MJO/LR Forecasting Thread

[Bryant]

What is the MJO? How does it affect the weather?

The MJO is a 30-60 day oscillation which measures the suppressed and convective rainfalls over the warm waters of the Indian and Pacific Ocean. The MJO typically initiates in the Western Indian Ocean, and travels east at approximately 4 to 8 m/s (9 to 18 mph) until it dies out over the Pacific. These storms produce a latent heat release to the north, which initiate an increase Jet Stream, causing a favorable area of cyclogenisis to form to the east. This low pressure system pumps up a ridge to the east, which ultimately results in a downstream trough. I found 2 different images from the previous thread, which illustrate the above in a visual manner. As you will see, where you find the convection, you will find an increased jet stream to the north, followed by a ridge and downstream trough.

http://i.imgur.com/IsZPCDF.gif


How does the MJO affect OUR weather?

It may be difficult to tell in the images above, but typically when convection is around the MC (Maritime Continent), the downstream trough is located over the West. The MJO affects change during the season, but during the winter time, phases 3-6 are favorable for the west. I threw together the following image to show the different regions to the best of my ability. This image also demonstrates why you see the MJO favor different zones during different ENSO events due to the shifting of warm and cool waters.

http://i.imgur.com/t5BjxrE.gif


Pineapple Express

As some of you may already know, the Pineapple Express events we receive are directly related to the MJO. As the intense rainfall spreads over the Pacific nearing the end of an MJO cycle (phases 7-8), the moisture gets picked up in the jet stream, and aimed directly at the coast. For the visual learners like myself, here is an image I found online. As you will see in the (7-10 Days Before Event) image, the convection is just east of the MC. Note the similarities to one of the image posted above with the yellow boxes, which also features convection just east of the MC.

http://upload.wikimedia.org/wikipedia/commons/a/a7/Mjo_north_america_rain.png



Tracking the MJO

There are many ways of tracking the MJO, CPC's site probably being the most popular. However, viewing those forecasts can be deceiving due to other tropical waves. The RMM index used by CPC measures the clouds and winds at the upper and lower levels of the atmosphere to determine the strength and location of the MJO. Other waves such as CCKW's (Convectively Coupled Kelvin Waves) project onto the RMM indexes, giving a false reading of the actual MJO. I refer to these forecasts as unfiltered. Filtered forecasts on the other hand attempt to separate individual waves using their own formulas. These forecasts aren't perfect, but do a much better job in my opinion than the unfiltered forecasts.

Here are a few links for unfiltered and filtered forecasts.

CPC Unfiltered
Multi Model Unfiltered
Kyle Macritchies 30 Day CFS MJO
Roundy Waves Filtered
Mike Ventrice's Site

[snow_wizard]

Excellent stuff! I'm very excited about the projections for this current MJO wave. It could easily break the back of what has been a very shaky El Nino.

 

Based on the ECMWF based MJO forecast I could easily see a significant cold event in December for the NW. The expected strat warming could just add fuel to that fire.

[TT-SEA]

Excellent stuff! I'm very excited about the projections for this current MJO wave. It could easily break the back of what has been a very shaky El Nino.

 

Based on the ECMWF based MJO forecast I could easily see a significant cold event in December for the NW. The expected strat warming could just add fuel to that fire.

 

 

That would be nice... but does not feel right after such and extended period of cold already in November.   We will see.

[westiztehbest]

Epic post.  It appears both the EMCWF & CFS are looking to revolve counter clockwise from phase 1-4/5 through December.  Things are looking good.  Coinsidentally, the Euro weeklies from 00z 11/17 show the idea of a cold, troughy early/mid December.

 

 

 

[Parksvillewx]

Thanks for starting this up again. I really liked the thread you had on the old forum.

[Bryant]

Thanks for starting this up again. I really liked the thread you had on the old forum.

Appreciate the kind words

[snow_wizard]

Epic post.  It appears both the EMCWF & CFS are looking to revolve counter clockwise from phase 1-4/5 through December.  Things are looking good.  Coinsidentally, the Euro weeklies from 00z 11/17 show the idea of a cold, troughy early/mid December.

Quite interesting the last CFS update shows it getting cold in the NW at the same time the ECMWF shows it.

[snow_wizard]

One thing for D**n sure is MJO 1 was poisonous for us this year. The epic torching happened with many MJO waves that were born and died in and around octant 1. The nearly constant negative frictional torque was probably related to that also.

[Bryant]

Epic post. It appears both the EMCWF & CFS are looking to revolve counter clockwise from phase 1-4/5 through December. Things are looking good. Coinsidentally, the Euro weeklies from 00z 11/17 show the idea of a cold, troughy early/mid December.

 

http://i57.tinypic.com/2llkfvm.jpg

 

http://i58.tinypic.com/293hpar.jpg

 

http://i59.tinypic.com/2ihxlrs.jpg

Appreciate the research. I've been preaching the Euro recently due to it's MJO progression. Much more in line with what I've been thinking, and I believe the other models are starting to build an MJO wave now as well. Whenever you see an MJO forecast completely reverse it's counter clockwise rotation, it should raise a red flag.

[Bryant]

One thing for D**n sure is MJO 1 was poisonous for us this year. The epic torching happened with many MJO waves that were born and died in and around octant 1. The nearly constant negative frictional torque was probably related to that also.

http://www.atmos.albany.edu/student/nschiral/research/gwo/gfsgwo_2.png

[snow_wizard]

Another sight for sore eyes is the recent return to robust positive OLR anomalies (5N - 5S) centered on 180.  A very definite anti El Nino signal.  Pretty interesting how it turned cold right after that change took effect.

 

[Bryant]

As of now, I'd ignore the GFS all together just by going off of the MJO forecast. 

[Phil]

So if I'm reading this right, the MJO can move backwards?

No it can't. The CCKW interference can make it look that way on the phase diagrams, though. The MJO propagates eastward..

[Phil]

Can you elaborate how to read this? OLR = Outgoing Longwave Radiation. I would expect warmer SST's would show a positive anomaly.

Warmer SSTs can bias convective schemes there in the long term..hence often reduced OLR over warm SSTs..the higher frequency stuff is governed by internal resonance and the stratospheric boundary state. The current high-freq regime (anomalous from low-freq niño base state) is temporary..we'll revert back to a Niño configuration in December, imo

[Phil]

Great thread BTW, bigmack. Appreciate the effort!

[Bryant]

No it can't. The CCKW interference can make it look that way on the phase diagrams, though. The MJO propagates eastward..

Thank you for answering that one. When I see an MJO forecast throw itself into reverse, I typically throw out that solution until it comes into line. Ex: GFS vs. ECMWF

[Phil]

Thank you for answering that one. When I see an MJO forecast throw itself into reverse, I typically throw out that solution until it comes into line. Ex: GFS vs. ECMWF

Agreed...GFS's lower resolution is a detriment here..though none of the models differentiate these phenomenon well. Also the QBO & low-freq ENSO resonance(s) alters the effect(s) of the MJO, so it's important to factor that into a forecast, IMO

[snow_wizard]

Can you elaborate how to read this?  OLR = Outgoing Longwave Radiation.  I would expect warmer SST's would show a positive anomaly.

No...high SST's in the ENSO region normally cause increased convection which dampens OLR.

[Black Hole]

Such a nice post! This is one of the best explanations I've seen. Looks quite favorable for us in early December for a blast of cold air I think. We shall see.

[Bryant]

Such a nice post! This is one of the best explanations I've seen. Looks quite favorable for us in early December for a blast of cold air I think. We shall see.

 

Much appreciated

[Bryant]

Quick cross reference here....

http://theweatherforums.com/index.php/topic/663-november-2014-observations-for-the-pacific-northwest/?p=43771

 

Where is all this December-focus coming from? If it's MJO based, I don't understand it because the cold phases for the west (NDJ) are 1,2, & 7. We just went through those last week...now we're heading into phases 3-5 which are generally warm out there:
 

 

 

 

Wanted to throw a composite together real quick, and was pleasantly surprised at how well it lined up. Currently, the MJO is in phase 2, headed to 3 shortly

 

http://i.imgur.com/VLma0Ni.gif

 

Using a database of teleconnections/ENSO/MJO/GWO/etc I have put together, I filtered for dates which featured current ENSO conditions (warm neutral), as well as the MJO in phases 2-3. This left me with about 250 dates, which I then plotted a 500mb analysis of:

 

http://i.imgur.com/nUm5zIX.gif

 

Finally, today's ECMWF 500mb map. Cold anomalies in the NE as well as the SW, with warmth over the north

 

http://i.imgur.com/g2z901E.png

[Bryant]

Taking the above ENSO criteria (warm neutral), plotting a 500mb analysis of the MJO in phases 4/5 yields results which show potential, but has lacks the amplification we'd like to see due to an ugly +EPO which the models have shown for a while now

 

http://i.imgur.com/fBhSpJv.gif

[Phil]

Great post. Did you filter for the QBO/MQI? The tropical-mid latitude interactions are altered by stratospheric forcings & internal inertia (ENSO/AAM). My accuracy improved when I factored in the stratosphere to my tropical forcing analogs.

[Bryant]

Great post. Did you filter for the QBO/MQI? The tropical-mid latitude interactions are altered by stratospheric forcings & internal inertia (ENSO/AAM). My accuracy improved when I factored in the stratosphere to my tropical forcing analogs.

No other filters were used. Tends to narrow down the matches a bit too much the more factors I add in

[Bryant]

Mike Ventrice posted this on his twitter, thought I would pass it along.

[Phil]

No other filters were used. Tends to narrow down the matches a bit too much the more factors I add in

That can be a problem, especially when relying on Niño 3.4 SSTs for ENSO forcing. I prefer to start with +ENSO within 1.5 standard deviations, weight for the governing Walker Cell strength & basis, then filter for QBO...I do it all on the ESRL site..I don't know what I'd do without it.

 

Gives me eight acceptable analogs for the upcoming 2014-15 winter, which is kinda meh, but still workable. With at least five analogs, IMO, it's easier to apply research-based [projections] onto current observations and noted pattern tendencies.

 

Stuff like solar is still very experimental as far as theoretical physics go, but statistically it's super helpful

[Phil]

I only say this because the effects of the MJO are very dependent on the troposphere-stratosohere interaction. It took me two years to figure this out...I blew my 2010-11 and 2011-12 winter forecasts because I didn't configure my relationships properly.

[Snow]

Taking the above ENSO criteria (warm neutral), plotting a 500mb analysis of the MJO in phases 4/5 yields results which show potential, but has lacks the amplification we'd like to see due to an ugly +EPO which the models have shown for a while now

 

http://i.imgur.com/fBhSpJv.gif

 

Great analysis, the 12z EURO today showed what you were hinting at 10 days from now. Lots of cold frigid arctic air in Central BC but not enough amplification as too much energy swings out over the Pacific Ocean and the arctic air moderates before reaching us.

 

http://oi57.tinypic.com/1ptpw5.jpg

[Bryant]

Great analysis, the 12z EURO today showed what you were hinting at 10 days from now. Lots of cold frigid arctic air in Central BC but not enough amplification as too much energy swings out over the Pacific Ocean and the arctic air moderates before reaching us.

 

 

Appreciate the kind words. Potential is there... Just needs some tweaking!

[snow_wizard]

Appreciate the kind words. Potential is there... Just needs some tweaking!

I think the amplification will come. A possible trigger for that could be the strat warming that is supposedly not too far off. No question the MJO will be favorable for good block placement.

 

BTW...this is a fabulous thread. Your posts are awesome when you get inspired.

[snow_wizard]

Taking the above ENSO criteria (warm neutral), plotting a 500mb analysis of the MJO in phases 4/5 yields results which show potential, but has lacks the amplification we'd like to see due to an ugly +EPO which the models have shown for a while now

 

How does that map look when you enter MJO 5/6 or 5,6,7?

[snow_wizard]

Incidentally, I think the GFS MJO forecasts are so messed up now because it refuses to allow an MJO in regions 4-6 with the current SST configuration. It has consistently wanted to keep the wave too far west or kill it unrealistically fast.

[Bryant]

I think the amplification will come. A possible trigger for that could be the strat warming that is supposedly not too far off. No question the MJO will be favorable for good block placement.

 

BTW...this is a fabulous thread. Your posts are awesome when you get inspired.

 

Much appreciated Jim. I enjoy studying the MJO, as I feel it's a driver a lot of people look past. I like having yourself and others post their thoughts as well. I'm making all these charts with the spreadsheet I sent you

 

MJO 5/6/7 is ugly by the way...

 

http://i.imgur.com/8ycNU0P.gif

[snow_wizard]

Much appreciated Jim. I enjoy studying the MJO, as I feel it's a driver a lot of people look past. I like having yourself and others post their thoughts as well. I'm making all these charts with the spreadsheet I sent you

 

MJO 5/6/7 is ugly by the way...

 

Wow! That is a surprise considering we have had some great cold waves with MJO 6/7. Those must be years where other forcings are different.

 

BTW the GFS MJO forecast continues to look ludicrous. The wave is now in 3 and it kills the wave and heads it back to re-emerge into 1 very quickly. I think the GFS has to be thrown out by the end of week one as a result.

 

I certainly hope this MJO wave will be enough to give the mid latitude wave train a kick in the butt.

[Snow]

After looking at the EURO MJO, it looks like we enter Phase 7 around Dec. 10 and will be in that phase till around Dec. 15. Phase 7 should be cold for the PNW along with above average precip but the signal is not strong so mostly likely a cool NW flow during this time period of 500 to 1,000 snow levels dipping to sea level at night or under heavy shower. Also have a chance once we get back to Phase 1/2 with 1 being more probably because Phase 2 looks dry. So Dec. 21 to Dec. 31 as the best chance with Phase 1/2 but since the significance % is very weak all I see is a backdoor event at best like what we saw in November. Then after that I don't see any arctic air in January, especially with the warm Phases and the January Thaw later in the month. We always seem to get arctic air in February lately and that is our next best chance with Phase 7 coming then and a high significance %. 

 

Full summary

 

Dec. 10 - 15: Cool NW flow with generally 500 to 1,000 foot snow levels very probable.

 

Dec. 21- 31: Arctic air possible but most likely backdoor event like in Nov but a little colder.

 

Jan. 1 - 31: No arctic air with moist zonal flow first half, then drying out last half of month. A ridge of H pressure will build at this time bring very warm temperatures(near records) and then retrograde.

 

Feb: First half of Feb good chance of significant snowstorm like in 1992-1993 winter(neutral slightly weak El Nino) and 1994-1995 winter(moderate El Nino).

[snow_wizard]

 

After looking at the EURO MJO, it looks like we enter Phase 7 around Dec. 10 and will be in that phase till around Dec. 15. Phase 7 should be cold for the PNW along with above average precip but the signal is not strong so mostly likely a cool NW flow during this time period of 500 to 1,000 snow levels dipping to sea level at night or under heavy shower. Also have a chance once we get back to Phase 1/2 with 1 being more probably because Phase 2 looks dry. So Dec. 21 to Dec. 31 as the best chance with Phase 1/2 but since the significance % is very weak all I see is a backdoor event at best like what we saw in November. Then after that I don't see any arctic air in January, especially with the warm Phases and the January Thaw later in the month. We always seem to get arctic air in February lately and that is our next best chance with Phase 7 coming then and a high significance %. 

 

Full summary

 

Dec. 10 - 15: Cool NW flow with generally 500 to 1,000 foot snow levels very probable.

 

Dec. 21- 31: Arctic air possible but most likely backdoor event like in Nov but a little colder.

 

Jan. 1 - 31: No arctic air with moist zonal flow first half, then drying out last half of month. A ridge of H pressure will build at this time bring very warm temperatures(near records) and then retrograde.

 

Feb: First half of Feb good chance of significant snowstorm like in 1992-1993 winter(neutral slightly weak El Nino) and 1994-1995 winter(moderate El Nino).

 

 

Awfully negative take.

[Snow]

Awfully negative take.

 

Those are just my projections. I feel we will get a chance of 2 arctic outbreaks. One towards the end of December and one in the first half of February. I feel confident more for the one in February than the one in December but I wont be surprised if we get 2 arctic outbreaks like we did last year.

[SilverFallsAndrew]

Awfully negative take.

Probably more optomistic than how this winter will actually turn out.

[Jesse]

 

 

 

After looking at the EURO MJO, it looks like we enter Phase 7 around Dec. 10 and will be in that phase till around Dec. 15. Phase 7 should be cold for the PNW along with above average precip but the signal is not strong so mostly likely a cool NW flow during this time period of 500 to 1,000 snow levels dipping to sea level at night or under heavy shower. Also have a chance once we get back to Phase 1/2 with 1 being more probably because Phase 2 looks dry. So Dec. 21 to Dec. 31 as the best chance with Phase 1/2 but since the significance % is very weak all I see is a backdoor event at best like what we saw in November. Then after that I don't see any arctic air in January, especially with the warm Phases and the January Thaw later in the month. We always seem to get arctic air in February lately and that is our next best chance with Phase 7 coming then and a high significance %. 

 

Full summary

 

Dec. 10 - 15: Cool NW flow with generally 500 to 1,000 foot snow levels very probable.

 

Dec. 21- 31: Arctic air possible but most likely backdoor event like in Nov but a little colder.

 

Jan. 1 - 31: No arctic air with moist zonal flow first half, then drying out last half of month. A ridge of H pressure will build at this time bring very warm temperatures(near records) and then retrograde.

 

Feb: First half of Feb good chance of significant snowstorm like in 1992-1993 winter(neutral slightly weak El Nino) and 1994-1995 winter(moderate El Nino).

 

 

What about December 15th-21st??

[SilverFallsAndrew]

What about December 15th-21st??

 

We aren't having those days this year.