Category Archives: Winter Weather

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A Botched Forecast: What Went Wrong and How We Get Better

The hate mail rolled in today, mostly stemming from folks not getting the forecast amount of snow in their backyards or that the snowfall amounts were underdone. We “try” to predict the behavior of a science that is far from perfect, and more times than not, we come up short.


Since the start of the week, we had forecast a significant winter storm that would take shape across the Southeast and Mid-Atlantic regions, while threatening the coastal Northeast regions. Forecast models are your friend, but they can be your enemy at the same time. I always point out that computer models are ONLY a tool for the forecast and NOT a forecast themselves. Looking at model parameters illustrating surface precipitation type, QPF and projected snowfall amounts will do you NO good. We have to look beyond the surface to understand why what is projected at the surface is being projected there. With a number of items that need to be taken into account into a forecast, sometimes something gets overlooked, and the parameter that was overlooked was a critical one.

As the event transpired, it was becoming noticeable that warm air aloft was beginning to build just above the surface, which led to one of two things:

  1. No snow at all for areas that were forecast to receive snow
  2. A limited amount of snow giving way to more freezing rain

Because of these two things, the forecast was missed in several locations. Warm air aloft is not something models are great at picking up days in advance. It causes a forecast to shift into a “nowcast” event.


While computer models lead to a great deal of error at times, it’s the job of the forecaster to be able to weed out the fallacies of a forecast model and produce the best possible forecast they can and make adjustments as needed. The issue is, at times, we develop a one-track mind and overlook tools that can be critical. In this case, I overlooked sounding data near the surface and while I anticipated the chance that warm air aloft could build, I didn’t anticipate the magnitude/strength of the warm air layer above the ground which would, and in fact did, limit snowfall amounts in several locations.

Across the Northeast, many coastal areas got a good blast of snow today, and many areas got much more than forecast as the precipitation shield became far more expansive than anticipated as the low was within closer proximity to the coast than expected. All told though, it was noted many times throughout the week of the threat that back edge snow could make its way into coastal Northeast regions.

Overall, we can learn a lot from this winter storm: where we went wrong and where we MUST improve, especially on the communication front. Am I apologetic for the Southeast getting as much snow as it was forecast to receive, not at all. I’m ecstatic they did not receive as much as the last time they saw a significant winter storm, a city gridlock, lockdown and overall humanitarian crisis followed.

Onward and upward…

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Weekend Winter Storm Threat For The Southeast, Mid-Atlantic.

Confidence continues to increase seemingly by the hour on the threat for a potentially significant winter storm for the Southeast and Mid-Atlantic regions of the United States this weekend. And sadly, that first sentence is about the only thing that we know with any certainty at this point, but that we study all of the data we have at our finger tips, the easier (haha, easier…) it will be to put the pieces together to form a solid forecast for such an event.

In order to gain a solid understanding of this winter storm, as it is the case with every winter storm threat, we need to look at what is occurring at mid-levels of the atmosphere and the energy that is coming down the pike as well as the overall pattern we are working with. Looking at precipitation forecasts at the surface do not paint the whole picture. We need to dig deeper…

A look at the surface according to the latest GFS rendering shows a formidable winter storm across the Southeast early Saturday morning… 

The driver behind the winter storm threat will be a piece of energy that is currently out in the Pacific Ocean. This is a BIG reason why model guidance is all over the charts with this storm threat going from a significant winter storm to the very next run showing next to nothing. Once this piece of energy comes on shore of the western US, we will have a much better understanding of the nature, timing and placement of this threat.

As noted, the piece of energy that will form this winter storm has not reached land yet. As of this evening, model output has it located off the Pacific NW coast (illustrated by the reds and yellows).

Once this piece of energy comes on land, it will dive south and east along the southern branch of a split flow setup. Split flow jet streams are the ideal setup for winter storms as the northern branch of the jetstream carries your dose of cold air while the southern branch carries the energy needed for the storm. If you can get the perfect setup where the cold air and the energy work in tandem, then you have a winter storm on your hands. I suspect this will be exactly the case with this threat.

By Friday afternoon then evening, notice where that piece of energy is located… over the Rockies and then over the Panhandle of Texas.

By Saturday morning, the piece of energy is now over the Southeast US as a developing winter storm. 

The European model illustrates a similar solution but is much more robust on the magnitude of the energy coming across southern jet stream. Essentially, the European model is calling for a much more vigorous winter event across the Southeast.

Let me break down the keys to the pattern setup for this winter storm threat.

  • The GFS and European models (at the 500 mb level) are showing winter mischief this weekend across the Southeast
  • The GFS is weaker with its rendering of energy, while the European model is more robust with its solution
  • A piece of energy in the northern branch of the jet stream (located in the Canadian Prairies) will determine the placement of the system as well as the timing. The stronger and slower the northern piece of energy is, the stronger a storm we are looking at across the Southeast. In addition, the stronger and slower the northern piece of energy in the Canadian Prairies is, the more time and room this storm threat will have to come up the East Coast. Something we NEED to watch closely.
  • On the contrary, the weaker and faster the northern piece of energy becomes, the weaker of a Southeast winter weather threat we are looking at and a lesser chance the storm skirts up the East Coast.

Which solution am I leaning toward? With complete certainty, I honestly am not sure yet. If I had to choose, I’d lean towards the European solution. I can see the piece of energy in the southern branch outrace the northern piece of energy and developing into a winter storm threat for the Southeast and up a good extend of the East Coast. Obviously, things can and likely will change between now and the weekend.

LOCATIONS: Given what we know and what continues to be watched, I will say that folks across northeast Texas, southeast Oklahoma, southern Arkansas, far northern Louisiana, northern Mississippi, northern Alabama, northern Georgia, interior South Carolina, parts of North Carolina and parts of Tennessee and Virginia should be monitoring this situation closely and be prepared for a winter storm threat. Now if the low tracks even a bit further north, then we’ll have to add locations like southeast Pennsylvania, the Delmarva, NYC and parts of southern New England to the mix as well. For now though, all these areas I’ve mentioned should keep this threat in mind moving forward.

Note that I did not talk about snowfall amounts. As the piece of energy needed for this winter storm is just now coming on land, models have been all over the boards with anticipated snowfall amounts, so quite frankly, they are useless. Also, please be mindful that the locations that could be impacted by this winter storm threat or some degree of winter mischief could change and locations can contract or expand. Those in the threat area, there is no reason to panic… just be prepared.

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Winter 2016-2017: Preliminary Outlook

Another year is more than halfway in the books and as we have a month left until we reach the autumnal equinox, this is the time of the year I shed some insight as to what the upcoming winter could spell for us. Now keep in mind, as with any long-range outlook that spans the course of several months, there will always be margin for adjustment and tweaking. While my goal is to always present the big picture in a manner in which major outlook overhauls are not needed, I do plan on making adjustments and tweaks as needed, if new data comes out that would change my overall thinking.

As we finally begin cutting ties with the one of the strongest El Nino signals we’ve seen in history, we’ve begun to transition into its counterpart, La Nina. As strong as long-range model output had forecast the El Nino signal we were entrenched in this year, and while a vigorous El Nino indeed developed, model output actually had overdone its strength, to a point. Similarly, model output appears to be handling a La Nina phase in the same light. Recently, long-range model guidance has suggested a moderate to weak La Nina signal heading into Winter and Spring 2017, as oppose to its premature aggression illustrating a strong, vigorous La Nina. All considered, we are indeed moving from an El Nino signal into a La Nina signal.

As I talked about in last year’s winter outlook, while climate signals (i.e., El Nino, La Nina) do have impacts on the manner in which our winters develop and play out, they are not the only factors that drive out winter. Our winters are driven by how the ocean behaves as well, in fact, our weather and climate is driven by the “motion of the ocean” …. Sorry, I had to…

WHAT IS LA NINA: La Nina is a phenomenon that involves the interaction between ocean and the atmosphere and is the positive counterpart of El Nino as part of the ENSO (El Nino-Southern Oscillation) climate pattern. During a La Nina cycle, there is a cooling of the sea surface temperatures across the East Central Pacific Ocean, usually ranging from 3 to 5°C below normal.

Now, given a typical La Nina, especially a moderate to strong one, we’d see much cooler than normal temperatures across the East Central Pacific, even stretching as far north as the Alaskan Gulf in many cases. But this is not the case at all as warmer than average sea surface temperatures continue to dominate across the Northeast Pacific, an anomaly that would prevent a La Nina signal to achieve a strong phase, but rather a weaker version of the climate signal. Because of this, I suspect that the we are in for an entirely different version of winter, compared to last winter and the winter prior, although, it is very possible we could see stretches of cold temperatures rivaling the dangerous cold we saw two winters ago.

Here is a look at present sea surface temperature anomalies or departures from normal. The reds and the browns illustrate temperature above or well above normal.


Here are projected sea surface temperature anomalies or departures through meteorological winter (December, January and February) and we note that the northeast Pacific continues to exhibit sea surface temperature milder than normal. This is all indicative of a “weaker” La Nina.


As far as climate signals playing a role in how the winter will shape up, this winter I suspect, will be influenced again by other, critical drivers in addition to the effects that a projected “weaker” La Nina phase might have, similar to how the last two winters have played out, in correlation to the dominant climate signal that year.

KEY IMPACTS THIS WINTER: With everything considered from the discussions above, noted below are several focus points explaining the manner in which I suspect that the upcoming winter will play out.


2016-2017 Graphic Winter Outlook


As we head into the Fall months, it appears that milder air will remain in place, especially from the Southeast and up the Eastern Seaboard. As we progress deeper into the winter months, though, I suspect that these regions will see much colder temperature values and good chance at a number of systems that will deliver snow and ice, but do not be alarmed if the start of winter activity is a bit tardy.

Early on it appears that the bullseye for much of the winter activity, focusing on cold, snow and ice prospects will be from the Central and Southern Plains to the Great Lakes, just to the west of Appalachia. Focusing in on the Great Lakes region, I suspect this winter will ramp up another episode in the series of the Lake Effect Snow Machine. I could see a very active winter in terms of Lake Effect Snow events throughout much of the winter for the Great Lakes as a whole.

Throughout the High Plains and Upper Midwest, particularly from Montana into the Dakotas and the upper and western Great Lakes, a winter reminiscent to two years ago may develop for these regions in terms of magnitude of cold. Depending on the exact setup of the jet stream, if a deep, persistent trough sets up over the central and eastern part of the country, there will be a good chance for several episodes of Arctic air to funnel into and across the aforementioned regions. With prospect for colder air comes the threat for pattern of winter activity with the prospects for snow and ice.

As noted previously, parts of the eastern US will likely begin on the milder side of things, transitioning from a mild Fall into a colder winter. Because of this, the Northeast may begin on the milder side as we head into winter, but as we move further into winter, the mild air will subside and give way to much colder temperatures, particularly for the areas across the Northeast east of the Appalachian Mountains. West of the Appalachian Mountains, I see a more abrupt transition to a colder, active winter pattern.

The Northwest region of the US always seems to present the most challenges for long-range forecasting and this year, it will be no different. Early on, it appears that the Northwest is in line for cooler than normal temperatures values and above to well above normal precipitation. On the contrary, unfortunately, the Southwest looks to remain mired in drought conditions, overall, with few exceptions.

All considered, early on it appears that the brunt of winter will be felt most across the heart of the nation; from the Rockies to the Eastern Seaboard. Keep in mind, this does not mean everyone east of the Rockies will have a snowmaggedon this winter, rather that anyone East of the Rockies, with few exceptions, could see a number of chances for very cold air and several snow and ice chances.

As I noted previously, this outlook covers the span of 3 months, and while I am confident in my outlook, over, things can easily change over such a haul, especially when an outlook is produced using a number of factors and variables that can and usually do change over time. As time moves forward, heading into Fall and winter, if I find it necessary to adjust this outlook any degree, I will do so, but only if thoroughly convinced that any new data that comes in will have a drastic impact or cause a drastic change in my overall thoughts. Please do no take this outlook as gospel truth, but more as a guide and a tool, using this to get an idea of the kind of winter we may be in store for. This is an imperfect science, as is why any outlook should be used as a guide.

As always, you can follow me on Facebook or Twitter for the latest weather updates.

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Much Colder, Snowier In The East; Warm In The West Through February

The groundhog made its appearance earlier this month and whether it saw its shadow or not has no impact on how the remainder of winter will turn out, but science can give us insight on this. As I’ve mentioned since my winter outlook was released in September, winter would have a tardy arrival this year as December would be on the mild side, then January would be a “limbo” month where temperatures started trending more winter like, and as we went into February, winter began paying us several visits. The February thaw was expected and it is quite normal to have a mild spell, albeit it an abbreviated stint of mild temperatures.

Over the remainder of February the pattern will again revert to one that is common for an active cold and winter weather pattern, particularly across the eastern US. This will happen as the result of expansive ridging in the west causing a major dip in the jet stream across the eastern US. Model guidance is suggesting, over the same time frame, a major disturbance in the Polar Vortex is appearing likely to take place. This is due to stratospheric warming, specifically Sudden Stratospheric Warming (SSW). If the stratospheric air warms rapidly in the Arctic (SSW), it throws the circulation of the Polar Vortex off-balance. This can cause a major disruption to the polar vortex by stretching it or splitting it apart.

Taking all this into consideration, when we have expansive ridging in the west and troughing in the east, with a very weak Polar Vortex, pieces of the Polar Vortex break off and get pulled down with that pronounced, digging trough over the eastern US. As pieces of the Polar Vortex plunge into the eastern tier of the country, this will bring with it very cold, Arctic air… and likely the coldest air we’ve seen this winter. Here is a look at a series of time slots from the GFS showing pieces of the Polar Vortex that had plunged across the eastern two-thirds of US through mid-month.

These are past models run illustrating the pattern encountered before the run-in with more mild temperatures, before winter makes a nice comeback through early March…

gfs_t850a_noram_24 gfs_t850a_noram_27 gfs_t850a_noram_41

By mid-month, we had some of our coldest air of the year intrude across the eastern US. As you can see in the last image in the series of GFS outputs, a large pieces of the Polar Vortex comes surging south into the lower eastern two-thirds of the country. I suspect this pattern will remain locked through the remainder of the February as waves of stratospheric warming, expansive ridging in the west and troughing in the eastern tier of the nation will allow for pieces of the Polar Vortex to continue to surge into the eastern two-thirds of the country. Quite frankly, I see this pattern lasting into March, albeit some localized, acute warming trends will also take place, but the overall trend appears to be much colder through the remainder of the month.

A climate model that meteorologists and forecasters use often for long-range climate assessments is the CFS model. While the CFS is still a model output that is still a work in progress, it still gives useful insight into general trends. Here is a series of two CFS outputs illustrating the same solution… the idea of a locked in pattern that supports much colder air across the eastern two-thirds of the nation through the end of the month… the first in the series is for was though February 18th, the second is the last day of the month.



As we can clearly see, the cold is real and it’s going to stick around for a while. As cold air surges into the states, particularly from the Rockies on east, it will setup boundary layers. Boundary layers are just that… a boundary that separates a cold air mass from a warm air mass. On each side of the boundary, to the north and west, you have cold, dry air… and to the south and east of the boundary, you have warm, moist air. With an active subtropical jet stream, we have pieces of energy continuing to come in from the Pacific and their route of transportation is that boundary layer as these pieces of energy “latch on” to the boundary layer. If a piece of energy comes around and latches onto the boundary layer, you get winter storm to develop with snow to the north and west of the low pressure and rain and thunderstorms to the south and east of the low in the warm sector, as we saw with the major winter storm earlier this month. All considered, seeing the remainder of February being much colder across the eastern two-thirds of the country and keeping in mind these boundary layer setups, coupled with an active subtropical jet stream feeding in energy from the Pacific, I can see the remainder of February and well into March featuring a more active pattern for winter weather east of the Rockies to the Eastern Seaboard.

Since this article focused on the overall pattern likely through the end of the month, I am not going to dissect every winter storm threat over the remainder of winter. The reason for this is that while we can keep our eye on these threats, so many variables and factors can change with timing, moisture content, cold air, trough placement and tilt… all of these, with even the slightest change can have a drastic impact on the overall forecast and threat. Going forward to Valentine’s Day, I do see a few winter storm threats that have my attention… I will cover these threats in greater detail as we move closer to these time frames.

Overall, the remainder February into March has the makings of one last ride of winter madness with cold and snow opportunities, especially across the eastern tier of the country while the western US will see mainly warm and dry conditions. I realize this article ran a bit longer that I had hoped it would as I don’t want to plaster folks with too much, overwhelming information, but the information presented in this article was important to cover in an effort to prepare for what has the makings of winter’s potentially final hoorah…

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Coldest Air Of The Season Coming This Weekend Across The East With Dangerous Wind Chills Likely

As noted in several articles and social media weather discussions, following a brief, February thaw, the gates to the Yukon would open up and Arctic air would flood into the eastern tier of the US. As we head into Valentine’s Day weekend, the confidence in this solution has increased significantly. Model guidance suggested that around this time frame, a perturbation, or disturbance, would impact the Polar Vortex. When there is no disturbance the Polar Vortex, it remains confined in the high latitudes of the North Pole causing very limited, if any, Arctic air intrusions. On the contrary, when the Polar Vortex does encounter a disturbance, it can weak or split causing a piece of the Polar Vortex to be pulled south into the US, providing a punch of cold, Arctic air. This will be the case this weekend. Many regions across the eastern US will see the coldest air of the season this weekend, especially the Northeast.

Looking at European model guidance for Saturday morning, February 13th and temperatures at the 850 mb level (4,700 ft above ground) are well, well below normal.


A quick peek at GFS model guidance for Valentine’s Day Eve and it’s on board with the solution of very cold air at the surface, and likely the coldest air of the season. This is suggesting widespread temperatures that are anywhere from 10° to 40° below normal… for this time of the year. Keep in mind, we’re approaching the middle of the “coldest” of the winter months, historically so consider the average temperature being already very cold… add to it a tremendous blast of Arctic energy and we have some dangerously frigid temperatures.


Here are a series of forecast wind chill values from the Midwest to the Northeast and New England by Sunday morning at 6:00 AM… Widespread wind chill values between -10° and -20° will be likely, while some areas across New England could see wind chill values in the -30° to -40° range. This will be a bitter cold air mass, with dangerous implications if not prepared for… dress in bundles!

gfs_windchill_mw_21 gfs_windchill_ne_21 gfs_windchill_neng_21

Here is a look at temperature probabilities across the northeast tier of the US… we note an 80-99% probability of temperatures values of “0” (and likely far colder) across the Northeast…


With this rush of Arctic air and with the lake temperatures relatively warm in comparison, we may see some Lake Effect Snow squalls set up across the Great Lakes. It’s impossible to gauge how much Lake Effect Snow will eventually develop, as snowfall amounts all depend on wind flow setup across the lakes. I’ll have more updates on the Lake Effect Snow aspect in the coming days as we get closer to the weekend. The cold, on the other hand, is coming… as there is no way around it. Be prepared and bundle up as this looks to be the coldest air of the season. I wouldn’t be entirely surprised to see many areas struggling to get out of the teens and single digit temperature readings as high temperatures. The wind chill values will be frigid, and likely dangerous across many regions. Frostbite, hypothermia among other illnesses need to be prevented and can easily be prevented with common practices and safety measures. It’s going to be a frigid weekend so bundle up!

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Widespread Snow Likely Sunday-Tuesday Across Eastern US; Possible Nor’easter for New England

Last night, I broke down three possible scenarios that could evolve with several pieces of energy that were in play across map. These pieces of energy were either to work in tandem or act independently to produce either a set of minor snowfall events or one larger snowfall event. As we look at the same situation, all players remain on the table, but no answer is entirely definite at this point… but we can get determine which solution is most likely to happen.

Looking at upper air charts and we still have the same setup of energy present as we did earlier… the only thing different is energy piece #1 which is the cold air that has established itself across the Northeast. If we look at the upper air pattern below, it appears that energy #3 might rob energy #2 if its strength, not entirely, but enough to not allow #2 to become a major New England winter storm comparable to the “Blizzard of 2016”. That said, looking at the GFS solution, I’m not entirely buying how south the placement of energy #2 is… note the wind speeds along the east and southeast side of the upper low with energy #2… these are 90-100 knots upper level winds coming from the south. With that much energy, I could see this driving further north, more into southern New England and if the trough can turn negative even quicker and more west, that will provide more room for energy #2 to curve back into New England with an even more potent winter storm. Am I saying that will happen? No, but we cannot discount that possibility moving forward. This setup is for Monday morning at around 6:00 AM

New Skitch

Looking at the upper air pattern for Monday evening and a lot of widespread energy will be in place across the eastern US, and with energy #1 establishing the cold air ahead of this system, I suspect a widespread snow event for many areas across the eastern US. Understand though that will this appears to be a widespread snow event, I don’t suspect this will be a major winter storm piling up over a foot of snow, but it could bring enough snowfall to shovel or brush off for many regions across the eastern tier of the country.


With both of these systems interacting with each other to some degree, I suspect both, working in tandem, will produce measurable snows across the upper Midwest, Great Lakes, Northeast and New England. Other regions that could see some lesser, but still measurable snows would be across parts of the Southeast and into the Mid-Atlantic. I could see parts of northern Mississippi, northern Alabama and northern Georgia picking up a coating to an inch or two of snow… while parts of the Carolinas could pick up a few inches as well. Across the upper Midwest, Great Lakes, Northeast, widespread 2-4″ snowfall amounts will be likely with some spots locally seeing higher amounts into the 6″ range. Moving over to New England, depending on if the system can track farther north as I noted earlier and the solution cannot be overlooked, areas across New England, especially southern New England could see 6″+ of snowfall. I do suspect that much of southern New England will see a solid 6″ of snow from this system, but if push comes to shove and the system tracks farther north, we’re looking at higher end snowfall amounts.

Here is a look at projected radar on Monday at 9:00 AM from the 4-km NAM… a hi-resolution, short-range model…


Here are projected snowfall amounts from the folks at the Weather Prediction Center… through Tuesday morning, in the 75th percentile…







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Multiple Winter Storm Threats Next Week Across The East

As we move into next week, things become very interesting when looking at potential winter storm threats through the early and middle parts of next week. The pattern is loaded, and the pieces are on the table… but the biggest question that always surfaces with these winter storm threats is… “can it all come together and produce something”. If we look at the 500 mb upper air pattern illustrating all the energy in place, we can see 3 critical players on the map that could produce a number of winter storm threats, and a number of scenarios that all have an equal chance of happening.

New Skitch

DISSECTING THE THREAT POSSIBILITIES: Energy piece #1 as illustrated in the upper air chart above is our supply cold air across the Northeast which will be pulled down like an anchor from the winter storm last night and today across New England. This isn’t an issue… the cold air will be in place. The biggest issue will be what will happen of energy pieces #2 and #3? A few solutions for this question, but at this time, it appears that there are more questions that answers, but we can try to take a look at the most likely scenarios…

The biggest question is whether or not energy #3 can swing down and retain enough energy to produce another winter storm across the Eastern Seaboard or whether energy #3 is not kicked out far enough out to sea, gets pulled back into New England from a negatively tilted trough and “zaps” a lot of the energy from #3. This scenario would allow for widespread snowfall across the Northeast and New England and another shot for more snow with whatever energy remained from piece #3 of energy, but neither system would produce a major winter storm, but enough snow to shovel.

The upper air chart below illustrates this concern of how energy #2 may feed off energy #3 which could produce two solid snowfall events, but nothing terribly major.

New Skitch 2

Another scenario that could play out, looking at the upper air chart above is that energy #3 kicks energy #2 out to sea, but instead of energy #3 becoming the “big” winter storm, the trough does not go negative in time and remains positively tilted, kicking energy #3 out to sea and no one sees any snow… are very little. The scenario that I see that could become the “big” thumper for a winter storm would be if energy #2 gets kicked out to sea, without zapping any energy or very little energy from #3. The energy from #3 races along the base of the trough and it goes negatively tilted sooner which would send winter storm right up the east coast becoming stronger as it reaches the Northeast Coast. This would be your “big” winter storm if this pans out.

I know this a lot of information to take so let’s recap…

SCENARIO ONE: Energy #2 and #3 work in tandem. As #2 “zaps” energy from #3, rather than being kicked out to sea, it gets pulled back into New England as a winter storm with widespread snowfall across the Northeast and New England, but not becoming a major winter storm.

SCENARIO TWO: Energy #2 gets kicked out to sea by energy #3 without energy #2 ever really coming together to produce a winter storm. As energy #3 comes across the base the trough, the trough does not become negatively tilted in time and sends energy #3 out to sea as well. With this scenario, no one would really see much, if any, snow from either.

SCENARIO THREE: Energy #2 gets kicked out to sea by energy #3 without energy #2 ever not coming together to produce a winter storm. As energy #3 races across the base of the trough faster than SCENARIO TWO, the trough becomes negatively tilted farther west and sends a winter storm up Eastern Seaboard and as the energy tracks up the coast, it becomes strong with an ample supply of cold air in place producing a big winter storm for the Northeast and New England.

For those confused by what is meant by the tilt of a trough, a positively tilted trough generally supports a storm going out to sea while a negatively tilted trough generally supports a storm to track up the US east coast or another scenario as mentioned above is a storm can get pulled back into the coast if the trough barely turns negative in the nick of time.

Looking at the GFS solution below through Monday evening and it illustrates an incredibly complex forecast with snow spanning from the Great Lakes and Northeast down to the Southeast.


Looking at the upper air patterns through next week, I suspect a good chance that we’ll see at least one, possibly two winter storm threats across the Northeast and New England next week. Understand that the bust potential is as real of a possibility as a winter storm threat next week. This is a very complex forecast with many players on the table as illustrated in the upper air patterns above. Do I know which scenario will pan out right now? No, I don’t, but each scenario must be considered and respected at this point. The focus of this article wasn’t to disseminate which winter storm threat will pan out, the exact locations for these threats or snowfall amounts because we just don’t know the answers yet given the world of possibilities that could occur with this type of setup, rather my intent is to show you every angle and possibility at this point. More to come… check back for updates on my Facebook and Twitter.


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Major Winter Storm To Impact Rockies to The Upper Midwest; Severe Weather Threat To the South

Well, the ingredients are nearly all on the table for a major winter storm across the Rockies, Plains and upper Midwest beginning Monday. I say nearly all because the energy needed to produce this winter storm has yet to reach land, as it is still in the Pacific Ocean. This will all change by tonight as this piece of energy will enter California tonight.

Here is a midday look at radar and you’ll notice some snow and rain out to the west… this is not the winter storm, as that will begin to develop later tonight and into tomorrow.


Here is a look at the 500 mb, upper air pattern which shows that piece of energy, entering California later tonight, that will be the winter storm producer over the next several days…

New Skitch


WINTER STORM IMPACTS: As the low develops Sunday evening across the Southwest, this system will have a dual supply of cold air to work with, which increases the threat for widespread heavy snow. As the systems tracks northeast through Kansas Monday afternoon and into Iowa on Tuesday, the low is expected to deepen, or strengthen, which will allow it to produce its own supply of cold air along the with injection of cold air the system will be receiving from the north. As the low moves up through southern Wisconsin by Tuesday night and into far northern Michigan, the low should begin to gradually broaden as the system begins to move off. With this deepening the low pressure system, not only with this create an ample supply of cold air causing heavy snow, but it will also lead to widespread blizzard conditions from the Rockies through parts of Kansas, Nebraska, Iowa, southern Minnesota and Wisconsin.

SNOWFALL: This is always the million-dollar question, and a topic that has more questions than answers. This winter storm threat is no different. For days and even the last week, computer snowfall maps have been tossed around social media like the plague. The projected snowfall values showed anywhere from 45″ to 4″ and this is natural for computer models to do as they will teeter back and forth to get an understanding of this system. The biggest issue with these snowfall maps being shared that far in advance is that the energy needed for the winter storm was thousands of miles off the west coast far in the Pacific Ocean. Models struggle mightily with energy off-land and this is why snowfall maps are incredibly inaccurate that far out as they don’t accurately illustrate the big picture.

Here is my current thinking for general snowfall amounts through Wednesday morning with this winter storm threat, and it really hasn’t changed to this point. However, looking at the overall scope of this storm, if the low continues to maintain its strength across Wisconsin, I could see a swath of a foot or more of snow extending into central and northeast Iowa and into central Wisconsin as noted by the “adjusted extension of the dashed-orange zone” into Iowa and Wisconsin. I extended this threat zone because if the low continues to deepen, heavier snow is very possible with snowfall amounts anywhere a 6-12″ or over a foot, depending on how deep the low can sustain itself. This is an area we need to watch for…

TRAVEL IMPACTS: Interstate networks likely to be significantly impacted by this winter storm and potential blizzard will be I-70 through Kansas and I-80 through Nebraska. Heavy snow and blizzard conditions will likely lead to treacherous or impassable interstate corridors and very dangerous travel conditions. Interstate closures are a real possibility as well.


SEVERE WEATHER: With this dynamic storm system, in the warm sector of the system will come the threat for widespread severe weather from the central Gulf states through the Mississippi, Tennessee and Ohio Valleys. Damaging winds and a few tornadoes will be possible Tuesday into Tuesday night. Here is the outlook as issued by the folks at the SPC (Storm Prediction Center) for Tuesday. We note an “enhanced” risk over northern Mississippi, far northwest Alabama, western Tennessee, far eastern Arkansas, the boot heel of Missouri and far western Kentucky.


Overall, this has the makings of a major winter storm from the Rockies to the Midwest, with heavy snow and blizzard condition likely, especially across parts of Kansas, Nebraska and Iowa where I suspect the worst of this winter storm will be felt. In the warm sector, a severe weather threat comes into play from the central Gulf to the Ohio Valley where all modes of severe weather will be possible on Tuesday. A lot happening to begin the week… be prepared, stay up to date with the latest information and be aware of any changes or adjustments to the forecast.

To touch on this again, I will be coming out with a February outlook in the week to come that will discuss what will be the return of Arctic air after the first week of February and another volatile pattern on the way, supporting additional snow and cold opportunities across the eastern US, and perhaps the chance the Southeast has been waiting on for their first real taste of winter this year… more on this later…




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Major Winter Storm Set To Impact A Large Part Of The Eastern US This Weekend With Significant Snow

Parts of Maryland have been placed under a Blizzard Watch beginning Friday, while parts of the central Plains to the Middle and Upper Middle Atlantic regions are under some type of winter weather warning, watch or advisory. All of this in advance of what is likely to evolve into a major winter storm set to impact a large part of the eastern US late in the week and through the weekend with widespread, significant snow possible and blizzard conditions for many areas.


MODEL MADNESS: Computer models are beginning to hone in on a consensus solution across the three major global models… the GFS (American), ECMWF (European) and CMC (Canadian) models all show a slightly southern track of the storm. If this solution verifies, this means a major snow event across the Mid-Atlantic region, while southern New England still sees a good deal of snow but lesser amounts would be likely. Now, this is where I’m not sold on the southern track. Why? The manner in which the northern branch (remember the “split-flow” jet stream patter… northern component and southern component) of this jet stream is set up, there is plenty of room for this system to push a little farther north than what computer models are indicating… not saying that will wind up happening, but the potential is still there for this system to traverse farther north. If it does jog slightly more north, then we would be looking at much more snow across southern New England. This is why I haven’t discounted that possibility. Those across southern New England need to be prepared, regardless of the outcome, and remain weather aware of the latest developments.

IMPACTS: I highly suspect that the area of greatest impact for significant snow and blizzard conditions will be across parts of West Virginia, Virginia, Maryland and southeast Pennsylvania. Some highly populated metro areas I expect to see a potentially long-duration blizzard would be from the Baltimore-DC Metro area into Philadelphia where I’m confident that foot or more (perhaps well over a foot) of snow will fall. The biggest question is whether or not ice will mix in these areas at some point during the event and that is very possible. If, however, there is no mixing (freezing rain, sleet, ice), then we could be looking at significant, potentially historic snowfall amounts when all is said and done across these cities. Also, we must introduce strong winds in excess of 40-50 mph coming into the picture leading to potentially blinding snowfall rates. I don’t use historic too often or even blizzard too often so this should go to show what I think of the implications this winter storm could hold. As we move closer to the Mid-Atlantic and Northeast Coast, with a deepening (strengthening) low pressure system, this scenario will drive in very strong winds into coastal areas leading to beach erosion, rough surf and wind gusts in excess of 50 mph leading to a very dangerous situation through the weekend.

Rather than listing what states could see snowfall and how much, I produce my first snowfall map for this winter storm threat and can be viewed below. Now keep in mind, these snowfall amounts are not “set in stone” but the closest to accurate solution I was able to derive based off model output trends, upper air charts illustrating the jet stream setup and what I feel the storm could ultimately do. One thing that continues to concern me and I will not discount the threat is the possibility of the storm moving even slightly further north than the models are illustrating, which I think could very well happen as models continue to adjust. In the event that a northern jog of the system does begin to occur, this would produce larger snowfall amounts across southern New England and NYC. This is something we need to keep a very close eye on moving forward. That said, New England, keep your eyes and ears open for the latest developments.




Again, these snowfall amounts are subject to adjustment. That said, confidence is very high that this will evolve into a high-impact winter storm for many across the eastern US, especially across the upper Mid-Atlantic area where significant snowfall is likely though the weekend. Be sure to check my social media accounts for the latest on this winter storm threat.




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Major Winter Storm Likely This Weekend Across The Eastern US

As I’ve talked about since well before the start of Winter, Winter would arrive this year… but on a tardy schedule, and this has been the case. The long and oft-talked about “pattern-flip” has taken place and we are in the midst of wave after wave of cold, Arctic air and prime conditions for winter storm development, especially across the eastern US. Several weeks ago, I noted a threat that grabbed my attention in the long-range that could impact a large part of the eastern US and eastern seaboard. Confidence has tremendously increased in this threat and it is becoming very likely a major winter storm will be delivering a winter “punch” across the Northeast by late week and into the weekend.

I always say we have to look beyond the surface to understand the nature of the system and what it can do by analyzing the energy in place, the supply of cold air and the moisture source. All of these are critical to understanding not only a winter storm threat, but how the threat can materialize. All the pieces and parts are on the table for this winter storm to become a significant winter weather producer across a large part of the eastern US and confidence is very high that the cards will come together to develop a major winter storm with potentially significant snow implications, from the Ohio Valley to the upper Mid-Atlantic and across the Northeast. Later in this article, I’ll be sharing computer model output illustrating “potential” snowfall amounts. Now, I setting the record straight that the snowfall map I’ll be sharing is NOT an official forecast, but a “solution” from one computer model, or an “idea” that one computer model thinks will happen with this winter storm. There should be NO “last call” snowfall maps anywhere close to being issued, and those that are being tossed around are done so for clickbait, a tactic used to garner “likes and shares” on social media.

STORM TRACK: When understanding the impacts of a winter storm threat, first and foremost is understanding the track of the storm and where it could setup. The exact track of the low pressure system is something we can all speculate on, but nothing will be concrete until we get closer to a 12-24 hour window for this winter storm. Early on, it appears as the low might track just south of the Ohio Valley, across the upper Mid-Atlantic and along the New England coastline or just off the coastline. However, this can and more than likely will change between now and late week so we need to keep an eye on the situation. The track I just noted was just to give you a broad overview of where recent model output has suggested the track setup is. This could easily jog north of south some.

IMPACTS: The threat for significant winter weather with this winter storm will span the Ohio Valley, the Mid-Atlantic, parts of the Northeast, including southern New England. Within the threat area, significant amounts of snowfall are possible. Now within this threat area, now every spot will see significant snowfall, as some spots may see several inches, but across the highest impact areas, a foot or perhaps even several feet of snow will be possible. Now where exactly the high impact snowfall area will setup is something that still is uncertain at this point. The closer we get to this event, the clearer things will become. For now, I outlined a generalized threat area where significant will be possible, keyword… possible.


When viewing this graphic, please note the following…

Grey outlined area: Potential to see some snow from this winter storm

Blue outlined area: Significant snow is possible in this area… keyword, possible

Pink outlined area: This is likely to be the “highest impact” area for significant snowfall amounts.

As I mentioned, if you are in the blue outlined area, not all areas will see significant snowfall, but the threat is there.

SNOWFALL AMOUNTS: Those those that follow me on social media know that I do not share computer model snowfall maps very often if at all. I’ll change the course here just to show you why snowfall amounts are still very much uncertain. While snowfall amounts are still up in the air, we can the idea that, regardless, this is likely to evolve into a high-impact winter weather situation for many across the eastern US. Snowfall forecasts should not be finalized until at the very earliest, 12 hours before the event begins, if even that early. The reason for not issuing snowfall amounts any sooner is because of the complexity of this system. Any jog in the track of the storm north or south could mean the difference between an area getting an inch of snow or 18″ of snow… yes, such a small change in the track could send a forecast awry in a heartbeat and could cause a vast difference in snowfall amounts, and this is why we must be watchful when observing and issuing snowfall maps. If this winter storm pans out as anticipated, overall, many areas in the “blue” and “purple” regions outlined above could see anywhere from 6″ of snow to well over a foot of snow, with some spots potentially seeing feet of snow throughout the entirety of this event.

Here are the GFS (American Model) and GGEM (Canadian Model) outputs for “projected” snowfall amounts through Monday morning of next week. As you can see, there are differences in snowfall amounts as projected by each model, which means, “concrete” snowfall totals are still far from certain. The European model (cannot share that due to legal reasons) actually shifted the track of the storm further south and brings the heaviest snowfall amounts further into the heart of the Mid-Atlantic. Keep in mind, these are NOT forecast snowfall amounts, but computer model outputs; essentially what each computer model thinks will happen with this winter storm threat at this point. While the models have been amazingly consistent in illustrating this winter storm threat since the weekend, snowfall amounts are not truly representative this far out, but models should begin to hone in on more accurate snowfall values as we get closer to this event.

gfssnow ggemsnow


Here is a look at the winter storm as it is projected (GFS) to reach the Northeast by Saturday morning…



As a final note, this is a very complex winter storm and has the potential to become a major winter storm with significant snow implications across a widespread area in the eastern US. Now please note that while this has the potential to become a significant event, there are ways this system can “underperform”. One way this could underperform is if the low pressure system does not cut off and close off and stays a weaker system overall. When the low pressure system cuts off and closes off, it has a much higher chance to deepen (strengthen) and create its own supply of cold air, creating much heavier snows on the north and western side of the low pressure system. That said, however, I do think the low will close off and strengthen as it moves northeast… but, only time will tell. I’ll continue to post weather notes and discussions on social media about this winter storm threat.