December Mid/Long Range Discussion

[Weather Will]

WB 6Z GFS....welcome rain heading in Sunday

[frd]

Interesting post by @bluewave

 

 

One of the main issues with the longer range model forecasts for the MJO beyond 10 days is that the ensembles weaken the convective signal too much. This is also true with the RMM charts. So some of the posts on twitter stating that the MJO will quickly weaken or progress to 8-1-2 are basing that on an an inherent model bias. So it’s no surprise that the convection in the warm phases this week is verifying more intense in the warm phases than the runs back in late November were indicating. This is one of the reasons ensemble forecasts have been correcting warmer for December than they were indicating later in November. So even if the MJO can eventually get over into phase 8-1-2, that is also a warmer signal from December into January with an El Niño.

New run

Old run

[Terpeast]

27 minutes ago, frd said:

Interesting post by @bluewave

 

 

One of the main issues with the longer range model forecasts for the MJO beyond 10 days is that the ensembles weaken the convective signal too much. This is also true with the RMM charts. So some of the posts on twitter stating that the MJO will quickly weaken or progress to 8-1-2 are basing that on an an inherent model bias. So it’s no surprise that the convection in the warm phases this week is verifying more intense in the warm phases than the runs back in late November were indicating. This is one of the reasons ensemble forecasts have been correcting warmer for December than they were indicating later in November. So even if the MJO can eventually get over into phase 8-1-2, that is also a warmer signal from December into January with an El Niño.

New run

Old run

I like what these VP forecasts are showing. Nice trend. I don’t agree that 8-1-2 necessarily means warm in the east if the MEI stays under 1.2 (iow the nino doesn’t go super)

[CAPE]

23 minutes ago, Terpeast said:

I like what these VP forecasts are showing. Nice trend. I don’t agree that 8-1-2 necessarily means warm in the east if the MEI stays under 1.2 (iow the nino doesn’t go super)

The bias corrected Euro and GEFS take it into the COD before/just as it gets to phase 7.

[Ralph Wiggum]

Didn't we deal with a stubborn Western Atlantic Ridge in 2015-2016 until it briefly rolled over in January 2016 prior to the big storm?

That feature looks persistent late in the ens means BUT also look like the pattern wants to progress right beyond this with the Aleutian low anchoring, the SW trof moving East slowly, and the Scan Ridge retrograding. 

[Scarlet Pimpernel]

9 hours ago, nj2va said:

I hear palm trees are growing in NYC…

"A (Palm) Tree Grows in Brooklyn"??? 

[WxUSAF]

22 minutes ago, CAPE said:

The bias corrected Euro and GEFS take it into the COD before/just as it gets to phase 7.

I haven’t seen MJO charts in the last couple days, but I’d agree with @bluewave that it’s very likely the wave will go around the horn into 8-1-2. Doesn’t make sense for the wave to die as it’s getting to the best SSTs supporting convection.

[mattie g]

54 minutes ago, Ralph Wiggum said:

Didn't we deal with a stubborn Western Atlantic Ridge in 2015-2016 until it briefly rolled over in January 2016 prior to the big storm?

That feature looks persistent late in the ens means BUT also look like the pattern wants to progress right beyond this with the Aleutian low anchoring, the SW trof moving East slowly, and the Scan Ridge retrograding. 

Have we had a persistent WAR over the last month or so? Sounds like you think we have.

[CAPE]

1 minute ago, mattie g said:

Have we had a persistent WAR over the last month or so? Sounds like you think we have.

Ralph has a WAR phobia.

[clskinsfan]

12z 3K does manage to hold the clipper together enough to get some precip into the Winchester area tonight. Its rain. But pretty close. We'll see. 

 

 

[WinterWxLuvr]

1 hour ago, clskinsfan said:

12z 3K does manage to hold the clipper together enough to get some precip into the Winchester area tonight. Its rain. But pretty close. We'll see. 

 

 

I don’t see how, if we get any precip, that at least some of it will be snow.

[thunderbolt]

3 hours ago, frd said:

Interesting post by @bluewave

 

 

One of the main issues with the longer range model forecasts for the MJO beyond 10 days is that the ensembles weaken the convective signal too much. This is also true with the RMM charts. So some of the posts on twitter stating that the MJO will quickly weaken or progress to 8-1-2 are basing that on an an inherent model bias. So it’s no surprise that the convection in the warm phases this week is verifying more intense in the warm phases than the runs back in late November were indicating. This is one of the reasons ensemble forecasts have been correcting warmer for December than they were indicating later in November. So even if the MJO can eventually get over into phase 8-1-2, that is also a warmer signal from December into January with an El Niño.

New run

Old run

One is not a warm phase for December

[thunderbolt]

Just now, thunderbolt said:

One is not a warm phase for December

That also goes for number two

[psuhoffman]

3 hours ago, Terpeast said:

I like what these VP forecasts are showing. Nice trend. I don’t agree that 8-1-2 necessarily means warm in the east if the MEI stays under 1.2 (iow the nino doesn’t go super)

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

[Maestrobjwa]

2 minutes ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

Consider the source...lol I find it rather annoying when there are knowledgeable posters with a HEAVY warm bias. So it's just enough to contribute, yet some of them can troll too.

[aldie 22]

5 minutes ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

looks like 7 is left?

[Daniel Boone]

4 minutes ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

Yeah really, lol . Never saw anything differentiating MJO Phases based on Enso. 

[mattie g]

Just now, aldie 22 said:

looks like 7 is left?

But what if it's close to 8? I think maybe that's warm phase 7.

[wxdude64]

Just now, mattie g said:

But what if it's close to 8? I think maybe that's warm phase 7.

Warm AROUND the dial!! 

[WxUSAF]

8 minutes ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

Our hearts 

[brooklynwx99]

9 minutes ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

I think phase 8 is warm in El Nino Decembers, not later in the year. it's a cold signal for Jan and Feb

either way, the MJO becomes a lot more favorable and there are reasons for optimism late-month

[Daniel Boone]

3 minutes ago, brooklynwx99 said:

I think phase 8 is warm in El Nino Decembers, not later in the year. it's a cold signal for Jan and Feb

either way, the MJO becomes a lot more favorable and there are reasons for optimism late-month

Exactly. 

[brooklynwx99]

El Nino Decembers are usually just crappy regardless of MJO, honestly

[Maestrobjwa]

1 minute ago, brooklynwx99 said:

El Nino Decembers are usually just crappy regardless of MJO, honestly

Shows you how much of a unicorn 2009-10 was. And even that event was followed by a torch, and those 19 inches were already a memory by Christmas night, lol (Now I can't remember how that month started temp-wise though)

[Weather Will]

Latest WB EURO seasonal Jan. Thru March.  Looks pretty good to me.

[Chris78]

7 minutes ago, Weather Will said:

Latest WB EURO seasonal Jan. Thru March.  Looks pretty good to me.

January 2016 redux?

[Terpeast]

1 hour ago, psuhoffman said:

So let me get this straight...according to him the traditional warm phases 3-6 are warm, but in an el nino the cold phases 8-1-2 are also warm?  SO WTF is cold?  

Consider the source. Smart guy, but heavily biased towards persistence in favor of CC. He will be proven wrong for a time eventually. He has a tendency to cherry pick the warmest analogs for any given pattern. First it was 2015-16, then it was 1997-98, and on it goes. 

[psuhoffman]

22 minutes ago, brooklynwx99 said:

El Nino Decembers are usually just crappy regardless of MJO, honestly

Everyone keeps saying this but it's not true.   

The following stats are for snowfall in all El nino years since 1950.  26 years.  

BWI had at least 4" of snow before January 1 in the following el nino years... 1951, 1952, 1953, 1957, 1963, 1968, 1969, 1982, 1987, 2002, 2009

So roughly 42% of el nino winters had significant snow (4") in November/December.  

There have been 48 non el nino years since 1950.  In those years BWI had 4" of snow by January 1 in only 13 years or 27%.

Baltimore is significantly more likely to get snowfall early in El Nino's than in neutral and nina seasons. 

Additionally...

Avg Nino snowfall in years BWI gets 4" by Jan 1 = 34"

Avg Nino snowfall in years BWI does not get 4" by Jan 1 = 17"

Why does everyone keep saying Decembers always suck in a nino.  They suck in SOME Nino's...and guess what those usually end up being the crappy nino's.  yes SOME are years like 1966 and 1987 that flip around New Years.  But there are more examples like 1959, 1973, 1992, 1995, 1998, 2007 where a bad early season went on to be a dud nino season.  I am not expecting that this year...but I get annoyed everytime I see this assertion that we just toss December in a nino when that data does not support that at all.  Actually Nino's have a higher probability of early snow than non ninos.  

 

[Stormchaserchuck1]

3 minutes ago, psuhoffman said:

Everyone keeps saying this but it's not true.   

The actual tropical forcing should favor a cooler Dec as well. What is so special about the month December that makes it break normal ENSO-forcing? Too many lazy correlations imo

[WxUSAF]

56 minutes ago, Chris78 said:

January 2016 redux?

Don’t know about that, but odds of KU storms are certainly higher than normal this winter, particularly mid Jan-mid Feb.