The Mystical Month of February--Long Range Discussion

[Vice-Regent]

5 minutes ago, SnowGoose69 said:

In regards to that Furtado post yesterday it seems that his idea of above normal in phase 8 or 1 is remote.  Since 1995 there have been 24 months in Dec-Feb where the MJO has had moderate amplitude in 8 or 1.  If you take BOS NYC DCA in those 24 months, 68 of the 72  averaged below normal.  All 4 misses occurred in December and the biggest positive departure was +0.6F  

Is this not telling of where we stand in 2019? That there are greater forcings at work. The entire Hadley Cell seems tilted north. These analogs may still be relevant for the far NE and Canada.

[Bob Chill]

1 hour ago, Inverted_Trough said:

Thanks for the primer!  I should rephrase:  the MJO has been talked about by experienced mets, but this season it's being discussed by nearly everyone.  The volume of MJO posts appears to be 10x higher this season compared to past seasons.  Which is a good thing - we should be talking more about the drivers of teleconnections (such as MJO) rather than just the "effects" of these drivers (i.e. the teleconnection indices themselves)

There's an obvious reason for all the MJO talk. Nearly every long ranger busted this year so far so the MJO is being used as a hindcast explanation for why things went wrong. The MJO is not a predictable teleconnection in the long range. It's not even that predictable with 2 week leads. 

Also, the MJO isn't a 1:1 correlation. Different phases can behave differently depending on other atmospheric drivers. Sometimes it fits perfect (and is talked about left and right) and other times the MJO is barely looked at when other forces are at work forcing the atmosphere to behave differently than what the phases would indicate.  It's entirely possible (and likely) that the MJO isn't the only reason for the unexpected hemispheric longwave patterns so far this year.

We talk about the long range excessively all over Amwx but the reality is that long range forecasting skill isn't anywhere close to being accurate for monthly or seasonal predictions. Some years are easier to predict than others and those years are almost exclusively driven by ENSO. Any year that isn't at least a moderate Nino/Nina will contain curveballs and unexpected weather patterns as you go out in time. Enso clearly didn't couple with or drive the atmosphere so far. All bets are off in any winter where ENSO doesn't take over. 

Lastly, analogs are are commonly used to predict seasonal weather patterns. There is some skill to using analogs but the dataset is extremely small. 100 years of the earth's weather is a drop in the bucket compared to the billions of years the earth has been around. If we had accurate upper air data for 1,000 years then analogs would likely be far more accurate and better tools for predicting monthly or seasonal weather patterns but even 1,000 years of data is a drop in the bucket in the big picture. 

[frd]

 

Wondering if this is skewed or how reliable due to changing MJO forecasts

 

 

[Ji]

21 minutes ago, Scraff said:

Oh no! @Bob Chill must be taking a mid day power nap. Every time he sleeps, things go to hell. Wake up Bob!! 

not sure why @Bob Chillis not posting. Winter is about over..he has all spring and summer not to post. Weird that he is taking this time off. Btw..John wall tore his ACL slipping at home. out another 14 months

[Delaware Valley Weather]

Looks like 8 by mid-month

[SomeguyfromTakomaPark]

Overrunning starts on the euro 12z Tuesday. 

[BristowWx]

1 minute ago, DCTeacherman said:

Overrunning starts on the euro 12z Tuesday. 

Oh boy.  Good overrunning or the kind if someone farts the boundary retreats north?

[poolz1]

1038 High anchored in a prime spot.

[NorthArlington101]

Oh boy.  Good overrunning or the kind if someone farts the boundary retreats north?

The good kind. It’s a real nice storm.

[Chris78]

I would assume this is good. 

[psuhoffman]

18 minutes ago, Bob Chill said:

There's an obvious reason for all the MJO talk. Nearly every long ranger busted this year so far so the MJO is being used as a hindcast explanation for why things went wrong. The MJO is not a predictable teleconnection in the long range. It's not even that predictable with 2 week leads. 

Also, the MJO isn't a 1:1 correlation. Different phases can behave differently depending on other atmospheric drivers. Sometimes it fits perfect (and is talked about left and right) and other times the MJO is barely looked at when other forces are at work forcing the atmosphere to behave differently than what the phases would indicate.  It's entirely possible (and likely) that the MJO isn't the only reason for the unexpected hemispheric longwave patterns so far this year.

We talk about the long range excessively all over Amwx but the reality is that long range forecasting skill isn't anywhere close to being accurate for monthly or seasonal predictions. Some years are easier to predict than others and those years are almost exclusively driven by ENSO. Any year that isn't at least a moderate Nino/Nina will contain curveballs and unexpected weather patterns as you go out in time. Enso clearly didn't couple with or drive the atmosphere so far. All bets are off in any winter where ENSO doesn't take over. 

Lastly, analogs are are commonly used to predict seasonal weather patterns. There is some skill to using analogs but the dataset is extremely small. 100 years of the earth's weather is a drop in the bucket compared to the billions of years the earth has been around. If we had accurate upper air data for 1,000 years then analogs would likely be far more accurate and better tools for predicting monthly or seasonal weather patterns but even 1,000 years of data is a drop in the bucket in the big picture. 

It’s like a big 3 dimensional puzzle with missing pieces. But it’s a fun mental challenge. 

I do buy the mjo influence. There is a lot of objective evidence. It’s not a 1:1 like you said but if you take the look day 15, factor in major features caused by other factors like the tpv displacement last week from the sswe, then combine those with the mjo phase everything was shifted towards the mjo analogs. Not all the way. Not 1:1 but the affect seemed obvious. It even worked the other way the one time the mjo got into 8. It also makes sense given the mjo amplitude. A weak mjo wave often can be muted by other influences. But when the mjo is amplified and the other factors like enso are weak signals it overwhelms. 

So I’m admitting total and complete bustage. My call was awful. And saying it was the mjo isn’t an excuse because the mjo was part of my forecast and I screwed that up.  I said back in December I expected either a muted mjo or for it to spend most of the time in cold phases. I couldn’t have been more wrong. 

Imo the mjo’s usefulness as a predictor depends on the situation. When the mjo is low amplitude or is deamplifying or there are conflicting waves...it’s useless beyond a few days. But when it’s in the process of amplifying and there is a strong signal then it usually is somewhat reliable to day 7-10 and since there is a lag time that makes it useful in a 10-15 day (or slightly beyond) forecast. So just like all the other factors we use it’s hwlpful under the right circumstances and useless at other times.  

I think right now is a useful time. There has been a clear mjo tendency this year. This next wave is initiating now and gets amplified into phase 8 on all guidance soon and that fits the seasonal trend of more amplified waves.  Doesn’t mean it can’t bust but right now it seems a fairly safe bet as far as long range bets go. 

[SomeguyfromTakomaPark]

We lose the 850s at some point but the surface is cold throughout. 

[NorthArlington101]

We flip to FRZA/sleet but that is a lot of wintry precip. Nice. 

[psuhoffman]

Just now, Chris78 said:

I would assume this is good. 

Euro showing consistency in the face of American guidance. There were some hits in the gefs but overall the gefs was a shotgun of everything indicating the gfs has no clue what’s going on.  

[Bob Chill]

6 minutes ago, Ji said:

not sure why @Bob Chillis not posting. Winter is about over..he has all spring and summer not to post. Weird that he is taking this time off. Btw..John wall tore his ACL slipping at home. out another 14 months

It's his achilles isn't it? DC is a cursed city for ball sports. Skins, wiz, and nationals all have their own separate curse but the end result is the same. No championships and quick exits in the playoffs. lol

I'm still watching everything. Just not picking anything apart because it's not worth the mental exercise when everything you analyze and think about changes every 24 hours. That will probably change here shortly if one of these potential threats turns into a legit shot. 

[frd]

2 minutes ago, poolz1 said:

1038 High anchored in a prime spot.

Hopefully this trends colder in future runs, or not. Folks up North and far West should be happy. 

I am more interested in the events after the 15th to be honest. Very keen on seeing the EPS for hints.    

[Scraff]

Who’s going to post a Euro clown map for shizzoly and giggles?

[psuhoffman]

1 minute ago, Bob Chill said:

It's his achilles isn't it? DC is a cursed city for ball sports. Skins, wiz, and nationals all have their own separate curse but the end result is the same. No championships and quick exits in the playoffs. lol

I'm still watching everything. Just not picking anything apart because it's not worth the mental exercise when everything you analyze and think about changes every 24 hours. That will probably change here shortly if one of these potential threats turns into a legit shot. 

I don’t root against the DC teams unless they are playing philly. I don’t like people around me being miserable and I lived around DC for many years. But imo you just have some really awful owners. I know what that looks like, for a long time philly had god awful owners of most of our teams. Coaches, players, general managers would change year after year but the same crap would keep happening.  And yea there was bad luck along the way but after seeing a Phillies run where they won some years despite bad luck and seeing an Eagles super bowl in a year we lost multiple key starters...I realized luck evens out but bad owners can’t be overcome.  I know you know this..and I feel bad for redskins and Wizards fans. 

I would feel a lot better about the next threat if we could get other guidance on board. Often when there is such a split a compromise works but a Compton here is no good for us. Even the euro has been too far southeast with some of these waves lately so I’m not getting excited until I see evidence this won’t become another cutter that looked good from range. 

[Weather Will]

Looks like .5 to .75 for the event.  Temps a close call in DC, but definitely in the game from about 7 days out and an operational perspective.  EURO OP can be a tease this far out but makes it 3 runs in a row showing a moderate wintry event for the 12-13th.

[Bob Chill]

Just now, Scraff said:

Who’s going to post a Euro clown map for shizzoly and giggles?

Here's Kuchera. It's lower than 10:1 and is very reasonable considering the mixing issues. I like that the mixing is ZR. I love me some glaciers in Feb

 

[SomeguyfromTakomaPark]

2 minutes ago, frd said:

Hopefully this trends colder in future runs, or not. Folks up North and far West should be happy. 

I am more interested in the events after the 15th to be honest. Very keen on seeing the EPS for hints.    

Even if it doesn't trend colder it's a great event for the metros as is.

[jaydreb]

This is Kuchera.  10:1 is a bit better.  Storm still going in NE at this point.  

[Bob Chill]

Euro's progression is a classic CAD. Northerly surface winds/cold drain leading in. It's textbook for our region as shown. 

[Bob Chill]

Check this out. Here's the 850 temps, 10m winds, and surface at onset. Classic CAD with wiggle room in the column. Pretty nice run imho. Beef up CAD and it's all snow. If the midlevels are overestimated then it's still a snow to ZR event. Very good HP placement. Just need it to hold for 5 days. lol

 

 

[jaydreb]

3 minutes ago, Bob Chill said:

Euro's progression is a classic CAD. Northerly surface winds/cold drain leading in. It's textbook for our region as shown. 

I’m cool with 3-4” with some freezing rain/sleet on top.  

[jaydreb]

Just now, Bob Chill said:

Check this out. Here's the 850 temps, 10m winds, and surface at onset. Classic CAD with wiggle room in the column. Pretty nice run imho. Beef up CAD and it's all snow. If the midlevels are overestimated then it's still a snow to ZR event. Very good HP placement. Just need it to hold for 5 days. lol

 

 

Lol and suddenly Bob is back making posts!

[jaydreb]

Euro setting up a sequel at the end of the run?

[poolz1]

6 minutes ago, frd said:

Hopefully this trends colder in future runs, or not. Folks up North and far West should be happy. 

I am more interested in the events after the 15th to be honest. Very keen on seeing the EPS for hints.    

A slightly stronger 50/50 and blocking this run....would have thought the transfer and coastal development would have been even better than 0z.  Lets get this to 120 hours....where the euro will lock onto a close to reality outcome...Nice to have something on the table tho..

[psuhoffman]

4 minutes ago, Bob Chill said:

Euro's progression is a classic CAD. Northerly surface winds/cold drain leading in. It's textbook for our region as shown. 

Surface is, the h5 progression looks more typical of a New England big storm so I’m hesitant to jump in. We can sometimes do good with that setup but I’m always looking for the north trend when I see that. 

[Bob Chill]

Just now, jaydreb said:

Lol and suddenly Bob is back making posts!

I'd say this is a real threat now. All models have different versions of the same general thing in the same time frame. It's right on the edge of believable skill but it's also not a complicated setup. All comes down to timing/hp placement. I made a post a few days ago pointing out that tracking HP placement/timing to the north is equally as important as SLP placement/timing to the south. 

If the overunning precip drags its feet then it gets really dicey along 95 and SE. PSU/Winterwxluvr are no doubt in the climo favored locations for this type of event. If the progression on the euro is right then they'll almost surely be the jackpot zones.