January 2020 Mid/Long Term Discussion

[psuhoffman]

23 minutes ago, Bob Chill said:

I'm not sure where we would go from the end of the 12z EPS but there was nice uptick in legit storms between the 18-21st. Another solid run in the books. 

It’s a convoluted look that has to be the result of higher than normal divergence. But there are features to like. The pac ridge relax and pressing into the west coast. Hints of a southern stream. Ridging west of Hudson. Still things not to like, the NAM. My take is the eps is unsure where to go which is better than some other options. 

[CAPE]

2 minutes ago, psuhoffman said:

It’s a convoluted look that has to be the result of higher than normal divergence. But there are features to like. The pac ridge relax and pressing into the west coast. Hints of a southern stream. Ridging west of Hudson. Still things not to like, the NAM. My take is the eps is unsure where to go which is better than some other options. 

The weeklies from yesterday might provide a hint as to where we go going forward. If you haven't taken a peak, it looks familiar.

[Maestrobjwa]

30 minutes ago, WxUSAF said:

Euro holds off the rain for after the Ravens game.  GFS brings it in for the game.  Go Euro!

Lol I've been meaning to ask about what the EURO was saying! (seems the GFS has been waffling a bit...but overall, does it seem like a lighter storm than the driving rain it was advertising a couple days ago?)

[psuhoffman]

16 minutes ago, C.A.P.E. said:

The weeklies from yesterday might provide a hint as to where we go going forward. If you haven't taken a peak, it looks familiar.

I’m trying to be optimistic about the eps. But the danger if the NAM stays super positive and pac ridge relaxes but stays centered too far southwest once a trough pulls back into near AK ( which it would when the pac ridge relaxes) we would just transition to a zonal pac puke pattern. If we want a stable better pattern we either need AO/NAO help or an epo ridge.  Absent either of those were rooting for luck with a perfectly timed transient feature like today. A ridge traverses the pna domain at the exact perfect time but even so it’s got limited potential and some will fail because of the overlying crap pattern. Who knows maybe we keep lucking our way to a decent year in an overall craptastic pattern but I don’t want to have to roll that way if we can avoid it. 

[snowmagnet]

I've been reading Judah Cohen's twitter feed and he seems to be relying on the GFS and predicting the end of winter if it's correct. Hopefully the EURO knows what's up.  

 

[frd]

 

Of note, of course the implications are uncertain, but some changes are most likely going to happen., maybe a reshuffle up top and a weakening to a degree.  

Hugo suggesting the GFS versus the GEFS is more believable. We know that the GEFS does have a bias, so maybe this time the GFS has a clue. 

Look at the date on the image below , Jan 23 rd,  and then check out the post form HM further down......, funny things seem to happen near the 20th  

 

 

 

 

 

[psuhoffman]

2 minutes ago, snowmagnet said:

I've been reading Judah Cohen's twitter feed and he seems to be relying on the GFS and predicting the end of winter if it's correct. Hopefully the EURO knows what's up.  

 

End?

[Ralph Wiggum]

1 minute ago, psuhoffman said:

End?

Also referred to around these parts as "winter cancel". Let them jump ship....this isnt over yet.

[frd]

5 minutes ago, snowmagnet said:

I've been reading Judah Cohen's twitter feed and he seems to be relying on the GFS and predicting the end of winter if it's correct. Hopefully the EURO knows what's up.  

 

Judah is silly...........

One minute winter is coming .... then it is over .... no its back.............I have heard this before from .............hmmmm.......... DT ........LOL  he cancelled and then un-cancelled and then cancelled the un-cancelled.......  Sorry got distracted back to topic . Webb thinks otherwise. Here you go - 

 

 

 

 

 

 

 

[WxUSAF]

GFS op wanted nothing to do with the GEFS in early-mid December when it was trying to advertise Strat PV disruption.  Interesting that it's now hinting at a Strat PV split later this month.  

[snowmagnet]

1 minute ago, frd said:

Judah is silly...........

One minute winter is coming .... then it is over .... no its back.............I have heard this before from .............hmmmm.......... DT ........LOL  he cancelled and then un-cancelled and then cancelled the un-cancelled.......  Sorry got distracted back to topic . Webb thinks otherwise. Here you go - 

 

 

 

Thank you!  I missed this tweet by Webb as I was distracted by our winter weather today!  I trust this forum for my weather information anyway, but I found his tweet a bit concerning earlier today.  I would never believe winter was "over" in January anyway!

 

 

[osfan24]

Judah cancelling winter might mean winter is about to start LOL.

[frd]

It raining here so thinking about the future.  

Great Update from @donsutherland1  courtesy 33andrain 

I really thought the part about the EPS  was an eye opener.  I am hopeful though that the pv weakens later in Jan and Feb. But, I am still unsure whether we see sustained and significant weakening or whether any weakening is simply based on passing peak strength pv climatology. 

Here it is :

< 

Some quick thoughts on the long-range pattern evolution...

1. The GEFS remains stuck with essentially the western trough-eastern ridge pattern.

2. The EPS appears to have accelerated the onset of a colder pattern.

Both ideas are actually problematic.

First, the base case from historical data is that the MJO will likely progress  into Phases 7 and 8 in the extended range. The GEFS idea seems not to reflect that development. The shift in the MJO, even with lags, should start manifesting itself in some hemispheric changes.

Second, in past cases where strong AO+/PNA- regimes rapidly collapsed, the period of troughing in the East was often short-lived (late January 2000 followed by February 2000 provide an illustration). Also worrisome is that strong polar vortex that is shown on the extended range of the EPS. There would be a risk that its persistence would lead to a scenario where above normal 500 mb heights are elongated and eventually stretch across the CONUS with the coldest air being bottled up mainly in Canada (with only some transient shots).

Overall, I still think a slower pattern evolution still makes more sense, especially if the MJO progresses as typically is the case following very high amplitude passage through Phase 4 during the January 5-20 period. Colder shots would be transient until perhaps the closing week of January and then more sustained cold could develop. Interestingly enough, some of the recent CFSv2 weekly forecasts show such a situation.

 

>

[CAPE]

1 hour ago, psuhoffman said:

End?

Judah never predicts winter will end.

He is busy figuring out another creative way to take credit in case things do flip, despite his theory failing yet again.

[Maestrobjwa]

25 minutes ago, frd said:

Second, in past cases where strong AO+/PNA- regimes rapidly collapsed, the period of troughing in the East was often short-lived (late January 2000 followed by February 2000 provide an illustration). Also worrisome is that strong polar vortex that is shown on the extended range of the EPS. There would be a risk that its persistence would lead to a scenario where above normal 500 mb heights are elongated and eventually stretch across the CONUS with the coldest air being bottled up mainly in Canada (with only some transient shots).

Hey...I'd rather transient cold shots be the worst case scenario than a pac flood, lol (and btw...we still managed a pretty good storm at the end of January 2000...so there's that! ) Hey @psuhoffman Ya got one of those maps for that month?

[pasnownut]

Just now, Maestrobjwa said:

Hey...I'd rather transient cold shots be the worst case scenario than a pac flood, lol (and btw...we still managed a pretty good storm at the end of January 2000...so there's that! ) Hey @psuhoffman Ya got one of those maps for that month?

Agreed.  Lobes of cold running to the north with well timed vorts to the south can lead to multiple events like today.  Pac flood if the ridge rolls over would suck arse.  tts not a sustained cold pattern but one that give chances for snow.  In a year like this, thats better than nothing.

[frd]

8 minutes ago, pasnownut said:

Agreed.  Lobes of cold running to the north with well timed vorts to the south can lead to multiple events like today.  Pac flood if the ridge rolls over would suck arse.  tts not a sustained cold pattern but one that give chances for snow.  In a year like this, thats better than nothing.

I hardly ever look at the Euro Control but way out in fantasy lands it develops a West based NAO / Davis Straights block. Not sure the mechanism to how it achieved this, possibly the Scand retro and or wave breaking etc. Anyway, Webb mentioned this possibility today, ironic it shows up on the Control, and we know what a well timed and placed West based NAO block can do via some of the recent updates psu posted about ( re how the Atlantic can help us when we have a crap Pacific )    

[Bob Chill]

12 minutes ago, frd said:

I hardly ever look at the Euro Control but way out in fantasy lands it develops a West based NAO / Davis Straights block. Not sure the mechanism to how it achieved this, possibly the Scand retro and or wave breaking etc. Anyway, Webb mentioned this possibility today, ironic it shows up on the Control, and we know what a well timed and placed West based NAO block can do via some of the recent updates psu posted about ( re how the Atlantic can help us when we have a crap Pacific )    

Back to back powerful north altantic ulls moving through the 50/50 region and create a pretty stout -nao ridge in their wake. Looks like it's a byproduct of the NA weather pattern and not from europe. Sick d15 panel to enjoy for another 6 hours or so

[Bob Chill]

Even with the large upper level differences between the EPS and GEFS the 18z GEFS is pretty busy d10-15. Majority of members drop frozen and a handful are pretty good. The 18-21st window keeps looking better. We have 10 days of deadspace to get through first so patience pills will be needed

[frd]

As a follow up to the previous post from Matt Hugo re the GFS and the PV

Simon points out the CFS also has the same time period ( Jan 17 to the 22 rd ) with a decrease as well, but afterwards while the GFS continues the downtrend the CFS rebounds.

I could speculate that what happens during this time frame, and shortly thereafter, along with the latest QBO numbers may have a pretty significant impact on what occurs in our weather during February , well at least in regards to the HL and the NAM state.  

 

 

 

[BristowWx]

1 minute ago, Bob Chill said:

Even with the large upper level differences between the EPS and GEFS the 18z GEFS is pretty busy d10-15. Majority of members drop frozen and a handful are pretty good. The 18-21st window keeps looking better. We have 10 days of deadspace to get through first so patience pills will be needed

I’m like a lion that ate a gazelle after this full day of snow and 3 inches.  I can wait for sure. 

[frd]

1 hour ago, Bob Chill said:

Back to back powerful north altantic ulls moving through the 50/50 region and create a pretty stout -nao ridge in their wake. Looks like it's a byproduct of the NA weather pattern and not from europe. Sick d15 panel to enjoy for another 6 hours or so

Given previous powerful and even record breaking North Atlantic storms, the past several months, this is not really that far fetched an idea/outcome.

This is also around the noted time period of Jan 17 to 22 nd. 

[frd]

Don't forget we may even get some help from the high amp MJO to encourage HL influence, as Matt mentions here, and also as mentioned previously last week by Don S and Bluewave .   

 

[Wonderdog]

9 minutes ago, BristowWx said:

I’m like a lion that ate a gazelle after this full day of snow and 3 inches.  I can wait for sure. 

Lol. I got close to 3 inches so I broke out the toy. It was glorious. 

[BristowWx]

12 minutes ago, Wonderdog said:

Lol. I got close to 3 inches so I broke out the toy. It was glorious. 

Ha Now it’s winter.  Never expected to shovel today.  Best part winter is just starting.  Rest up next 10 days.  We will be back in the mode soon enough.  

[Bob Chill]

12 minutes ago, BristowWx said:

Ha Now it’s winter.  Never expected to shovel today.  Best part winter is just starting.  Rest up next 10 days.  We will be back in the mode soon enough.  

Appears ens guidance is moving towards the idea that we may get another event inside of 2 weeks. Gefs has looked like utter crap for the 18th-22nd until 18z today. Long leads are always muddy and scattered witn discrete events so I don't focus on any single solution. I like using the meteos for activity in general. For d10-15 this is pretty busy. Epsecially considering how lame the previous 4 runs have been.

 

I would feel more confident if the gefs and eps looked more similar in the upper levels. Maybe we see the gap close within a couple days. EPS has had 3 good/steady runs in a row. Get another 3-4 that stay busy with the same general pattern and it's prob going to be right. 

I'm not hyping the period at all as it can go poof in an instant so I'm just looking fpr consistently at this stage. So far I like most of what I'm seeing for another chance this month with the caveat being the prog'd upper level pattern is decent but not great and not a big storm look.

[Ji]

I think we need to forget about pattern change and just hunt for windows. This winter is heading towards abysmal

[Bob Chill]

7 minutes ago, Ji said:

I think we need to forget about pattern change and just hunt for windows. This winter is heading towards abysmal

It's been that way since thanksgiving. Windows opening and closing. Today wasn't even much of a window but worked out anyways. Would be nice if our next event is all snow with cold surface to start

[BristowWx]

3 minutes ago, Bob Chill said:

It's been that way since thanksgiving. Windows opening and closing. Today wasn't even much of a window but worked out anyways. Would be nice if our next event is all snow with cold surface to start

That seems harder and harder to come by. Cold start all snow cold finish that we track for more than couple days. It’s so hard to get all those ingredients in the bowl with any consistency.  Last time was Jan 16 maybe.  Seems nearly impossible. 

[psuhoffman]

3 hours ago, frd said:

It raining here so thinking about the future.  

Great Update from @donsutherland1  courtesy 33andrain 

I really thought the part about the EPS  was an eye opener.  I am hopeful though that the pv weakens later in Jan and Feb. But, I am still unsure whether we see sustained and significant weakening or whether any weakening is simply based on passing peak strength pv climatology. 

Here it is :

< 

Some quick thoughts on the long-range pattern evolution...

1. The GEFS remains stuck with essentially the western trough-eastern ridge pattern.

2. The EPS appears to have accelerated the onset of a colder pattern.

Both ideas are actually problematic.

First, the base case from historical data is that the MJO will likely progress  into Phases 7 and 8 in the extended range. The GEFS idea seems not to reflect that development. The shift in the MJO, even with lags, should start manifesting itself in some hemispheric changes.

Second, in past cases where strong AO+/PNA- regimes rapidly collapsed, the period of troughing in the East was often short-lived (late January 2000 followed by February 2000 provide an illustration). Also worrisome is that strong polar vortex that is shown on the extended range of the EPS. There would be a risk that its persistence would lead to a scenario where above normal 500 mb heights are elongated and eventually stretch across the CONUS with the coldest air being bottled up mainly in Canada (with only some transient shots).

Overall, I still think a slower pattern evolution still makes more sense, especially if the MJO progresses as typically is the case following very high amplitude passage through Phase 4 during the January 5-20 period. Colder shots would be transient until perhaps the closing week of January and then more sustained cold could develop. Interestingly enough, some of the recent CFSv2 weekly forecasts show such a situation.

 

>

That’s pretty much what I was saying my fear wrt where the eps look could evolve if we don’t get epo help with a strong +AO but it doesn’t have to go that way. But I would feel better if we got some indication forcing would change in the pac.