Saturday, December 31, 2011

Happy New Year to those in the East US!

Potentially Major Winter Storm Shown on ECMWF

Hour 192 of 12z ECMWF
Here, we see two low pressure systems- a cutoff low in the Southwest as well as another system moving onshore Canada. As of right now, they appear to be 2 separate storm systems.
Hour 216 of 12z ECMWF
At hour 216, we are seeing the same two low pressure systems moving eastward. It looks like the cutoff low may be getting some energy from the Gulf, and I could see a snowstorm hitting Missouri and states to the west of Missouri. The other disturbance in Canada continues to move east.
Hour 240 of 12z ECMWF
At hour 240, we are seeing some major phasing occur in the Western Great Lakes, which may indicate a major winter storm could hit the far Northern Midwest areas into Canada.

12z ECMWF Strengthens Polar Vortex-Disrupting Ridge; GFS Introduces Deep Trough Pattern to Great Lakes

Both the ECMWF and GFS are portraying at least some sort of disruption in the polar vortex, as well as at least a slight indication of a cutoff low pattern in the Southwest judging by the 500mb height isobars. However, each model has a different scenario.
The ECMWF brings in a very strong ridge into the polar vortex. If this were to stay in place, essentially the polar vortex would break down, and all of the bitterly cold air would come rushing south, as the lack of motion by the deep low pressure systems would eventually take its toll. This would certainly be a very interesting development. But because not all models do good in the long range, we will have to take this as a 'heads up' item, rather than a sure fire assurance. Additionally, the ECMWF places a ridge in the Northeast.
The GFS introduces a lesser ridge into the polar vortex, but it's still enough to cause problems. A much bigger interest is how the GFS is showing a deep trough pattern in the Great Lakes, which appears to be stemming off of the low pressure systems in the polar vortex itself. It also shows a weak cutoff signal in the Southwest, judging by the isobars.
All in all, this will definitely be something to watch. I would get your snow removal equipment ready, because this is something i'm having a feeling may cause a snowstorm somewhere in the US.

New Years Day Forecast - Valid 1/1/12

New Year's Day 2012 is already upon us, and that means it's time for your New Year's Day Forecast!
POPcast from
Valid 7:00 am EST
Throughout the Day, we will be seeing some precipitation throughout the upper Midwest and Great Lakes as a system will be moving eastward from Canada. It will be a strong system, so plowable snow is likely. We have snow accumulations below.
POPcast from
Valid 7:00 pm EST
In the evening hours, there will still be potential for some precipitation in the Great Lakes area, where strong winds will bring in harshly cold air to start the new year.

48 hour snowfall from

48 hour snowfall from
There is potential for upwards of 8 inches in Michigan from this lake effect snow, with some 1-4 inches of snow across Minnesota and Wisconsin from the system itself, and some lake effect snow closer to the Lakes. By far, Michigan's both upper and lower sections will be the hardest hit. Accumulations may look light on the Eastern side of the Lakes, but that may be because the lake effect machine is only starting to kick in at the 48 hour mark.


WINDcast from
Winds will be very strong on New Year's day, with sustained winds over 30 MPH on land, and over 45 MPH on Lake Michigan.
Here's a meteogram based in Chicago IL, one of the harder hit areas we are expecting of the winds. You can use the dashed lines that say (i.e. 06z GFS Max MT) for wind gusts, because 'Max MT' is essentially meaning the maximum wind gust that may happen in the area, in this case Chicago. (Mean MT is the mean wind gust expected.)
Click to enlarge
The 6z GFS Max MT is up at 70 MPH! Now keep in mind that the Max MT is the ultimate maximum for wind speeds and probably will not happen. A more reliable wind gust measurement would be the mean MT.

Have a great New Years!

Friday, December 30, 2011

ECMWF/GFS Showing Polar Vortex Breaks, Cutoff Low Pattern to Return in Southwest

Both the 12z ECMWF and 12z GFS are showing a break in the polar vortex- a significant development that may lead to the much-anticipated pattern change. Another thing we're seeing in these 8-10 day height anomaly outlooks are trough patterns in the Southwest as well as offshore the Southeast. This means that the cutoff low pattern may return to the Southwest and bring some snowy weather to the Plains. Possibly. A lot has to be determined, but it does match up with my theory of cutoff lows returning.

January 3-5 Lake Effect Snow (Great Lakes Affected)

Hour 90 of 12z GFS
As the system that will be bringing harshly cold air into the US departs, this cold air will work quickly to ignite the lake effect snow system for the Great Lakes. This lake effect snow, while it may not stick, the snow may be enough to coat the ground. Here's the forecast snow depth from the 18z GFS.
The snowfall from the lake effect snow may put down up to a foot of snow up in the far northern reaches of Michigan. Lake Michigan may put down up to 6 inches of snow, with lesser accumulation in the eastern Great Lakes.

January 2-4 Snow Event (Midwest, Great Lakes Affected)

Hour 42 of 12z GFS

Hour 48 of 12z GFS
The 12z GFS is showing the strong system expected to cross Canada also drop down some precipitation in the Upper Midwest and Great Lakes. Seeing as how it appears that a cold front of sorts will be bringing in cold air behind this wave of precipitation, I can see snow accumulations in the Upper Midwest.
There are two sides to this storm: precipitation and temperatures. Here's 850mb temperatures from the ECMWF.
Hour 48 of ECMWF

Hour 72 of ECMWF

Hour 96 of ECMWF
As this system moves through, we will be seeing the coldest air of the season move through the Midwest, and even down to Florida before curving back up to the Northeast. The coldest air should flow through the Midwest and Northeast as this major cold wave moves through. The ECMWF is showing 850mb temperatures below 0 degrees down through Florida. By far, this will be the biggest cold wave the nation has experienced. If the wave of storm systems continues to come through Canada in the same fashion this one did (as is expected), we will continue to see big cold blasts as well as likely displacing some of the polar vortex.

Icy Mix Possible This Evening in the Northeast

PrecipCAST from
Time valid for 10:00 PM EST
As a clipper system moves east-northeast into Canada, we will be seeing a mix of precipitation in northern parts of New York, as well as north Vermont. This could make for some slippery conditions on roads for that area. Some snow may mix in, depending on the temperature gradient for the area as a from precedes the system itself. Rain and embedded thunderstorms will be occurring right near the storm system itself out by Michigan. However, it isn't looking like any huge thunderstorms will be present. There is a freezing rain advisory for a small portion of northern New York depicted below:
Map is not interactive

Full Winter Update, Snowstorm Predictions, Long Range Predictions

We are seeing a major stratospheric warming event take place in the last several days. We are seeing some big temperature anomalies from the 30mb level up to the 1mb level. The big part is that the warming is occurring over Alaska. Because the warming is occurring over Alaska, we might be seeing the semi-permanent low pressure system over Alaska weaken as the warming may progress down into the troposphere. If this warming continues, the pattern change would definitely be helped along. The warmth may be able to propagate into the North Pole, where a disruption in the Polar Vortex could break the stubborn +AO/+NAO regime which has been producing a snow drought over the East US.
Here we have the 0z ECMWF 500mb analysis over the far North Hemisphere. We see the strong low pressure systems right over the North Pole. We can see the strong low pressure system over Alaska, where we are seeing warming occurring. Now let's skip ahead to hour 168.
At hour 168, we are seeing a ridge from Asia pump north into the polar vortex and interrupt it for a little bit. This ridge will be pulled north into the main polar vortex and disrupt the vortex. Essentially, the NAO and AO will also be disrupted. The AO, which is based in the North Pole, is the biggest piece that will be affected. If the vortex breaks, the extremely cold air that has been locked up may flow southward as the vortex breaks. Moving ahead to hour 240 is seeing the low pressure system over Alaska take a big weakening hit, which may bring some active weather into the US. However, no model does well at 10 days out, so take this as something to watch.
But let's say that this disruption does happen. Well, what would happen to the all-important NAO?
The old 0z ECMWF shows the point of when the expected break in the polar vortex is, as well as the effects of the polar vortex break. The new 12z ECMWF does now show the downward trend, but an up-and-down pattern similar to what we have outlined as the time when the vortex breaks. We are still seeing a more persistent ridge break into the polar vortex, however, so the NAO image above should not be discounted.

The NAO has been wildly swinging. With stronger systems bringing stronger positive NAO values, this means the potential for lower NAO values, going off of Newton's laws: With every action there is an equal and opposite reaction. If we use that law, it can be determined that a strong +NAO value will eventually lead into a strong -NAO sometime this winter.

Pre note: Confidence is low on these predictions. It is entirely possible that these snowstorms will not happen. In other words, don't hold me to these.

January 6-11: An active period is already setting up that should lead into the first couple weeks of January, if not longer. Among those possibly affected include the North Plains and the Northeast.

January 14-18: A couple shots of low pressure systems into the Southwest could make for a good snow somewhere in the Plains or Midwest.

A quick start to January will continue as the deep low pressure system over Alaska weakens as the ridge interrupts the polar vortex in the early new year. Late January may bring a deep chill to much of the country as the Arctic Oscillation dips far enough into negative territory to unleash pure Arctic air. Using Newton's Laws mentioned above, we can expect a BIG snowstorm for the Northeast sometime this winter when the NAO goes negative in response to a very positive NAO so far this winter.

Pattern Change Update at 3:00 PM CST

Thursday, December 29, 2011

Clipper Snowfall Forecasts Lowered

48 Hour Snowfall Accumulation
Centered on Brainerd, Minnesota.
Image from Intellicast's SNOWcast.

48 Hour Snowfall Accumulation
Centered on Chicago, Illinois.
Image from Intellicast's SNOWcast.
Snowfall Forecasts for the Alberta Clipper are lowering, as shown by Intellicast's SNOWcast 48 hour snowfall accumulation forecast above. It looks like the maximum totals will actually turn out to be around 1-2 inches for South Wisconsin, with up to 4 inches in Minnesota from this clipper. I am not surprised, as it takes a lot of moisture for 4 inches of snow to fall, especially for an Alberta Clipper, which is moisture starved to begin with.

Clipper System to Lay Down Up to 6 Inches of Snow

Maximum Possible Totals Shown
A clipper system is expected to lay down up to 6 inches in some spots of the Northern US in the next couple days. While 6 inches is unlikely, this is a maximum snowfall accumulation map.
Some notes on the map:
-Some light accumulations may occur a bit farther south than what the accumulations show above.

Signs Appearing that +AO/+NAO Regime May Break

Initial 0z ECMWF 500mb Analysis
Above we have the initial 500mb heights analysis from the latest 0z ECMWF. We see the tight polar vortex of low atmospheric pressures encircled in the black area. This polar vortex is what supports the +AO/+NAO regime. That said, if there were high pressure systems over the same black area, we would be seeing some sort of -AO/-NAO. Let's jump ahead into the ECMWF's forecast.
Hour 192 of 0Z ECMWF
At hour 192 we're seeing the Polar Vortex break apart as a ridge forces itself into the vortex from Asia. This in turn forces a low pressure system towards Greenland, making for a West Based +NAO. While we aren't showing it, this ridge does break down at the end of the ECMWF forecast timeframe. It does show that there is potential for a ridge to break in and possibly bring in some colder weather for the US.
This is another view of the top 2 images, with the analysis period at the top and the hour 192 image on the bottom of these latest 2 images.

Wednesday, December 28, 2011

Update on January 2-4 Potential Snow Event

We've got our eye on the storm system that may go into the Northeast, the Midwest, or just move along the US/Canada border. That same storm is outlined in a gray circle above. We will be seeing it move northeast as a ridge offshore the West Coast will pump up the storm northward. This storm should push the disturbance currently on Canada's coast eastward, so both systems can go on land. Because it looks like this system is going into Canada, I'm close to ruling out a Midwest storm solution. The ECMWF/GFS models are probably right with keeping the system in Canada and not going into the Midwest or even the Northeast.

January 2-4 Potential East Coast Snowstorm Event Update

Well, the 0z ECMWF was a major disappointment. It kept the system in Canada all together, pretty much leaving the US out of the big snows that were initially possible. But for this update, we are going to say that there is a storm that might affect the Northeast- and why it might trend west instead.

NAO Forecast
The ensemble forecasts for the NAO are showing a general downturn from the positive phase towards a more neutral phase after New Years. Some ensembles are even going as far to say that the NAO will turn negative. If this were to happen, the chances of an East Coast snowstorm, in my mind, would greatly increase. However, that's a bit too far out to make a definitive prediction on. But what does all this positive NAO (+NAO) and negative NAO (-NAO) mean?
During a +NAO, a low pressure of sorts is over Greenland, which in turn moves the jet stream more north and gives the East Coast some warmer weather. In a negative phase, it is basically the opposite- we see a high pressure over Greenland give the Northeast cold and snowy weather, which is shown as an enhanced trough.
Putting those together indicates that there would be at least some potential for an East Coast snowstorm if the ensembles go as planned and the NAO moves for neutral of even negative territory.

The NAO isn't the only thing that has effects on the US. There is also the MJO. Right now, we're sitting in a moderate Phase 5 stage. We are forecasted to move into a weakening Phase 6, an almost nonexistent Phase 7 and right into the Circle of Death- when the MJO switches phases by moving in a circle in a repetitive pattern, seen by the jagged red circle in Phases 4 and 5. That is what has already happened. As we move into Phases 5, 6, 7, it comes to mind what the effects of each stage are.
Precipitation Anomalies by Phases
The stronger the Phase indicates the more these precipitation anomalies will show themselves. We are going into at least a moderate Phase 6, so let's take a look. Phase 6 includes a wet precipitation anomaly over the Ohio Valley, Southern Plains and Great Lakes, while leaving the East Coast dry. In fact, Phases 6 and 7 (the phases in which the storm will happen) both are discouraging for precipitation in the Northeast. That would provide a sort of building ground that the storm, if it is to come into the US, would affect the Midwest more than the Northeast. However, as a knowledgable weather enthusiast has said, it is a 'marriage of sorts' with the teleconnections. That means, some indices can be favorable for a storm while some are not, and the ones that are not prevail in the end.

For those wondering, the PNA is going to be moving into a very weak positive phase during this storm, per the CPC Ensembles, so I would say it might not be a factor.

As of right now, I am in a wait and see mode, as the models are having trouble with this. I am closely watching the MJO, NAO, among other indices to see if I can find some hints that this storm may or may not happen.

Update on Potential East Coast Snowstorm Coming Out at 12:00 PM CST Today!

An update on the potential East Coast Snowstorm- and why it may shift west- will be out at 12:00 PM CST Today! Be there!

Tuesday, December 27, 2011

Models Page Update

We have implemented 7 new models into our Models page, bring our total to 34 weather models and ensembles! Click Here for the weather models page.

18z GFS Sees Montpelier, Vermont get 4 FEET OF SNOW

The 18z GFS is predicting Montpelier, Vermont (the capital of Vermont) to receive 4 FEET OF SNOW on January 10th. This comes as a disturbance is forecast to move around just offshore the Northeast Coast. If this were to turn out, it would, no exaggeration here, collapse roofs. Home would be flattened. 4 feet of snow is about as tall as a 9 year old boy. Luckily, this is the long range GFS, which we all know is not reliable in the least.

Something to look out for: If the January 4th snowstorm happens, this storm would be worth watching, because at both time periods the NAO is forecasted to drop. Not into negative territory, but still a drop. Storms can happen during a fluctuation in the NAO, even a drop like what is possible during the 2 storms.

Update on Potential East Coast Snowstorm

See here for the original post on the east coast snowstorm.

We will be doing an update probably tomorrow on how the ECMWF may have shifted too far east with this snowstorm- and there is some hard evidence to prove it. Stay tuned!

12z ECMWF Shows 2-Footer Snowstorm for Northeast...Will it Happen?

The ECMWF is showing a once in a lifetime snowstorm for the Northeast on January 4th. Above, we see the ECMWF image for the January 4th timeframe. On the top right image we see the incredibly strong low pressure system moving up the coast of the East US. If this were to verify, it would be ALL SNOW. Totals, if this were to happen, would EASILY EXCEED 18 INCHES OF SNOW.  So the question is, will this happen?

The NAO says NO. When the NAO is positive, historically snowstorms are fighting a very uphill battle to happen, thus the lack of snowstorms this winter as we have seen a very positive NAO. Despite this, we are trying to see if the LRC pattern may have this storm in its sights. By using a comparison between 45-50 days (the estimated cycle time this year), a storm did show up 45-50 days ago that can be matched loosely with this ECMWF forecast. We will continue monitoring this, but the +NAO can be a real killer.

Tornadoes Possible This Afternoon as Severe Risk Increases

There is a tornado risk today for the eastern regions of North Carolina and South Carolina. It is interesting, as the 5% region of the tornado risk is unusually large. This is indicative of an increased tornado risk, but not enough to rise to 10%. Let's take a look at some maps indicative of the severe weather risk.
Mesoscale Convective System Maintenance
A mesoscale convective system (MCS) is basically a cluster of thunderstorms. Maintenance means the ability to upkeep. Putting it together means that this graphic indicates the potential for a cluster of thunderstorms to upkeep itself. Right now, we are seeing over a 90 in the Carolinas into the Virginias. This means that conditions are favorable for a cluster of thunderstorms. Clusters of thunderstorms typically are not as conductive for tornadoes as single cells are. If you're thinking that this is just one parameter of many, you are wrong. This MCS Maintenance parameter contains over 340 other parameters.
300mb wind speeds (jet stream)
We are seeing a split flow in the jet stream with these storms. If you follow the jet stream along the Gulf Coast, we come to a separation of the main path the jet stream takes as well as a smaller, almost nonexistent mini jet stream. This is what's called a split flow. Split flow patterns happen when the force of rising air is able to divert the jet stream off its original path. The split flow pattern is a good indicator that some severe weather is possible.

Here's a little indicator we've put together of severe weather using many severe weather indices.
Region: North Carolina, South Carolina

Chance for...
Severe Thunderstorms: 80%
Hail: Up to 45%
Damaging Wind: 60%
Tornadoes: 30%

Update on Notice

We are conducting a massive scan of our entire publishing station at this time after Facebook indicated that we hard contracted a malware virus.
However, we are denying this theory.
Thanks to a couple active viewers of this blog, we are able to determine that other computers are not affected by this potential malware.
We are thinking that this was a false alarm and, if it was indeed a false alarm, we know why.

Again, we do not believe there is any malware and that this was a false alarm on Facebook's part.
However, we do take these potential security threats very seriously and thank those who conducted security scans and were able to tell us a lot of information.


It appears that our publishing station has contracted some form of malware.
We have found that we cannot post links on our Facebook Page, and we believe that this is the suspected malware.
Facebook has temporarily locked us out of our account due to this suspected malware.
We have not found any problems on our blog here, and have every reason to believe that this blog is unaffected. 
However, if you feel that your computer may be at risk (we do not believe it is), please run a security scan soon to see if your computer contracted any form of bad software. If you did, we highly encourage you to comment on any post with what the malicious software is. Then, we can try to compare it to our security scans and see if we can fix this problem.
This blog will continue to provide weather regularly. This will not be interrupting our posting duties.

Again, as of now, we have no reason to believe that this has infected other computers. The only problem we have had is being unable to post links on our Facebook Page.


Changeover to Snow Starting in Great Lakes- 12/27

Precipitation is occurring in big green blob over Great Lakes.
Theoretically, everything inside the black and red lines is snow.
We are beginning to see a changeover to snow in the Great Lakes this morning as a storm system moves eastward across the southern half of the country. There is an outline of a red line. Inside that red outlined area is the boundary layer at 0 degrees celsius. That same red outline also contains a black outline. That black outline symbolizes that everything inside that area is surface temperatures at the freezing level. We expect this area of freezing temperatures to expand as a cold front works its way from Canada down south. It appears that states such as Ohio, Pennsylvania, and western New York could get in on the heavier snows.
850mb temperature advection
We can see that the cold front is present by taking a look at 850mb Temperature Advections. There is a region of substantially lowered temperatures over the last several hours in the North Great Lakes as that cold front progresses southeast-ward. We need to keep an eye on the cold front, as the amount of interaction, area of initial 'impact', and temperature difference all depend on snow totals. If there is a greater amount of interaction than forecasted, i.e. the cold front dips farther south than anticipated, snow totals may increase further south. If there is less interaction, snow totals may be lower than forecasted. The area of initial impact is where we expect the first cold wave from the cold front to hit. If it hits somewhere other than forecasted, that 'somewhere' may end up with more snow due to a quicker changeover. Finally, temperature difference depends on the snowfall. Like a cold front in spring that ignites storms, this cold front may ignite areas of heavy snowfall. Depending on how much difference there is in temperature, we may be seeing heavier snow if there is more difference, or less snow if there is a lesser difference in temperatures.
HRRR Total Snowfall Accumulation

Monday, December 26, 2011

Mid January Arctic Blast?

Gary Lezak, the man who discovered the LRC, is indicating that an arctic blast of cold air is possible come mid January. We are investigating this, but at this time his confidence level seems fairly high. We are working to see if this may coincide with a possible break in the weather pattern.

December 26-28 Snow Event (Ohio Valley, Northeast Affected)

A low pressure system will be moving across the Ohio Valley and through the Northeast. We will be seeing this system be moving pretty quickly, but accumulations will be on the increase as we see a cold front moving southeast from Canada. This front will bring cold air right up against the precipitation. Much like how a cold front ignites heavy precipitation in the summertime, snowfall will increase right up against the front. Because we don't know how much influence this front will have on the precipitation, accumulations might be a little heavier than what we have shown right now.

UPDATED 2011-2012 Winter Forecast

For the rest of winter, we are expecting the east Coast to end up above normal, temperature wise. We find this likely, as the fall was very warm, and trends in fall can move into winter, which has happened this season. Additionally, no blocking has been present. Blocking involves a high pressure over Greenland, which enables cold air to move into the Northeast and push the storm track south, so that the Northeast is in a prime spot for snowstorms. That is not happening this year. This is due to stratospheric warming, among other things. Usually, the stratosphere will warm in the early days of winter and start up the snowstorms. However, the stratosphere has not been warming until the last couple of days. This means that the pattern change will take at least 2 weeks to take effect. Essentially meaning at least 2 weeks until a major snowstorm.
The Ohio Valley southwest-ward into the Southern Plains will be experiencing wet conditions. Ohio has already broken all-time records for rainfall. This is expected to continue through the winter, and when the pattern change occurs, we will be seeing big snowstorms cut through the Ohio Valley. I am expecting several, if not many, 'major' snowstorms once the pattern changes for the Ohio Valley.
Down in the far Southern Plains we see an area of dry conditions expected. This is due to the La Nina, but has been helped by a +NAO/+AO.
Far out west, cooler than normal conditions are expected.

Notes about the indices:
-NAO should average above normal for the winter, but will dip negative at least once the rest of the winter. When it does dip into a good negative, I can see a big snow hit the Northeast.
-AO is in the same boat as the NAO.

6-10 Day Outlook: 12/31/11 - 1/4/12

6-10 Day Temperature Outlook
The Climate Prediction Center is forecasting a high probability- possibly the highest confidence we have seen in the 6-10 day temperature outlooks- of above normal temperatures for the very heavy majority of the country. Every state in the continental US is forecasted to have above normal temperatures over the 6-10 day period, except for Florida, where some slightly below normal temperatures are forecasted.

Before you jump to the conclusion that this is Global Warming at its best, it's not. This is simply a weather pattern gone bad. The same bad weather pattern has delayed winter. And no, this bad pattern is not due to global warming.

6-10 Day Precipitation Outlook
Most of the country is forecasted to be below normal, precipitation-wise. It appears that the storm track will be displaced slightly more north, leading to above normal precipitation in the far northern reaches of the country. The Northwest may get in on some above average precipitation amounts.

UPDATED Winter Forecast will be released at 12:00 PM CST

Our updated winter forecast will be released at noon CST.

Sunday, December 25, 2011

UPDATED Winter Forecast Tomorrow!

We will have our UPDATED winter forecast out tomorrow, along with stratosphere articles concerning the pattern change.

Saturday, December 24, 2011

Your Christmas Day Forecast

For Christmas, an upper level low will be moving into the Texas area, putting down rain. There could very well be some snow in the western parts of the precipitation shield of this upper level low. The precipitation shield may actually extend farther east than what is shown here on our map. Up in the Northwest, some snow can be expected from a weak disturbance in Canada affecting that region. The entire Northeast should be in for a could Christmas. The Great Lakes will be dealing with some scattered lake effect snow showers, which won't accumulate to much of anything. However, some cities could be dealing with flurries throughout the day from these showers. Down in the Southeast, an isolated sprinkle of rain cannot be ruled out, but an abundance of rain is not looking likely. Out in the Central Plains, a strong high pressure system will eventually build in to make for a quiet Christmas.

Merry Christmas!