December/January 2019/20 Winter Speculation Thread

[John1122]

31 minutes ago, Carvers Gap said:

Yeah, that is impressive. @John1122, we talked about this yesterday.  Think we actually have a chance to pull that off(cutter to SE slp)?

I don't remember ever seeing it happen with a front passing quickly. But maybe the front is slowing down enough for some development down south?

[Holston_River_Rambler]

Can we just pretend the BOM's version of MJO phase 1 is where we really are now?

 

[jaxjagman]

Looks like a active CCKW  is passing east of the IDL.The subsurface is warm as well.3.4 ,3 AND 1.2.Seemingly the STJ is going to get active towards the end of the month into the first of next.Seems like the up and downs of the SOI we could be looking at a decent system around this time .need teleconnections to work out for once tho

Date	Tahiti (hPa)	Darwin (hPa)	Daily Contribution	30 day Av. SOI	90 day Av. SOI
19 Jan 2020	1012.31	1007.65	0.24	-5.28	-6.36
18 Jan 2020	1010.58	1007.80	-8.62	-5.57	-6.28
17 Jan 2020	1009.03	1007.95	-16.62	-5.51	-6.06
16 Jan 2020	1009.70	1007.85	-13.00	-5.22	-5.76
15 Jan 2020	1009.84	1007.70	-11.63	-5.24	-5.59
14 Jan 2020	1009.50	1007.15	-10.64	-5.35	-5.43
13 Jan 2020	1009.89	1005.85	-2.68	-5.49	-5.34
12 Jan 2020	1009.84	1005.45	-1.03	-5.78	-5.46

[Carvers Gap]

0z Euro still has a transfer of energy on its run.  Its low is slightly closer to the Apps.  The GEFS snow mean for the next 16 days is hefty for most of E TN.  In SW VA it is over 6" of snow.  NE TN is 4-6" of snow, but most areas closer to 6".  The EPS has 2-4" of snow over NE TN.  Overall, decent trends again over night in the medium and LR.  The storm the weekend still needs to be watched.  The Euro has been fairly adamant that a lee side low is going to form to our ESE.  The further south that forms, but better shot folks in NE TN have.  I realize this winter has been lousy since early December, but that is a set-up that we have scored on before at TRI.   LR, still marginal temps with lots of energy rotating underneath a HB high.  Very good example how we can have chances with marginal temps.  Cold from AK discharges at the end of the lates GEFS and EPS runs.  Where it goes is anyone's guess.  Verbatim, looks like it would head in the front range in MT and spread out as the HB high rolls out.  The RMM1 MJO ducks into five for three days and abruptly heads back into the COD.  Let's see where the Euro goes when it updates.  It is about 1-2 days ahead of the GEFS trends.  My guess is the MJO just never really dies...going to have to have the cold overpower the signal if we are to get anything decent or hit a big storm or two.  Definitely potential for a big hitter w that HB anomaly in place.  Suppressed storm pattern at times.

[PowellVolz]

Well..... it’s snowing right now


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[Carvers Gap]

2 minutes ago, PowellVolz said:

Well..... it’s snowing right now


.

Awesome.  TRI is showing yet another way a rain shadow can develop here.  LOL.  Not much here at the moment.  Looks like some decent returns to my SE.  Still, the "thunder in the mountains and snow within ten days" rule is doing well yet again.  

[PowellVolz]

Awesome.  TRI is showing yet another way a rain shadow can develop here.  LOL.  Not much here at the moment.  Looks like some decent returns to my SE.  Still, the "thunder in the mountains and snow within ten days" rule is doing well yet again.  

Lower elevation roads in the mountains are closing

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[PowellVolz]

I’m off today with nothing to do so I’m gonna ride up that way


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[Carvers Gap]

Just now, PowellVolz said:

I’m off today with nothing to do so I’m gonna ride up that way


.

Take some pics.

[PowellVolz]

Wow


https://www.resortcams.com/webcams/ober-gatlinburg-tram/


.

[Carvers Gap]

Super close for NE TN and SW VA on the 12z GFS between 108 and 114.  Temps crash as a developing slp to our southeast swings inland inside of Hatteras.  This is not a miller A at this point but has energy transfer that switches from a low to our west to the coast.  Still an outside shot, but that look can work for areas NE of I-26 and into SW VA. We want that low to our SE to continue trend stronger and a bit earlier.  

[Carvers Gap]

Nice upslope event for areas above 2500' as well with higher elevations seeing anywhere from 2-6."  Not bad considering this is right smack in the middle of the warm-up.

[Carvers Gap]

Might actually see some wrap-around snow showers in the valleys north of I-40.  

[Carvers Gap]

10 day run of the CMC had 4-6" over TRI and similar amounts on the Plateau w/ 2-3" amounts north of I40 in the valleys.

[weathertree4u]

1 minute ago, Carvers Gap said:

10 day run of the CMC had 4-6" over TRI and similar amounts on the Plateau w/ 2-3" amounts north of I40 in the valleys.

So are the models just seeing the warm up as more muted now or are they still in process of ingesting data? I honestly think that we will get a storm similar to today. For example, no one around here was really saying too much about flurries most of the day, granted, it is not sticking too well but no one forecasted there to be snow in the air most of the day today as it has been either.

[Carvers Gap]

Here is the CMC for this weekend and the upslope event after....please note this is on the high end of things.

[weathertree4u]

1 minute ago, Carvers Gap said:

Here is the CMC for this weekend and the upslope event after....please note this is on the high end of things.

Interesting

[Carvers Gap]

Just now, weathertree4u said:

So are the models just seeing the warm up as more muted now or are they still in process of ingesting data? I honestly think that we will get a storm similar to today. For example, no one around here was really saying too much about flurries most of the day, granted, it is not sticking too well but no one forecasted there to be snow in the air most of the day today as it has been either.

I think this weekend's storm has been there for a bit.  @tnweathernut has been talking about it for a while.  I think NE TN  and SW VA will have to fight for the accumulations on this one with the actual storm w/ normal upslope areas cleaning up on northwesterly flow.  It is an outside shot, but as the CMC showed, not without possibility.  The warm-up is still there and not really muted.  The thing that modeling seems to be seeing is a suppressed storm track due to the anomalous area of AN heights over the Hudson Bay.  That area over the HB is often associated with big storms in the East.  Long range ensembles have been breaking down that area at around d12.  After that plenty of uncertainty.  Does it lift out and form a -NAO?  Does the trough in Alaska slide into the SE or the Plains(and then spread out)?  It would not shock me if November repeated itself and it would not shock me if we headed straight to spring.  I meant to check out the other models regarding MJO.   Will check back in a sec.

[AMZ8990]

12 minutes ago, Carvers Gap said:

 I meant to check out the other models regarding MJO.   Will check back in a sec.

 

 

  Looks like we should be in phase 7 today, looks to be heading towards the cod area though so we shouldn’t be in phase 7 very long if it pans out.  If it stays in phase 7 than that could be a sign of a spring though as most cold events in spring happen when we’re in phase 7.  Just some stuff  I’m noticing 

[Carvers Gap]

This is the Euro MJO from today.  Note how it is now trending into phase 5 and potential looping back into 6 - and I don't think it is done trending.  It had at one point flirted with this solution and dropped back into the COD.  I am actually not surprised by this look and won't be surprised if it indeed loops back into 6 and then into the cold phases.  There is an impulse going into the warmer MJO phases about the time shown.  I suspect MJO region 6 will not actually stay on a prolonged convection cycle this time.  But who knows...just a hunch.  My thinking is this current cycle will cool the upper levels of the ocean sea surface and give less fuel to the next wave.  Looks like we only spend 5 days in 6 this current time as the Nino will fight it.  I also think the MJO later in the season may actually favor cooler phases.  The CFS at one time was forecast to make the tour into the cold phases - no more.  As noted earlier, American modeling is not handling the MJO well this winter.  The short tenure in phase 7 also aptly matches the potential storm this weekend and the backing-off of the cold in the mid range.  What is interesting is that the EPS has been tipping its hand on the MJO.  IMHO, the EPS is about a day or two ahead of the Euro graph at CPC.  It had the phase 6 return late last week.  So, might not hurt to match the EPS 500 pattern during d10-15 with what one thinks the MJO will be.  Probably will get a good hint at where this is MJO graph is heading.  Usually it is the other way around...this graph will tip the next day's modeling.

[Holston_River_Rambler]

One thing I'm sheepish about is the Invest in the Indian Ocean:

now the convection is nowhere near as deep as what birthed Tino in the West Pac, but a big flareup and subsequent S Hemisphere TC preceded the big +AAM burst that coincided with the big flip in long range models last week. 

[Carvers Gap]

Additionally, the GFS and CMC are not

1 minute ago, Holston_River_Rambler said:

One thing I'm sheepish about is the Invest in the Indian Ocean:

now the convection is nowhere near as deep as what birthed Tino in the West Pac, but a big flareup and subsequent S Hemisphere TC preceded the big +AAM burst that coincided with the big flip in long range models last week. 

Where is that, Holston?  I can't tell...

[Holston_River_Rambler]

1 minute ago, Carvers Gap said:

Additionally, the GFS and CMC are not

Where is that, Holston?  I can't tell...

Sorry:

[Holston_River_Rambler]

Also interesting that the CFS and GEFS (I think they are both American models, right?) see stark differences in the current GWO and where it is headed:

CFS keeps in it in the Nino forcing phases and amplifies it again, but less so then the last one:

While the GEFS takes it down into the Nina phases, which I think would interfere with the pseudo Nino (and by that I mean nice STJ and Hudson's Bay ridge, but messed up N Pac) looks we're seeing now:

Now obviously this is only one variable of many, but like I said yesterday, I'm kind of in Murphy's Law mode now. 

 

[Carvers Gap]

Just now, Holston_River_Rambler said:

Sorry:

Looks to me like phases 1 and 2 are firing which is exactly what the 12z GFS looked like.  The GFS barely lets the trough at 500 return for more than 2-3 days.  Still a warm pattern, but that 500 look is an improvement.   The CMC operational actually has a GOA low vs an Alaskan vortex.  Minor change, but you can see the impact downstream at 500.  The wave could propagate eastward into warmer phases for sure.  Some of that looks like it is heading away from the equator in a southern trajectory.  That would be a plus.  Check out 384 on the GEFS (North American) view...I have seen that movie before.  Anyway, looks like a very active weather pattern.  The GFS actually has three storm to monitor.  The trend has been suppression.  So, it might be that a storm to our northwest actually trends back to us depending on the HB block.  If anything the message right now is that the pattern for late January and early February is far from settled.

[Carvers Gap]

2 minutes ago, Holston_River_Rambler said:

Also interesting that the CFS and GEFS (I think they are both American models, right?) see stark differences in the current GWO and where it is headed:

CFS keeps in it in the Nino forcing phases and amplifies it again, but less so then the last one:

While the GEFS takes it down into the Nina phases, which I think would interfere with the pseudo Nino (and by that I mean nice STJ and Hudson's Bay ridge, but messed up N Pac) looks we're seeing now:

Now obviously this is only one variable of many, but like I said yesterday, I'm kind of in Murphy's Law mode now. 

 

Yeah.  All of it will never be perfect for sure.  I was telling someone the other day that a lot of these other indices are like when your engine lights come on in your care.  You get a bunch of them going off about different things.  In the end, it is all likely tied to one or two causes.  I think the MJO, the PV, and ENSO state are driving this car right now.  I am actually interested to see if the QBO can induce blocking...we are at about the time of year when the Atlantic will throw us a bone.  One could probably make a case that the HB block is saving us from a true torch right now.  When things let up and it cools here, it is usually because the MJO has moved into a favorable phase.  It is playing with house money when forecasting right now.  

[Carvers Gap]

Do I think this is right?  Unlikely but worth a share for comparison purposes.  Full run 12z GEFS snow mean.  

[AMZ8990]

 

Thought some of you might find this interesting.

[Carvers Gap]

If anything, it may be that things don't really lock-in for more than 7-10 days at a time.  The 12z GEFS is colder in the d10-15.  Very interested to see where the EPS and Euro operational trend.  GEFS is nice to look at, but seems prone to some drastic fluctuations right now.  Also will be interesting to see where the GEPS goes.  Really just looking for trends at the moment, but I thought the mean was kind of interesting - just for kicks and giggles.  

[Carvers Gap]

12z Euro accentuated the northern stream energy for this weekend's storm.  That means the SE low takes longer to form.    Was very similar to the GFS.  That would leave an upslope event by not snow from the storm for really anyone.  Still, was not very different.  Given the Euro bias for being too strong, I wouldn't rule this one out just yet.