Historic Blizzard To Slam The Mid-Atlantic and Northeast

Latest Snowfall Accumulation Projections from the GFS Model Through Wednesday Morning

It’s not too often that you get to throw around the words ‘historic’ or ‘epic’ when talking about a potential winter storm or even blizzard, but given the continued forecast model consistency, I must acknowledge that this winter storm could be quite the doozy early this week for parts of the Mid-Atlantic and Northeast. At Firsthand Weather, I try get you prepared for such winter events without all of the nonsense and hype, and this potential blizzard is nothing that you want to take lightly. Before I get into the details, it’s important to understand that a small shift in the track of this storm could and would throw off the entire forecast, which makes it important to stay updated every few hours in order to adequately prepare for this event.

What Exactly Is Going On?

A piece of energy is diving south from Manitoba, Canada and has an associated surface low pressure system moving southeast with it. Many of you are likely familiar with the term ‘Alberta clipper’ even if you don’t actually know what that is. Simply put, an Alberta clipper is a fast-moving storm system in the winter that originates from the Canadian province of Alberta and moves into the United States. So what is a storm system called that originates from the Manitoba province during the winter? A Manitoba Mauler!

This Manitoba Mauler is currently located over the Central Plains and will be sweeping southeast during the day on Sunday going into Monday. This is going to originally bring a swath of snow from the Central Plains to the Ohio River Valley and eventually for parts of the Tennessee Valley. As this system moves eastward, its energy is going to be transferred to the East Coast, and a coastal low is going to develop and strengthen off the coast of North Carolina and Virginia.

Parts of the Mid-Atlantic and Northeast will get some accumulating snowfall before this system makes it to the East Coast, but once this storm is on the coast, it is literally going to explode. This rapidly intensifying storm system will move up the coast Monday night going into Tuesday and will bring a significant blizzard with it for parts of the Mid-Atlantic and Northeast.

This shows the blizzard moving up the East Coast on Tuesday morning.

This shows the blizzard moving up the East Coast on Tuesday morning.

Who Could Be Hit The Hardest?

I know that I’ve already discussed some of the regions that will be impacted before this system makes it to the coast, but I want to get into more specifics regarding the regions that will be slammed as this system moves up the coast.

The regions that could be hit the hardest will likely be from Philadelphia up through New Jersey, New York City and Long Island, Boston, and up through Maine. Blizzard conditions could occur along all of these regions, especially from the Jersey shore up through New York City and Boston and eventually up towards Maine. Forecast models have been consistent with dumping at least a foot of snow over all of these regions with New York City and the Boston area getting up to two feet of snow.

Latest Snowfall Accumulation Projections from the GFS Model Through Wednesday Morning

Latest Snowfall Accumulation Projections from the GFS Model Through Wednesday Morning

It’s important to note that this is on a 10:1 snow ratio scale, and snow ratios could be higher for some of these regions. Because of this, some of these snow totals could be higher.

The latest European model has the heaviest snowfall accumulations around the New York City area.

The latest European model has the heaviest snowfall accumulations around the New York City area.

Again, it’s important to understand that things could change, but with this kind of model consistency and agreement, it’s best to prepare for the worst-case scenario. If these kinds of snowfall accumulations fall over these regions, this would definitely be a historical storm for many regions.

Future Updates and Preparations:

I didn’t mention all of the regions that could be impacted by this storm, but it’s VERY important to make preparations for this coming storm. With these kinds of storms, changes can occur at the very last minute so please keep checking back with Firsthand Weather and your local meteorologists.

A local meteorologist in the Boston area has plans to send me a forecast later in the day on Sunday, and hopefully I’ll have his article posted on the site by Sunday afternoon or evening.

Winter Prepares To Visit The Northeast

Written By: Robert Millette

A coastal low will develop into the first Nor’Easter of 2015 this weekend as the first real snowfall for the year will hit sections of the Northeast region. By late Friday, low pressure will develop over Georgia and pass off the coast of the Outer Banks Saturday morning. Rain will begin on the Eastern Shore and Southern sections of Maryland and in Delaware Friday afternoon. While it will be mostly rain in these areas, snow will begin to fall in the Eastern panhandle of Maryland overnight with a mix and possible icy situation near the Baltimore and D.C metro areas. These areas will cool and begin to change to snow with the exception of right along the coastline of the Chesapeake. Extreme Northern areas of the Eastern Shore and Delaware will also begin to transition to a mix overnight as snow begins to move into New Jersey and Pennsylvania.

By Saturday morning, snow should have moved into the NYC metro area and the coastal areas of Connecticut and Rhode Island. By noon time on Saturday, snow should arrive in Boston with a rain/snow line setting up south of there as the Cape and Islands will see rain along with the New Bedford/Fall River metro region along the South coast of Massachusetts. Snow and rain will be tapering off or have already ended in Maryland, Delaware and Southern New Jersey by this time, but another area of precipitation will move into Coastal portions of this area for a time on Saturday afternoon.

During the afternoon, snow will move into the Southern and coastal areas of New Hampshire and Maine as the storm passes Southeast of Nantucket and moves toward Nova Scotia. Precipitation should wind down during the afternoon in New York and Saturday evening in the Boston metro region.

While exact totals are not set in stone at this time, several inches of snow can be expected from an area starting Northwest of DC and Baltimore passing through Philadelphia and NYC on towards Hartford and Boston. Locations north of Boston will see a drop off in the amounts of snow as this storm will be out at sea and not pass close enough to the coastline to give them significant snowfall.

Winter Storm Watches have been posted for Hampshire, Worcester, Central and Northwest Middlesex, Western Essex and Western Norfolk counties. 4-7 inches of snow are expected on Saturday in this area by the National Weather Service. I expect this area to expand to include more Eastern locations as certainty increases. Winter Weather Advisories will be posted as the timeframe approaches.

Beyond this weekend’s storm, an Alberta clipper-type system looks to rapidly develop in the Monday/Tuesday timeframe and may bring more snow to the region. This storm will need to be watched closely for further developments.

Is There Still Hope For Snow and Ice This Winter?

This is an upper-level map for the beginning of February that shows a storm and troughing across the Southeast, ridging building up over the West Coast and Alaska, and a trough west of Baja California.

I could go back over previous winter when the months of December and January were complete duds, but then February went absolutely crazy. Just because it happened certain winters doesn’t mean it’ll happen this winter, but it does definitely happen. This winter has just had a difficult time staying in the pattern that I was expecting it to be in for most of this season, but it has been trying ALL winter. That tells me that I have definitely been onto something, but something else has been pushing things back. That also tells me that we still have the opportunity to snap into that pattern, and what is currently taking place does give me hope that that is going to eventually happen.

I still believe that the warmer waters over the northeastern Pacific have been a big driver this winter, but the biggest difference between this winter and the last is that there have been some things pushing this winter pattern back. I have put out an explanation for this all winter, and we have continued to have a difficult time overcoming that. We have had very cold air over the eastern two-thirds of the U.S. but not at the same time that moisture has been over certain regions. So, it’s either been wet and too warm or cold and too dry. That makes seasonal outlooks kind of deceptive because technically, a group of meteorologists can be right on their seasonal outlooks but wrong on what took place to make things come out right.

Do I Believe February Will Be Active and Stormy?

From what I can see right now, the answer to the above question is yes. At the least, ridging will continue to build up over the West Coast and Alaska. Even with a marginal AO/NAO, troughing will be able to setup over the central and particularly, the eastern United States. We’ve had a difficult time getting any true blocking over Greenland, but we didn’t have that last year either. The big ridge up over a Alaska (a negative EPO) dominated last winter, and with a weaker polar vortex, a piece of the vortex continuously broke off and pushed southward.

Sometimes, the overall pattern can be so cold that it suppresses storms way to the south, and most of the United States just ends up with bitter cold and dry weather. Many times, these more volatile and constantly changing patterns bring many opportunities for snow and ice, even into the South. You may get a cold rain on numerous occasions, but more times than not, you’ll eventually score big with a winter storm. That’s what’s going on now.

This is an upper-level map for the beginning of February that shows a storm and troughing across the Southeast, ridging building up over the West Coast and Alaska, and a trough west of Baja California.

This is an upper-level map for the beginning of February that shows a storm and troughing across the Southeast, ridging building up over the West Coast and Alaska, and a trough west of Baja California.

There’s currently an anomalous region of troughiness west of the Baja Peninsula, and that is expected to continue into February. Pieces of energy should be able to slide under that ridge into the United States, and with sufficient cold air being available, that could lead to some fun and games down the road. In fact, we already have a big winter storm potential at the very beginning of February, and although forecast models for once agree with this, the other things that I look at to make my long-range predictions generally support this. We’ll see how things play out this weekend, and I’ll have more details in a few days if the threat still exists by then.

Most of the time, you don’t need a record-breaking, apocalyptic, non-stop, bone-chilling winter to get some major action. All it takes is an active pattern, and some cold air. Folks, there’s still plenty of hope for all you snow-lovers in the South.

Late Week/Weekend Winter Storm Will Impact Many

Latest snowfall accumulation projection through Sunday from the NAM

We’re finally getting some action across the United States. It’s either been very cold and dry or warmer and wet. Things have become a bit more active, and given that the overall pattern looks to remain active with several shots of Arctic air, I’d say the chances are quite high that many regions will get snow/ice over the next couple of weeks. This first storm will likely give wintry precipitation to many, but there will be a few regions further south that will have to deal with a cold rain (with possibly some wrap-around snow/sleet on the backend). I’ll be detailing that below.

Latest snowfall accumulation projection through Sunday from the NAM

Latest snowfall accumulation projection through Sunday from the NAM

Currently this system is pumping copious amounts of moisture across New Mexico, Oklahoma, and Texas. The snow is already starting to pile up across the panhandles of Texas/Oklahoma and over New Mexico. Heavy snowfall accumulations are likely over those regions. The moisture is going to continue to spread eastward, moving further into Texas and Oklahoma. Parts of southwestern and western Oklahoma into parts of central Oklahoma could also end up with some heavy snow before all is said and done.

I wouldn’t be surprised if regions near the Dallas/Ft. Worth area (particularly just north of there) ended up with a changeover to some heavy snow/frozen precipitation that could bring accumulations. Those regions are not currently under any winter weather advisories, but that could easily change. They may end up being in one of those surprise areas. It’s always important to realize that a degree or two can make a huge difference.

Moisture will begin to spread eastward over Louisiana and Arkansas tomorrow and then eventually east and northeastward into the Tennessee Valley and Gulf Coast states tomorrow night going into Friday. Cold air is going to rush in behind this system, so a changeover to heavy, wet snow is definitely possible over south and central Arkansas, northern Mississippi, and particularly over Tennessee. I wouldn’t even be surprised if a few wet flakes or ice pellets fell over northern Louisiana.

As this system moves along the Gulf Coast states on Friday, it will eventually cross over northern Florida and then up the East Coast, where this system will rapidly strengthen. As this system begins to pull up the coast Friday night, I wouldn’t be surprised at all if certain areas in northern Alabama and northern Georgia changed over to some frozen precipitation towards the end of the event. Parts of northern Upstate SC could also transition to some wet snow or frozen precipitation, and in fact, latest model guidance has some very light accumulations over the area. We’ll have to wait and see if anything comes of that, but given that cold air will be rushing in behind this system, I’d say that it’s definitely possible.

Bombogenisis is likely going to occur with this storm as it slides up the coast, meaning the pressure will likely drop over 24 millibars in a 24-hour period. This will pull copious amounts of moisture up the coast, and it’s going to all come down to the track of this system, which will determine who gets very heavy snow or just a cold rain. I’d say that from the western NC mountains, Tennessee/Kentucky and up through western and central Virginia into West Virginia has a decent shot at snow and/or ice. The highest risk area will be from the DC area up to around Boston. Again, a few mile jog west or east can change the entire forecast. That’s why it’s so hard to predict these kinds of systems when they go up the coast like this.

I hope this gives you a good idea as to what you can expect. This system is likely going to be bringing a big winter storm to many, and I wouldn’t even be surprised if it brought a little surprise to other areas, too. Generally this will be a very heavy rain event across the Gulf coast states, but like I mentioned, some regions could see a changeover to some frozen precipitation. I will monitor everything as the event unfolds.

Multiple Winter Storm Potentials and Arctic Surges

There is a lot that is about to take place over the next seven days and beyond, and there is no way that I can cover everything in this one article. Instead, I’m just going to give basic bullet points to give you a general idea as to what’s going on, and then I will detail each individual event in future articles and updates. Let me also make you aware that we have entering into another period that is going to be challenging to forecast. The amount of cold air in place, storms tracks, surface high pressure locations, and other variables are going to play a huge role in who gets what and how much.

Cold Air Surge On The Way:

  • The last week of January is going to flip back cold, particularly in the eastern third of the nation.
  • There could be a bit more volatility (back and forth temperatures) across portions of the central United States.
  • The western United States are going to really warm up as ridging will build over the area and into Alaska.
  • The overall pattern is going to become very active.
  • While some volatility in the pattern is likely, several surges of Arctic air could push south over the eastern United States continuing into February.

First Winter/Rain Storm Potential:

  • Two pieces of energy out West are going to combine into one over the southwestern United States.
  • Heavy moisture is going to develop and move in over New Mexico, Texas, Colorado, Kansas, and Oklahoma. This will bring heavy snow particularly over parts of New Mexico and the panhandle of Texas. Regions including parts of Colorado, Oklahoma, Kansas, and eventually further east over Texas will also be getting snow from this.
  • This system will push copious amounts of moisture over the Gulf coast states and eventually further up the coast late week into the weekend.
  • This will likely take the track that would typically bring a big winter storm across the Southeast and up through the Mid-Atlantic, BUT there may not be a high pressure system to the north that will be pumping cold air into the region.
  • Forecast models handle these kinds of systems horribly so there are still many questions. Parts of the Tennessee Valley, the Mid-Atlantic and Northeast could get snow from this, and if they do, it could be heavy.
  • I’m still watching the Southeast VERY closely given the track that this storm will likely be taking. IF more cold air were to get pulled south into this storm, then there would be an entirely different scenario. Model guidance currently doesn’t show that, although some wrap-around moisture could change over to some wet snow.
  • I will have an article out tomorrow night on this particular storm with more details.

Second Winter Storm Potential:

  • Right after this first storm moves off the coast, ANOTHER storm will be moving across the United States early next week.
  • This will be after the cold air has plunged south across the eastern United States.
    This system will be diving south from the north and could trigger a coastal low to develop off the East Coast.
  • Depending on where this coastal low develops, this will be the determining factor as to who gets moisture and who doesn’t. Given the amount of cold air that will be in place, most of this moisture would be snow or wintry weather, except in the warm sector of this system.
  • These storms can be a big deal for places like the Tennessee and Ohio River Valleys, parts of the Mid-Atlantic and Northeast and even areas further to the south. Please note that I always questions these kinds of systems further south because the Appalachian mountains tend to block any moisture getting to the south. IF the coastal low were to develop further south however, this would increase snow chances further south.
  • I will have more details on this in a couple days. Details are still very uncertain, at best.

I talked about two storms here, and guidance indicates that other storm potentials could follow these two. Some of you will be really happy if you like snow, and some of you won’t. It’s important to realize that we are entering into the active and colder pattern that I have been talking about for several weeks now. Your chances of getting snow/ice during this period will be much higher than it has been so far this winter (this includes regions across the South). It’s important to realize that many regions across the Southeast don’t typically get snow/ice until late January and February anyway. I hope this gives you a decent overview as to what to expect, but realize that things could quickly change. I have much more studying to do on all of this, but I am simply sharing with you what I see so far.

Brutal Winter Cold and Potential Late January Winter Storm

The Climate Prediction Center is already predicting the late January cold.

This winter is about to get very active and cold, and it’s going to happen fast. I have been saying for several weeks now that the most memorable part of this winter could be the last week of January going into the first couple of weeks in February. Even beyond that, the weather could remain very cold and active, but I’ll begin discussing that timeframe when we get closer to it.

Some of you have pointed out to me that your weather apps and local meteorologists are predicting a moderation in temperatures, and for a few days, temperatures are going to be warmer for many. It’s important to point out that this January was not the blowtorch that many began to predict once the entire month of December ended up warm, and this coming warmup is only going to be moderate. Despite the absence of upper-level blocking over Greenland and the Arctic in January, it has remained very cold. That’s very important to take note of, and I’ll explain why later in the article.

I mentioned several times that it seems to me that what kept us warm in December and forced the unfavorable upper-level pattern setup in January was an abnormally strong Pacific jet stream that was pushing all of that warm, Pacific air in a west-to-east motion. There were other factors at play also, but I believe that they were being weighed too heavily in the meteorological community. What’s ironic about this is that January HAS been very cold for most of the United States with the exception of the West Coast and parts of Florida. Let’s not forget that we live at the surface and not in the upper-levels of the atmosphere. Again, that has strong implications and further confirms with me what has been the main driver of this winter.

What Is The EPO, and Why Is It So Important?

EPO stands for Eastern Pacific Oscillation, and once again, I believe that it is in the driver’s seat this winter and has been. The EPO is an index that measures the amount of blocking, or lack thereof, over portions of the West Coast and Alaska. During a negative EPO, temperatures tend to be warmer over Alaska and over the western United States and colder in the central and eastern United States. This was a HUGE driver that brought the bitter cold that we experienced last winter, which is why I explained why we didn’t need a huge amount of blocking over Greenland to get cold into the United States. We saw how last winter turned out, and as you know, it wasn’t on the warm side of things.

As expected, we are about to experience a brief warmup, and it just so happens that the EPO is now in its positive phase. That will only be brief, and model guidance brings the EPO back into it’s strongly negative phase, just as model guidance is projecting a potentially significant Arctic blast during the last week of January and likely extending well into February.

After briefly going positive, the EPO goes negative again.

After briefly going positive, the EPO goes negative again.

The main culprit behind the EPO being so negative over the last two winters has been the warm pool located in the northeast Pacific. It was there last winter, and it is still there today. As the Pacific jet stream (the band of really strong winds in the upper-levels) begins to relax somewhat, the negative EPO should become an even stronger player.

Why I Believe The Last Week Of January Into The First Couple Weeks Of February Will Be The Most Memorable Part Of This Winter?

As I mentioned above, I believe that I have correctly identified what delayed the cold in the second half of December, and the index that kept us cold in January, despite the lack of ridging over Greenland and the Arctic. Those cold Arctic high pressure systems kept the cold air funneling south into the United States earlier this month, but for the snow lovers along the East Coast and the South, the snowfall totals have not been that great thus far. It’s not unusual for the Southeast not to see snow or ice until later in January or February, but it has been unusually snowless in the Mid-Atlantic and Northeast. That could change in a hurry.

The Climate Prediction Center is already predicting the late January cold.

The Climate Prediction Center is already predicting the late January cold.

The upper-level pattern could begin to shift from a non-favorable pattern for East Coast winter storms to a much more favorable pattern for bigger storms riding up the coast. It’s important to point out that regions all along the South will continue to be under the gun regardless of what happens due to a very active sub-tropical jet stream. If any amount of cold air is in the right place at the right time with adequate moisture, parts of the southern U.S. could get snowy/icy conditions later this month into February. The big question right now is whether or not these storms will strengthen and pull up the East Coast.

I know that I explained that a strongly negative EPO alone can bring colder conditions to the central and eastern United States, but the latest model guidance continues to strongly hint at blocking setting up over the Arctic and Greenland. That would further reinforce the brutal cold over the central and eastern United States and greatly increase the chance of big winter storms moving across the South and up the East Coast.

I also recently discussed that the recent warming of the stratosphere could weaken and even potentially split the polar vortex. Warming over the North Pole like that typically has effects a few weeks down the road, and if the pattern is right over a particular region, brutal cold across the mid-latiudes can be the result.

The regions that will be impacted by the brutal cold will be the Great Plains, the Upper Midwest, the Ohio River Valley, the Tennessee Valley, the Northeast and Mid-Atlantic, and the Southeast. So basically, that covers about everyone east of the Rockies. While the focus of the cold air so far as been over the Great Plains (further west), the core of the cold could shift slightly to the east. That will be interesting to see how that evolves. Again, the period that I am watching most closely is the last week of January into the first couple weeks of February. After that, the pattern could continue to remain active and cold.

Major Winter Storm Potential In About 8 to 10 Days:

Before I end this article, I want to discuss the potential for a major winter storm around this timeframe. I am more confident than usual that there will be a pretty sizable winter storm during this period. What is currently happening around the globe supports this event occurring, and recent model guidance has continued to support this potential. It’s important to note that model guidance will likely be all over the place this far out, but again, the other factors that I look at to make my long-range forecasts strongly support this.

Given that guidance has continued to show blocking setting up over Greenland and the Arctic, I am leaning more towards this system moving across the southern United States and eventually up the East Coast. That could change given that this storm could occur just as we are transitioning into a much colder pattern. Like I mentioned above, the EPO will continue to be a big driver this winter, so even a neutral or slightly negative NAO/AO would probably do the trick. Still, the more negative those teleconnections are, the better!

At this point, I can’t tell you if you’re going to get snow or ice in YOUR backyard. What I can tell you is that a storm will likely develop, and wintry weather chances will be on the increase. There could even be another storm several days later, but let’s not get ahead of ourselves just yet.

Given the changing pattern, wintry weather chances will likely increase for the Southern Plains, the Upper Midwest, the Ohio River Valley, the Southeast, the Mid-Atlantic, and the Northeast. I may have left out some locations, but I’m just trying to give you a general idea at this point.

Conclusion:

  • The pattern could shift very cold for the central and eastern United States towards the last week of January. If this does occur, temperatures, as a whole for this month, could be just as cold or colder than last January. Records could be challenged or broken in certain regions.
  • A big winter storm could take place in about 8 to 10 days. Details are still uncertain, but I am more confident that a larger winter storm will develop.
  • The pattern will remain active, and several Arctic blasts are possible between the last week of January going into February. Several winter storms are possible.
  • Winter isn’t over like so many seem to believe. What is currently occurring compares quite well with winters that are similar to this one. There are some differences, but there are definitely some major similarities.

Active Winter Pattern On The Way

Projected Jet Stream Pattern For Next Week

I mentioned that I am in the process of putting together a detailed forecast for the rest of January going into February. I am still convinced that our winter is about to get active across the southern United States and eventually up the East Coast. If the potential ice storm doesn’t come to fruition this weekend, then I plan on releasing that detailed forecast this Sunday at 2 pm ET.

Before I point out something about the coming pattern, I can’t stress enough how everyone doesn’t need to be outside for long periods of time tonight and tomorrow if you’re in the central and eastern United States. This is some serious cold! Remember to bring your pets inside, and keep a check on the elderly and sick. Hopefully schools will be delayed or closed tomorrow, but if for some reason they’re not, dress your kids in multiple layers.

Below are the projected temps by the 4 km NAM for tomorrow morning. These are actual temps, and wind chills will be much worse.

Projected Low Temperatures For Tomorrow Morning

Projected Low Temperatures For Tomorrow Morning

Active and Stormy Pattern Setting Up:

I have mentioned dozens of times over the course of the last several months that I believed that a very wet (and snowy/icy) pattern would be shaping up for the southern U.S. and potentially up the East Coast this winter. You may also remember me mentioning that a very active sub-tropical jet would be setting up across the southern U.S., and that we’d be dealing with a split-flow pattern. I’ll explain what all of that means.

A jet stream is a narrow-band of fast-moving winds in the upper-levels of the atmosphere (6 to 9 miles above the surface). The Pacific jet stream has been extremely active so far this winter. In fact, it has been so strong that it has been responsible for pushing Pacific air over the United States and initially cutting off our Arctic air source.

While the Pacific jet stream is still very strong, a split-flow pattern is about to begin setting up over the western United States. Basically what that means is that the jet stream will split into two separate jet streams with a southern jet (the sub-tropical jet) and a northern jet (a polar jet). Later this month, I expect a more amplified polar jet to set up over the central and eastern United States (basically this will pump Arctic air over those regions) and for the polar jet to interact with the active sub-tropical jet. Remember, the active sub-tropical jet stream will be responsible for transporting moisture across the southern United States and up the East Coast.

To help you better visualize this, I included the GFS ensemble for the middle of next week. Where you see the brighter colors on the map is where the jet streams are located. Those dark reds and bright purples indicate very strong winds in the upper-levels of the atmosphere. I included arrows to outline the sub-tropical and polar jet streams.

Projected Jet Stream Pattern For Next Week

Projected Jet Stream Pattern For Next Week

For those of you that have studied meteorology, you can see that this has a very “El Nino look” to it. This is a pretty progressive pattern (for now), but my point is that the moisture is going to be available across the South. If you get just enough cold air in place, then you know what that means. We’re going to have a very close call this weekend with the potential ice storm threat, but it will all come down to timing. Can you imagine if we would have had a huge winter storm this week with all of that cold?

I can’t help but think that with what’s currently taking place in the stratosphere at the North Pole that the cold air is really going to be unleashed. For the naysayers going around talking about how winter is over, I honestly just don’t see it. I truly believe that the East Coast and southern U.S. will have several winter storm chances this season.

On a side note, residents up towards the Great Lakes need to watch things, too. With those lakes as warm as they are, the lake effect snow machine could really get going later in the month going into February. Like I mentioned above, if we don’t have too much going on with the weather this weekend, then I’ll have more details then.

Southeast Ice Storm Potential This Weekend/Next Week

We have a complicated forecast shaping up for this weekend, so please understand that there is going to be a lot of uncertainty regarding this potential ice storm. I suppose I could have waited a little longer before I put out this forecast, but these kinds of potential winter storms are complicated to forecast even a day before they happen. I figured I might as well share my early thinking. In this article, my goal is to detail the projected overall setup this weekend into next week and explain why this COULD lead to a significant ice storm across parts of the Southeast. Notice that I used the word ‘could.’

A potentially record-breaking high pressure system is currently moving into the United States and will be responsible for the brutal cold that the majority of us will experience this week. Like I explained several days ago, these high pressure systems can bring really cold air with them by pulling the cold air down from Canada as they move into the U.S.

Once we move into this weekend, everything gets very interesting, and anytime I tell you that things are getting interesting, you know what that means. Another high pressure system is going to be moving south and east from Canada later this week and will be located near the East Coast by the end of this weekend. Because of the location of this high pressure system, the clockwise flow around this high is going to wrap around cold air from the north and cause it to dam up east of the Appalachian mountains. This is what is called ‘cold air damming’ in meteorology. The cold air can’t keep past those high mountains so it pools at the base of the mountains. In this type of scenario, you can actually have the mountain tops warmer than the valleys.

As you can imagine, if you get any kind of moisture to move over those areas at the same time, then you can have major icing issues. In many cases, the cold air is shallow, and the air above the surface is above freezing. Instead of the white, beautiful snow, you get a nasty ice storm instead.

After this high pressure system moves off the coast late this weekend, we have ANOTHER strong high pressure that will be moving across Canada and eventually over the Great Lakes and Northeast regions. This is going to set up a classic cold air damming situation east of the Appalachians, and if moisture is available, southeast regions of the U.S. will have another shot at an ice storm.

With all of that said, there could be two cold air damming scenarios setting up back to back.

What In The World Does All Of This Mean?

I’m going to tell you right out of the chute that forecast models handle these types of setups horribly. In the past, residents across the Southeast have gone to bed thinking they’re going to get a rainstorm and wake to a crippling ice storm or vice versa. Forecast models typically underestimate the amount of cold that will be in place with cold air damming scenarios, and in some cases, underestimate the amount of moisture over the region.

This weekend, moisture should begin to get pulled up from the Gulf of Mexico. Initially, places like eastern Texas, northern Louisiana, Arkansas, and eventually regions north and eastward could get freezing rain and sleet. As cold air starts to build east of the mountains later in the weekend, any moisture that moves over the region could be freezing rain and maybe some sleet. Regions that I am watching particularly close late this weekend are northern Georgia, Upstate South Carolina, central and eastern North Carolina, and southeastern Virginia. Please understand that areas just outside of those regions also need to keep a close watch on things.

Another ice storm treat could be possible early next week around Tuesday, and the regions that I am watching most closely are central and eastern Georgia, Upstate and central South Carolina, central and eastern North Carolina, and southeastern Virginia. Northern portions of Alabama may also need to be monitored.

It’s all going to come down to if a) adequate cold air is available and if b) the moisture doesn’t go south of the regions mentioned above. Again, I can’t stress enough how horribly forecast models handle these types of setups, so your mobile weather apps that give you a weekly forecast will pretty much be useless right now.

Don’t go buying up all of the bread and milk just yet. We have a couple days to really watch everything, and I will be coming out with another forecast as things get a little more concrete. Residents located in the possible impact areas need to keep watching everything very closely, and if you rely on my forecasts to make your plans, be sure to check back on this site multiple times a day. These high uncertainty forecasts are subject to change.

I may have an article coming out tomorrow, explaining how all of this ties into my original winter forecast. I would have included that in this article but didn’t want to make this post too long.

Get Ready For Next Week’s Arctic Blast

Projected temperature departures from average on the 12z Canadian model for Thursday morning, January 8th.

The United States needs to get ready for an Arctic blast next week that will likely be comparable to last winter’s bitter cold. The main culprit behind the Arctic blast coming next week is completely different than what brought the central and eastern United States cold last year. A very strong 1060 millibar bar high pressure system is going to be moving south from Canada by mid-week, bringing brutally cold air with it. In fact, records could be broken across many regions, particularly across the upper Midwest and eventually into areas south of that.

The first round of cold will be pushing into the central United States and across northern portions of the United States beginning tomorrow and going into early next week. The main round of Arctic cold will be pushing across the central and eastern United States around mid-week and will eventually make its way south and east, impacting the East Coast and Deep South.

We do have some ridging that will be building over the West Coast and up over Alaska next week, while an amplified trough digs south over the eastern United States. Combining that with this strong Arctic high pressure system will be all that is needed to make this a pretty dangerous cold spell.

What To Expect For Your Region:

Early next week, an Alberta clipper will be pushing across the Upper Midwest and eventually across the Northeast states and could dump accumulating snowfall before the main Arctic blast makes its way across the area. Temperatures will dip well-below zero across the Northern Plains, the Upper Midwest, parts of the Northeast, and even into a few areas south of that. The central and southern Plains will remain very cold throughout most of the week.

By mid-week, the Tennessee Valley should also expect to have temperatures well into the single digits at night, and the temperatures will likely dip into the single digits and teens across much of the Southeast. Even along the Gulf Coast, 20s should be expect across a widespread area with some of those coastal regions possibly getting down into the teens also.

Projected temperature departures from average on the 12z Canadian model for Thursday morning, January 8th.

Projected temperature departures from average on the 12z Canadian model for Thursday morning, January 8th.

If you’re located anywhere on the East Coast, you will be impacted by this Arctic blast. The further north you are, the greater the impact will be. Make sure you take care of and warn your elderly friends and family.

What To Expect After That:

Model guidance continues to suggest that this will not be the last Arctic high to move across the United States after next week, but they may not be quite as strong. The mid and upper-levels haven’t been as favorable for prolonged cold over the eastern United States so far this winter, but these Arctic high pressures are doing the trick for now.

I expect a favorable cold pattern to set up over the United States later in January going into February. Middle January may warm up some across a large portion of the United States, but then again, those high pressure systems diving south from Canada could keep things colder even during that timeframe.

I think the best chance at getting a Southeastern U.S. or East Coast winter storm will be later in the month when the mid and upper-level pattern could become a bit more favorable. Like I mentioned on the site the other day, the strong polar vortex over the North Pole could really weaken this month and displace some of that Arctic cold further south. It just depends if and where any blocking sets up.

It’s important to note that sometimes you can get a surprise winter storm across parts of the southeastern U.S. when high pressure systems wrap around cold air into the region. With all of these surface highs diving south, that can’t be ruled out for later in the month if a piece of energy is able to squeeze in under the ridge. Regardless of how all of this plays out, I’ll keep everyone updated. Be sure to like Firsthand Weather on Facebook.

Polar Vortex: What Is It and Why Is It Important?

The image on the left shows the polar vortex stronger and well-placed, while the image on the right shows the polar vortex much weaker.

In 2014, almost all of you became quite familiar with the term ‘polar vortex’ when it brought brutal cold to the United States during the 2013-14 winter. The polar vortex is nothing new among meteorologists and has been responsible for some of the United States’ worst Arctic outbreaks. Some winters, the polar vortex stays quite strong and well-placed over the North Pole, but other winters, it can become weaker and displaced, bringing bitter cold to different locations in the mid-latitudes. It’s important to note that all of the Arctic blasts that move across the United States are not caused by the polar vortex becoming displaced and/or splitting. Polar vortex has been rated one of the most overused terms in 2014, but nonetheless, it is still important.

What Is The Polar Vortex?

The polar vortex is an area of low pressure that is located over the North Pole in the upper troposphere and stratosphere which can become particularly strong during the winter months. Because of the sharp contrast of really cold air at the North Pole and the warmer air further south during the winter months, very strong winds rotate counter-clockwise around the polar vortex and bottle up all of that colder air. When the polar vortex is strong and well-placed, the cold air has a difficult time getting past those strong rotating winds. As I stated above, there are other ways to tap into that cold, Arctic air during the winter, but typically when the polar jet stream stays further north (north of the United States), then the nation doesn’t experience extended periods of cold. When it all comes down to it, it all depends on where that jet stream is.

What Causes The Polar Vortex To Weaken?

You can kind of think of the polar vortex as one of those spinning tops. When you spin it really fast on a table, it typically rotates very quickly in one place. Now if you were to tap the spinning top or if it were to just slow down on its own, it may continue to rotate in one spot, but its rotations would become more wavy. In some cases, the spinning top may completely move all over the table. You can think of the waviness of this slower spinning top as tentacles of colder air being displaced due to the weaker spin. Last winter, the polar vortex was all over the place, or to put it another way, it was spinning all over the table. Because of the weaker polar vortex, the polar jet stream was all wavy, and it just so happened that a piece of the vortex became displaced and moved into the United States on multiple occasions last winter.

The image on the left shows the polar vortex stronger and well-placed, while the image on the right shows the polar vortex much weaker.

The image on the left shows the polar vortex stronger and well-placed, while the image on the right shows the polar vortex much weaker and split.

There are various ways to weaken the polar vortex. To put it simply, warming over the Arctic weakens the polar vortex. This creates a weaker temperature contrast between the North Pole and the warmer regions further south; therefore causing the polar vortex to displace, elongate, or even split. The jet stream that was once nicely rotating around the vortex becomes wavy and all over the place. If you are under one of those wavy tentacles of cold, then you are in for some really cold, Arctic air.

That’s why you hear so much about the Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Eastern Pacific Oscillation (EPO), sudden stratospheric warming events, etc. Those can indicate that blocking (the building of high pressure) is setting up over the Arctic, Greenland, Alaska, etc., which would indicate warming over the Arctic regions. Sudden stratospheric warming events can warm the North Pole enough to really break down and weaken the polar vortex. That will likely occur this month also, and the effects of this warming could be felt in the form of very cold air over parts of the United States later in January and February.

Will The Polar Vortex Pay The United States Another Visit This Winter?

So far this winter, the polar vortex has remained very well-placed and strong over the North Pole. While many regions around the globe in the Northern Hemisphere have already experienced really cold air so far this winter, other regions have not. Much of the United States has missed out on some of the brutal cold so far, but that could drastically change later in January. If the polar vortex weakens later in January, that could bring brutal cold to the mid-latitudes. Determining where that cold will set up is the challenge.

Model guidance continues to hint that strong warming in the stratosphere is going to weaken the stratospheric polar vortex, which will eventually make its way down to the troposphere. Over the next two to three weeks, this could have major consequences at the surface. We’ll have to watch where exactly this warming occurs, which will ultimately determine where this Arctic cold gets displaced.

To help you visualize this, check out the two images below. This shows you the North Pole, and notice all of the warming that is currently taking place. You’ll notice on the next image how in a few days, all of that warming weakens and splits the polar vortex into two vortices. While it takes time, these effects will eventually be felt at the surface.

Notice the warming currently taking place.

Notice the warming currently taking place.

Even over the course of a few days, things will begin to drastically change over the North Pole.

Notice how in a few days the warming begins to weaken and split the polar vortex.

Notice how in a few days the warming begins to weaken and split the polar vortex.