February/March 2020 Winter's Last Chance Thread

[Carvers Gap]

16 minutes ago, Holston_River_Rambler said:

Don't want to put words in Mr Bob's mouth, but I think he was pointing out the weeklies look nice the next two weeks:

 

Are those the Weeklies?...WxBell has not loaded.  When they are this late, sometimes they don't load.  How does the run look after d20?  

[Holston_River_Rambler]

3 minutes ago, Carvers Gap said:

How does the run look after d20?  

Same old, same old. Trough out west, ridge east, 

[Carvers Gap]

15 minutes ago, Holston_River_Rambler said:

Same old, same old. Trough out west, ridge east, 

Was able to finally able to get them.  They have flipped through the first week of March at 2m.  Pretty remarkable flip compared to Monday at this short of a range.  Still digging through them.   Here is the 20th-27th.  If they are bouncing around like this, highly doubt they are done bouncing(for good and for bad).  The first 30 days of the run are now normal for temps where they were pretty warm.

[jaxjagman]

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS COLLEGE PARK MD
0239Z FRI FEB 14 2020


...UPDATE DATAFLOW PROBLEM WITH WCOSS...

IBM and NCO`s Dataflow Team continue to investigate a problem
with dataflow to the supercomputers. This is impacting model
production and dataflow to various NCEP data feeds and servers,
including NOMADS. Users can expect NCEP model delays of 20-40
minutes.

[Holston_River_Rambler]

OP Euro went for the suppressed/ held back energy overnight, but still several EPS members that get moisture back into the TN valley. 

6z GEFS meanwhile has its best looks yet (give the gif a few seconds to start)

[Holston_River_Rambler]

Jon Wall on twitter (also on southernwx), posted a really nice trend showing why the Euro had backed off, but the 6z Euro seems to have gone teh otehr way now, so hopefully we are back in business at 12z

 

12z NAM looks similar 

[Carvers Gap]

Wonder if the data problem is fixed and if it caused any model issues?  

[Holston_River_Rambler]

One of my model pages had a notice about it earlier this AM, but can't find it now, so maybe its fixed? 

[Holston_River_Rambler]

I think I found the site:

https://tgftp.nws.noaa.gov/tgstatus/

 

"

NOUS42 KWNO 141334
ADMNFD

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS COLLEGE PARK MD
1331Z FRI FEB 14 2020


The 12Z NAM started on time with 14 Alaskan...27 Canadian...
70 CONUS...14 Mexican...11 Caribbean...and 9 Pacific stations
available for ingest.


12Z NAM RAOB RECAP...
72240/LCH - No report for the NAM.
70414/SYA - Missing Part TTBB.
72214/TAE - 10159.


CRITICAL WEATHER DAY STATUS...
NCEP does not anticipate a CWD during the next 3 days."

[Holston_River_Rambler]

12z GFS is trying to play ball:

 

[Carvers Gap]

Yeah, the timeframe later next week still looks good despite the storm looking suppressed and strung out right now.  Notice the 12z GFS is not holding all of that energy in the Southwest.  That is a truck load of cold coming down the Plains and a lot of precip coming out of Texas.  Have to think that those two have a chance to collide somewhere in the South.

[Carvers Gap]

12z CMC manages to show some frozen precip over the forum area albeit during a short time frame.  I just don't think modeling has this handled quite yet.  Again, this is the time frame that we have noted has been poorly modeled due to cut-off lows and such sitting and spinning for infinity.  Actual verification likely means that we have two cold fronts rolling through between the 10th and 20th.  IMHO, that precip next week is coming north of where it is.  It has done this(northern creep) all winter.  Cold HP heights are verifying slightly lower(or much lower) than originally modeled.  This allows the system to creep northward.  Now, during some winters the highs and attack the HP.  The other trend is to hold less energy back.  Right now, pretty much everyone is in the game in the forum area from northern Alabama to TRI.  North Carolina isn't looking to bad either.  Verbatim, this is suppressed below I40...but still quite a bit of time for this to move around.  

PLUS...still not totally convinced that whatever happened last night is totally resolved.  Seems like those types of mishaps can take a few runs to get the kinks out.  12z runs might be fine, but when we have seen data ingest problems before and things were wonky for a few days.  I actually though modeling looked a bit different this AM.  Sort of holding my thoughts on that until we know 12z is clear of any problems.  It was odd to see the storm late next week vanish at 0z.  Looks like it is back at 12z, but a bit weaker.  

[Carvers Gap]

...And having anything to track right now seems like a minor miracle given the trends for this winter!  LOL.  

[Holston_River_Rambler]

Euro suppressed again, but UKMET offers a compromise between the OP GFS and Euro:

[Carvers Gap]

12z Euro is very suppressed.  Again, will it stay there?  Time will tell.  It is cold today, but sure nice to see the sun.  

[Holston_River_Rambler]

Euro also getting a little punchy with the strat late in the run:

 

some of that even shows up in lower down in the Pac at H5:

If we can get that lobe of the SPV/TPV positioned just right over the Aleutians, we can hopefully get some ridging over AK.

But, I'd say there is a chance, at least at this range, that it could shift right back over AK instead of the Aleutians. 

A further hypothetical, as noted by Masiello earlier in the year, -NAOs are often preceded by that sort of a low. 

 

 

[Holston_River_Rambler]

The last frame hadn't loaded on that Euro strat map when i posted it, but here it is now:

[snowmaker]

Next weekends system or non system still has my eye, maybe with a little luck this system will start trending our way. Hopefully we can get the moisture and cold to meet right over Tennessee! All we have is hope! LOL!

[Holston_River_Rambler]

Longer than usual EPS to show a variety of things

 

 

Next week threat, then zonal coolish, then what looks like a severe threat, and then cold signal again. 

[Holston_River_Rambler]

I wonder if the Canadian blocking would be higher latitude this year if it wasn't for the super, ultra SPV?

Some of these lower latitude blocking episodes have coincided with isotherm's predictions and +AAM states, they just don't get as far north as they might have without the SPV

[Holston_River_Rambler]

WPC rather optimistic about precip. getting back north, days 5 - 6, not so much on it being wintery though:

[weathertree4u]

38 minutes ago, Holston_River_Rambler said:

WPC rather optimistic about precip. getting back north, days 5 - 6, not so much on it being wintery though:

This may be a Birmingham to Atlanta system 

[Carvers Gap]

15 minutes ago, weathertree4u said:

This may be a Birmingham to Atlanta system 

Not Holston, but that could be right.  That is a bruiser of a high pressure rolling in.  However, seasonal trends have generally not been suppression - especially this time of year when things tend to trend north as models recognize they are have a little more juice.   And some years, we want to see a system in Cuba because it will move so far north.  I will say this, at this time range if it was over NE TN, I would say someone from Lexington to Cincinnati would be more likely to get snow.  What we need to hope for is that the cold is over modeled as it has been all season.  But yeah, I don't dislike your track though from an unbiased perspective.  If this stays on modeling, I would be feeling pretty good anywhere between the Huntsville and Knoxville latitudes and including Memphis.   Really would like to see the Euro get it back though.  It has issues with being too slow in the West, and that might be messing with its run.  Just keep pulling for that big high....likely only way anyone has a chance at snow in the South at this time of year.

[snowmaker]

From a personal perspective I hope it gets north enough for the tn-ky border areas to be involved. Sitting in Montgomery Co, I hope it at least makes it close to Nashville anyway, I could snow chase pretty easy at that point. I also have friends in Henry Co and Christian Co Ky that love snow and hope they can get them one before the end of the year as well. But it's weather and we have no option but to take what it delivers.

[Carvers Gap]

3 hours ago, Holston_River_Rambler said:

I wonder if the Canadian blocking would be higher latitude this year if it wasn't for the super, ultra SPV?

Some of these lower latitude blocking episodes have coincided with isotherm's predictions and +AAM states, they just don't get as far north as they might have without the SPV

I have been thinking about what the seasonal drivers have been.  The really amped ENSO region 4 has really behaved as a moderate to strong Nino.  JB shared that thought the other day, and I have to agree.  And since it has been positioned right under phase 6 of the MJO, it really has been the driver this winter.  In some ways, our weather pattern has been one of a strong El Nino.  IMHO, that is the culprit for excessive rain and warm temps.  I don't think the PV has been helpful either.  So, with those two in conjunction and the result is we have what we have.  Not sure many had ENSO region 4 as a problem.  I think the Indian Ocean threw fuel on that fire, because it kept sending wave after wave of convection right over the top of the phase 6 area.  Jeff mentioned the IO as a concern early on...Two of those(the IO and ENSO region 4) will probably factor into future forecasts as variables we know to be watchful for.  The PV deal is almost a crapshoot...no way to have guessed that one.  BTW, the 30mb QBO is now officially negative at -2.51.  It did not stall as it fell at a steady rate all winter.  However, it is probably a bit too early in the cycle to really help us.  The good thing about that is that it runs on roughly 14 month cycles, so it should be there for most of next winter though heading for positive(but still negative).  Plus the MJO is just trumping everything with warm phases.  Now, with the QBO negative would not surprise me to see blocking develop this spring and make things miserable.  I hope not!  And we all know the NAO will be negative all summer, and go positive right at the end of November...LOL. That is @tnweathernut's favorite index trend.

[Holston_River_Rambler]

1 hour ago, Carvers Gap said:

And we all know the NAO will be negative all summer, and go positive right at the end of November...LOL. That is @tnweathernut's favorite index trend.

Yeah, I wonder how that eventual shake up will go down. Will we flip to a + one some summer in the future, or will we just get a winter with one at some point regardless of the preceding summer or fall.

What do you think about this:

I went through and looked at the CPCs data set for the NAO and tried to pick out the summers preceding a mean Jan NAO of at least -1, from 1972 - 2012 (just an arbitrary number I picked to keep this image smaller). Red underlines are the preceding summers and black are Octobers. The big recent year of a -NAO (2009 - 10) actually had pretty negative numbers in the summer (sorry looks like I underlined the wrong October for 2009 - 10, but just look below that lowest black line).

Other than 2009 - 10, Januaries that average a negative NAO typically have an October value that is near neutral or positive. Probably a warm signal for that month in our area. Again, other than 09 - 10, the preceding summers tended to be neutral to positive as well. 

I threw 94 - 95 in there because it had a highly +NAO average for the preceding summer, but still gave a positive value in the winter. 

[Holston_River_Rambler]

I feel like if I stared at that data long enough, I might be able to figure out Isotherm's formula, lol. 

Here's the location of the data set for those who may want to look too:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

[Holston_River_Rambler]

By the way, this past October's averaged NAO value was -1.41

[Holston_River_Rambler]

Just eyeballing some of the other years outside of my image above, it looks like October is a pretty good gauge. I wonder if that is why many of the winter outlooks don't come out until early November. Remember last year (18 - 19) when Isotherm predicted a predominantly negative NAO:

 

source: https://www.lightinthestorm.com/page/3

 Coincidence that 1950 is when the CPC begins as its dataset? Obviously we only have so many tools, but I kinda wonder if it is just as simple as looking at the October value. I suspect it isn't for him, but, even if that was all a person did, using that dataset, you'd be right 80% of the time. 

The years previous to 2018, the NAO averaged closer to neutral, though still positive, than in 2018. 

I'm going to venture a guess that his 4 variables are from one of the following QBO, ENSO state, solar state, Oct. NAO average, AMO.

[weathertree4u]

1 hour ago, snowmaker said:

From a personal perspective I hope it gets north enough for the tn-ky border areas to be involved. Sitting in Montgomery Co, I hope it at least makes it close to Nashville anyway, I could snow chase pretty easy at that point. I also have friends in Henry Co and Christian Co Ky that love snow and hope they can get them one before the end of the year as well. But it's weather and we have no option but to take what it delivers.

Mid Sumner County here, I agree, north please