Come on RC, that's Dec 8th!
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Pattern Dazzling December
- Thread starter Rain Cold
- Start date
jeremyt
Member
So it’s not okay to live and die by each individual run? ?
I know man. That's my point. It's December 3rd. The models are awful. There's way too much worrying for December 3rd. This is middle of January level worrying, and we're barely 2 toes down in December.
Brick Tamland
Member
Happens every winter.
severestorm
Member
JMA might have something! modernweenie
L
Logan Is An Idiot 02
Guest
JMA might have something! modernweenie
What is the JMA?
Sent from my iPhone using Tapatalk
jeremyt
Member
You serious Clark? If so it the Japanese model! Japan Meteorological Agency!
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NCSNOW
Member
- Joined
- Dec 2, 2016
- Messages
- 9,572
- Reaction score
- 19,074
I knew you where being sarcastic
Sky86
Member
-1 in Jackson Hole
Balmy here!
jeremyt
Member
Had to move all that way for cold temps but yet still a lack of snow! ?
Drizzle Snizzle
Member
Iowa is known more for its cold than it's snow.
jeremyt
Member
Fair enough, I’ll go to bed tonight like my wife, dreaming of that solid 10+ incher (Carolina Crusher) but realizing that at most I’ll have to settle for 2-3! Oh well.
griteater
Member
Hope yall don't mind, but I wanted to step away from the models for a moment and go thru some thoughts on where we are and where we are headed with tropical forcing.
First off, here is OLR averaged over the last 3 months. This is the ENSO signal (also referred to as the low frequency signal) whereby convection has been anomalously high (-OLR) in the Maritime Continent / Indonesia and anomalously low (+OLR) near and just to the west of the dateline. This is a classic La Nina profile. A mature El Nino would have the exact opposite profile of -OLR near the dateline and +OLR in Indonesia.
Now, superimposed on top of the low frequency ENSO signal is the MJO which travels west to east in the tropics (also referred to as the high frequency signal). One way to track the MJO is by viewing the anomalous Velocity Potential signal (also referred to as CHI200 on this chart below). Velocity Potential / CHI200 is simply an indication of anomalous divergence (-VP / -CHI) or convergence (+VP / +CHI) at the upper levels of the atmosphere (200mb). If there is anomalous divergence in the upper levels of the atmosphere, that is a convection enhancer (upper level divergence fosters rising motion and convection / thunderstorms in the tropics)....and anomalous convergence in the upper levels fosters sinking motion (anomalously low amounts of convection).
We can see on this chart below that the MJO signal for enhanced convection in the tropics for Dec1-2 extends from South America thru the Atlantic Ocean, and thru Africa.
Both the GEFS and EPS move this -VP signal east and maximize it in the Indian Ocean here on Dec 7th
The MJO doesn't have full control of weather patterns of course, but on average, when the convective signal is maxed out in the Indian Ocean in early Dec (-VP in blue in Indian Ocean on image below), this favors a -PNA / +NAO pattern as seen here (of course, we have other processes ongoing that favor a -NAO developing).
The question then becomes, how fast will the convective signal move east to where it is maximized in Indonesia, then the West Pacific, then finally in South America (during La Nina, the convective signal is weak across the central and eastern Pacific, and it will later ignite convection in S America as the signal moves east). As E Webb pointed out, there has been some level of delay shown on the modeling with the propagation of the MJO east out of the Indian Ocean, but based on the repeating MJO cycle we've seen this fall, we should expect to see the signal eventually move east. Once this occurs, the MJO will enhance the background La Nina convective signal (referred to as constructive interference). That constructive interference should have the capability to impart more of an impact to the atmospheric pattern over N America.
On the GEFS (EPS is similar), we can see the convective signal in the eastern Maritime Continent and W Pacific on Dec 16, with the signal shown also extended to S America on Dec 18
Here is the average pattern map for mid-Dec when the convective signal is in the Maritime Continent and W Pacific....-EPO / -NAO
And here are the average pattern maps for late-Dec when the convective signal has move east to S America....-EPO / -NAO to -EPO / +PNA / -NAO
Anthony M highlighted his thoughts on this progression here:
Bottom line: if we can get the MJO convective signal to move out of the Indian Ocean and then constructively interfere with (combine with) the background La Nina convective signal, then move east out of the Maritime Continent, this would favor better prospects for ridging moving closer to the west coast, not to mention a continued signal for a -NAO. The fly in the ointment to watch would be if the -VP MJO signal stalls and somehow just collapses in the Indian Ocean....that would favor a problematic continuation of a heavy -PNA regime. So far this fall, we haven't seen this type of stall in the Indian Ocean....we've actually seen more of the opposite where the convective signal is largely bypassing that region due to a bit cooler waters there this year associated with the -IOD...but we'll have to see how this turns out this round.
Lastly, I wanted to post the most recent Mtn Torque chart which shows a sharp recovery in the previous very low numbers. You can see on the chart how the E Asia Mtn Torque numbers (red line) were lower in Sep, higher in Oct, and lower in Nov. I suspect / hope that the number will rebound higher in Dec. Higher E Asian Mtn Torque helps to extend the Pacific Jet which is needed during La Nina to get the ridging closer to the west coast.
If you've made it this far, you deserve some type of reward or compensation. May tonight's model runs be good ones!
First off, here is OLR averaged over the last 3 months. This is the ENSO signal (also referred to as the low frequency signal) whereby convection has been anomalously high (-OLR) in the Maritime Continent / Indonesia and anomalously low (+OLR) near and just to the west of the dateline. This is a classic La Nina profile. A mature El Nino would have the exact opposite profile of -OLR near the dateline and +OLR in Indonesia.
Now, superimposed on top of the low frequency ENSO signal is the MJO which travels west to east in the tropics (also referred to as the high frequency signal). One way to track the MJO is by viewing the anomalous Velocity Potential signal (also referred to as CHI200 on this chart below). Velocity Potential / CHI200 is simply an indication of anomalous divergence (-VP / -CHI) or convergence (+VP / +CHI) at the upper levels of the atmosphere (200mb). If there is anomalous divergence in the upper levels of the atmosphere, that is a convection enhancer (upper level divergence fosters rising motion and convection / thunderstorms in the tropics)....and anomalous convergence in the upper levels fosters sinking motion (anomalously low amounts of convection).
We can see on this chart below that the MJO signal for enhanced convection in the tropics for Dec1-2 extends from South America thru the Atlantic Ocean, and thru Africa.
Both the GEFS and EPS move this -VP signal east and maximize it in the Indian Ocean here on Dec 7th
The MJO doesn't have full control of weather patterns of course, but on average, when the convective signal is maxed out in the Indian Ocean in early Dec (-VP in blue in Indian Ocean on image below), this favors a -PNA / +NAO pattern as seen here (of course, we have other processes ongoing that favor a -NAO developing).
The question then becomes, how fast will the convective signal move east to where it is maximized in Indonesia, then the West Pacific, then finally in South America (during La Nina, the convective signal is weak across the central and eastern Pacific, and it will later ignite convection in S America as the signal moves east). As E Webb pointed out, there has been some level of delay shown on the modeling with the propagation of the MJO east out of the Indian Ocean, but based on the repeating MJO cycle we've seen this fall, we should expect to see the signal eventually move east. Once this occurs, the MJO will enhance the background La Nina convective signal (referred to as constructive interference). That constructive interference should have the capability to impart more of an impact to the atmospheric pattern over N America.
On the GEFS (EPS is similar), we can see the convective signal in the eastern Maritime Continent and W Pacific on Dec 16, with the signal shown also extended to S America on Dec 18
Here is the average pattern map for mid-Dec when the convective signal is in the Maritime Continent and W Pacific....-EPO / -NAO
And here are the average pattern maps for late-Dec when the convective signal has move east to S America....-EPO / -NAO to -EPO / +PNA / -NAO
Anthony M highlighted his thoughts on this progression here:
Bottom line: if we can get the MJO convective signal to move out of the Indian Ocean and then constructively interfere with (combine with) the background La Nina convective signal, then move east out of the Maritime Continent, this would favor better prospects for ridging moving closer to the west coast, not to mention a continued signal for a -NAO. The fly in the ointment to watch would be if the -VP MJO signal stalls and somehow just collapses in the Indian Ocean....that would favor a problematic continuation of a heavy -PNA regime. So far this fall, we haven't seen this type of stall in the Indian Ocean....we've actually seen more of the opposite where the convective signal is largely bypassing that region due to a bit cooler waters there this year associated with the -IOD...but we'll have to see how this turns out this round.
Lastly, I wanted to post the most recent Mtn Torque chart which shows a sharp recovery in the previous very low numbers. You can see on the chart how the E Asia Mtn Torque numbers (red line) were lower in Sep, higher in Oct, and lower in Nov. I suspect / hope that the number will rebound higher in Dec. Higher E Asian Mtn Torque helps to extend the Pacific Jet which is needed during La Nina to get the ridging closer to the west coast.
If you've made it this far, you deserve some type of reward or compensation. May tonight's model runs be good ones!
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Excellent post. However, I'm sure all will be lost once again when the GFS shows orange colors over the eastern US in a few minutes. ?Hope yall don't mind, but I wanted to step away from the models for a moment and go thru some thoughts on where we are and where we are headed with tropical forcing.
First off, here is OLR averaged over the last 3 months. This is the ENSO signal (also referred to as the low frequency signal) whereby convection has been anomalously high (-OLR) in the Maritime Continent / Indonesia and anomalously low (+OLR) near and just to the west of the dateline. This is a classic La Nina profile. A mature El Nino would have the exact opposite profile of -OLR near the dateline and +OLR in Indonesia.
Now, superimposed on top of the low frequency ENSO signal is the MJO which travels west to east in the tropics (also referred to as the high frequency signal). One way to track the MJO is by viewing the anomalous Velocity Potential signal (also referred to as CHI200 on this chart below). Velocity Potential / CHI200 is simply an indication of anomalous divergence (-VP / -CHI) or convergence (+VP / +CHI) at the upper levels of the atmosphere (200mb). If there is anomalous divergence in the upper levels of the atmosphere, that is a convection enhancer (upper level divergence fosters rising motion and convection / thunderstorms in the tropics)....and anomalous convergence in the upper levels fosters sinking motion (anomalously low amounts of convection).
We can see on this chart below that the MJO signal for enhanced convection in the tropics for Dec1-2 extends from South America thru the Atlantic Ocean, and thru Africa.
Both the GEFS and EPS move this -VP signal east and maximize it in the Indian Ocean here on Dec 7th
The MJO doesn't have full control of weather patterns of course, but on average, when the convective signal is maxed out in the Indian Ocean in early Dec (-VP in blue in Indian Ocean on image below), this favors a -PNA / +NAO pattern as seen here (of course, we have other processes ongoing that favor a -NAO developing).
The question then becomes, how fast will the convective signal move east to where it is maximized in Indonesia, then the West Pacific, then finally in South America (during La Nina, the convective signal is weak across the central and eastern Pacific, and it will later ignite convection in S America as the signal moves east). As E Webb pointed out, there has been some level of delay shown on the modeling with the propagation of the MJO east out of the Indian Ocean, but based on the repeating MJO cycle we've seen this fall, we should expect to see the signal eventually move east. Once this occurs, the MJO will enhance the background La Nina convective signal (referred to as constructive interference). That constructive interference should have the capability to impart more of an impact to the atmospheric pattern over N America.
On the GEFS (EPS is similar), we can see the convective signal in the eastern Maritime Continent and W Pacific on Dec 16, with the signal shown also extended to S America on Dec 18
Here is the average pattern map for mid-Dec when the convective signal is in the Maritime Continent and W Pacific....-EPO / -NAO
And here are the average pattern maps for late-Dec when the convective signal has move east to S America....-EPO / -NAO to -EPO / +PNA / -NAO
Anthony M highlighted his thoughts on this progression here:
Bottom line: if we can get the MJO convective signal to move out of the Indian Ocean and then constructively interfere with (combine with) the background La Nina convective signal, then move east out of the Maritime Continent, this would favor better prospects for ridging moving closer to the west coast, not to mention a continued signal for a -NAO. The fly in the ointment to watch would be if the -VP MJO signal stalls and somehow just collapses in the Indian Ocean....that would favor a problematic continuation of a heavy -PNA regime. So far this fall, we haven't seen this type of stall in the Indian Ocean....we've actually seen more of the opposite where the convective signal is largely bypassing that region due to a bit cooler waters there this year associated with the -IOD...but we'll have to see how this turns out this round.
Lastly, I wanted to post the most recent Mtn Torque chart which shows a sharp recovery in the previous very low numbers. You can see on the chart how the E Asia Mtn Torque numbers (red line) were lower in Sep, higher in Oct, and lower in Nov. I suspect / hope that the number will rebound higher in Dec. Higher E Asian Mtn Torque helps to extend the Pacific Jet which is needed during La Nina to get the ridging closer to the west coast.
If you've made it this far, you deserve some type of reward or compensation. May tonight's model runs be good ones!
Evolution this GFS run is gonna be much better imo
jeremyt
Member
Would be nice to see some consistencies in the model runs. I know we all can only take what’s given but the ebb and flow of the runs is getting old as usual.
That’s the thing this pattern is known to keep models inconsistent until forcing and things are well mapped out which usually doesn’t happen until and under your 180 .. but it’s okay things will work out and once the forcing grit was talking about becomes more well established and we get further into winter where wave lengths get larger the models should get somewhat more trustworthy than they are right now
The inconsistency is crazy lol. But back to a more euro solution with polar pacific energy getting stuck and amplifying under the block
