Winter 2015-16

[jaxjagman]

As alluded to at the end of the Medium Range Forecast, the threat for an immense storm affecting the southern and eastern tiers of the nation is the major factor in how the rest of the February 2016 outlook turns out. There are many features favoring a warm West vs. cold Central/East alignment. The Madden-Julian Oscillation seems to be shifting toward a Phase 6/7/8 passage with linkage to a persistent sub-Aleutian vortex (easily seen on satellite imagery of the Pacific Basin. The El Nino episode is slowly weakening with emphasis on the western and central sectors. Note that the Pacific Decadal Oscillation is still in a positive mode (matches up very well with classic +PDO description provided here), which would seem to indicate capacity for -EPO, +PNA and -AO ridge signatures. Snow cover is dense and abundant through North America and the Northern Hemisphere in general, which enables rapid replenishment of cold air following storms in the lower latitudes.

One important (and this season, overlooked by many) aspect to the February puzzle is how the stratosphere looks. Before mid-month, if the 10MB level is warmer than normal and the circumpolar vortex either split, or skewed toward the coastline of western and central Eurasia, then blocking ridges will form in the -WPO, -EPO, +PNA and -AO positions. This configuration has emerged at the very top of the atmosphere and looks to stay past the "Valentine's Day Benchmark", where SSW events are not a solid teleconnection to cold weather in the middle latitudes (because we enter cutoff low season, and cold pools do not get established as easily despite the tendency for ridges above 50N).

There are two more considerations to look at in judging how the longer term prediction, and the month of February in general, turns out. The analog system, which did fairly well in January (a bit too cold perhaps, but not the blowtorch predicted in some broadcast and social media sources), strongly implies a warm ridging pattern in the western U.S. as well as in northern and eastern Canada. This matches up well with many of the numerical model ensemble groups. Another concern is the intensity and track scenarios for the storm shown by the predictive equations over Texas on February 9. If, as I suspect, the disturbance is quite strong and moves very close to the shorelines of the Gulf of Mexico and Atlantic Ocean, then a major snow and ice event will affect parts of Dixie, Appalachia, the lower Great Lakes and Eastern Seaboard. Interestingly, the comparative season mean and the Canadian variant package takes the deep low inland over New England. That may afford the northern third of the fabled Interstate 95 corridor a change to rain before the cold air returns around February 13 - 14. This is a system we must keep close watch on because it has historical precedents in 1958, 1978, 1994, and 2003.

In summary, much of what I see points toward a very cold period east of the Rocky Mountains, including Texas and the Deep South, which have largely been bypassed by winter so far. For those who despise the cold and the frozen precipitation, you can take heart that these same analogs used suggest an abrupt end to winter very close to the calendar transition to Spring.

But until then....six more weeks of fun and excitement!

Prepared by Meteorologist LARRY COSGROVE

[jaxjagman]

[Carvers Gap]

Just browsing through some wx models, the 6z GFS puts us in the ice box for about one week and then warming the SE. The CPC ensembles now show the PNA going negative, the AO going negative, and the NAO remaining slightly positive. Robert wrote yesterday about the PNA ridge on the models not lasting which certainly appears to be the case on the CPC teleconnections. At first glance those teleconnections show cold in the West and a warm East in the LR. The NAO, though (+), does take a dip towards neutral. It is possible that the teleconnections today are in transition w the NAO. The MJO is still out of phase for LR cold. I think we have a month w several winter chances, but it is wise to proceed w caution in believing the severe cold actually locks in. Far too many important indices argue against that. But the second week of Feb does look cold and stormy as I mentioned a while back when I said a thaw was coming for the first week of Feb and last week of Jan.

[Carvers Gap]

12z Gfs providing a good lesson in the power of the MJO. The concerns mentioned above appear to be bearing some fruit on the afternoon GFS. Again, a cautious approach should be taken w Feb to echo Jeff who spotted the pitfall first.

[Carvers Gap]

Unless you have reasoning to w go your remarks, this belongs in banter. You also did not believe a thaw was coming after the blizzard during the last week in Jan and first week of Feb.

[Carvers Gap]

12z Euro after early week is tranqil. Will be interesting to see the EPS.

Edit: not saying I buy that look either.

[Carvers Gap]

12z EPS Control 1.31.16 is bone chilling cold. Some -20C (edit) departures in the mid section of the country(spreading eastward) in the day 10-15 range. Going to be very interesting to see how this month plays out.

Edit: Monster omega block at d12. Way out there and may change but is pretty impressive.

[John1122]

It's all in how the day 10 storm evolves. It's shifting all over the place on the GFS right now. It's either  a powerful Miller A. A powerful apps runner, or in the 12z run, a weakish clipper.

 

How it handles the storm is effecting how much cold it sends down after the storm.

 

 

The Euro shows a southern slider, followed by another gulf storm and much better with it's ridge over Alaska to drive cold into our area.

 

We'll see if it quickly breaks down or not. It took over a month for the December pattern to break down. It took 3+ weeks for this brief break down to occur in the favorable pattern, I personally don't believe it will break down in 3-5 days if it sets up like the last run of the gfs shows.

[Carvers Gap]

It's all in how the day 10 storm evolves. It's shifting all over the place on the GFS right now. It's either a powerful Miller A. A powerful apps runner, or in the 12z run, a weakish clipper.

How it handles the storm is effecting how much cold it sends down after the storm.

The Euro shows a southern slider, followed by another gulf storm and much better with it's ridge over Alaska to drive cold into our area.

We'll see if it quickly breaks down or not. It took over a month for the December pattern to break down. It took 3+ weeks for this brief break down to occur in the favorable pattern, I personally don't believe it will break down in 3-5 days if it sets up like the last run of the gfs shows.

Did you see the cold on the LR EPS? Red herring or does it verify? Edit...Euro has been pretty steady in banging the cold drum.

[John1122]

Did you see the cold on the LR EPS? Red herring or does it verify. Edit...Euro has been pretty steady in banging the cold drum.

I've not seen it beyond 240. As I posted the other day, long range models handle set ups over oceans somewhat well beyond two weeks but not so much over continents.  I just rarely see such excellent blocking break down as fast as the GFS breaks things down in my observance of how weather behaves. Even though models often try to do it and seem to try to trend towards climo a lot of the time.

[John1122]

The Euro builds this baby and it appears to be getting stronger and stronger up to this point.

 

[Carvers Gap]

I've not seen it beyond 240. As I posted the other day, long range models handle set ups over oceans somewhat well beyond two weeks but not so much over continents. I just rarely see such excellent blocking break down as fast as the GFS breaks things down in my observance of how weather behaves. Even though models often try to do it and seem to try to trend towards climo a lot of the time.

12z EPS does not break blocking down at all. Actually forms an omega block. The 12z GEFS and EPS are worlds apart after day 10. GEFS is warm w the EPS having a textbook block that gradually lifts out mid-month. (Edit...lol...see slide above)

[John1122]

Bastardi says the 5th-20th should be the coldest two weeks of winter. He's that and one decent snow event away from nailing his winter forecast for most of our area.

[weathertree4u]

Bastardi says the 5th-20th should be the coldest two weeks of winter. He's that and one decent snow event away from nailing his winter forecast for most of our area.

I agree. For my area it would just take a snow of 4" - 6" to put us at 150% - 200%.

[Carvers Gap]

Bastardi says the 5th-20th should be the coldest two weeks of winter. He's that and one decent snow event away from nailing his winter forecast for most of our area.

I read his post for today and watched his video...the MJO has him spooked. Said the phase 4 piece is the real deal and will fight any cold prior to the 20th tooth and nail. Says it would be a steal to get cold before the 20th and that the MJO will really want to flood the EC w warm air. Says he is concerned(fears) that at some point the models will flip warm. After that, he feels the MJO will move to our favor and extend well into March. Stated that strat warming might be enough to overcome the MJO.

[Carvers Gap]

18z GFS shows the "cold option." Over-running. Northwest flow event - huge one. Arctic cold. 12z went zonal after d12. But I think that model today shows the options that are on the table. I will try to add more later or in the morning. But similar to this past cold outbreak, the GFS found it and lost it. The Euro was late to the party and then locked-in. Wonder if the same happens this time as well? The Weeklies tomorrow might be interesting to see if they continue their cold look from Thurs. Very interesting times.

[John1122]

I read his post for today and watched his video...the MJO has him spooked. Said the phase 4 piece is the real deal and will fight any cold prior to the 20th tooth and nail. Says it would be a steal to get cold before the 20th and that the MJO will really want to flood the EC w warm air. Says he is concerned(fears) that at some point the models will flip warm. After that, he feels the MJO will move to our favor and extend well into March. Stated that strat warming might be enough to overcome the MJO.

 

He is flopping like the GFS. Not 2 days ago he was harping on the 5th - 20th being the coldest period in all of winter.

[Daniel Boone]

The Mjo is playing havoc on the models as well as forecasters. If it were in a favorable Eastern trough mode as the other indices appear to be heading, there would be alot of eye candy for cold, snow lovers. It is possible the euro has less Mjo influence factored in than gfs. IMO however, It probably is that the Euro is seeing more blocking, thus overpowering the Mjo.

[Carvers Gap]

He is flopping like the GFS. Not 2 days ago he was harping on the 5th - 20th being the coldest period in all of winter.

LOL. Lot of flip-flopping going on. Feeling like I have a bad case of it myself. But that is why this will be interesting. If in doubt, go with climo for the month of Feb. Favors better chances for snow and cold shots with some transitional spring days thrown-in for good measure. Climo will generally trump all other cards.

[Carvers Gap]

The Mjo is playing havoc on the models as well as forecasters. If it were in a favorable Eastern trough mode as the other indices appear to be heading, there would be alot of eye candy for cold, snow lovers. It is possible the euro has less Mjo influence factored in than gfs. IMO however, It probably is that the Euro is seeing more blocking, thus overpowering the Mjo.

Great post. Major climate cards on the table. Some strat warming, MJO not in a good phase, Feb climo that that favors snow and blocking, models w cold in the LR...will make for some fun discussions.

[John1122]

I like this look on the Euro.

 

[John1122]

Euro and EPS also once again pump up a beautiful -epo/pna ridge and over all blocking  set up from day 5-10.

 

 

 

 

[Runman292]

MRX just put up this graphic for next week:

[weathertree4u]

MRX just put up this graphic for next week:

Not sure that they are working with surrounding offices, have a feeling Nashville not on board with that just yet.

[Carvers Gap]

Not sure that they are working with surrounding offices, have a feeling Nashville not on board with that just yet.

 

Next week looks very cold.  It is the week or so after that in which I am not sure it stays cold.  If we get snow early next week w/ those temps roaring out of the Plains, could be very cold.  But probably not unwise to wait a bit.  Even our late week temps this are warmer than the models had them last week. 

 

I know you all are watching it....The 12z GFS now has a storm on 2.8.16.  Bit east but it now has the storm.  We have seen these storms show-up at this range and then totally disappear.  If the 12z Euro has it today, might warrant more discussion(not a thread though)...just more discussion in this thread.   

[weathertree4u]

Next week looks very cold.  It is the week or so after that in which I am not sure it stays cold.  If we get snow early next week w/ those temps roaring out of the Plains, could be very cold.  But probably not unwise to wait a bit.  Even our late week temps this are warmer than the models had them last week. 

 

I know you all are watching it....The 12z GFS now has a storm on 2.8.16.  Bit east but it now has the storm.  We have seen these storms show-up at this range and then totally disappear.  If the 12z Euro has it today, might warrant more discussion(not a thread though)...just more discussion in this thread.   

I agree, if we can get more modeling on board, this time tomorrow, might warrant a thread.

[Carvers Gap]

I agree, if we can get more modeling on board, this time tomorrow, might warrant a thread.

 

Watching the Euro roll right now...the 12z GFS has a low in the GL region and again(has been the case several times this winter) it is making a mess of the thermal profile.  It does now have the SLP on 2.8...interestingly the GEM now has two storms.  Makes me wonder if the models are trying to figure out which piece of energy to key on...  Still, waaaay out there.

[Carvers Gap]

The 12z Euro jumps on the first piece of energy and not the piece holding back.  GL low interferes w/ the dynamics of the storm as it rolls up the coast.  Very different solution than 0z.  Seems the models can see a storm going up the EC.  But right now at 12z it looks too warm and the GL is not allowing the storm to fully form during the 2.8-2.10 time frame.  Will continue to watch it.  But right now model agreement is low except they all pretty much show a GL low. 

 

Of note, JB notes that strong cold will dominate the East next week...but as opined about yesterday, it now appears that the MJO is going to warm things up quickly after the 15th.  So...JB, Jeff, WxSouth, DonS all expressing doubts about the duration of the cold.  Good enough for me at this point.  Going to enjoy the cold next week and hope for one last cold shot towards the end of the month if the MJO can get around to more snow conducive stages.  This is how Super Ninos roll.  You have limited chances that are often pretty big opportunities.  But in the end, the Pacific wins.  So at this point, really hoping that something materializes next week while it is cold.

[Coach B]

The GFS is a little faster than the GEM with the system on the 7th/8th. Both look a little too warm at this point, but time for details later. Plenty cold for the GEM system on the 10th, GFS doesn't really have that one unless you count it as maybe a clipper look. Both are plenty cold by then. Ensembles for both are kind of vague with not many specifics to key on.

[Coach B]

 

 

Of note, JB notes that strong cold will dominate the East next week...but as opined about yesterday, it now appears that the MJO is going to warm things up quickly after the 15th.  So...JB, Jeff, WxSouth, DonS all expressing doubts about the duration of the cold.  Good enough for me at this point.  Going to enjoy the cold next week and hope for one last cold shot towards the end of the month if the MJO can get around to more snow conducive stages.  This is how Super Ninos roll.  You have limited chances that are often pretty big opportunities. 

I know I'll be perfectly happy if we can score even just a little something with the cold next week and then have another chance towards the end of the month. Historically, it seems that significant February cold shots are less likely to be totally dry when compared to January Arctic blasts.