Indian Ocean Signal is for Real

[keggwx]

Lets see, where did we leave off....something about retrogression in the North Pacific at the end of November to Dec 1...perma G1 G2 comments from Gibbs.

And, interesting insight from bluewave regarding Aleutian ridge into Dec....

[Sarwx]

quote name='keggwx' timestamp='1289588905' post='2101']

Lets see, where did we leave off....something about retrogression in the North Pacific at the end of November to Dec 1...perma G1 G2 comments from Gibbs.

And, interesting insight from bluewave regarding Aleutian ridge into Dec....

Not for Real!!

[Mallow]

I love being in the path of retrogression.

[keggwx]

Start making hot love to the Euro...

[VAwxman]

Anyone invite Tacodude so this thread will be more active?

[Mallow]

Anyone invite Tacodude so this thread will be more active?

He's here. "tacoman25"

[tacoman25]

Anyone invite Tacodude so this thread will be more active?

Hi

[Yes_Probably_Maybe_No]

For those that haven't paid attention in a while, is anyone willing to do some type of summation regarding this Indian Ocean Signal? I'm assuming that it may have something to do with the MJO heading into phase 7?

[usedtobe]

The MJO is in phase 7 but where it goes from there is a big question mark according to the dynamic models as the Ukmet dives it back into the circle of death back towards phase 5 and the NCEP keeps it moving into phase 8 and barely 1 before it starts diving into the circle of death.

Phase 7 and 8 at this time of year still aren't great for the southeast as the temp anomalies suggest the southeast ridge tries to hold.

Despite the MJO signal on the wheeler diagrams in phase 7, I wonder how much impact it will have. It often is not much of a player in moderate to strong ninas though it was in 2007-2008 so there are no hard and fast rules. What makes me wonder is the OLR signal when you look at the nina and mjo affects combined.

http://cawcr.gov.au/staff/mwheeler/maproom/RMM/hov.sumplot.a.olr.gif

If you click on the link above, you'll note that the convection still has been pretty steady near 120E. Right now that's not bad but later in the season it would give a warm look to much of the u.s. unless help comes from the nao. The day 10 euro from 12Z had a nice negative nao look but still looked warm across much of the middle of the country with the warm looking like it would spread east into the mid atlantic region and southeast at the very least. Of course, the next run probably will look much different as the models continue to have a hard time with the pattern.

[am19psu]

FWIW, Wes, the Euro shows the same think as the UKM.

[JBG]

He's here. "tacoman25"

Not ElTacoman?

[CoastalWx]

Another question I have regarding the physical features that develop at least partially in response to the MJO; What are the thoughts of the features that develop as a result of phase 7 and 8 staying in place if the MJO wave weakens and moves into the circle of death? In other words, with no strong forcing in the ENSO region through the IO, would the features stay in place without any strong forcing to give it the boot? The euro weeklies do suggest the -nao hangs around, along with the Aleutian ridge. It makes sense from a physical perspective anyways.

[usedtobe]

Another question I have regarding the physical features that develop at least partially in response to the MJO; What are the thoughts of the features that develop as a result of phase 7 and 8 staying in place if the MJO wave weakens and moves into the circle of death? In other words, with no strong forcing in the ENSO region through the IO, would the features stay in place without any strong forcing to give it the boot? The euro weeklies do suggest the -nao hangs around, along with the Aleutian ridge. It makes sense from a physical perspective anyways.

That's a good question, I would think eventually the forcing from La Nina would take over. If you look at the OLR signal of the mjo plus nina, the convection stays pretty far west which suggests that we'll circle back towards phase 5. At least that's my guess. Maybe someone like HM2 can provide his thoughts.

[CoastalWx]

That's a good question, I would think eventually the forcing from La Nina would take over. If you look at the OLR signal of the mjo plus nina, the convection stays pretty far west which suggests that we'll circle back towards phase 5. At least that's my guess. Maybe someone like HM2 can provide his thoughts.

Yeah I think eventually the La Nina signal takes over, especially with the chart you posted showing convection hanging around 120E. I just wonder how long this current setup will last, some indications seem like it wants to hang around for a while.

[usedtobe]

Yeah I think eventually the La Nina signal takes over, especially with the chart you posted showing convection hanging around 120E. I just wonder how long this current setup will last, some indications seem like it wants to hang around for a while.

I think it likely it will for awhile and that we do go cold towards the end of the month as the atlantic blocking shifts west a little and forces the heights in the east to fall. THe ANO correlation with Temps in November is pretty weak compared to the correlation with the PNA and temps across the CONUS. However, by winter, the NAO correlation becomes much stronger. The 384 hr GFS is starting to show such a westward shift. It's a 300hr plus GFS forecaast so it might be hoey but that's the kind of transition we'd like to see going into December.

[Mallow]

Did the Indian Ocean foretell this? If so, how?

:wub:

[BlizzardWx]

I'm with Mallow, sweet! I really would be curious though to get some detailed explanation of the forcing that is going to lead to this blast of cool air for the west. What causes a block like that to form up north? (I don't mean generally, I mean specifically if we know)

[bluewave]

We have seen impressive blocking patterns of that magnitude set up there during this time of year with other La Ninas also.

[Gibbsfreeenergy]

FWIW, Wes, the Euro shows the same think as the UKM.

what can be said really...models have been piss poor. 6-10 day will be A-MA in entire eastern half of the country when last week's 11-15 days were frigid. AWESOME!

11-15 day should be Below east, but Pacific quickly changing during the period. Unless the NAO block is perfectly located and oriented, my experience says pac jet =manny pacquiao vs NAO block=antonio margarito

[keggwx]

Good for one round, then break da face...

[am19psu]

what can be said really...models have been piss poor. 6-10 day will be A-MA in entire eastern half of the country when last week's 11-15 days were frigid. AWESOME!

11-15 day should be Below east, but Pacific quickly changing during the period. Unless the NAO block is perfectly located and oriented, my experience says pac jet =manny pacquiao vs NAO block=antonio margarito

Yup, I suspect the MJO will be P4-P5 the week after Thanksgiving, which ought to send us to a +EPO and some above normal in the East.

[usedtobe]

Yup, I suspect the MJO will be P4-P5 the week after Thanksgiving, which ought to send us to a +EPO and some above normal in the East.

LOL, I actually think it likely to be cold in the east the week after Thanksgiving as the blocking associated with the Neg NAO works west and lowers heights in the east. The ensembles sure show lots of different looks but with lots of blockiness. Up until then, it should be warm and I wouldn't be surprised to see dca hit 70. We got close yesterday.

[am19psu]

LOL, I actually think it likely to be cold in the east the week after Thanksgiving as the blocking associated with the Neg NAO works west and lowers heights in the east. The ensembles sure show lots of different looks but with lots of blockiness. Up until then, it should be warm and I wouldn't be surprised to see dca hit 70. We got close yesterday.

My first foray into medium range forecasting this winter is going to have a lot of fail, I see

[tacoman25]

what can be said really...models have been piss poor. 6-10 day will be A-MA in entire eastern half of the country when last week's 11-15 days were frigid. AWESOME!

11-15 day should be Below east, but Pacific quickly changing during the period. Unless the NAO block is perfectly located and oriented, my experience says pac jet =manny pacquiao vs NAO block=antonio margarito

This is basically due to a lot of the cold dumping further west (into the Pacific) than was originally modeled...which lessens the impact of the -EPO on the eastern US. In a lot of ways, kind of a waste of a nice blocking pattern - at least in the short term.

Models were rushing the pattern change to where we are at now originally, so I would not be surprised if they are rushing the change in the Pacific somewhat as well.

[CoastalWx]

This is basically due to a lot of the cold dumping further west (into the Pacific) than was originally modeled...which lessens the impact of the -EPO on the eastern US.

Models were rushing the pattern change to where we are at now originally, so I would not be surprised if they are rushing the change in the Pacific somewhat as well.

GFS as usual was too quick, but the euro ensembles were too cold as well, although not as bad.

[ORH_wxman]

GFS as usual was too quick, but the euro ensembles were too cold as well, although not as bad.

The initial burst of cold was forecasted to really blitz the upper plains and even get into the northeast before 11/20...but we mentioned in the pattern change thread in the NE subforum (back on the the other site) that it was likely rushing things at the time and that thinking looks like it turned out correct.

It looks like the east could be below average for a while after Turkey Day even if the EPO starts to go back toward positive...the cold is already dumped into Canada and the -NAO will help hold in whatever cold is there and potentially move it southeast. It won't be a huge frigid outbreak since the two blocking mechanisms aren't working in tandem in the ideal locations, but we should definitely see the NAO working to keep it cool for at least a while. How much moderation there is after that probably depends on just how much the GOA low and +EPO comes back and its orientation. If we keep a bit of ridging north of AK/Bering straight, then it can still deliver cold to Canada even if the EPO is positive and there is a GOA low.

[CoastalWx]

The initial burst of cold was forecasted to really blitz the upper plains and even get into the northeast before 11/20...but we mentioned in the pattern change thread in the NE subforum (back on the the other site) that it was likely rushing things at the time and that thinking looks like it turned out correct.

It looks like the east could be below average for a while after Turkey Day even if the EPO starts to go back toward positive...the cold is already dumped into Canada and the -NAO will help hold in whatever cold is there and potentially move it southeast. It won't be a huge frigid outbreak since the two blocking mechanisms aren't working in tandem in the ideal locations, but we should definitely see the NAO working to keep it cool for at least a while. How much moderation there is after that probably depends on just how much the GOA low and +EPO comes back and its orientation. If we keep a bit of ridging north of AK/Bering straight, then it can still deliver cold to Canada even if the EPO is positive and there is a GOA low.

I don't think that can be hit hard enough. Time and time again models rush pattern changes.

[tacoman25]

The initial burst of cold was forecasted to really blitz the upper plains and even get into the northeast before 11/20...but we mentioned in the pattern change thread in the NE subforum (back on the the other site) that it was likely rushing things at the time and that thinking looks like it turned out correct.

It looks like the east could be below average for a while after Turkey Day even if the EPO starts to go back toward positive...the cold is already dumped into Canada and the -NAO will help hold in whatever cold is there and potentially move it southeast. It won't be a huge frigid outbreak since the two blocking mechanisms aren't working in tandem in the ideal locations, but we should definitely see the NAO working to keep it cool for at least a while. How much moderation there is after that probably depends on just how much the GOA low and +EPO comes back and its orientation. If we keep a bit of ridging north of AK/Bering straight, then it can still deliver cold to Canada even if the EPO is positive and there is a GOA low.

I don't think the EPO rushing back to positive (especially signficantly +) is necessarily going to happen before the end of the month. There is no real consistency in the ensembles beyond 200 hours...some model runs actually indicate a +PNA/neutral EPO pattern in conjunction with -NAO for the end of the month. Other runs indicate the GOA ridge mostly maintaining for awhile while the NAO trends negative. Either solution is possible and would probably be pretty cold for the NE/Great Lakes.

[tacoman25]

GFS as usual was too quick, but the euro ensembles were too cold as well, although not as bad.

It was not only too quick, but too far east with the Pacific blocking originally. That shortwave energy digging out into the Pacific over the next few days is really dampening/delaying what would have otherwise been an impressive cold shot for the northern tier of the country over the next week.

[CoastalWx]

It was not only too quick, but too far east with the Pacific blocking originally. That shortwave energy digging out into the Pacific over the next few days is really dampening/delaying what would have otherwise been an impressive cold shot for the northern tier of the country over the next week.

There will still be some impressive cold in the nrn high Plains imo. Some of that will move east in conjunction with a nice -nao. Hopefully this will last through part of December, but it may not last that long from the MA south. Who knows.