confidence for most winter storms.  The following will lay out the latest thinking, concerns and scenarios for Xmas travel.  Updates will be persistent the next several days.


Concerns and Trends:

• THE TRACK, always the largest component of who sees what, snow or rain
• The strength of storm #1, and its influence on the track of storm #2
• The extent of the cold air, will the strong Canadian air mass crash into the precipitation field fast enough to create the heaviest of snows
• Will thunderstorms rotate into the cold air quick enough, i.e. before it departs into Canada
• Will the pressure gradient forecast pan out, if so BLIZZARD conditions are likely
• EURO vs. GFS  Illinios and Wisconsin 6"+   or    Michigan 4-7"+    or   something else?

Something to note:  This set up is eerily similar to a winter storm from November 24th.  A strong surface cyclone with the influence of a northern stream dumped near 6" of snow in parts of Wisconsin (Post). Models did not show the heavy snow until a few days before the event, as models thought the northern stream would block the cold air from impacting the precipitation field.  This storm, a month later, is even stronger and we are placing a 70% chance of an area of 6"+ somewhere in the Great Lakes by Christmas Day.

The most consistent model (over the past few runs) has certainly been the GFS. It brings a deep low pressure from Mississippi into lower Michigan, dumping heavy snow on the back side in Illinios and Wisconsin.  It has all the makings of a full blown blizzard, with tightly packed isobars in the area of heaviest snow.  The storm will continue to strengthen as it pushes off to the north.

Above are the two latest model runs from the the two major weather computer models.  To wet the appetite, the GFS had a couple runs of 12-15"!  The GFS, or American Model, has been more consistent in a solution similar to this, while the EURO has also been somewhat consistent.  The EURO believes the cold air will not be present in time for heavy snow.  As stated before, recent history would suggest the contrary, but this will certainly be something to watch closely in the coming days, be sure to check back here and our facebook page for continued updates.  To put in proper weather terms...this could be a big one! 

A White Christmas? Major and Complex Winter Storm Possible Dec 22nd-25th

A couple systems will effect the eastern half of the country right in time for Christmas.  A broad area of accumulating snow is possible with storms one, with an area of heavier snow possible for storm #2. Confidence on the first system for December 22nd-23rd is fairly high, but specific track and snow amounts are still up in the air.  The major unknown deals with system number two, where it will go and how it might interact with system #1 somewhere in the Great Lakes, such a scenario would amplify the forcing and subsequent snow in the area.

The Set Up:
A large trough will set up over the eastern half of the country during the time period of our storms.  This will provide the relative cold air needed for snow, but more importantly will determine the track of system number two.  An area of low pressure will develop in the left exit region of a jet core, somewhere over the Mississippi River Valley.  It will then propagate to the northeast, along the jet stream.  The exact location and amplitude of the trough/cold air mass will determine the effects of system #2.

On the left is the vorticity at 500mb along with geopotential heights in solid black contours. Notice signs of the trough, or dip, in the middle of the country.  Areas of positive vorticity advection will likely see ascent and precipitation. This atmosphere is setting up in a way where there is ample vorticity or "spin" to work with.  Along with the fact that system #1 is closed off from the jet stream and not going anywhere until system #2 influences its core, complexity may be an understatement.  The exact influence will need to monitored and we will update as this possibly active period draws closer.

Dreaming of a Midwest White Christmas?

A white Christmas is defined in the record books as a snow depth of at least an inch on Christmas morning. The plot to the left shows the historical percent chance of seeing a white Christmas across the Midwest (courtesy of noaa data). For the most part; North Dakota, South Dakota, Minnesota, Wisconsin and Michigan have the best year to year chance of seeing such an event. After a snowy November brought snow to much of the are, the snow pack has since dwindled, as seen below.  A post about a potential Xmas Eve storm will be out soon!

Dangerous Wind Chills Tonight and Monday

A sharp cold front is passing through the Midwest this Sunday afternoon.  Gusty winds and much cooler temperatures will accompany the front.  Numerous locations in Nebraska recorded a 50-60 degree 24 hour temperature change, near 80 to near 20!  While the change will not be this drastic everywhere, it will begin to feel like winter yet again.  Wind chills will range from 20-40 below zero in the hardest hit locations Monday.  The map on the left shows the GFS model projection of wind chills Monday morning.

Wind chill advisories (light blue) and wind chill warnings (darker blue) encompass much of the upper Midwest.  Much of the winter weather headlines last into Monday.

Winds shift to a more southerly component Tuesday, as warmer weather will return! Temperatures appear to be at or above normal for the next week after Monday and beyond.  For those that hate the cold, just make it through Monday. That is all for now, be sure to check back for future winter weather updates.

Thanksgiving Travel to the East Coast? Beware!

An early season nor'easter is rapidly developing of the coast of Florida and is poised to disrupt the eastern seaboard on the busiest travel day of the year.  This will certainly effect travel at the nation's largest airports and will have a substantial ripple effect through the air transportation grid.  Be sure to check ahead if you are flying in the next couple days, as flights could be effected around the country.  On the left is the official Midwest Weather snow forecast, a special product, as many will be traveling to the east coast for Thanksgiving.

Let's dive into the dynamics of such a strong cyclone.  It actually has orgins in the Gulf of Mexico, noted by the left side of the plot.  A large and substantial area of curvature vorticity will set up in the base of a large trough at around 1:00am Wednesday.  As this "spinning" of the air is advected into the core of our developing cyclone it increases the intensity. However it then becomes more elongated through much of New England (right side), which will stop the system further strengthening.

On the left is the upper level jet stream at 250mb. It shows a large trough over the eastern half of the country with intense upper level winds flying through New England and eastern Canada.  At this time the cyclone is sitting downstream of this trough, which is a favorable location for upper level divergence, which in turn will evacuate mass out the top of the system and increase the cylcone's pressure. Computer models are showing a drop in mean sea level pressure of around 12mb in a 12 hour time period!

On the right is the mid to lower tropospheric relative humidities. The largest take away from this map is to notice the long fetch of moisture that will eventually wrap into the cold sector of the system in New England.  A feed of moisture stretches, without resistance, all the way into the Caribbean.  It has plenty of moisture to work with and a constantly supply.  With ample forcing and intense amounts of moisture to work with, along with very cold air it is now wonder why a foot of snow is on tap for the Thanksgiving eve. Thanks for reading, if you enjoyed what you heard please give the post a share of facebook like to show support. Thank You!