February/March 2021 - Frigid or Flop? Pattern/Longterm Forecast Thread.

[John1122]

Euro builds a big snowpack to our north and has some true arctic air over it  but through 198 we are spared the brunt of it due to no snowpack. 

At 204 we'd probably set record lows with snowpack on the ground.  But it was showing those Temps for Monday a couple days ago. So color me skeptical when cold hangs around D7-8 on a model run. 

 

[John1122]

Snow watch from Houston to Tallahassee with the highs dropping in. January 2018 redux when the creek here froze 6 inches thick with no snow on the ground at all and the deep south had 2 snow events. 

[John1122]

If we could get a 1049 H over Wisconsin we'd be in business. A 1049 over Eastern Kansas sends everything to the south central GOM and puts Jacksonville in play. 

[John1122]

South Georgia jackpot that run.  Frozen brown ground here. 

[Carvers Gap]

May be running out of runway for the Sunday system.   I think the trend is OTS with no phase, but going to watch modeling today to see what happens.  Likely is nothing, but not sleeping on it either.  The 6z GFS and 6z ICON are not completely benign.  The cold is less severe (speaking in generalities) on modeling this AM, and that includes pretty much all of the Lower 48.  As John notes, the trough amplification is massive and suppresses everything.  We can get suppression without the vodka cold.  However, I will note that has been an error all winter on modeling re: the SE.  Generally, modeling has over-estimated the depth that cold penetrates into the SE at mid-range.  Just take a look at d5-7 now.  That front is not going as far south as was originally projected, and allows for rain for a system, which at one point, was snow without a doubt.  One of the reasons I really like cold on modeling is that modeling has been modifying it of late.  I still think we see cold.  Would be somewhat surprised if someone in the subform doesn't see accumulating frozen precip during the two weeks which follow Feb 5th.  A

[Holston_River_Rambler]

Where are you getting the Para from Carvers? I've been trying to look at it since yesterday. Pivotal and weathermodels haven't updated. Does weather bell have it?

 

I was kinda hoping NCEP had cut off data since they might be about to make it the OP GFS

[Carvers Gap]

2 minutes ago, Holston_River_Rambler said:

Where are you getting the Para from Carvers? I've been trying to look at it since yesterday. Pivotal and weathermodels haven't updated. Does weather bell have it?

Man, hope I am not looking at an old run...let me check.

[Carvers Gap]

3 minutes ago, Holston_River_Rambler said:

Where are you getting the Para from Carvers? I've been trying to look at it since yesterday. Pivotal and weathermodels haven't updated. Does weather bell have it?

 

I was kinda hoping NCEP had cut off data since they might be about to make it the OP GFS

Yep, it is a day old.  Give me a sec to amend my comments above.  Saw 6z and assumed it was legit.  

[Holston_River_Rambler]

As John mentioned earlier the UKMET has been pretty bad this year, at least in terms the details over CONUS. Here is the overnight new UKMET, hopefully it improves the model's performance:

 

 

 

[Carvers Gap]

Thoughts on Sunday are still generally the same.  If we assume the 6z GFS(not the para) is East of where it will verify AND the northern  stream stays with the same speed, I think that will be a bigger storm.   Should know by tomorrow morning what that trend is(meaning does it trend back towards a phase?).  Seriously though, if that thing phases it could cut well west of current solutions.  Again, pretty much out of runway by mid-day tomorrow on that system.  I would think if it trends back towards a storm, that would begin to trend that way today.

[Holston_River_Rambler]

I think the big TPV chunk over southern Canada or the northern US (depending on the model/ run/ time stamp) is just giving models fits. It's like having a big storm trying to clear the east coast and trying to see how it changes the flow, except it is on a continental level. 

And this comment is aimed more after the storm Carver's is talking about above, say in the days 5 - 10 time range. 

[Carvers Gap]

The problem is that the Sunday system is just missing a phase...literally by hours.  That could change.  Interesting find on the UKMET.  Did it have anything yesterday?  Thought I remembered a whiff on Pivotal?

[Carvers Gap]

Just now, Holston_River_Rambler said:

I think the big TPV chunk over southern Canada or the northern US (depending on the model/ run/ time stamp) is just giving models fits. It's like having a big storm trying to clear the east coast and trying to see how it changes the flow, except it is on a continental level. 

Good point.  Any time there is severe cold on modeling, things can go haywire in a NY minute.  Will be interesting to see where this all goes during the next 72 hours.  

[Holston_River_Rambler]

Here's the run to tun change on it on the Euro for the past 4 runs (for those wondering what we're talking about with the TPV):

 

When it was depicted rounder and further east, the cold could sink south, but if it gets stretched out across the N. border, that cuts off the cold. 

[Holston_River_Rambler]

6 minutes ago, Carvers Gap said:

The problem is that the Sunday system is just missing a phase...literally by hours.  That could change.  Interesting find on the UKMET.  Did it have anything yesterday?  Thought I remembered a whiff on Pivotal?

As far as I can tell, no one else has the new Ukie yet except F5wx, or they are all running it out to only 144 hours.  I'll look to see if there are any differences at 12z. But F5 has had some problems getting the new UK version's data to load, so some of the panels weren't available yesterday. I do think it seemed less cold that the old Ukie on Pivotal. 

[Holston_River_Rambler]

Just trying to find data on how the new UKMET is different, and saw there is apparently a UKMET ensemble: MOGREPS. Wonder if any service has that one, lol? 36 members. 

https://www.metoffice.gov.uk/research/weather/ensemble-forecasting/mogreps

 

[PowellVolz]

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[Carvers Gap]

28 minutes ago, Holston_River_Rambler said:

As far as I can tell, no one else has the new Ukie yet except F5wx, or they are all running it out to only 144 hours.  I'll look to see if there are any differences at 12z. But F5 has had some problems getting the new UK version's data to load, so some of the panels weren't available yesterday. I do think it seemed less cold that the old Ukie on Pivotal. 

I just use the UKMET on Pivotal.

[Carvers Gap]

Thing to remember about the UKMET, it has a tendency to oversimplify in the mid-range.  Just have to take into account that bias.

[Carvers Gap]

Going to make a correction...the 6z GFS does indeed have record cold back on that model.  It is in the d7-10 timeframe but looks remarkably like the Euro yesterday.  Temps overnight in my area on d10 are -8F to -13F.   There is very nearly some -20 stuff in SW VA.

[Carvers Gap]

Just now digging through ensembles this morning, I don't see a ton of major changes to the pattern overall.  If there is one trend it is to shave off the cold on the SE end of the are of BN heights which extend from the Mountain West deep into the SE.  We will watch trends today.  Again, the 6z GFS has the cold back on its run, though about 72 hours later.  Dig through my comments yesterday, and I said rthat the MJO phase 6/7 was going to fight the cold.  That is a very warm MJO signal.  You can see the SER try to pop but get knocked down by the cold.  Occurs at least a couple of times on the Euro run.   What we do have in play now is very cold air at times making intrusions into the Lower 48.   I still think the potential for severe cold into our area is very real.  I just think modeling is trying to get the timing of each system down, and as Holston noted, modeling really struggles when cold air is on the playing field.  As for storms, systems that run the gradient are tricky.  But I will say if you want big snow, you really have to be willing to be right on the edge where the freezing line is.  Again the 6z GFS is probably the coldest run that I have seen for my area in many years.  Going to be plenty of fluctuations.  if we get any snow on the ground before the cold moves in, that is going to be some seriously cold air sliding in along the snow pack.

[Holston_River_Rambler]

1 hour ago, Carvers Gap said:

I just use the UKMET on Pivotal.

What I'm trying to say is that I think the UKMET  has just been upgraded to a new version (higher resolution) and I think only F5 has that version so far. 

[Shocker0]

Wow, in less than two days our projected temps on Monday went from 22/5 to 46/28 here.

[Carvers Gap]

27 minutes ago, Holston_River_Rambler said:

What I'm trying to say is that I think the UKMET  has just been upgraded to a new version (higher resolution) and I think only F5 has that version so far. 

It may have been.  Have you seen where it was upgraded?

[PowellVolz]

I feel like a dog that’s had it’s bone taken away and set up on a shelf that I cannot reach.


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[Carvers Gap]

Just looking at NCEP MJO stuff this AM...definite trend to head towards phase 8.  Many of the OLR maps also show this.   I noted yesterday that I wasn't overly enthused with the MJO as most models had it stalled in phases 6-7 which are warm. Let's see if modeling doesn't react to that trend today.  If anything modeling may have gotten ahead of itself yesterday.  That said, if the trend to move towards 8 is legit, then I think we are in business.  Right now phase 6/7 is going to fight everything.  (NAO has saved us from the torch all winter and has been a key driver this winter). For several days it seemed the MJO plot and actual modeled OLR maps were out of sync - meaning OLR looked like phase 8 but the plot was not.  And again, this really seems like the '89/90 analog merged with the '95/96 analog.  I think we just need to be ready for some wild swings in modeling coming up.  

[tnweathernut]

Just a heads up.  Most now know the GFSv16 hasn't updated since 6z yesterday. Looks like they don't yet know when this will resolve.

(02 Feb 2021) GFSv16 and HRW FV3 data have been unavailable since 12z due to NCEP data flow problems. We are not aware of an ETA from NCEP.

 

[Holston_River_Rambler]

1 hour ago, PowellVolz said:

I feel like a dog that’s had it’s bone taken away and set up on a shelf that I cannot reach.


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If we woof loud enough, @Stovepipe will come give it back. 

 

[Holston_River_Rambler]

1 hour ago, Carvers Gap said:

It may have been.  Have you seen where it was upgraded?

Yeah, F5wx says it is a new 10km resolution version. I'm just not sure why or if other sites have or will start using the new one. Hopefully it is better than the Ukie we have had so far this winter. I was actually thinking about cancelling F5 subscription since I only use it for the UKMET precip. maps and it hasn't had a hot hand very often if at all this winter.

[PowellVolz]

Just a heads up.  Most now know the GFSv16 hasn't updated since 6z yesterday. Looks like they don't yet know when this will resolve.
(02 Feb 2021) GFSv16 and HRW FV3 data have been unavailable since 12z due to NCEP data flow problems. We are not aware of an ETA from NCEP.
 

Does this effect other mods?


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