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February 2019 Winter Speculation

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Some straight talk from isotherm about tropical convection. He's been a little cautious lately, so the force of this statement makes me feel pretty good:

"Let me refrain from equivocating: the GEFS is dead wrong with the circling back to phase 6. The ECMWF is closer, but still a bit too much wandering in phase 7. The VPM has been most instructive, and indicates some slowing in phase 7 in early February before phase 8 entrance at the beginning of the second week of February. So the bottom line is that the pattern, a priori, should become progressively improved."

Found at: https://www.33andrain.com/topic/868-global-teleconnections-a-technical-discussion/?page=34&tab=comments#comment-128834

 

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Just takes one big storm imo make the season a memorable one.


Yep. This winter has been above average for me based on one day. 13” in one day is something I’ll never forget. I won’t remember about the rest of the crappy winter.
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Just my thoughts, but after looking at everything from back in to the beginning of winter and the current weeklies...im not too enthused about what's left of winter (think we need a lot of help). In December we had a nigative/rising QBO which made an argument for slightly AN temps, once you factor in it was occurring during a weak Nino, the odds increased of an AN winter (which we began that way with the late Dec/early Jan warmth. The start split was our saving grace, once the effects of it wear off (and no other splits in the future), we lose that influence. To offset the Dec rising neg QBO,  we need the AO/NAO/EPO all three to go neg (1 or 2 of those neg won't work so well). Looking at the weeklies for all 3, while we have a weak neg AO/NAO, the EPO turns positive  (at times mod +) starting mid month (sooner on the control). A good example is currently..AO dropping, NAO dropping, but EPO shooting back to neutral....even with historical cold just to the north, we go AN. Maybe I'm completely wrong, but I think we need a lot of help starting mid month for winter lovers (based off current modeled teleconnections). 

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Certainly possible we go one of two ways to end winter.  Will be interesting to see what happens. There are arguments for both camps (warm and cold).

Looking at modeling (in general) the look is there for a cold shot with energy underneath around the 8th or so.  It’s there on GFS, GFS FV3, and Euro at 12 and 18z.  If the NAO isn’t a unicorn, I think we can stumble our way back into a workable pattern.

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2 hours ago, TellicoWx said:

think we need a lot of help

We always do. 

The rest is not a direct response to you Tellico, but what the heck, if I'm going to throw myself out there, might as well go all out. Where do I stand?

Beware!! Full weenie mode from here on out:

I am in the isotherm camp, in thinking that the SSW hurt instead of helped. I think the hypothesis that the SSW invigorated the tropical convection by redistributing cold air to the tropics through the Brewer-Dobson circulation helps explain what happened. Furthermore, I think that the strengthened convection helped further disrupt the stratosphere, by reinforcing high pressure patterns that deflected the jet over east Asia and created a positive feedback loop. Like the energizer bunny or the Bandit, it kept on truckin'.  I'm glad the strat. is done. 

I do also think, as Bob Chill has pointed out, that the PDO has played a role in the Pacific as well and without the SSW it certainly may have run even more interference. Go back and look at isotherm's outlook, at 40/70s outlook, at Sutherland's outlook. None initially called for the PDO to be a negative/ cool phase (though Sutherland was suspicious). Until very recently it's been rather washed out.

(Please note this is not meant to be a critique of their overall forecasts; I have no business doing that, but it does seem to have been either discounted or underestimated). 

Forecasts were for a Modoki El Nino, but only recently have most of the anomalies moved west. Even now though, on Tropical Tidbits the SSTs are anything but a good match to be shoehorned into a "typical" ENSO state. But I'm over ENSO. Has anyone ever seen an ENSO map of SSTs over a 3 month period that consistently looks like an exact copy of the "stock ENSO state" images?  Around 70% of the earth is water and most of that is the sea. It's not static. Currents redistribute water across the surface as well as upwelling and downwelling. Storms can lower water temps in any given season and the sun can raise them. SSTs only matter insomuch as they help develop convection above the sea surface. 

Last but not least, that dreaded coronal hole seems to have given that La Nina-esque convection that extra umph. 

I am, perhaps stupidly, still optimistic. What can you do but laugh, be bitter, or not care at this point? NWP has done more to many of us this winter than Lucy every did to Charlie Brown.  

So, where are we at now? 

SSTs do look somewhat better. Sorta kinda a warm/ horsehoe rather than 'warm blob of death' PDO. Sorta kinda a Modoki to teh south near the equator. All relative to November. The near incessant convection in the Maritime Continent has had an effect on SSTs there as well:

giphy.gif 

Models now move the convection which impacts the Pac jet to/ past the dateline. If warm SSTs encourage convection, real time observations would seem to favor those areas relative to Maritime Continent. 

AAM, (ok, I'm still not sure how to interpret this) is more similar to November than what it has been for the past 2 months: 

giphy.gif 

As far as I can tell it is aimed more at the equator than poleward in the N. hemisphere. I have no clue how to extrapolate that for us in the TN valley. I'm at the point with this where I just say: "that's the state that got us the nice late Nov through early Dec. pattern that made many think this winter would be epic". Was it? No. But that particular pattern made some pretty smart people think it might be, so let's roll with it. Can't be worse than what we've seen so far. And NE TN got a pretty good storm as it decayed. 

Now on to blocking. Does blocking matter for us? Yes it does/ can. But what does it mean? The flow needs to slow for a chance for phasing, but also to shut off the Pac jet of doom (EPO/ PNA) and for backing and causing confluence by locking HPs in place (NAO). Is this the time the fabled -NAO appears? Sure looks like it may be. For me though, I want upstream blocking (PNA/ EPO) before downstream blocking (NAO). If my thoughts (well, mostly my summary of others' thoughts) are correct, we get that a split flow in about 10 -15 days that allows opportunities for upstream blocking and cold air intrusions as well as downstream blocking helping lock HPs in place. Yet, these oscillations are after the fact measurements at the surface. The Pac/ upstream jet is what we want to buckle/ split/ weaken and after the latest Pac intrusion there looks to be more buckling/ splitting/ weakening, not a particular forecast for this or that oscillation. 

giphy.gif 

 

I know most people want to see pretty, trackable storms and snow maps. I do for sure. Fv3 is love; Fv3 is life!!! But this winter has taught me a lesson about NWP no matter how high the resolution, that I probably should have learned years ago. NWP puts numbers in and gets numbers out. If those numbers are generated from an unfavorable/ favorable atmospheric state (Pacific of doom), I suspect they will produce unfavorable/ favorable results. I suspect the output changes with the input. If you drop the PLINKO chip on the right side of the board, is it more or less likely to end up on the left side? Sure it could happen, but will it? We're already getting wild Fv3 storms, I bet we get some better looks on more reliable NWP as we go forward and models initialize with better upstream looks. 

Results matter more than pretty models, and we tip-toe the razor's edge of the boundary for most of our good storms. Not everyone cashes in. It looks like the boundary sets up over us if not a bit south after Feb 10th.  I, like others have said today, think there will be chances. Feb. often offers more than March. 

When I was younger I asked my dad in Kingsport why every snow storm we had was marginal. He told me that most of the best storms he remembered were right at 30 - 32. In Kingsport 30 -32 may not be good for the whole forum at all, but it is indicative of where we need to be. We need moisture. We need cold. We have to walk a path of daggers (to paraphrase Robert Jordan).

Get the jet pattern. Then get the energy. Then walk on the tight rope. 

Stray but a little..... 

What the heck, go big or go home:

giphy.gif 

 

 

 

 

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I really like the look on the EPS...especially “and selfishly” for the mid state.  There’s enough blocking to hold the cold and the cold doesn’t look too overwhelming, but enough to get it done.  Also, just enough of a SER to possibly prevent too much suppression.  All-in-all, it’s one of the best “looks” we’ve had this season. 

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Excellent post! Worth reading the whole thing, but just one thought from me...

11 hours ago, Holston_River_Rambler said:

I am in the isotherm camp, in thinking that the SSW hurt instead of helped. I think the hypothesis that the SSW invigorated the tropical convection by redistributing cold air to the tropics through the Brewer-Dobson circulation helps explain what happened. Furthermore, I think that the strengthened convection helped further disrupt the stratosphere, by reinforcing high pressure patterns that deflected the jet over east Asia and created a positive feedback loop. Like the energizer bunny or the Bandit, it kept on truckin'.  I'm glad the strat. is done. 

That Philippines cold front! Things are calming down over there, including upstream China. SSW definitely delivered the cold to the US Midwest; but, westerly winds shielded the US South. One could argue La Nina type shield and Maritime-Continent Indonesia convection.

More broadly, I have growing concerns about getting a storm in February. My optimism trends down the second day in a row. Mid-State or even the whole Mid-South looks better than the Eastern Tennessee Valley. That said more cold still looks reasonable.

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7 minutes ago, nrgjeff said:

La Nina type shield

In the back of my mind, I've been thinking if this pattern does continue for one more month, I was going to post: "Y'all, we just had a La Nina". \

Front loaded for NE TN, a good cold shot, but warm up rain - cold/ dry. 

Still time for that to change for sure though, as we've been saying, all it takes is one good storm even if it is toward the end. 

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I think the SSW stuff is chicken and the egg.  I could make a case that the abnormal convection in the Indian and Pacific Oceans put the MJO into high amplitude phases, especially noteworthy in eastern NA.  I think some have noted that when the big, mega(MJO induced?) ridge goes up(just like last spring) over eastern NA, the PV gets jostled around and splits.  Basically, the eastern NA ridge is transporting vast amounts of warm air northward.  We are seeing that again in modeling.  I probably diverge(see long post in banter) in blaming the SSW.  I think the PV split was symptomatic and not causal.  I think the abnormally strong MJO convection sent a ton of energy and heat in to the higher latitudes, jostled the PV, and split it.  In turn, I think it is highly plausible that that subsequent pattern did sent plenty of cold towards the equatorial direction.  And then one gets a repeating pattern that feeds back on itself.  Without the energy from the convection in the tropics of the Maritime Continent...I think the rest of this is moot.  The SOI was abnormally positive(Nina territory) for much of December.  That happened before the PV split.  An even crazier deal, did we ever confirm that the PV split over South Pole as well?  I am likely disagreeing with people much wiser than myself, but I think the SOI/MJO combo coupled w the positive QBO brought some bad MOJO.  

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...But we probably should add a caveat lest we look back and potentially get a really good laugh should we get a couple of more events.  Winter is not over.  Still a month to go.  DC saw a good event recently.  We had a minor event here and saw record cold over the northern Plains and portions of the Mid-West.  So, the PV split did its dirty work even if not over our back yard.  Basically, I am saying if we stick a fork in this prematurely(with the models flipping all over the place) by saying winter was a dud...in the end it may not verify as such.   El Nino winters(not all of them) have a way of showing up late - again, that is why I don't like backloaded winters.   Just no way to know.  This winter will already be remembered if you live in Illinois, Minnesota, portions of the Dakotas, the Upper Peninsula, and Wisconsin.  Probably the one thing that would concern me is that cold was 84-85 level type cold...and when that cold left that winter, it did not return.

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8 minutes ago, Carvers Gap said:

confirm that the PV split over South Pole as well?

Apparently it was going through the final warming phase and dying out while the N. hemisphere one was doing it's thing too. 

 

8 minutes ago, Carvers Gap said:

 I think the PV split was symptomatic and not causal.

I totally agree and I think that's what your isotherms/ masiellos/ etc... would say. Without the convection/ highs helping to deflect the heat and energy poleward there wouldn't have been a split.  But I do think there was some kind of feedback loop that was created then and acted to enhance the whole mess and that may have hurt us more. Do I know for sure, no. Hindsight model is 20/20 and you could be right and it may have been even worse without the split. 

 

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2 minutes ago, Carvers Gap said:

Basically, I am saying if we stick a fork in this prematurely(with the models flipping all over the place) by saying winter was a dud...in the end it may not verify as such

Agree 100%. If I didn't I wouldn't have taken 2 and a half hours to write that giant post last night. 

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I think once the models ingest data without the convection in the wrong places, we see better looks. Take the -NAO.  It was looking really good on the GEFS for example, when the GEFS saw the MJO getting to high amplitude 7 quicker. Now that it does the loopty-loop back to 6, the mean isn't as sure. 

That being said, and this is bantery, but why not, you can't make this stuff up, lol: 

giphy.gif 

giphy.gif 

Loopiness aside, split the difference gets us to 8 at a decent amplitude. But getting there is going to be a wild ride with NWP with all those different solutions. Imagine the GEFS is right. Not saying it is at all, but hypothetically... 

In a week we're back at a low amplitude phase 6. What bizarro solutions will it spit out when it initializes there? You could basically argue the same thing with he Euro's prediction. 

But, when (and sadly for me I have to say "and if" here) we get to 8, I think we start to see some more hopeful solutions.  

 

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Agree with causal and effect. However, in the end the MJO Rooster ruled the Roost. IF that Rooster would decide to roost in a more favorable area we should still get things lined out for a decent snowstorm... or 2. Late Feb. and March may be the saves. 

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14 minutes ago, weathertree4u said:

So EURO was uneventful I take it

Yeah, if you discount the under 200 hour 3-5" snow it shows from eastern Arkansas to Memphis to Nashville to much of southern and SE Kentucky.  :)

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14 minutes ago, tnweathernut said:

Yeah, if you discount the under 200 hour 3-5" snow it shows from eastern Arkansas to Memphis to Nashville to much of southern and SE Kentucky.  :)

Oh 

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Yeah, silence does not necessarily mean nothing is on the line.  :thumbsup: Problem is that some of this is at d7 and beyond.  Here is one thing I think some of us are watching...around Feb 8th-ish, some modeling(varying models, varying operationals, varying ensembles) show another cold front sagging slowly into the forum area w/ a possible wave or two making a run along the front.  Very far out there.  The placement of the front has been understandably all over the place.  I have seen solutions ranging from ice in the TN Valley to a winter storm in the Mid-West.  

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15 minutes ago, Carvers Gap said:

Yeah, silence does not necessarily mean nothing is on the line.  :thumbsup: Problem is that some of this is at d7 and beyond.  Here is one thing I think some of us are watching...around Feb 8th-ish, some modeling(varying models, varying operationals, varying ensembles) show another cold front sagging slowly into the forum area w/ a possible wave or two making a run along the front.  Very far out there.  The placement of the front has been understandably all over the place.  I have seen solutions ranging from ice in the TN Valley to a winter storm in the Mid-West.  

Bingo.  Unfortunately, we just lost a storm under day 4.  It's hard to get excited again when models are showing a pattern that "could" be conducive to a winter system. The next 7 days are going to be pretty boring.  Maybe early to mid next week we have something we are watching more intently.

I think the period of the 10-20th could certainly produce, just hard to get excited about anything with the way our luck has gone so far.  If we had been hitting the snow jackpot regularly this winter I think we'd ALL be tracking the period shown on the GFS and Euro much more intently.

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Yeah, I'm a little burnt out after last week and need a couple days without a specific threat to track. 

Some cryptids hijacked the weeklies though... 

giphy.gif 

 

 

As psu just said in the MA forum: "They are either finally going to pay off in the most epic delayed but not denied ever...or they are going down with the ship in the biggest tease/bust in history." 

 

Interesting how different the 5 days averages make the run seem vs the hindcast above:

giphy.gif 

giphy.gif 

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Very interesting series of tweets from Masiello this PM. Especially interesting (maybe more so for trying to understand his approach to social media) if one looks at the order he tweeted them in. 

I know I have shared some of these without much additional thought. Will try to be better about that.

We've been looking for something to slow the Pac flow. We like things that are closer in time than not. 

Upper level back ups there in the near term = slowing of the flow downstream eventually for us.  And maybe, just maybe, the unisquatch -NAO  as the backing flow also retrogrades in the higher latitudes. 

Is this a guarantee for snowmageddon?

No.

But I think it mixes up the forecast Pac flow if it happens. IMO jet buckles can help us by amplifying the flow downstream of them and eventually amplified/ redirected stream flows upstream of us will = amplified/ redirect flows downstream of us and combined with more favorable SSTs for W. hemisphere convection (pretty please), may help change up the Pac dominated regime on a global scale. 

 

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Just a quick glance at the Weeklies...the cold definitely settles more in the West throughout the run w pieces of it breaking off and coming eastward.  At least that is what it looked like on the daily means.  The Pacific teleconnections appear to be uncooperative as the PNA is predominantly weakly negative and EPO is predominantly neutral to very weakly positive.  The NAO is predominantly negative, and that is what saves the East on that run.  If the NAO does not go negative, going to be a rough slog...but I do think it is correct w the -NAO.  Overall a good run with the core of the cold in the front range of the Rockies and or nation's center(western Plains).  The East was by no means warm...the nation as a whole is fairly cold. Going to have to get through 8-10 days of warmth first beginning this weekend.   Looks like things get Rocking around Valentine's Day per the Weeklies...earlier if the GFS is on to something(or even the Euro operational for that matter).  I think modeling in general is struggling w the MJO...but I suspect(to quote a friend) that El Nino climatology finds a way w or without the MJO.  With that said, the snow mean is about as weak as one can get w a 46 day mean...but it has been a poor indicator excluding the first week of winter.  I am actually looking forward to February....hopefully we get a couple of nice events to track.

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Looks like Feb 10-20 is our window. MJO is trying to get into colder phases for us. Looks like a choppy road still. PNA issue is a mess until some NAO help arrives. Pray hard!

Ensembles and weeklies point to the quasi-stationary boundary over the region by mid-Feb. Temperature forecasting will suck, but agree with Carvers regarding chances of precip. Should be mostly liquid next week and perhaps next weekend. Finally looks colder after the 10th.

Late Feb could be colder but drier. Middle of February features the best precipitation signature Deep South and normal here. Fourth quarter 2 minute drill.

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20 minutes ago, nrgjeff said:

Looks like Feb 10-20 is our window. MJO is trying to get into colder phases for us. Looks like a choppy road still. PNA issue is a mess until some NAO help arrives. Pray hard!

Ensembles and weeklies point to the quasi-stationary boundary over the region by mid-Feb. Temperature forecasting will suck, but agree with Carvers regarding chances of precip. Should be mostly liquid next week and perhaps next weekend. Finally looks colder after the 10th.

Late Feb could be colder but drier. Middle of February features the best precipitation signature Deep South and normal here. Fourth quarter 2 minute drill.

Let's hope we can pull out a win in the fourth quarter 

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2 hours ago, weathertree4u said:

Let's hope we can pull out a win in the fourth quarter 

And lets hope the refs (models) don't blow another call!!!!

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However even the colder FV3 warm noses Tennessee in fantasy land. ECMWF is a disaster. Good grief I'm going to try to forget all the 12Z data today. Time to just enjoy a few warm days. Have a good weekend!

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Let's hope we can pull out a win in the fourth quarter 

Looks like we might need at least one overtime


.
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26 minutes ago, PowellVolz said:


Looks like we might need at least one overtime


.

 

51 minutes ago, PowellVolz said:


Looks like we might need at least one overtime


.

Well, wouldn't be Winter in TN if we didn't 

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It is often like TN football, isn't it? 

Not much else going on, so dug around for the progression of last year's - NAO for any possible comparisons to this year's pattern. 

Last year:

 

GEFS this year:

giphy.gif 

EPS:

giphy.gif 

Not exactly the same, but some similarities. 

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