January 2019 Medium/Long Range Pattern Discussion

[Holston_River_Rambler]

Thought it might be worth a look to go back to the composites I made last Feb while we were awaiting the pattern change then:

Originally posted in the Historic Winter Storms thread last February:

So this AM I thought it might be fun to add to the above image by looking at how we got to those dates.  We often see analogues for the date of a particular storm, but not the weeks before and if many storms come at the end of major blocking, it might be a good idea to check out how things looked before. Below are the images for one week (top) and then two weeks (bottom) before the events above. It seems to me the NAO snaps and holds the ball while the Pacific finally kicks it.  

Looking at the composite for where we were last year, the Pac was quite a bit different then:

Then I did a 500 mb composite one week before our best storms (for the above I used specific dates supplied by John, for the below I just went through the KU book and looked for anything that looked good:

 

 

[Holston_River_Rambler]

EPS 10+ day

 

 

[Holston_River_Rambler]

And look, just to be clear, I'm not saying we're going to have the most epic of all epic storms soon, I'm just saying that the pattern, as is currently modeled to evolve, is about all we could ask for. 

[tnweathernut]

Good posts this AM, guys.  Loving the animations, Holston! 

I have been checking around looking through all the ensembles and other data trying to find the reason we don't go into an active tracking period late January through a decent chunk of February.  It's really hard to find anything that argues against cold and active. 

Really, the only thing I could find is the MJO. It's projected to head back through the warm phases 4,5,6,and 7 (7 is a warm signal later in the winter).  Looks to be at a decent amplitude as well.   I hope other signals can overwhelm the MJO.  It has driven the bus for too long now.  I don't know about you all, but I'm ready to get on another ride for the rest of winter.  I never wanted to be on the MJO ride in the first place!

If we can realize the pattern being depicted (-AO, -EPO, and -NAO) you have to think it's just a matter of time before we have the southern jet attacking cold that should hold for a widespread winter storm.

Other than the MJO, I suppose we could miss winter storms by having too much of a good thing (i.e. the PV sitting in the lakes that squashes precip to the gulf coast) or we could lose the southern stream, but since it's been so active this winter you have to think that's a very minor concern.

All in all, i'd say it's all systems go....................... but it's the waiting for liftoff that is the hardest part, and EVERY OP model run will probably be scrutinized when it doesn't show cold and snow.  It's probably best to stick to the ensembles, ignoring bad AND good OP runs.  Like Carver's said, getting anything right past day 5/6 isn't likely.  As long as the ensembles continue to reel in the pattern I think we are good region wide, IMO.

[nrgjeff]

European Ensembles have almost no mild members (out of 50) two runs in a row (12/00Z). Clusters are pretty much 100% cold. Only question is how cold. Elsa took over the GFS, pissed off from a party.

Can't really find any problems in the current Pacific pattern or the forecast models. MJO is the only question, and a valid concern, but that's a forecast. Confidence is unusually high in a prolonged cold pattern. Snow south of I-40 remains wait and see.

However I pretty much expect snow at/north of I-40. North of I-40 should have multiple opportunities. This is not really a brave call given the forecast weather pattern. Enjoy!

GFS Op continues to perform better than the FV3/Para. Likely shut-down related. Op gets the only attention.

[Holston_River_Rambler]

1 minute ago, nrgjeff said:

Elsa took over the GFS, pissed off from a party.

Thank you for that image

[Carvers Gap]

4 hours ago, AMZ8990 said:

I commend you on sticking with your forecast buddy,  you’ve been saying for months that more than likely this would be a back loaded winter and that we would have to be patient with the cold air.  I know we aren’t quite there yet but as it sits now your prediction looks pretty spot on.  Your getting pretty good at this hobby as you call it!!  

Thanks for compliment.  I can't take a ton of credit, though.  First, as you say, still a ways to go before we know the final outcome of this upcoming reversal...though we certainly have a good idea of where it should go.  Second, I miss a ton of calls as well...I totally missed the November cold shot.  That said, November taught me a good lesson about how the EPS behaves during d10-15.  I just do this hobby, because it is fun.  I began doing this to follow snowstorms.  Over time, I actually now enjoy the medium and long range stuff as well, especially fall/winter/spring.  Also, most of what I have learned...I learned from others here.  I just went with Nino climatology this winter(now admittedly some years like 09-10 get started early).  One thing that I have learned from the mets on this forum and those on other forums is that they let the ENSO and overall ocean state be the foundation of their long range discussions and forecasts.  And sometimes the weather just does not cooperate even if reasoning is well grounded.  The MJO being so active this winter has been unusual.  If it had not been present, the early season cold forecasts likely verify and easily at that.  I very much believe the base cold pattern had been established and would likely have been difficult to break had the MJO remained in a state that is normally found during Nino years.  But honestly, this sub-forum is a great place to kick around ideas and take forecasts/discussion risks.  Our meteorologist and the collection of people who do this for a hobby really make this a great subform.  

[Holston_River_Rambler]

Not going to waste a bunch of time or graphics on this since it is a long shot, but there was a (admittedly one run) trend on the Euro to have more separation between the N and S stream for this weekend, thus allowing the possibility of a more progressive (south) solution. 

Interestingly the 12z UKMET was much further south and showed similar separation. 

What the heck, can't resist a good gif:

UKMET, H5:

 

0z and the 12z Euro, same but vorts to show the separation and trend to be more separate until east of our longitude:

Maybe something for western areas to keep an eye on?

Maybe something to get drawn back into for no reason? 

You be the judge. 

 

 

 

Disclaimer: Stole this idea from another forum/ region, but thought I'd pass it on. 

[Carvers Gap]

Just glanced at the GEFS snow mean...at first glance there are a ton of tracks.  That tells me that the model is still working to narrow things down which is not unexpected.  The moral to that story, with that much spread in the modeling...everything is on the table from sliders to cutters to coastals.  I have said this before, but we probably need to see a one-two combination in order to get cold until the trough establishes.  A few models are flirting with sending cold west and then east.  Not a huge concern, but that tells me the MJO is still being a gremlin.  

[John1122]

The GEFS is just extremely cold. 12 to 20 degrees below normal temps basically from day 6-16 and these departures are coming at the coldest time of winter. That would equate to 10s and 20s for highs and lows near or below 0 in our forum area. For a 5 day average on an ensemble mean, that's very very impressively cold. I am getting concerned that we will go into suppression city. A lot of the analogs showing up at 500 from D10-16 were ones that produced deep South snows and left us high and dry.

There is a lot of energy, all taking wildly varying tracks right now. One day the GFS has the southern stream storm and gives us frozen, another has a miller A but it's too warm, another is a miller B, another cuts, and we have also gotten northern stream domination with a parade of clippers. That's how many different solutions are on the table over the  7-16 day time frame. The OP will roll up each of these scenarios at different runs over the coming days. I'd honestly expect more northern stream/clippers to be possible in this set up. 

[Daniel Boone]

That blasted MJO has been and may still be the proverbial thorn in our side. Hopefully, forecasts are wrong concerning it. Even if not, with high lat blocking and Nino affect kicking in, it may not be so much a bad thing as it may help keep systems from being too suppressed. Winter 78-79 comes to mind although it was more neutral enso. The entire continental US was cold and snowy except extreme SE and Maine of which was slightly milder than avg. there. Strong HL blocking ruled the roost.

[Daniel Boone]

9 hours ago, Carvers Gap said:

Thanks for compliment.  I can't take a ton of credit, though.  First, as you say, still a ways to go before we know the final outcome of this upcoming reversal...though we certainly have a good idea of where it should go.  Second, I miss a ton of calls as well...I totally missed the November cold shot.  That said, November taught me a good lesson about how the EPS behaves during d10-15.  I just do this hobby, because it is fun.  I began doing this to follow snowstorms.  Over time, I actually now enjoy the medium and long range stuff as well, especially fall/winter/spring.  Also, most of what I have learned...I learned from others here.  I just went with Nino climatology this winter(now admittedly some years like 09-10 get started early).  One thing that I have learned from the mets on this forum and those on other forums is that they let the ENSO and overall ocean state be the foundation of their long range discussions and forecasts.  And sometimes the weather just does not cooperate even if reasoning is well grounded.  The MJO being so active this winter has been unusual.  If it had not been present, the early season cold forecasts likely verify and easily at that.  I very much believe the base cold pattern had been established and would likely have been difficult to break had the MJO remained in a state that is normally found during Nino years.  But honestly, this sub-forum is a great place to kick around ideas and take forecasts/discussion risks.  Our meteorologist and the collection of people who do this for a hobby really make this a great subform.  

Agree 100% in that we were in line for a wall to wall cold Winter if the MJO had not pulled it's high jinx.

[Holston_River_Rambler]

MJO is trying to come back around to the dreaded (at least by me) Maritime Continent. There's naught we can do. I say let it do its thing. Maybe? 2-3 cutters, lay the snowpack down in the Midwest and pump up the -NAO. Still gives us 4-6 weeks. 

Progression weaker in amplitude, faster in progress, and hopefully no more ill-timed coronal holes. Tropical tropopause looks warmer as the SSW is ending, leading to somewhat lower lapse rates and weaker convection, if some of the hypotheses postulated in Dec were correct.

Fortune favors the Masiello:

 

 

 

I hope...

[John1122]

2 hours ago, Holston_River_Rambler said:

MJO is trying to come back around to the dreaded (at least by me) Maritime Continent. There's naught we can do. I say let it do its thing. Maybe? 2-3 cutters, lay the snowpack down in the Midwest and pump up the -NAO. Still gives us 4-6 weeks. 

Progression weaker in amplitude, faster in progress, and hopefully no more ill-timed coronal holes. Tropical tropopause looks warmer as the SSW is ending, leading to somewhat lower lapse rates and weaker convection, if some of the hypotheses postulated in Dec were correct.

Fortune favors the Masiello:

I hope...

Keep in mind that it takes 14-16 days for the MJOs effects to be felt downstream in the Eastern US. But other factors override it at times. Especially blocking in the Pacific. There's a paper about the MVP (Multi-variable PNA) that I read. It indicated that the MVP completely mutes the effects of the MJO on North America at times, regardless of which phase the MJO is in at a given time. A few years ago it moved at fairly high amplitude through 8, 1, 2 and I was hoping for a return to cold in two weeks. No such luck, the PNA region remained unfavorable and we stayed warm. 

This from that paper, regarding the effects of the MJO on NA in relation to a + or - MVP.

Quote

The North American temperature anomalies following each RMM phase change with the phase of the MVP (Fig. 3). For example, the warm signals over eastern North America in RMM phases 2 and 5 only occur when the MVP is negative. This behavior is consistent the MVP's 200-hPa streamfunction EOF (Fig. 1a), which contains a ridge over the eastern United States when it is negative. Conversely, the cold signals in RMM phases 8, 1, and 2 occur almost exclusively when the MVP is positive, which would be associated with a 200-hPa trough.

In other words, unless the PNA is positive 8, 1, 2 don't bring cold here. Unless it's negative 2, 5 don't bring warmth.

[Holston_River_Rambler]

My point was more in line with yours, at least as I meant it for results for us. I need to lay off the Masiello for a while.

I'll lay all my cards in the table and just say what I think; what I was trying to say in that post:

MJO effects and convection itself will be muted this time unless there really is some bizarro coronal hole thingy that randomly amps it up.

Trough's not carved out yet, but will be after the next two storms, regardless of their outcomes for us.

Then we have 4-6 weeks of winter and what we get is what we get. Could be good, could be bad, but couldn't ask for a much better pattern as it stands now. Even if suppression is a worry, I'd take a 2-4" clipper like in the days of yore, any year.

Obviously always room for strange late season storm in April in addition, but too far out there for now think much about. 

 

 

[Holston_River_Rambler]

0z Euro has come back out to play for West TN:

 

[Holston_River_Rambler]

84 NAM looks similar to the Euro with the energy for this weekend. If those two are in agreement, there used to be an old rule that said to use that agreement. That rule was for previous iterations of both models though, so not sure if it still applies. 

[Carvers Gap]

I think the AK and Greenland block are about to rule the roost.  The MJO will try to fight it.  We have seen a few operational runs trying to dump the cold in the West and maybe one EPS run as evidence of that.  Overall though, the majority of runs dump the cold into eastern NA in one fashion or another.  JB likes to point out that during 1978(think I have correct year and an extreme analog BTW), the East saw three snowstorms(one a blizzard) during the warm phases of the MJO.  Sometimes, when really cold air and blocking are in play...the MJO does not behave as it does if it is the only driver.  It is a thorn, but hopefully it may not be the three-headed monster that it was during December and early January.  Sure, anything can bust(including a cold and wintry outlook on modeling) and everything will never be exactly perfect at this latitude.  However, I think the discussions about suppression being the long term nemesis are likely more accurate than cutters being a mainstay.  Until that tough matures a bit, each time cold rotates through it appears that storms are going to head for the warm-ups that follow each cold shot.  Just a timing issue, but very common to see cutters early w a new blocking pattern over the EC. The great thing about this time of year, is that the wavelengths switch-up and what looks like a "warm-up and rain" pattern has trouble holding.  The biggest thing is just waiting for the trough to stick which happens after the warmup after this weekend's storm.  Then the cold attacks the cold boundary...might be even one more cutter after that.  As the cold presses south though, confluence begins to push southward which I think helps us later this month.  That said, to me everything looks on track.

[AMZ8990]

31 minutes ago, Holston_River_Rambler said:

0z Euro has come back out to play for West TN:

 

I’ve noticed that too, the euro definitely likes the backside snow for West Tennessee the past 2 or 3 days of modeling.  It’s always tough when you waiting on cold air to override your moisture though.  Overall I think it’s something to keep an eye on for sure.  It would be nice if just once south west tn out performed north west tn in regards to a wintry event.  

[Holston_River_Rambler]

@AMZ8990

6z Euro looked pretty good with the energy for W TN:

 

One more tick south and Memphis might be in for a treat! 

Maybe this one really will be the illusive rain to snow that actually works out like they used to. 

[tnweathernut]

You can see the Pacific isn’t ready to stop pushing things around.  The waves crashing the ridge are pushing it further east.  This is causing the northern stream and southern stream to stay separated longer and a further south track with the southern low as it has a chance to stay positively tilted longer.  

Will be interesting to see if that trend continues the next couple of days.  This really isn’t too far from something nice in west TN...

[Holston_River_Rambler]

06z EPS snowfall mean:

Not too bad for TN unless you live in Fall Branch, Chuckey, or Chatt. 

Jeff rule = Chatt blanked, must be right. 

[nrgjeff]

ECWMF does seem to want to dig the weekend system a little longer, which would put West Tenn and of course Kentucky in play for snow. Couple storms this year the ECWMF beat the NAM in short range (30-36 hr) in the Midwest. Will it translate South?

MJO wants influence later next week, but I tend to believe the strong blocking signals will outweigh. Looks like a mild interlude between arctic systems is likely. It might be 1-2 days. A West first arctic dump might give us 3-4 mild days. Still from the upper latitudes pattern I infer it comes east. Pretty safe call really. Still looks like a true arctic outbreak Jan 26-30.

Very end of the EPS has it easing up slightly, but one expects some ebb and flow. I expect more cold in Feb. 

[AMZ8990]

4 hours ago, Holston_River_Rambler said:

@AMZ8990

6z Euro looked pretty good with the energy for W TN:

 

One more tick south and Memphis might be in for a treat! 

Maybe this one really will be the illusive rain to snow that actually works out like they used to. 

I sure hope so, it seems like things always materialize extremly close to the said event when it comes to West tn wintry events.  We always cut it close, lol.

[1234snow]

Starting to see some potential for some flakes or a mix tomorrow morning and afternoon for NE TN and SWVA. The NAM, RGEM, and FV3 all show the possibility for some mixed precip before the warm air pushes in.

[BlunderStorm]

1 minute ago, 1234snow said:

Starting to see some potential for some flakes or a mix tomorrow morning and afternoon for NE TN and SWVA. The NAM, RGEM, and FV3 all show the possibility for some mixed precip before the warm air pushes in.

Perhaps a quick burst before a quick transition? I love it when these surprise events are shown but they rarely pan out.

[1234snow]

Perhaps a quick burst before a quick transition? I love it when these surprise events are shown but they rarely pan out.

 

I’m guessing similar to last Saturday morning. Quick burst of snow. Models have trended ever so slightly colder tomorrow. Still holding around freezing mark today in SWVA.

 

Edit: RGEM had freezing rain as far south as Chatty in the morning.

[John1122]

The OP runs are slowly starting to show more snow falling with the next couple of systems. The Canadian is all in from the deep south up across the Eastern half of the Valley for the day 8 or so system. It may be that we have to be within 3-4 days to get details to come into focus.

Otherwise, ensembles remain cold with precip signals staying pretty decent.

The pattern has flipped, we are still working on the full transition but other than a brief semi-warm up things still look on track for a cold base pattern.

[beavis1729]

5 hours ago, nrgjeff said:

ECWMF does seem to want to dig the weekend system a little longer, which would put West Tenn and of course Kentucky in play for snow. Couple storms this year the ECWMF beat the NAM in short range (30-36 hr) in the Midwest. Will it translate South?

MJO wants influence later next week, but I tend to believe the strong blocking signals will outweigh. Looks like a mild interlude between arctic systems is likely. It might be 1-2 days. A West first arctic dump might give us 3-4 mild days. Still from the upper latitudes pattern I infer it comes east. Pretty safe call really. Still looks like a true arctic outbreak Jan 26-30.

Very end of the EPS has it easing up slightly, but one expects some ebb and flow. I expect more cold in Feb. 

I was thinking the same thing too, based on the FV3 and the EPS runs over the past few days.  Then, today's 12z FV3 lost the arctic outbreak completely.  Could the MJO really be the culprit, again?  It was only one op run, so we'll see what happens.

[nrgjeff]

Both sets of Ensembles keep the 11-15 day colder than normal. GFS/FV3 may have both been bad runs. Perhaps a bird farted near a jet taking samples over the Pacific.