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nj2va

January Medium/Long Range Discussion

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9 minutes ago, nj2va said:

I’m ignoring 500 maps at 384 on the ensembles. It’s all about MJO and SOI at this point. 

I was considering suggesting this as well, but since I don't actually provide useful analysis and since I am not even in my home forum I refrained from trying to boss everyone around.

But from various sources it seems probable that the mjo is in the driver seat right now.  Don Sutherland seems to think that the SOI is critical now as well, and he is one of the posters that I trust the most.

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Comparing 18z to 6z....I've never seen a model change so much so close to an event. What gatbage

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1 minute ago, Ji said:

Gfs is a close call but heartbreaker

What's your take on the gefs look day 15?   Our problem lately has been the mjo forcing a trough off the west coast blasting Pacific air across. The long range backs that off into what should be a good longwave configuration (Aleutians trough epo ridge typically a cold look) but it's still a blowtorch across the US. 

 

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What's your take on the gefs look day 15?   Our problem lately has been the mjo forcing a trough off the west coast blasting Pacific air across. The long range backs that off into what should be a good longwave configuration (Aleutians trough epo ridge typically a cold look) but it's still a blowtorch across the US. 
 
I think its wrong in terms of real temps. In fact the anomalies look near normal at day 15. Which is okay for mid jan. I thought eps improved

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Lol yea right. It's trending towards all the other guidance. Will be 40 and rain here too by tomorrow night. 
This isn't the worse look for a storm...f162eb6a8397ec8d635ea941a1722f7a.jpg
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****See that we have a new thread so I thought I would repost this****

Have seen enough on the overnight runs to keep me somewhat interested in the Jan 3rd threat. Still very much in the air how this system and the 500's will evolve though as both models go about it in their own way.

I am sure most have seen the GEFS which leaves energy behind at 500's giving us a strongly positive tilted trough with a weak shortwave running through the region. The 500's have improved somewhat as they allow the low and moisture to progress farther north then the more suppressed solutions we were seeing on early runs. The one positive with going this route is we don't see the positive height builds and a stronger push of warm air northward as the system runs to our south. As depicted now we are talking an extremely marginal setup though as there is just not much cold to work with initially and no mechanism to really pull in or create cold. Unless the GFS is off a good deal on the temps this is probably a fail for the cities. Even think the favored areas N and W of the cities would struggle greatly to even see a little bit of snow. But we have seen improvements so you never know.

gefsday5.gif.feb21528a89a9f551486398c0364eead.gif

 

EPS on the other hand has moved to a more amplified trough and we are seeing a closed low. The negative with this evolution is that we are seeing a stronger push north of warm temps that is eroding what little cold we initially had. That said this evolution is probably more favorable for our snowfall chances when all is said and done. What this evolution does is gives us the ability to possibly bring in/create the cold needed before the moisture departs (flip to snow).  

epsday5.gif.897c0d307cc126bfdd7856c76e384554.gif

 

Below we see the 850's. What we have is a pocket of colder air in the lower Mississippi Valley moving northeastward. Though not overly cold they are sufficient and there is even colder air above heading up to 700 mb's. Now you may wonder how this helps us if the system is already moving through our region. Well depending on the trough configuration and the upper closed low running behind the surface low we can quite often see the upper levels influencing the surface where it can slow down, stall or even retrograde a low. And we are seeing this occur to a certain degree at this point. Now the trough (above) has a positive tilt which mitigates this influence somewhat so we are still seeing the low escape before the upper levels can catch up to it. BUT... get that trough to at least a neutral tilt, even better a negative tilt, and chances are decent that we see the upper levels catch up to the surface somewhere in our region for a possible capture. What we then would see is the surface to 500's attempting to stack and the low intensifying. With the cold now overhead all we need are the rates to draw this cold down and with an intensifying low chances are good we would see that.

 

epsday850temps.gif.a1cabc53dd4ff01d5ef7d4be5d35f6c6.gif

 

Now I am not sure how many realize it but the Euro op run was very close. Great pass with the 500s to our south with the closed low just opening up at that point. The problem we had was that the trough stayed positively tilted just a touch too long so we didn't see the 500s catch up with the surface until just to our NE off the Jersey coast where the low begins to bomb. Trough goes negative tilt just a touch quicker and that low is bombing and stalling somewhere over our general region. Then we are talking rain possibly flipping over to a potentially heavy wet snow.

Now if I had to rate which evolution I prefer (GFS vs. Euro) I would take the Euro hands down. Think the odds are better with potentially much more upside then the GFS. That said, 5 days away and much can change so it will be interesting to follow.

eta: Nothing earth shattering but we did see a bump up on the EPS snowfall means for this time. 1/2' through the cities and 1" in the NW burbs. Ens members showing snow has also increased.

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6 minutes ago, Ralph Wiggum said:

Holding out hope but we've seen similar looks at 5 days fizzle quite a few times in the past 5 weeks so maybe *maybe* this will change and will be part 1 of the step up towards mid January. Any change in the trends/recent patterns would be a plus. Keeping hope alive!

With the east based -NAO and the 50/50 in place this more amplified solution makes more sense. Doesn't mean it's right, just that it makes more sense. Think if we are going to score here we need this evolution. Think the weak GFS solution is doomed to be a fail no matter how it goes about it.

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We have seen a marked improvement with the GEFS for our Jan 3 rd system. Moved strongly towards the EPS with showing more amplification of the trough. Snowfall means have responded with a decent increase through this time period. 

overnight

00zgefssnowfall.thumb.gif.d87c58eb1392612df0ccc65edb3afb39.gif

 

morning

06zgefssnow.thumb.gif.5b43eed5a7c27ad632405625e2575ad8.gif

 

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Most of what you see posted are 500's when we are discussing what to expect as far as patterns and potential. But sometimes it gets hazy between the EPS and the GEFS because there can be a fine line between what is good or bad. So I thought I would throw up something a little different to give you a clearer view. Now there for awhile (few days ago) I thought the EPS was throwing up some very good looks while I wasn't particularly enamored with the GEFS. That has done a complete 180 where I actually like the GEFS much more then what the EPS implies for the longer range. To see why, I am going up to the 200-300 mb level where the jet streams flow which I think gives you a much clearer understanding of the differences then what the 500s show..

Below we have the EPS. Two features really stick out to me. First the strong undisturbed jet that circles 4/5 ths of the Globe from Africa to the west coast. For being 15 days out where you would expect smoothing to occur (fuzzy and hazy features) this is actually very sharp in detail. It implies many/most of the members agree with this depiction of the jet that is basically an uninterrupted fire house of PAC air into the CONUS. The other feature is the pv over the pole which is circled. Notice how round and consolidated it is where the cold air is allowed to pool. Now look within that circle. Do you see any intrusions of a jet whatsoever? There are none, not even a hint of one. What this setup basically means is that we have the cold air locked in the polar regions by the mid-Latitude jet with no mechanism to drive any of that cold south. Now to give you an idea what I mean by a mechanism to drive the cold south look in the gulf states where we see the Sothern Stream bumping northward. Where this meets with the mid-latitude jet we are seeing some ridging develop south and east of Greenland. In response we are seeing the pv bulge slightly into NE Canada. Now this is a very weak feature that does little to disturb the pv let alone allow cold to move southward into the US. This isn't really what we want to see.

epsjet.gif.81e3122c5c8ee4ab84425657d4a1c7d4.gif

 

Now compare the above to what the GEFS has. Notice the difference we are seeing with the jet? Still showing a strong jet from the western Pacific to around Hawaii with that feature being sharp and distinct which implies good agreement between the members. And yet look at the rest of the jet circling the globe. Hazy and indistinct which implies no clear consensus within the members. You can just look off the west coast to see how diverse the solutions between members probably are. Now look around the pole to the PV. What stands out is the fact that at least some members see jet intrusions into the pv. One over-top the EPO ridge in Alaska and one over-top the ridging into Greenland. Both favored spots for our region and its snow chances. And in response we are seeing the pv bulge much farther south into Canada as the flow buckles. This look has much more potential then the EPS as it not only enables cold air to be driven south but it is also drives it in a favorable location for the NE and Mid-Atlantic.

 

gefsjet.gif.289879979f6a811abe788f5f0ef40abe.gif

 

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The whole eps thing.....I dont get. What's the purpose of the ssw and PV split? I thought that would prevent eps is showing lol

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6 minutes ago, Ji said:

The whole eps thing.....I dont get. What's the purpose of the ssw and PV split? I thought that would prevent eps is showing lol

Not all ssws and splits are created equal. Some are beneficial while others aren't. In some cases what we see occur within the strat pv doesn't propagate down into the troposphere pv to impact it. I think that is probably what we are seeing occur with the EPS by how it is responding. Doesn't mean it is right, especially when we see the GEFS response, just that at this current time the EPS seems to favor no impact. The fact that the GEFS is muddied in this regards suggests that the EPS solution isn't quite the done deal it suggests, especially when you consider the models have a hard time resolving the top down evolution of SSW and splits.

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3 minutes ago, nj2va said:

Today’s daily SOI is +6.64 down from the previous two days of +18.27 and +15.98.  30 day average is +9.46.  

Hopefully that is a trend! If we can reverse that SOI into sustained negative territory, the rest including the MJO and AO should follow not far behind in response. Many of the old-time pros have hinted at this scenario and suggest this may be the catalyst to finally get things moving along as we approach mid month. Very rarely during a Nino will a positive Dec SOI anomaly (common) remain positive into January and iirc this year has been near, if not a record level SOI anomaly for December. ENSO history suggest the reversal will happen so this is decent news. Thanks for posting.

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Hopefully that is a trend! If we can reverse that SOI into sustained negative territory, the rest including the MJO and AO should follow not far behind in response. Many of the old-time pros have hinted at this scenario and suggest this may be the catalyst to finally get things moving along as we approach mid month. Very rarely during a Nino will a positive Dec SOI anomaly (common) remain positive into January and iirc this year has been near, if not a record level SOI anomaly for December. ENSO history suggest the reversal will happen so this is decent news. Thanks for posting.
It's not....it was around 1 or 0 a few days ago

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9 minutes ago, Ralph Wiggum said:

Hopefully that is a trend! If we can reverse that SOI into sustained negative territory, the rest including the MJO and AO should follow not far behind in response. Many of the old-time pros have hinted at this scenario and suggest this may be the catalyst to finally get things moving along as we approach mid month. Very rarely during a Nino will a positive Dec SOI anomaly (common) remain positive into January and iirc this year has been near, if not a record level SOI anomaly for December. ENSO history suggest the reversal will happen so this is decent news. Thanks for posting.

Well a few days ago it fluctuated between slightly negative to positive single digits and then spiked the last few days so don’t think its a trend. At least its not continuing to increase I guess.  But yeah, in the past Nino years when we had a historically + SOI in December, it turned negative for January.  History is on our side at least...

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15 minutes ago, Ralph Wiggum said:

Hopefully that is a trend! If we can reverse that SOI into sustained negative territory, the rest including the MJO and AO should follow not far behind in response. Many of the old-time pros have hinted at this scenario and suggest this may be the catalyst to finally get things moving along as we approach mid month. Very rarely during a Nino will a positive Dec SOI anomaly (common) remain positive into January and iirc this year has been near, if not a record level SOI anomaly for December. ENSO history suggest the reversal will happen so this is decent news. Thanks for posting.

Apparently there is a correlation with strong phases 3-6 in a nino and soi spikes. There is also a correlation with the soi dropping once the mjo gets to 7/8/1.

Wish I could remember where I read that. Been doing so much research and scanning of experts in this stuff lately I can't remember where I saw what. 

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Apparently there is a correlation with strong phases 3-6 in a nino and soi spikes. There is also a correlation with the soi dropping once the mjo gets to 7/8/1.
Wish I could remember where I read that. Been doing so much research and scanning of experts in this stuff lately I can't remember where I saw what. 
Probably the soi obsessed jb

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7 minutes ago, psuhoffman said:

There is also a correlation with the soi dropping once the mjo gets to 7/8/1.

Which would be nice, assuming it ever gets to 7/8/1.

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6 minutes ago, Ji said:
11 minutes ago, psuhoffman said:
Apparently there is a correlation with strong phases 3-6 in a nino and soi spikes. There is also a correlation with the soi dropping once the mjo gets to 7/8/1.
Wish I could remember where I read that. Been doing so much research and scanning of experts in this stuff lately I can't remember where I saw what. 

Probably the soi obsessed jb

It wasn't him actually.  but can't remember who posted it. 

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