January Medium-Long Range Discussion

[PowellVolz]

6z GFS gives you hope Matthew (so it can take it away later)

 
I like this very realistic (read with sarcasm)
close up snap shot from that run:

There is no way if there is a valley warm nose and a low over Tellico that I'm staying snow, lol. 

The best thing we have going for us in the valley is it’s very unlikely that this is the right path. It will either get better or it won’t. It’s mostly rain as of now so it can’t get worse.


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[PowellVolz]

Wish I could remember the year. It’s been in the last 6 or 7 years but we had a very interesting system that came through ETn. The forecast for my area was snow to rain and backend snow. NWS thought a couple of inches up front before the changeover. For some crazy reason the valley had CAD north of 40. At my house 30 min north of Knoxville, the temp never broke 30 degrees and it stayed snow 95% of the event. I ended up with 8+ inches but Knoxville got only an inch and it switched to rain pretty quick. I remember my temp was in the upper 20’s and I was watching opps in the foothills and mountains waiting on WAA. I remember Gatlinburg was in the mid 40’s. One of the craziest storms I could remember.


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[Jed33]

16 minutes ago, PowellVolz said:

Wish I could remember the year. It’s been in the last 6 or 7 years but we had a very interesting system that came through ETn. The forecast for my area was snow to rain and backend snow. NWS thought a couple of inches up front before the changeover. For some crazy reason the valley had CAD north of 40. At my house 30 min north of Knoxville, the temp never broke 30 degrees and it stayed snow 95% of the event. I ended up with 8+ inches but Knoxville got only an inch and it switched to rain pretty quick. I remember my temp was in the upper 20’s and I was watching opps in the foothills and mountains waiting on WAA. I remember Gatlinburg was in the mid 40’s. One of the craziest storms I could remember.


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That system is archived here still on page 8. 2nd from bottom. I just went back and looked it up if yall would like to read it again. It was so fun watching it fall! The one time the valley had CAD and the mtns went rogue warm!

[PowellVolz]

That system is archived here still on page 8. 2nd from bottom. I just went back and looked it up if yall would like to read it again. It was so fun watching it fall! The one time the valley had CAD and the mtns went rogue warm!

Could you link me the page please?


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[Jed33]

Here ya go! Sorry for the delay I had to run out of the house for a minute 

[Carvers Gap]

One of my kiddos plays for the Pride of the Southland.  They are in Orlando.  I have been keeping track of the wx there.  Frost and freeze advisories are in north Florida.   But check this out....what a cool sign off.

East Central Florida Forecast Discussion
National Weather Service Melbourne FL
637 PM EST Sat Dec 30 2023

.DISCUSSION...

...Below Normal Temperatures Forecast Tonight...
...Patchy Frost Possible North of I-4...

Currently-Overnight...Skies continue a clearing trend as high
pressure over the deep south works closer to the area. The area
should be under clear skies by around 10 pm. the present forecast is
in good shape and no adjustments are planned. Radiational cooling
more optimal overnight should allow for pockets of frost to develop
mainly in Lake and Volusia co`s.

RETIREMENT...This is my final forecast discussion, and I will be
retiring tonight. I am so fortunate to have been able to witness
central Florida weather for the past 50 years, as well as forecast
it from this office for 25 of those. As I leave the way for the next
generation of very capable professionals in this office going
forward, I want to thank all the members of the media, emergency
managers, fellow employees and lastly you, the many and diverse
users of our products. I would take satisfaction knowing that some
how you have used, and continue to benefit in your own way from our
forecasts and warnings, as we watch out 24 hours a day, 365 days a
year.

Have a happy 2024.

John Pendergrast

 

[Carvers Gap]

Tonight's GEFS ext has rediscovered high latitude blocking.  We will watch this trend for the next few days, but modeling seems to be can kicking the MJO warm phases.  I can say this, if cold wx was being can kicked in the same way...I would be worried it wouldn't come to pass.  Maybe this time the can kicking is in our favor?  

[TellicoWx]

00z CMC looking better for the next system

[fountainguy97]

North trend for the win? Right where we want it honestly.
 

 

I know focus will be on the "big dog" after this one but our last event trended way south around the 5 day mark but came roaring back north in the 2-4 day period. Watch for this to potentially do the same. There are still GEFS members with some northern solutions. 
 

We need a faster ejection of the southern piece and a slower northern to get that negative kick to pop the surface low further north. 
 

Trailing piece could be the bigger story. A lot of times we get the "setup" system and then the trailing delivers the goods. Best chance of the season for winter action for the Southeast so far! This first week of Jan has been in the discussion for a while now. Glad to finally stop kicking the can and see some verification in the mid-range.

[TellicoWx]

Have to get the 1st system out of the way, but if the GFS can consolidate the energy with the southern piece of energy like the CMC, then the 2nd system could get very interesting.

[Holston_River_Rambler]

NW precip jog continues at 6z:

trough trending sharper and deeper:

 

 

Let's see where it goes. 

[Holston_River_Rambler]

6z GFS also trying to split the SPV again:

Like others have said it doesn't matter so much if it splits, only if it is distressed and not a tightly coupled wound ball over the pole.

Speaking of coupled, what an -AO at 500 mb on the 6x GFS:

 

There is 100% some major warming happening in the strat over the next week, it just probably won't qualify as a major SSWE based on the wind reversal criteria.

GFS has temps approaching 0 degrees celsius at 10 mb:

 

Euro isn't quite as aggressive but similar:

 

It seems to be trying to drip down, and I wonder if that is the -AO the GFS is starting to see at long range. Maybe not, but worth keeping an eye on:

[Carvers Gap]

The 0z Canadian was decent......

[Carvers Gap]

Some decent trends (better than decent) on global ensembles overnight (d10-15).  That gets us through the first half of January.  If that is our winter, then so be it.  This could be our shot.  Like several others, I do think we see a warm-up after that....then cool back down.  Interesting to see Cosgrove really hammer home that March should be warm, and honestly if this plays out as a cold Jan25-Feb28, we will all probably be glad for the arrival spring.  His thinking is that the Nino is going to break down quickly and that La Nina is going to arrive quickly.  

[Carvers Gap]

I must say, the late night crew put up some great content.  Awesome, ya'll!  Tracking on NYE....that is a good thing.

[fountainguy97]

4 minutes ago, Carvers Gap said:

I must say, the late night crew put up some great content.  Awesome, ya'll!  Tracking on NYE....that is a good thing.

Love seeing all the input! We have  nice crew of posters here these days! 12z inbound!

[TellicoWx]

12z GEFS screams model chaos after the first system...will be very hard for it to determine where/how to interact with this many lows parading across the country.

[Daniel Boone]

38 minutes ago, TellicoWx said:

12z GEFS screams model chaos after the first system...will be very hard for it to determine where/how to interact with this many lows parading across the country.

Yeah, 12z GooFuS has that System coming way North. At least CMC, UKMET still look good. Hopefully we get more HP to the North. The close proximity of the Lows hurts as it doesn't allow cold to funnel behind them. That can be a problem with Nino's. It does generally keep one from becoming strong and amping. However, the GFS has that first one a strong one and amping. 

[Carvers Gap]

The 12z GEFS is less impressive, but the GEPS/EPS are pretty frigid d10-15.  I will post the control in a minute.  That big red ball over Greenland is how one fights the MJO.  That is a really cold look for NA.  And I might caution, we have seen this look many times during the past few winters, and it is TOUGH to get it to verify....but there it is again.

 

[Carvers Gap]

This is the cold front the Euro control has during the second weeks of Jan....It is just an example, but impressive.  These are departures.  Some temps are 45 below normal during the coldest week of the year.  Those would create highs below freezing in the Panhandle of FL with lows in the mid to upper teens there.  I doubt it comes to pass exactly like that, but that might be the most impressive cold front I have seen generated by a wx model for this time of year.

Without snow on the ground, TRI doesn't get out of the teens and drops to below zero.  This run is courtesy of a couple of cutters which drop ample snow to our north.  Then, as referenced in my previous post(the ensemble!), the PV gets trapped and sent southward.  The GEFS is more west, and that makes sense.  But this would wreck havoc if it came east without modification.

 

[Carvers Gap]

I hate to overhype this, the CFSv2 has a similar solution as does the CMC.  I do caution this could end-up west, but there is very little mechanism to keep it there (no Nina).  The GEFS is not much warmer, but it isn't like 500 standard deviations below normal like the others.

[Carvers Gap]

I am guessing we are getting ready to take a ride on the strat split express.  For Jan 10-20, there is probably going to be model mayhem as we get closer (IF this ensembles are even close to accurate).  Again, it is pretty rare to get all of NA that cold...and models have tried during past years.). But often extreme patterns are recognized at about this range.  So, time will tell.

[Carvers Gap]

And I should add this pattern is within 8 days.  The first of it knocks on door at the US/Canadian border by Jan 7.   

[Carvers Gap]

And you know, there is more.  Euro Weeklies and CFSv2 for fun.............I will trust that you will look at the stamps to see the duration.  

 

 

 

[BNAwx]

I wonder if the difference with the GEFS is in how it’s handling the MJO progression.  How has its MJO verification skill compared to EPS or GEPS?

[Daniel Boone]

I buy into the Arctic Airmass coming into the lower 48. Not typical for a strong Nino but, with a rather Nina/Nino hybrid Pac Pattern to coin it,along with a strong -NAO and AO very much possible if not probable. 

I am rather saddened by the nw turn in the early Jan big Storm. Really not surprising though. Need a HP dropping down from the N or NW to keep that thing from doing that. A banana High would do the trick but, doesnt look to be a chance of that happening either. 

[Carvers Gap]

6 minutes ago, BNAwx said:

I wonder if the difference with the GEFS is in how it’s handling the MJO progression.  How has its MJO verification skill compared to EPS or GEPS?

Modeling isn't too far off.  I started noticing the CFSv2 with strong highs at the surface undercutting the 500 eastern ridge on the 6z runs.  At this range, they are close.  I don't think any model has handled the MJO progression very well of late.  It is more of a which model has been worse.  Here is the GEFS 5d temp profile fro Jan 10-15.  The pattern itself begins to slide into place next weekend.  

 

[Daniel Boone]

3 minutes ago, Carvers Gap said:

And you know, there is more.  Euro Weeklies and CFSv2 for fun.............I will trust that you will look at the stamps to see the duration.

 

 

 

That EC Ensemble 500 depiction is very close to Ideal. 

[Carvers Gap]

5 minutes ago, Daniel Boone said:

I buy into the Arctic Airmass coming into the lower 48. Not typical for a strong Nino but, with a rather Nina/Nino hybrid Pac Pattern to coin it,along with a strong -NAO and AO very much possible if not probable. 

I am rather saddened by the nw turn in the early Jan big Storm. Really not surprising though. Need a HP dropping down from the N or NW to keep that thing from doing that. A banana High would do the trick but, doesnt look to be a chance of that happening either. 

This has some 09-10 in it.  It is almost a pay me now or pay me later type of pattern.  If the system cuts, more cold is coming down.  I do wonder if the strong cutter next weekend is what provides the mechanism for this.  In other words, modeling is now leaning towards a cutter next weekend, but that in turn, makes it colder during weeks 2-3.

[Carvers Gap]

2 minutes ago, Daniel Boone said:

That EC Ensemble 500 depiction is very close to Ideal. 

It may or may not come to pass, but the model 12z suite across the board for Jan10-15.  The GEFS is simply "warmer" but still very cold.  Modeling has had this timeframe picked-out for a long time.  So, it isn't overly surprising.   I would guess there will be some twists and turns along the way, but that is impressive.  Honestly, this is what hit Europe a few weeks back it looks like.