Winter 2014-2015 Thread

[AvantHiatus]

Yeah, that weak Nino will bring record setting warmth.

Lol, decent chance of it...wowzers dude. Reverse trolling. 2010 is the warmest year on most datasets btw.

[Deck Pic]

We'll see how it shakes out. Lead is pretty long. There seems to be a persistent but progressive pattern of storminess in the npac right now. I'm hoping this helps the ssta config resemble a more classic +PDO and not just a mathematical one.

 

The correlation between an "Aleutian" low (it is ideally south of the Aleutians) in October and winter blocking/big snow is significant...pretty much all positive enso winters over 20" had it...even the ones where nino never got there or was in its infancy had it (below)

 

 

 

[Deck Pic]

The correlation between an "Aleutian" low (it is ideally south of the Aleutians) in October and winter blocking/big snow is significant...pretty much all positive enso winters over 20" had it...even the ones where nino never got there or was in its infancy had it (below)

 

 

 

oct.png

 

looks like the composite of neg enso 20"+ winters have an OCT low anomaly as well...the signal is robust

 

[Deck Pic]

Here is the October composite for all DCA 20" winters since 1950, regardless of ENSO state

 

[Bob Chill]

The correlation between an "Aleutian" low (it is ideally south of the Aleutians) in October and winter blocking/big snow is significant...pretty much all positive enso winters over 20" had it...even the ones where nino never got there or was in its infancy had it (below)

GEFS looks pretty good overall with the lowest heights centered well south of the Aleutians d8-15. Euro looks similar but not as amplified. We won't know if this is the beginning of a persistent pattern for a couple weeks but for now the npac is quite stormy on the models.

One thing for sure, the GOA is very stormy over the short-med term. It's under assault as we speak. It will be interesting to see the change in the SSTA config over the next week or 2.

[mitchnick]

Here is the October composite for all DCA 20" winters since 1950, regardless of ENSO state

 

20inchoct.png

I recall Stormchaser Chuck arguing some years back how we wanted a +NAO in October

that map pretty much proves why

[Deck Pic]

GEFS looks pretty good overall with the lowest heights centered well south of the Aleutians d8-15. Euro looks similar but not as amplified. We won't know if this is the beginning of a persistent pattern for a couple weeks but for now the npac is quite stormy on the models.

One thing for sure, the GOA is very stormy over the short-med term. It's under assault as we speak. It will be interesting to see the change in the SSTA config over the next week or 2.

 

my "research" suggests that if we have a -PDO, we want the warm anomalies shoved west of the dateline toward Japan...then it doesn't seem to matter as much...so I think it is more placement than actual index number..as with most indices...ideally we want to get rid of all that warm water at 30-35N east of the dateline..

[GaWx]

GEFS looks pretty good overall with the lowest heights centered well south of the Aleutians d8-15. Euro looks similar but not as amplified. We won't know if this is the beginning of a persistent pattern for a couple weeks but for now the npac is quite stormy on the models.

One thing for sure, the GOA is very stormy over the short-med term. It's under assault as we speak. It will be interesting to see the change in the SSTA config over the next week or 2.

 

Would the very warm GOA tend to promote surface low pressure/storminess there at times just because of the strong warmth, itself, causing a lot of rising air?

[Bob Chill]

Would the very warm GOA tend to promote surface low pressure/storminess there at times just because of the strong warmth, itself, causing a lot of rising air?

Water temps are in the 50s and 60s through the entire region so the warmth is relative in some ways. I'm not really sure how it impacts things irt enhancing storminess.

[Bob Chill]

my "research" suggests that if we have a -PDO, we want the warm anomalies shoved west of the dateline toward Japan...then it doesn't seem to matter as much...so I think it is more placement than actual index number..as with most indices...ideally we want to get rid of all that warm water at 30-35N east of the dateline..

I'm less worried about the PDO sucking than I was a month ago. Weather patterns have already shifted and the look down the road the next few weeks should enhance a more +PDO config than the other way around. We'll see how it goes. Almost the entire npac basin was near or above normal to start Sept. That seems to be changing now. Hopefully it continues.

[Bob Chill]

Are you referring to day 32 on the Euro ens.? Looks pretty decent.

No, just the next couple weeks. Agree that the weeklies look fine as well. No red flags.

[GaWx]

No, just the next couple weeks. Agree that the weeklies look fine as well. No red flags.

 

 Bob, Did you see this on yesterday's Euro weeklies? Judging by the 2 meter temp.'s fwiw, it doesn't look bad at all along the dateline as air temp.'s generally cool off through week 4 to modestly below normal while E PAC remain pretty solidly above normal. That would at least imply a continued pretty solid +PDO through week 4 (week ending 10/19) based on the pretty sig. partial correlation of two meter temp.'s and SST's.

[Bob Chill]

Bob, Did you see this on yesterday's Euro weeklies? Judging by the 2 meter temp.'s fwiw, it doesn't look bad at all along the dateline as air temp.'s generally cool off through week 4 to modestly below normal while E PAC remain pretty solidly above normal. That would at least imply a continued pretty solid +PDO through week 4 (week ending 10/19) based on the pretty sig. partial correlation of two meter temp.'s and SST's.

I only get 850's on the weeklies but the look is the same as you described. There is good agreement between the GEFS/EPS that the N central pac will be dominated by BN heights and surface pressure over the next couple weeks and the weeklies are showing a strong signal that type of lw pattern to continue. It's a good sign for sure. Let's hope it's a harbinger of sorts and not a false weenie signal ending in cancels, panic, and death.

[StudentOfClimatology]

Weird. Here's the DJF...

Do you have the 500mb height anomalies? I find them a lot more useful than 2m temps on these prognostications.

[StudentOfClimatology]

Would the very warm GOA tend to promote surface low pressure/storminess there at times just because of the strong warmth, itself, causing a lot of rising air?

It would, all else being static. You need adequate tropical forcing in these cases to get it, though...macroscale lift in the W-PAC generally promotes Typhoon Activity which can really help.

[JoMo]

Would the very warm GOA tend to promote surface low pressure/storminess there at times just because of the strong warmth, itself, causing a lot of rising air?

 

I don't think it did last year, did it? The GOA was very toasty and we saw a ridge over the area in the winter months.

 

http://www.pmel.noaa.gov/ocs/news/news_story-TheBlob2014.html

[wildweatherman179]

I don't think it did last year, did it? The GOA was very toasty and we saw a ridge over the area in the winter months.

http://www.pmel.noaa.gov/ocs/news/news_story-TheBlob2014.html

The ridge was actually centered east of there if I'm not mistaken.

[AlaskaETC]

The NASA model website is still kaput.

[GaWx]

The ridge was actually centered east of there if I'm not mistaken.

 

 Actually, I do believe that if the ridge is centered a little east of the GOA (maybe near the west coast?), it is colder for the E US due to average wavelengths though maybe not as cold for the central US. Any other opinions on this? Also, I think SoC was even saying that a GoA warm area/+PDO actually promotes downstream ridging rather than ridging right there since the warmth tends to promote rising air/lower presures. I had never seen even a pro met. explain it quite this way. He at least sounded as if he new about what he was talking. SoC, please comment if you see this.

[StudentOfClimatology]

Actually, I do believe that if the ridge is centered a little east of the GOA (maybe near the west coast?), it is colder for the E US due to average wavelengths though maybe not as cold for the central US. Any other opinions on this? Also, I think SoC was even saying that a GoA warm area/+PDO actually promotes downstream ridging rather than ridging right there since the warmth tends to promote rising air/lower presures. I had never seen even a pro met. explain it quite this way. He at least sounded as if he new about what he was talking. SoC, please comment if you see this.

Warm SSTs favor lower surface pressures in a *static* model without inter-domain relations, yes. So if we were to hypothetically assume that N-PAC SSTs are a governor of sorts, you'd expect lower pressures over the N-PAC/Aleutians in the means.

Unfortunately, it's a lot more complicated than that. Tropical forcings (ENSO/MJO) and the QBO are the primary governors of both the mid-latitude wave train and the resulting SSTs, based on what I know.

[JoMo]

Here we go. The synoptic discussions from last year from the NCDC shed some light on what drove things last year on a month by month basis. 

 

You can start with December here:

http://www.ncdc.noaa.gov/sotc/synoptic/2013/12

 

 

The overall 500MB height anomaly for Dec-Feb (primarily due to the Pacific ridge in D/J as it was undercut in Feb)

 

[millwx]

The NASA model website is still kaput.

 

It's fine.  For some reason the link I posted doesn't jump there properly.  Dunno why... I just cut and paste the URL.  Their site is fine and up and running... and updated earlier today.

[millwx]

Do you have the 500mb height anomalies? I find them a lot more useful than 2m temps on these prognostications.

 

Here ya go, SoC... I'm not a fan of 5H anomalies, as the 5H climo isn't flat, zonal pattern.  So, the placement of the 5H anom maxes/mins is not necessarily the ridge/trough positions.  But, no matter, the GEOS5 site doesn't provide the 5H mean pattern forecast... just the anoms.  So, here they are:

 

[millwx]

Don't know why the link I posted before doesn't work.  The NASA GMAO/GEOS5 website is working just fine.  Try this one (use the menu on the left to navigate to the parameters you want):

 

http://gmao.gsfc.nasa.gov/cgi-bin/products/climateforecasts/GEOS5/index.cgi

 

...hope that works!

[mitchnick]

Here ya go, SoC... I'm not a fan of 5H anomalies, as the 5H climo isn't flat, zonal pattern.  So, the placement of the 5H anom maxes/mins is not necessarily the ridge/trough positions.  But, no matter, the GEOS5 site doesn't provide the 5H mean pattern forecast... just the anoms.  So, here they are:

 

strikes me as a suppressed pattern with SE to MA having a shot at more fun than further north

[StudentOfClimatology]

Here ya go, SoC... I'm not a fan of 5H anomalies, as the 5H climo isn't flat, zonal pattern. So, the placement of the 5H anom maxes/mins is not necessarily the ridge/trough positions. But, no matter, the GEOS5 site doesn't provide the 5H mean pattern forecast... just the anoms. So, here they are:

Thanks.

Interesting prediction over the N-PAC. That might actually be the weirdest looking height anomaly forecast I've ever seen. The seasonal ECMWF and CFS also have the warm-bias issue, for whatever reason.

Definitely am skeptical of the Aleutian ridge on that map.

[StudentOfClimatology]

Don't know why the link I posted before doesn't work. The NASA GMAO/GEOS5 website is working just fine. Try this one (use the menu on the left to navigate to the parameters you want):

http://gmao.gsfc.nasa.gov/cgi-bin/products/climateforecasts/GEOS5/index.cgi

...hope that works!

Nope

[mitchnick]

Interesting prediction over the N-PAC. That might actually be the weirdest looking height anomaly forecast I've ever seen. The seasonal ECMWF and CFS also have the warm-bias issue, for whatever reason.

Definitely am skeptical of the Aleutian ridge on that map.

that's a whole lot of high pressure over the Pole too.....can we say b-l-o-c-k-i-n-g! (-AO)

[GaWx]

 Regardless of global warming (I mean it isn't nearly that warm, is it???), this NASA map is strongly suggesting a pretty strong warm bias as has already been implied.

[StudentOfClimatology]

Regardless of global warming (I mean it isn't nearly that warm, is it???), this NASA map is strongly suggesting a pretty strong warm bias as has already been implied.

Eh, I don't think CC is responsible for bad model forecasts. Correct me if I'm wrong but I don't believe the JMA has the warm bias problem.

That said I have no idea what their radiative forcing equations are.