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00z/18th Ensemble Comparison 11/18-12/3.  Avg 850mb temp +1C.  

GEFS:  (same) Below normal 850mb temp anomalies into Nov 19th, (same) above normal anomalies Nov 19th into Nov 23rd, (same) below normal anomalies Nov 24th, above normal anomalies Nov 25th thru Nov 28th, (colder) below normal anomalies Nov 29th thru Dec 1st and above normal anomalies on last two days Dec 2nd & 3rd. 

GEPS:  (same) Below normal 850mb temp anomalies into Nov 19th, above normal anomalies Nov 19th into Nov 23rd, (colder) below normal anomalies Nov 24th into Nov 26th, above normal anomalies Nov 26th-27th, (colder) near normal anomalies Nov 28th & 29th, above normal anomalies Nov 30th thru end of run Dec 3rd.

EPS:  (same) Below normal 850mb temp anomalies into Nov 19th, (same) above normal anomalies Nov 19th into Nov 23rd, (same) then above normal anomalies on Nov 19th into Nov 23rd, (day longer) below normal anomalies night of Nov 23rd into Nov 25th, back to above normal anomalies Nov 26th into Nov 28th, (new, colder) below normal anomalies Nov 29th into Dec 1st, above normal anomalies on last day Dec 2nd.

NAEFS Week 2: Week of November 26th-December 3rd. Trending toward confidence in near normal temperatures (from previous above in earlier days).

 

Day 8 Teleconnections:           EPS:     +EPO/  -PNA/ +NAO

                                                  GEFS:   +EPO/  -PNA/ +NAO

                                                  GEPS:   +EPO/  -PNA/ +NAO

 

End of run Teleconnections:    EPS:     +EPO/  neutral PNA/  neutral NAO

                                                          GEFS:   +EPO/  -PNA/  +NAO

                                                  GEPS:   +EPO/  neutral PNA/ neutral NAO

 

MJO:  (WH Sectors) Trend was too slow! Currently Phase 2.  MJO outlook to reach Phase 6 at end of forecast period (12/1-12/2) on GEFS, EPS does a total COD collapse. MVentrice weak phase 4 at start of December.  

MJO phases in November 2 cold, 3 & 4 warm, 5 cold

MJO phases in December.  3 thru 6 warm, 7 thru 1 cold, 2 transitional.

Strat: NASA slightly below average Wave 1 hit, increasing but still at 30th percentile at end wave 2 activity. NASA owned the EC with this one.  Might have been related to that one cold run its EPS had mid month.

NAM/SPV: See the trop cold shot Thanksgiving week, otherwise SPV outlooked to increase in strength. 

 

Tom's expression about islands of cold among an ocean of warmth continues.  The trend for cold shots (albeit still islands) to appear and then be longer and colder continue. Not surprising. This works both ways, sustained cold, sustained warmth are rarities.  A little more jumbled about the MJO, but they are heading for warmer in December phases regardless.  Have to watch how this progresses beyond the time period of this outlook for colder phases. 

 

00z/15th Ensemble Comparison 11/15-11/30.  Normal 850mb temp +1C.

 GEFS:  Arriving today below normal 850mb temp anomalies (same) into Nov 19th, (day longer) above normal anomalies Nov 19th into Nov 23rd, below normal anomalies Nov 24th and above normal anomalies Nov 25th thru the end of its run on Nov 30th.

GEPS:  (day longer) Arriving Below normal 850mb temp anomalies into Nov 19th, above normal anomalies Nov 19th thru end of run Nov 30th.  (new) There is a 24hr period of near normal anomalies around night of November 23rd. 

EPS:  (continued) Below normal 850mb temp anomalies into Nov 19th, (same) then above normal anomalies on Nov 19th into Nov 23rd, below normal night of 23rd & 24th and then back to above normal Nov 25th thru end of run on Nov 29th.

 

 

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Can see it here better, see the angle of the cold as the flow is over the ridge  

Heisy probably hacked into that one

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So here is the eps day 15 map, ugly ugly. I mean if this comes true it would not be good as you can see the zonal flow ripping across Canada and the US.  Lets imply the thought I stated this morning that at large lead times ens mean will over smooth troughs and ridges due to disagreement amongst members. So lets say we get more of a look that I drew once we get closer in time. The trough around AK is not as broad and is a bit further west. This then gives room for ridging to build a long the west coast and would then put a trough into the eastern US. 

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png

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2 hours ago, tombo82685 said:

So here is the eps day 15 map, ugly ugly. I mean if this comes true it would not be good as you can see the zonal flow ripping across Canada and the US.  Lets imply the thought I stated this morning that at large lead times ens mean will over smooth troughs and ridges due to disagreement amongst members. So lets say we get more of a look that I drew once we get closer in time. The trough around AK is not as broad and is a bit further west. This then gives room for ridging to build a long the west coast and would then put a trough into the eastern US. 

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png

Such an odd look, I can't imagine it ends up like that, your instinct seems sound to me. 

GEFS have been hinting at that setup last few runs.  I sense some sort of larger scale change, and I agree that may argue for more west coast ridging as the mean trough trickles west towards the Aleutians. 

Still, ugly is ugly, the question is what's around the corner thereafter as we venture into the dawn of met winter 

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8 hours ago, susqushawn said:

Such an odd look, I can't imagine it ends up like that, your instinct seems sound to me. 

GEFS have been hinting at that setup last few runs.  I sense some sort of larger scale change, and I agree that may argue for more west coast ridging as the mean trough trickles west towards the Aleutians. 

Still, ugly is ugly, the question is what's around the corner thereafter as we venture into the dawn of met winter 

We will have to see, but as far as the next 15 days no help from the pv, as it continues to strengthen, approaching record levels. Unless we get a shifting around of the h5 features as I was stating last night it will continue to be seas of warmth with islands of chill

 

u_60N_10hpa.png

gefs_extended_u1060_timeseries.png

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15 minutes ago, tombo82685 said:

We will have to see, but as far as the next 15 days no help from the pv, as it continues to strengthen, approaching record levels. Unless we get a shifting around of the h5 features as I was stating last night it will continue to be seas of warmth with islands of chill

 

u_60N_10hpa.png

gefs_extended_u1060_timeseries.png

Yikes....exactly like last year 

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1 hour ago, tombo82685 said:

We will have to see, but as far as the next 15 days no help from the pv, as it continues to strengthen, approaching record levels. Unless we get a shifting around of the h5 features as I was stating last night it will continue to be seas of warmth with islands of chill

gefs_extended_u1060_timeseries.png

LOL, bad though this is, it is a slight improvement, with the mean starting to dip at the end and one easterly.  Could be the first GEFS easterly all year.

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15 hours ago, tombo82685 said:

So here is the eps day 15 map, ugly ugly. I mean if this comes true it would not be good as you can see the zonal flow ripping across Canada and the US.  Lets imply the thought I stated this morning that at large lead times ens mean will over smooth troughs and ridges due to disagreement amongst members. So lets say we get more of a look that I drew once we get closer in time. The trough around AK is not as broad and is a bit further west. This then gives room for ridging to build a long the west coast and would then put a trough into the eastern US. 

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png

This is what I'm talking about with the gefs. Now this will probably change since we are at day 15 here, but since we aren't going to get any help from the pv we need to see the broad scale h5 features shift. Can see the difference from 0z to 6z with the trough placement up by Alaska. 6z further west into the Aleutians and downstream that helps pop a +pna and you start getting some meridonal flow instead of zonal Chinook across the country 

 

gfs-ensemble-all-avg-namer-z500_anom-71048001.gif

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As I have been saying over the last couple days with my posts about ens over smoothing things. Till this trough gets out of AK to the Aleutians, which will then help pump a +PNA ridge, it's pretty much game over for snow threats and sustained cold outside of some transient piece of crap. If we time something absolutely perfect with that cold shot then maybe a chance of wintry precip. IMO, that chance is less than 15%. You can see with the current map with the hgts lines, it's just a pac pukefest just ripping into Canada and the US. Whatever cold that does come south out of Canada is pure blah and going over bare ground for it to modify. If we can pop a pns ridge and shift the trough to the Aleutians it will start to draw colder air into Canada and then we can start looking potentially. 

 

ecmwf-ensemble-avg-namer-z500_anom-7083200.png

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15 minutes ago, tombo82685 said:

As I have been saying over the last couple days with my posts about ens over smoothing things. Till this trough gets out of AK to the Aleutians, which will then help pump a +PNA ridge, it's pretty much game over for snow threats and sustained cold outside of some transient piece of crap. If we time something absolutely perfect with that cold shot then maybe a chance of wintry precip. IMO, that chance is less than 15%. You can see with the current map with the hgts lines, it's just a pac pukefest just ripping into Canada and the US. Whatever cold that does come south out of Canada is pure blah and going over bare ground for it to modify. If we can pop a pns ridge and shift the trough to the Aleutians it will start to draw colder air into Canada and then we can start looking potentially. 

 

ecmwf-ensemble-avg-namer-z500_anom-7083200.png

So here is a good illustration of what you need. The cfs on weatherbell runs 4 times a day, this was the 12z run, this will most definitely change, but shows what you need. Trough over Alaska moves to Aleutians, this in turn pumps the pna ridge that dumps a big trough into the east. To top it off, it also has a WNAO, thats a snowstorm pattern in the making there on that look

cfs-daily-all-avg-namer-z500_anom_7day-7817600.png.eb5ca9046bc110effb8d47639620e1f4.png

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51 minutes ago, tombo82685 said:

Another illustration from end of gefs run on what we need to happen. Cold air is still an issue but it would get a better airmass south. 

A82348B5-1E0A-4802-9B1A-F7658557A156.png

Appreciate the updates. I'm trying to get more enthused in following the long range, but enjoy the few here that post the goods. Too much flux for me day in and day out in the long range.

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0z gefs continue to move towards what I have been saying over the last couple days for what we need and what to look for on ens oversmoothing things. Looks like there may be a possible window for something to start December as long as the pna comes about. Can see here on 0z gefs, trough by AK has moved to the Aleutians, which pumps the pna ridge and drops the trough in the east. Still have to see how much cold can pour south but I would imagine with a decent meridonal flow you would gets some cold starting to invade eastern Canada. 

gfs-ensemble-all-avg-namer-z500_anom-6888800.png

gfs-ensemble-all-avg-namer-z500_anom-7104800.png

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On 11/18/2020 at 6:44 PM, tombo82685 said:

So here is the eps day 15 map, ugly ugly. I mean if this comes true it would not be good as you can see the zonal flow ripping across Canada and the US.  Lets imply the thought I stated this morning that at large lead times ens mean will over smooth troughs and ridges due to disagreement amongst members. So lets say we get more of a look that I drew once we get closer in time. The trough around AK is not as broad and is a bit further west. This then gives room for ridging to build a long the west coast and would then put a trough into the eastern US. 

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png

Off the eps, but like I've been saying as we get closer and we get more agreement amongst ens members things tighten up. See all those negatives in western Canada, gone now. Much more pacific ridging. Wouldn't shock me that we continue to see the ridging build along the west coast

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png.2e02fc9eaccc1e9beebb4af1884cbe6a.png

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1 minute ago, tombo82685 said:

Off the eps, but like I've been saying as we get closer and we get more agreement amongst ens members things tighten up. See all those negatives in western Canada, gone now. Much more pacific ridging. Wouldn't shock me that we continue to see the ridging build along the west coast

ecmwf-ensemble-avg-nhemi-z500_anom-6996800.png.2e02fc9eaccc1e9beebb4af1884cbe6a.png

Where is the mjo going? P7? 

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1 minute ago, tombo82685 said:

Notice the persistence of the ridge on the west coast and then how the blues start fading in AK, hopefully that is legit 

ecmwf-ensemble-avg-namer-z500_anom-1605830400-1606694400-1607126400-10.gif

Not that the end of the eps was some amazing pattern but one thing has been the trend so far this month. We have consistently seen a awful looking pattern in the 11-15 day ens only to Kick the can on it as we got closer

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2 hours ago, Allsnow said:

Where is the mjo going? P7? 

Looks like COD, very weak forcing. Main forcing in phases 1-5, with a bit in 8

chi200.cfs.eqtr.png

RMM plots are all COD, gefs look like they want to turn it towards the golden phases while euro is just stuck in COD

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