Thursday, November 19, 2015

Band of Heavy Snow to Coat Major Midwest Cities

A developing storm system will bring widespread heavy snow to the Midwest Friday into Saturday ahead of the coldest air of the season. The heaviest of snow looks to fall south of I-90 and north of I-80 on Friday. Models did come together in recent runs, HOWEVER, the european model has trended south in the last few hours. It is one of the more reliable models and could be on to something. With that said, the map to your left puts weight on prior runs as well as recent ones, a blend of models. For many areas across parts of Northern Iowa and Southern Wisconsin, this will has the potential to be the heaviest snow since the 2013-2014 season, depending exactly where the heavy band sets up! Winter storm watches have already been issued for the northern half of Iowa east through the WI/IL border. Most of these will kick over to winter storm warnings by the late afternoon or Friday morning time period. Otherwise, winter weather advisories will be issue just outside the band of heavier snow.

The timing of the snow has a larger role than usual. With it being so warm in recent weeks, and months for that matter, ground temperatures are rather high. A large portion of the snow will come at night which only amplifies the efficiency of snow accumulation on the surface. It will take a bit to accumulate on pavement, but the temperature and snow rate should overcome the warmer pavement temperatures relatively quickly.

Regarding timing, the storm looks to really ramp up by Friday afternoon. After about 12:00, a band of heavier snow will begin to train over central Iowa through Southern Wisconsin and Lower Michigan. Most of the snow will fall Friday evening into Saturday morning across these areas. This sets up a couple snowy college football games, such as the Northwestern @ Wisconsin games on Saturday. Otherwise, the map should give a general idea when the snow will begin to coast grassy surfaces!

Behind the system winds kick up out of the northwest and usher in cold air from Canada, here is a look at low temperatures for your Sunday. Very cold!...especially with fresh snow cover, off the 12z GFS model. It could be short lived however, as a surge of warm air is possible around Turkey Day! Maybe 15-25 degrees above average!

Wednesday, November 18, 2015

The Transition to Winter to Bring Accumulating Snow

A major pattern change is in the works for the end of the week. This change in weather will make things feel like mid-December across the Midwest and will be a shock to system for many. The surge of cold air will also bring the threat for accumulating snow in a narrow band over parts of Iowa to lower Michigan. Models are beginning to come together this afternoon, but still some uncertainties to work out in the next 24 hours or. The storm system has yet to come on shore the Pacific Northwest, where it can be better sampled in the weather balloon networks and ground reports. Once this happens, the model discrepancies will generally become filtered out. With that said, we will not publish a full snow map at this time, but rather give a more general forecast. As the system emerges out of the Plains it is expected to strengthen and drop several inches of snow on the back side by Friday evening. The heaviest of snow looks to fall from North Central Iowa to the WI/IL border to central Michigan. A half foot of snow will be possible in these areas, with more possible in SE Wisconsin and Lower Michigan as the storm ramps up and lake enhancement aids in the snow development. Be sure to check back for updates, our full snow map and forecast will be posted by this evening our early tomorrow afternoon. In the meantime, check out our social media platforms on the right hand side of the page.

Tuesday, November 17, 2015

Snow, Cold, Winter, Oh My

A pattern change is ongoing across the entire United States this week. A trough in the west will push east in the coming days and cold air funneling in from the north will bring the contrast in temperatures needed for atmospheric lift and precipitation. A wave of low pressure will develop along this boundary and move through the southern Great Lakes by the early weekend. On the cold side of the system a band accumulating snow will set up on the backside of the track of low pressure. We have plotted where "plowable snow" will set up according to three major numerical weather models, or 3"+ of snow. Some models takes the system up through lower Michigan and deepen the surface pressure. This could drop heavy snow over Lower Michigan and ramp up lake effect snows on the back side of the cyclone as it pulls away Saturday and Sunday. The potential exists for nearly a half foot of snow in areas such as Chicago through Grand Rapids, Michigan, with 2-5" as our best estimate over Iowa. With it being 4-5 days out there are a few discrepancies and issues in the forecast:

*The timing...warm ground and pavement temperatures would limit accumulations if the snow comes during the day, accumulates more efficiently at night
*The track...where the low pressure goes will determine the general area of snow
*Phasing...if this storm cuts north as it passes east of the Mississippi River heavier snow could fall

Either way, the storm will bring in northwest winds by Saturday and Sunday which will usher in much colder temperatures across the Midwest by the weekend and beyond. Low temperatures for Sunday morning are plotted below, off the ECMWF model. Notice the lows will be ~10 degrees cooler in areas with fresh snowfall, due to radiational cooling. Keep it here to Midwest Weather for updates throughout the week.

Monday, November 16, 2015

First Midwest Winter Storm?

Models, trends and the atmospheric set-up are look increasingly favorable for accumulating snow across the heart of the Midwest. A band of snow will develop along a line of frontogenesis, or an area where the difference in temperature across two points is increasing. These bands of precipitation can be tough to pin down exact locations, because they can be so narrow and not fully reliant on the track of low pressure. With the said, models are starting to finally agree on the location of such an event. The darker shade of blue is the location currently thought by numerical weather models to have the best chance of moderate snow accumulations. Either way, cold air will funnel in behind the system and bring the coldest temperatures of the season to much of the eastern half of the country by the weekend. A very similar situation set up last November, Post from Last Year, almost a carbon copy! That storm, like many sections of temperature gradient induced snows, trended north with time. This and prior model runs is why we included areas such and Minneapolis to Green Bay in the potential for accumulation. Now the real question, how much are we talking? Well, model runs in recent days have been impressive, but it looks like a general 3-5" with isolated amounts of 6+"  where possible banding could set up. The higher amounts look to develop east of the Mississippi River, lesser amounts west. This will need to be watched closely in the coming days, as we look to pin down the exact location of moderate snow. The pattern looks to kick over to cold and stormy beyond 5 days through the end of the month. You can always watch the snow models come in yourself on our Computer Snow Output page. Keep it here for updates throughout the week and our first snow map of the season when the event gets closer.

**Next update scheduled by Tuesday, 2pm CDT**

Tuesday, October 20, 2015

Official Midwest Weather Winter Forecast & Outlook 2015-2016

Like Us on Facebook                           Follow on Twitter

It's that time of year again, the leaves are changing, the presence of hoodies is on the rise and the wonder of what winter may bring proves intriguing. Long range forecasts are used by businesses to manage risk or manage supply of weather-demand products, they are becoming increasingly important. In the general community, long range forecasts provide for good debate and curiosity. Some people live for the snow and cold, and some could do without. No matter what side of the spectrum you fall, anticipating the upcoming winter can put you in the correct mantra and even plan ahead for those crazy few months of weather. Alright, let us dive into the Midwest Weather Winter Forecast for 2015-2016! Full forecast at the bottom of the page.


Long range or seasonal forecasting can prove to be a challenging endeavor, but understanding the moving parts of the "winter weather system" is not impossible. The key is to understand what factors have the strongest signal to the winter ahead. Last year we were able to pin down isolated features, such as the massive Siberian snow pack and record cold lake temperatures. These features added value to the analog years (or years with similar atmospheric and surface conditions) we chose. This year, we are in and heading to a plateau of near record El Nino conditions. The merit and significance of the warmer than average ocean temperatures in the Pacific will be discussed later.

Current State of Climate System, and ENSO:

Let us begin with Ocean temperatures, or from now on to be called SSTs, sea surface temperatures. Ocean temperatures are the most stable indicator, as water temps do not rapidly change, especially near the equator. Below is a map plotting the SSTs compared to the running mean from 1981-2010 as a good sample size, courtesy of Tropical Tidbits:

There are several areas to point out on this plot, many of which will provide significant clues into the fate of our upcoming winter. The vast area of above average SSTs in the Central Pacific are classified as the positive or warm phase in the southern oscillation, also called ENSO, but more commonly known as El Nino (Saturday Night Live Clip).  This feature on the planet is a stable indicator this winter, as ocean temperatures are forecasted to stay well above normal. However, the trend is to head back towards a neutral standing and possibly La Nina in a year, time will tell. Below is a probabilistic forecast from the Climate Prediction Center, CPC Link.

Furthermore, in relation to ENSO, the waters in the western Pacific are also relevant. Not so much the fact of warmer or colder than average, but rather the location of the gradient from warm to cold. In the Central Pacific a circulation in the vertical, called the Walker circulation develops. It is the main driver of prolonging the ocean anomalies. In an El Nino year, relative low pressure sets up in the Eastern Pacific and high pressure in the Western Pacific. Convective activity sets up in the east and tranquil weather in the west. Consequently, a cold pool of water will set up in the west. This year that transition sets up near the international dateline. This location is key as it affects the mid-latitude jet, and is very similar to the location in 1997 and 1983, which will be helpful in determining analog years, which we will get to further down.

The North Pacific:

ENSO is not the only determining factor, relating to ocean temperatures, next we look to the North Pacific and North Atlantic for more answers. The North Pacific is proving to be the largest wild card in our winter forecast, but let's discuss. At the moment, the eastern shore of the Pacific is seeing above average SSTs, the ocean circulation is slightly weaker, allowing for less upwelling along the coast. This observation does coincide well with the so called, "Super El Nino" of 1997.
This map above was made using an online program courtesy of the Earth System Research Labratory. It shows the SSTs of September through November in 1997 relative to average. This is also described as the warm phase of the Pacific Decadal Oscillation, or PDO. Historic data can be found Here.The Pacific Ocean temperatures match up very well to current conditions. However, an active period in the Gulf of Alaska is working to cool the ocean surface as storm systems continue to roll through the region. Strong surface winds bring cold water to the surface through a process called Ekman pumping. Watching these SSTs evolve over the next couple months could influence our winter, but the current thought is that these waters will stay above average, via climate models. 1997 does provide guidance in terms of the Pacific Ocean, but looking at the Atlantic, this year tells a whole different story.

The North Atlantic:
In terms of the Atlantic, 1957 proves to be a better comparison. The AMO index (Found Here) from 1957 is near 0.2, while this year we stand at 0.3. The confidence is higher that theses waters will stay cool through the season. With the presence of melting fresh water near Greenland and the weakening of the Gulf Stream, the water of the North Atlantic has been cooling for several months now and models hold steady through the winter.

Analog Analysis:

Looking at the variability in ocean temperatures over the course of the previous decade is a proven way to forecast the future, "Learn from your history." However, it may be very difficult to simply look at maps of the oceans to understand exactly whats going on. Dozens of teleconnection indices have been developed to quantify the oceans and atmosphere. We will look at three of the largest players in seasonal forecasts, or the ones that are the most stable; the ENSO, PDO, and AMO, mentioned earlier.  

The Method: 

Since ENSO will certainly be the largest influence in the Midwest weather winter forecast 2015-2016, the strongest El Nino episodes in the last 70 years were examined and the top 11 were chosen. These are the years that will pass through our analog analysis. On the left is historical data from the strongest correlation years, and current data below it. A positive PDO is characterized by warm water in the Gulf of Alaska stretching down through the East Pacific and Central Pacific, with the AMO considering conditions in the North Atlantic. These values were then scaled to give equal weight in determining how similar they are to current data, with the AMO given the least weight, since it is down stream of the Midwest. 

Scaled and weighted values give us a ranking a how similar the conditions of the oceans were in prior years. The ranking gives us an insight into how similar future weather may be in the long run. This analog forecasting method for the Midwest winter forecast 2015-2016 did prove valuable in Last Year's Outlook. It is no surprise that 1957 an 1997 were among the top, but a few other years did make tho list. The red colored years are the top 3 El Nino Episodes since 1950. The following maps will look at a monthly composite of these analog years as they compare to the normal values over the course of the previous century. 

The top 10 analog years were examined and given these weights:

 |1957: 25% | 1987: 20% | 1997:15% | 2002: 10%  | 1991, 1965, 1986, 1982, 1963: 5%


In general, we are looking at a warm and wet start to the season, with relatively cooler and dry weather working in as we close out winter. March is somewhat of a wild card. It will depending on how "wavey" or amplified the jet stream becomes and with a weakening El Nino expected by that time, March is a month to watch, and is not included in our winter forecast.

Putting the whole season together, precipitation values look like this, according to the analogs:
And overall temperature values look like this, according to the analog years:
The Climate models also agree! Check them out below.

There is a lot of agreement between analogs, models, overall patterns, and local effects. Confidence is very high that a warm winter will exist in northern regions, and a drier than usual winter will persist in the Ohio Valley. Overall snow is tougher to predict this year, with near average expected, but the potential exists for a few storms to skew some averages, more discussion below. 

THE OFFICIAL FORECAST: Be sure to share with your friends, the good/bad news!

After several weeks of deliberation and research, we finally come to the official Midwest Weather winter forecast. Based on the prior, it is no surprise we are looking for above normal temperatures across the Midwest, with the warmest air in the northern Great Plains and Great Lakes, cooler south. Lake temperatures are warmer than last year, via GLCFS, which among others is a large factor that trends to a longer lake effect season, but still overall less snow, with the absence of large cold air outbreaks. The past couple winters have featured a dominantly northwest to southeast jet stream, yet this year it will be much more zonal, west to east. Any amplification in the jet could bring us some large winter storms. It looks to be more active than past years, as storms systems originating from the west will have more moisture to tap into, than ones from the northwest. Depending on where each individual storm tracks, snow amounts could be below or above average in the highlighted area. With that said, it does look like more winter storms and less clippers (1-3"/2-4" like systems). Thanks for checking us out, we will continue to bring the latest forecasts heading into the Winter season. 
Feel free to ask questions across Twitter and Facebook, links below. Any personal inquiries can be directed at

Follow the author on Twitter for more conservation: Twitter Link

As Always, the Midwest Weather Facebook page will be very active: Facebook Link

Thanks for stopping by out 2015-2016 Winter Forecast, an update may be posted in November, depending on how much conditions in the North Pacific change, or if there is any new development in ENSO. In the meantime, be sure to keep it here to Midwest Weather for all the latest in weather forecasts and stories around the area. 

Tanner Verstegen
Bachelors in Atmospheric Science
University of Wisconsin-Madison

Thursday, October 8, 2015

Once Hurricane Oho to Bring Record Warmth to the Midwest

It's happening again! A tropical cyclone is set to have a major impact on the weather across the United States. Remember Nuri last year (Nuri Post)? It brought a major pattern change, one to a cold trend. Oho, seen below, is set to have the opposite effect. Its track takes it north right on into the jet stream, which will help to build a ridge to the east of its track. This ridge will then propagate to the east and set up over the mid-section of the country for the weekend, bringing widespread 80s and 90s the parts of the Midwest.
Building the ridge is one way to bring warm weather to the area, but another method is also in play. With the counter-clockwise rotation around the deepening area of low pressure the winds will be out of the SW and create an onshore flow from the Pacific Ocean. As this flow persists, heavy rains will fall in the mountains and air will be forced up the front range of the Rocky Mountains. As this occurs air parcels will cool as they rise to levels of lower pressure. This cooling will allow for saturation to occur and increase the amount of rain in the area.

Then on the lee side of the mountains the opposite will occur. The air that was once going up the mountain will fall down on the opposite side. This will bring warm weather through a process called orographic warming. The air is forced down to higher pressure, which will act to warm the air parcels. The image on the left is the GFS model for 850mb temps Saturday, notice the vast area of warmer temps through the Dakotas and points northwest? Orographic warming can be thanked, along with Hurricane Oho for the pleasant conditions!
The map attached to the right shows just how much above normal temperatures can get on Sunday. The high temperatures on Sunday will run 15-30 degrees above average and record highs will be in danger. Would not be surprised to see some 90s in the Northern Great Plains! The weekend will also feature dry Canadian air, with dew points in the 50s. It can definitely be described as Indian Summer, all aided from a Hurricane that once threatened Hawaii.

Tuesday, October 6, 2015

So Called, "Indian Summer" through mid-October

After a record warm September across much of the Midwest, the weather looks to hold its ground with more warm conditions. The pattern will set up to favor above normal temperatures through the next couple weeks, as the jet stream will push north into Canada and allow for winds to flow from south to north, bringing in warm weather. Precipitation will generally be limited through mid-October as the sun shine bright as we head into the meat of autumn.

Wednesday, September 16, 2015

Initial Winter Thoughts

We are back!! As the winter season nears, here are some initial thoughts on what the winter of 2016 will bring...It is starting to look more and more likely that warmer temps in the Pacific will hold the Polar jet stream further north than usual and keep the Midwest warmer than average. Big snows are still possible, with the best chance for above average snow in the southern Midwest feeding off the tropical jet. Otherwise we are leaning towards slightly below normal snow amounts, but certainty is lower for precipitation anomalies. One thing looks certain, above average temperatures do look very likely!

Follow me on twitter for continued discussion: Personal Twitter Page

Wednesday, June 10, 2015

Remnants of Hurricane Blanca to Dump Heavy Rain Thursday

Very heavy rain in on the way for Thursday across much of the Midwest. Flash Flood watches have already been issued and rightfully so. Moisture from Hurricane Blanca (which once made landfall in Mexico) will amplify an area of low pressure that will form over parts of the Great Plains. With a feed of moisture in from the Gulf of Mexico and Blanca's moisture, heavy rain will set up on the north side of the track of low pressure. A large swath of 1-4" will fall, with locally higher amoutns likely. Someone could walk away with near a half of a foot of rain by Friday. These types of totals can cause urban flooding and rising rivers. Be ready to take action if you reside in a low lying area. Meanwhile, severe weather to the south could drop local amounts of heavy rain and strong thunderstorms pass by. Below is the simulated radar off the 18z NAM Model for Thursday.

Wednesday, April 22, 2015

March Weather to Hold its own

More of the same right on through the first half of the weekend. After a week of above normal temperatures, we are stuck in a pattern of chilly weather. Welcome to April! A cut-off area of low pressure off to the northeast will slowly sift to the east over the next few days. For the Midwest, this means that winds will come straight out of Canada and usher in cold air. Areas near the lakes will be even cooler and water temperatures continue to be cool.
Meanwhile, another storm system will move up from the four corners regions and set up for a soggy, yet much need rain across central parts of the Midwest. Relief does set in by Sunday and next week as temperatures climb back to normal levels and the sun peaks out yet again.

Friday, April 10, 2015

Chasing Historic Midwest Tornadoes

Well, it has been a crazy 24 hours! My video and comments have been on local news around the country. I currently have a broker licensing my video of an EF-4 tornado to media outlets. It all started after bailing from a separate tornadic cell after it began to get wrapped in rain. After getting ahead of that cell, another super cell began to form to the east, so we chased after it. Witnessed the funnel form and then touch down. We then reported to emergency management, 2 minutes later a warning was issued. It rapidly grew into a large tornado. We stayed with it for an hour and 15 minutes before losing it in the darkness and trees. It might be safe to say I will never see anything like that again. It was historic. Here is our chase video:

Wednesday, April 8, 2015

Major Severe Weather Outbreak Likely Thursday

Thursday could feature large and damaging thunderstorms across a highly populated area Thursday. A strong cyclone will bring in warm and moist air from the south. This will fuel thunderstorm development, with large amounts of shear and instability some of the storms could be damaging. There will be a threat for large and long track tornadoes as well. Right now it looks like the largest threat will be from the Mississippi River up toward Chicago. Be sure to watch the latest local forecasts.

Thursday, April 2, 2015

Severe Weather and Heavy Rain on the Way, for some

Another round of severe weather and heavy rain will impact the Ohio River valley Thursday. A strong storm system that brought severe weather and 80+ degree temperatures to Minneapolis is pushing south and east. With a humid air mass in place and a cold front crashing south east, storms will have an ample amount of energy to work with, as well as a strong trigger in the form of a cold front. The main threat for severe weather will be damaging winds, along a squall line, with embedded areas of large to damaging hail.

Meanwhile, heavy rain looks to be an even larger problem. With deep Gulf moisture streaming north ahead of the strong cyclone over the Midwest, dew point and humidity will be primed for heavy rain. Precipiatable water values support almost a half of a foot of rain, Luckily, this area is running somewhat below average in recent precipitation. At the same time, 5" of rain across the Ohio River could cause major problems. A flash flood watch has been posted by the National Weather Service, in anticipation of the heavy rain over the next 48 hours.

Sunday, March 22, 2015

Heavy Snow to Parts of the Midwest Tonight

A strengthening band of baroclinicity across the region will bring the potential for very heavy and possible convective snow at times. The snow has already erupted this afternoon in Minnesota and is poised to develop further in areas near the MN/IA.WI corner. It appears that a wide area of 3-6" will be likely by Monday morning, but withing the swath areas will see amounts near 8" where the bands of heavier snow set up over. Winter weather advisories and warnings have been posted.

Wednesday, March 18, 2015

Typical March Weather through Next Week

After a week of well above normal temperatures and 2 weeks of well below normal temperatures prior, we are now heading into an average March pattern. The jet stream is currently running directly from west to east, and will hold its own over the next week. This feature usually brings near average weather to the Midwest, and this March will be no exception. The attached image is the temperatures compared to normal over the next 1 to 5 days off the CFS model. The next five days look very similar, before cooler weather works in late next week. As for precipitation, the Midwest looks to stay very dry, with minimal threat for large rain or snow events in the foreseeable future.

Sunday, March 1, 2015

Winter Storm to Bring Snow and More Cold

Yet another winter storm will impact the Midwest. This time around areas further to the north will get in on the action. A storm will develop on Monday over eastern Colorado and track east, northeast Monday night. Southerly winds ahead of the system will usher in warm and moist air along the Mississippi River. The moisture will wrap around the center of the storm Tuesday and drop several inches in the cold sector of the system by Wednesday morning. Our forecasted snow totals are mapped out for you. A general 2-5" of snow can be expected from northern Iowa to Canada. Areas further south will be limited in snow totals, as a warmer layer above the surface will change much of the snow to sleet, freezing rain and just plain old rain. Thunderstorms and even some severe weather is possible points further south. No matter where you are, cold air will once again filter in behind the system as Wednesday and Thursday get closer. Things look to warm up significantly Friday and Saturday, before a possible pattern change next week that could bring above normal temperatures to the Midwest. A welcomed sight for many!

Friday, February 27, 2015

Moderate Snow Saturday into Sunday

A developing area of low pressure will pass over the Ohio River Valley over the weekend. An area of snow will fall on the back side of the system. It appears that a general 3-6" snowfall will fall from Nebraska to Ohio. There may be some 7" amounts in isolated areas within the band.

The next storm looks to strike the Midwest Tuesday. It will be even stronger and affect areas further to the north that have been stricken of snow in recent weeks. Stay tuned for updates

Tuesday, February 24, 2015

Quick Hitting Alberta Clipper

A quick hitting, fluffy snow event will take place tomorrow, with Iowa in the bulls eye. The snow will be accompanied by an Alberta Clipper that is forming in southwestern Canada at this moment. Snow will begin to break out along a frontal boundary tonight in the Dakotas and develop rapidly, with a band of heavier snow through central South Dakota to Iowa, before weakening in the moisture stricken area near Illinois. Winter weather advisories and warnings have already been issued in anticipation. The weekend storm is looking less and less impressive.

Sunday, February 22, 2015

Persistent Alaskan Ridge to Favor More Cold Blasts, maybe a storm?

More of the same on the way for much of the United States, cold, and substantial cold. All time records are in danger yet again as we start this next work week, especially around the Ohio River Valley. The general pattern over the next 10-15 days will feature a massive ridge over the Pacific Ocean. This will allow multiple shots of cold, arctic air on the same caliber as the past 10+ days to filter into the US. As storm systems continue to pass into the north Pacific, warm air is ushered north.
As a result, the flow pushes the jet stream north. Since the Polar jet acts like a wave, any perturbation must be felt down stream. In this case a massive trough sets up in the eastern half of the country. The attached map shows the geopotential height anomalies off the GFS model, a good indication of where troughs and ridges will likely set up. The warm anomalies can be thought of as ridges, and cold anomalies troughs. The CPC agrees with continued cold air across much of the CONUS over the next 8-14 days. This pattern is similar to the one that set up in January last year. Luckily, we are heading into March, so the sun angle is higher in the sky and "Polar Vortex-like" temperatures will not be seen. However, departures from average will be extensive, and there will be nothing Spring-like about the next two weeks.

It has been generally dry, or snow free in the Midwest over the past month or so. This can be attributed to the northwest to southeast flow. Alberta clippers can form on such a pattern, but they are usually moisture stricken, as their origin is in a cold dry area of Canada. Meanwhile, the east coast was orientated directly in the active storm track. There is a potential that we could head into a more stormy pattern, in the Midwest. Some models suggest the trough to push far enough west and high pressure to build off the east coast. This would allow the jet stream and storm track to set up through the Great Lakes, with snow to the west of the storm track.  This would be very favorable for winter storms and cyclones in the Midwest. It would also signal warmer weather for the east coast. Our first opportunity of this change comes in next weekend. The European and american models are showing decent snow across Iowa and Wisconsin, as a storm system and substantial line of baroclinicity sets up. We will need to watch this closely and provide updates, as needed if these storms come to fruition.

Friday, February 20, 2015

Snow and Ice Across the Ohio River Valley Saturday

A storm system is beginning to get its act together in Northern Texas. An area of sleet and freezing rain has now developed ahead of the low pressure in an area of significant lift in the atmosphere, along an area of baroclinicity. Much of this precipitation will kick over to all snow as cold air wins out in Illinois and points east. As the system cross into the Southern Ohio River Valley, it will begin to deepen and draw in significant Gulf of Mexico moisture and deposit it into the cold air mass to the north. Ground temperatures will are cold enough for accumulation to begin at the onset of the snow. A wide area of 3-6" will be likely north of the Ohio River, with the potential for up to 7" or 8" in an area that has the potential to stay all snow throughout the event.

On the warm side of the system, freezing rain will be a concern. Winter storm warnings and ice storm warnings are in effect for tonight through Saturday. On the right is the freezing rain potential, courtesy of the WPC. With warm air aloft and a substantial cold air layer near the surface, ice accumulation is yet again going to stack up, on the order of a quarter inch or more. Power outages and impassable roads can be expected in the hardest hit locations. We have attached a snapshot of the 18z GFS, at the height of the storm. One thing to notice is that the rain/snow line, as per usual, will feature a sharp cut off. Any minor tweaks to the track, or strength of the cold air could majorly impact snow totals in some areas. Along with the expansive cold across the eastern US, winter is definitely not over yet. The pattern looks to stay cold for the next 10 days, when we may switch over to a more zonal and warm pattern, fingers crossed.