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November 2017 Discussions & Observations Thread


Rtd208

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7 minutes ago, snowman19 said:

Another thing to keep in mind about 2010, it was a +QBO. +QBO during a La Niña supports more blocking on the Pacific side. http://ionlyusethegfs.blogspot.com/2012/04/qbo-aleutian-high-relationship.html?m=1

With the exception of a year like 95-96 which occupied it's own special Nina universe, it can take a while for La Ninas to really click in the snowfall department. November 20-December 24th, 2010 is a classic example. Also remember in December 2000 how we almost didn't get the snowstorm at the very end of the month with the sharp cutoff in snowfall just to our S and W.

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33 minutes ago, bluewave said:

With the exception of a year like 95-96 which occupied it's own special Nina universe, it can take a while for La Ninas to really click in the snowfall department. November 20-December 24th, 2010 is a classic example. Also remember in December 2000 how we almost didn't get the snowstorm at the very end of the month with the sharp cutoff in snowfall just to our S and W.

Both 95-96 and 00-01 were special in that they had solid +PDO’s along with the La Niña...a rare combo. 95-96 also started with a +QBO that went weakly negative during that winter, 00-01 was a weak -QBO and had El Niño like forcing the entire winter, making it a very unusual breed

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2 hours ago, snowman19 said:

Another thing to keep in mind about 2010, it was a +QBO. +QBO during a La Niña supports more blocking on the Pacific side. http://ionlyusethegfs.blogspot.com/2012/04/qbo-aleutian-high-relationship.html?m=1

The composites used in that link that you posted are based on 50mb QBO.

It should probably be noted that 50mb hasn't flipped easterly yet.

nWEIbYu.jpg

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35 minutes ago, EasternLI said:

The composites used in that link that you posted are based on 50mb QBO.

It should probably be noted that 50mb hasn't flipped easterly yet.

nWEIbYu.jpg

Correct, however, it was dropping and neutralizing very fast back in October. I had read on twitter it went slightly negative a few weeks back, but I guess that was probably incorrect. We have to wait for the new updated number to come out for this month...

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8 minutes ago, snowman19 said:

Correct, however, it was dropping and neutralizing very fast back in October. I had read on twitter it went slightly negative a few weeks back, but I guess that was probably incorrect. We have to wait for the new updated number to come out for this month...

He did mention a couple years that were westerly and went easterly during the winter. Which would still be on the table for now.

Quote

The following years (3) were omitted because they were not clear either because of significant month-to-month variability, hybrid placement or some other factor that was significantly altering seasonal circulation (+PDO): 1983-84 (west/east), 1985-86 (westerly) and 2000-01 (west/east). Interestingly, all of these had some westerly shear stress involved at some point in the winter and had an Aleutian High develop periodically. 

 

And the composite he shows for those has the Aleutian low that has popped up on guidance occasionally:

n69pRuh.jpg

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1 hour ago, bluewave said:

The day 11 or November 29th control run looks like it could be interesting should that piece of SW energy eject ENE into the cold air.

Take a look at the weeklies ending the Dec 4th.

The EPS busts that so bad accross the CONUS ,check out the 10 thru 15  5 day mean anomalies against those weeklies.

Big bust If thats right 

The cold is here and just looking at that pole ward spike from Alaska over the top in the LR , you are going to end up with  a continued -EPO and a big PNA spike 

The reason I like day 10 to 15 to get cold is that look portends a source region switch.

That would be a massive bust.

 too bad the control is just an op run / but I think it's possible.

 

 

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Below are seasonal snowfall statistics for Baltimore, New York City, and Philadelphia for La Niñe events (1949-50 through 2011-12). The weak events were defined as having a December-January-February average ONI anomaly of > -1.00°C; Moderate events had an average ONI anomaly of -1.49° to -1.00°C; Strong events had an ONI anomaly of -1.50°C or below. PDO figures were averaged for the December-January-February period and paired with the ONI anomalies. 

All La Niña events:
Baltimore: 15.0” (σ: 12.3”)
New York City: 24.8” (σ: 17.2”)
Philadelphia:  22.5” (σ: 18.5”)

Weak La Niña events:
Baltimore: 17.1” 
New York City: 28.3” 
Philadelphia:  24.0” 

Moderate La Niña events:
Baltimore: 14.2” 
New York City: 33.8” 
Philadelphia:  35.4” 

Strong La Niña events:
Baltimore: 12.5” 
New York City: 14.8” 
Philadelphia:  13.0” 

PDO-:
Baltimore: 12.5” 
New York City: 20.1” 
Philadelphia:  18.9” 

PDO+:
Baltimore: 23.1” 
New York City: 40.0” 
Philadelphia:  34.1” 
 

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32 minutes ago, Snow88 said:

Why not? The pattern looks good. Let's see if we have a storm to deal with.

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2 hours ago, PB GFI said:

Take a look at the weeklies ending the Dec 4th.

The EPS busts that so bad accross the CONUS ,check out the 10 thru 15  5 day mean anomalies against those weeklies.

Big bust If thats right 

The cold is here and just looking at that pole ward spike from Alaska over the top in the LR , you are going to end up with  a continued -EPO and a big PNA spike 

The reason I like day 10 to 15 to get cold is that look portends a source region switch.

That would be a massive bust.

 too bad the control is just an op run / but I think it's possible.

 

 

GEFS are on board now. -EPO/+PNA ridging, weak -NAO reflection, plenty of cold air around. Source of cold is *almost* a CPF......getting there. But yeah, colder look for sure.

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12 minutes ago, Ralph Wiggum said:

GEFS are on board now. -EPO/+PNA ridging, weak -NAO reflection, plenty of cold air around. Source of cold is *almost* a CPF......getting there. But yeah, colder look for sure.

It looks to me that the LR GEFS does  introduce cross polar flow.

Check out the surface maps , HP hooks over the top and all the way through the UMW and lakes.

I know many don't care about the cold but aligning these anomalies sometimes lead to very good events.

Yes , cold and dry is always possible  but it beats a torch where snow isn't an option 

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1 hour ago, donsutherland1 said:

Below are seasonal snowfall statistics for Baltimore, New York City, and Philadelphia for La Niñe events (1949-50 through 2011-12). The weak events were defined as having a December-January-February average ONI anomaly of > -1.00°C; Moderate events had an average ONI anomaly of -1.49° to -1.00°C; Strong events had an ONI anomaly of -1.50°C or below. PDO figures were averaged for the December-January-February period and paired with the ONI anomalies. 

All La Niña events:
Baltimore: 15.0” (σ: 12.3”)
New York City: 24.8” (σ: 17.2”)
Philadelphia:  22.5” (σ: 18.5”)

Weak La Niña events:
Baltimore: 17.1” 
New York City: 28.3” 
Philadelphia:  24.0” 

Moderate La Niña events:
Baltimore: 14.2” 
New York City: 33.8” 
Philadelphia:  35.4” 

Strong La Niña events:
Baltimore: 12.5” 
New York City: 14.8” 
Philadelphia:  13.0” 

PDO-:
Baltimore: 12.5” 
New York City: 20.1” 
Philadelphia:  18.9” 

PDO+:
Baltimore: 23.1” 
New York City: 40.0” 
Philadelphia:  34.1” 
 

 

 

To Don or anyone else -  it would be great to see the monthly breakdown [Dec, Jan, Feb, Mar] as well for each Nina intensity, and juxtaposed with Nino's. Probably a time consuming project, but would be interesting to see.

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11 hours ago, bluewave said:

The block is further north due to the very fast Pac Jet cutting through underneath. Common occurrence in a fast La Nina flow. Remember how many times the Pacific didn't cooperate even with the record Atlantic block from November 20-December 24, 2010. 

Thank you for backing me up on this.

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6 minutes ago, bluewave said:

Looks like the MJO may get active again later in November. So forecast skill may continue to be lower long range until the models get a handle on what happens. This may be why models have been all over the place as they approach day 10 and beyond recently.

 

ECMF_phase_51m_full.gif.17219e6345716ac2168c92eba365c768.gif

NCPE_BC_phase_21m_small.gif.b340574b9172482dfa28107afbc77cb4.gif

Phase 2/3 are warm for us at this time of the year, I believe.  Right?

 

 

 

 

 

 

 

 

 

 

 

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1 hour ago, bluewave said:

Phase 3 in December with a La Nina would favor a trough over the SW US. But the downstream effects in our area would depend on how much blocking there is on the Atlantic side. Very low skill forecast for near the start of December depending on what the MJO actually does.

Is it possible for the vort to eject from the SW? If so. How? 

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5 minutes ago, bluewave said:

The weird thing is that MJO 3 is more of an El Nino thing this time of year. Maybe this is somehow related to the EPAC SST mismatch? Don't want to speculate too much yet until we see how the MJO actually verifies. 

That's actually very unique. I look forward to the progression of this Phase. 

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5 hours ago, Brian5671 said:

Heck of a way to run a -PDO!   Warm blob appearing....

 

globe_cdas1_anom(101).thumb.png.0d60cd4723a8280dfe0891726e24559c.png

pdo-warm-and-cold-phases.jpg?w=720 7 day change: cdas-sflux_ssta7diff_global_1.pngWith the exception of the waters off Southern California and the northern Mexican coast, that is a -PDO configuration in the SSTA map you posted. That warm water is not the famous blob location anyway. It’s in the normal spot warmth in a -PDO is found. Here are the old SST maps of the blob: SSTAnomaly4-7-15_NOAA_NCDC.jpg      

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