Re: Long Range Thread 9.0

[sroc4]

Good morning. This is def going to be an interesting winter to follow and learn from. Unfort we will cont to have to here all the "winters over" crys while we wait for it to start. Here are Larry Cosgroves latest thoughts on winter and the current El Niño. Spoiler Alert...el Nino is NOT the main driver to the anomalously warm Nov and Dec.

"It goes without saying that many who wish for "real winter weather" in the United States are deeply troubled by the very warm December temperatures so far. Many unfairly are pointing fingers at the El Nino episode, which actually is not behaving according to synoptic climatology for such events. The Pacific Northwest continues to see excessive precipitation, while California and Florida have largely missed out on the excessive rainfall cases seen in 1982-83 and 1997-98, the previous periods that featured a very high-end +ENSO signal.

The polar westerlies remain unified, and dominant, which is much more like what should occur in a well-defined "La Nina" influenced pattern in the colder months over North America. Curiously, conditions across Eurasia are performing fairly close to weather that transpires with an El Nino (split flow, colder northern third with occasional spillages of cPk and cA regimes into the Middle East and Indus Valley).

So the operative question that is bandied about: are we really going to miss winter this time around? Has "global warming" conspired with the "Super El Nino" to chase away Santa for snow lovers in the U.S. The answer is no, Virginia! The warm December was forecast well by the analog method used here (no snow in Buffalo, and in fact total lack of ice over the entire Great Lakes). And there are very valid reasons for a "for real" change in the jet stream configuration across the entire continent once we move deeper into January.

First of all, I should clarify what I think is causing the display of mild temperatures and the unusual array of precipitation in the lower 48 states. It is not El Nino. Rather, the dominant driver in this configuration is the immense circumpolar vortex (see 10MB temperature forecasts), which has fairly evenly covered the Arctic Circle up to this point after congealing in October. This +AO phase is impressive, no doubt. Such a strong cAk gyre blots out any and all chances for lasting blocking ridge formation above 50 N Latitude. But research on the subject shows that long-lived and intense circulations straddling the North Pole cannot go on forever. And I suspect that cracks in the vortex will show up soon, given what the numerical models are projecting as a shift in the skew of the frigid circulation toward northern Europe and western Russia.

Another factor to consider is the very warm oceanic sea surface temperatures. It is not just the El Nino signal; check out the Atlantic Basin (excepting near the Grand Banks/Flemish Cap) and the entirety of the Pacific and Indian Oceans. The atmosphere has been responding by moderating its boundary layer readings. But with a low sun angle and increasing snowpack in the Northern Hemisphere, something has got to give. With the aforementioned stratospheric warming in the western third of North America, and the still vigorous subtropical jet stream crossing Mexico into the Old South (forced there by the anomalous Southeast heat ridge), a mean 500MB trough should start to form between the Rocky Mountains and Appalachia during the first week of January. It continues to be my thinking that a +PNA/-AO configuration will take shape next month, with the risk of major storms tracking along the Gulf Coast and then up along or off the Eastern Seaboard. That means drainage of air from Canada and the snowpack which is expanding across our northern neighbor.

Until that time, I can assure you that the 11 - 15 day period, and probably most of the 16 - 20 day range, will again be a cold/cool West vs. mild/warm East alignment. Storms should still roll through the Pacific Northwest into the lower High Plains, than recurve into Michigan and Ontario. A key flashpoint in the last week of December and first week of January is snow cover in the Upper Midwest and Great Lakes. If we indeed are going to see a colder turn in the New Year, Minnesota, Wisconsin and the MI Upper Peninsula will see more of the white stuff as we greet 2016.

Winter is not over yet, gang. We've only just begun. "

[Frank_Wx]

Nice read. He brings up a great point - our atmosphere is not responding to El Nino. The STJ is displaced north into the central and northern Pacific. Storm systems effecting Pac NW should realistically be tracking into southern California during an El Nino. Additionally, the MJO has been very active the last several weeks. If you research the MJO during El Nino years, it's shown to be in the COD. In sum, the MJO and Stratosphere are the main drivers behind our current pattern and the El Nino acts more as an enhancement. So yea, def agree with Larry with this. Though I do feel the very strong 200-300mb jet streaks crashing into the western US have something to do with the intensity of El Nino.

[amugs]

Those who need to see the evolution of models - CFSv2

November 30th


Dec 12th - my my what a frickin change a good look - heights protract W and N and allow the colder air to cut underneath it to the coast for Jan - happening faster than some think

[sroc4]

Nice read. He brings up a great point - our atmosphere is not responding to El Nino. The STJ is displaced north into the central and northern Pacific. Storm systems effecting Pac NW should realistically be tracking into southern California during an El Nino. Additionally, the MJO has been very active the last several weeks. If you research the MJO during El Nino years, it's shown to be in the COD. In sum, the MJO and Stratosphere are the main drivers behind our current pattern and the El Nino acts more as an enhancement. So yea, def agree with Larry with this. Though I do feel the very strong 200-300mb jet streaks crashing into the western US have something to do with the intensity of El Nino.  

I think the STJ is being shunted south actually into the Mexico and into the "Old south" region.  The NW is being inundated via the Pac Jet.
" />

[algae888]

I do not recall ever seeing +15-20 temp departures on 10+ day ensemble mean. it's even on all guidance. this is the easiest 2 week forecast ever in winter.

[dkodgis]

Yesterday, I checked the temps at around 7 pm on my iPhone and for Seville Spain, Tokyo Japan, Glenmore PA, Wallkill, NYC...all said 54 degrees. I have friends in these places and I live in Wallkill; maybe even the weather widget for the iPhone is getting confused and there is a tech problem. It seems too convenient that the same temps are found in these places across the planet. I still have roses on one bush and I had to cut the grass again yesterday. I wonder what Spring 2016 will be: very dry? What happens in the spring in the NE after a strong El Nino?

[skinsfan1177]

Yesterday, I checked the temps at around 7 pm on my iPhone and for Seville Spain, Tokyo Japan, Glenmore PA, Wallkill, NYC...all said 54 degrees.  I have friends in these places and I live in Wallkill; maybe even the weather widget for the iPhone is getting confused and there is a tech problem.  It seems too convenient that the same temps are found in these places across the planet.  I still have roses on one bush and I had to cut the grass again yesterday.  I wonder what Spring 2016 will be:  very dry? What happens in the spring in the NE after a strong El Nino?

That's crazy. My wife's family lives in wallkill and pine bush by. We will be heading that way for the holidays

[Quietace]

Nice read. He brings up a great point - our atmosphere is not responding to El Nino. The STJ is displaced north into the central and northern Pacific. Storm systems effecting Pac NW should realistically be tracking into southern California during an El Nino. Additionally, the MJO has been very active the last several weeks. If you research the MJO during El Nino years, it's shown to be in the COD. In sum, the MJO and Stratosphere are the main drivers behind our current pattern and the El Nino acts more as an enhancement. So yea, def agree with Larry with this. Though I do feel the very strong 200-300mb jet streaks crashing into the western US have something to do with the intensity of El Nino.  

I think the STJ is being shunted south actually into the Mexico and into the "Old south" region.  The NW is being inundated via the Pac Jet.
" />

You are correct. You can clearly see the STJ ejecting out of the ITCZ as you pointed out. Though thats not to say some tropical convection that originated from the STJ ejected into a mid latitude cyclone giving the PAC Jet similar Precip Water Values; hence similar moisture characteristics.

[docstox12]

Nice read. He brings up a great point - our atmosphere is not responding to El Nino. The STJ is displaced north into the central and northern Pacific. Storm systems effecting Pac NW should realistically be tracking into southern California during an El Nino. Additionally, the MJO has been very active the last several weeks. If you research the MJO during El Nino years, it's shown to be in the COD. In sum, the MJO and Stratosphere are the main drivers behind our current pattern and the El Nino acts more as an enhancement. So yea, def agree with Larry with this. Though I do feel the very strong 200-300mb jet streaks crashing into the western US have something to do with the intensity of El Nino.  

I think the STJ is being shunted south actually into the Mexico and into the "Old south" region.  The NW is being inundated via the Pac Jet.
" />

That is just an incredible image Doc.Amazing!!!

[amugs]

This is just brutal - my god we'll finish December +12 with this = blow away any record in recent history!!!

[Quietace]

This is just brutal - my god we'll finish December +12 with this = blow away any record in recent history!!!

Warm and Wet with the position of that ridge.

[CPcantmeasuresnow]

This is just brutal - my god we'll finish December +12 with this = blow away any record in recent history!!!

This December may break the record for the greatest warm temperature deviation from average we have ever seen in any month. Al mentioned this in an earlier post and I agree.

I was hoping that after the warmest autumn in history in these parts that things might finally turn, in realty they have gotten much worse, at least for the short and mid term.

[amugs]

Maybe some white gold for a well timed system as per euro Friday night - inland??



Bastan get crushed of course

[Snow88]

^^ I will just be happy with snow flakes lol

[amugs]

^^ I will just be happy with snow flakes lol

Me too!!!!!!!!!!!!

[Snow88]

12z Euro is still showing the PV getting attacked.

[NjWeatherGuy]

Models have been showing weak precip along the frontal passage for a while now, but its very light and surface temps are warm, might not even make it to the ground and if it does it wont stick.

[HectorO]

Is it time for the "As December goes" thread?

[Guest]

Is it time for the "As December goes" thread?

Good one. Brings back memories!!!

[Snow88]

We will be good in the long haul as long as the PV keeps getting beat up

[amugs]

SROC - here we go buddy - Nino cooling and as I showed with that water depth chart of cooliong and you stated thyis too looky see:









Could have used this in mid November but we'll take it - peak has been reached and cooling off in a big way in just once week.

[amugs]

1.2 3 3.4 4
18NOV2015 23.8 2.1 28.0 3.0 29.7 3.1 30.4 1.8
25NOV2015 24.4 2.4 28.0 3.0 29.6 3.0 30.3 1.8
02DEC2015 24.7 2.4 27.9 2.9 29.5 2.9 30.2 1.7
09DEC2015 24.8 2.3 28.0 2.9 29.4 2.8 30.2 1.7

12-14 2.16 2.65 2.45 1.58

[Frank_Wx]

Here's some good news. It appears a substantial wave 1 warming event is taking place in the upper Strat between 1hPa and 10hPa in the 7-10 day range. The difference between this one and the one from Thanksgiving is there appears to be wave 2 induced warming involved. Someone correct me if I am wrong, but I believe wave 1 means one ridge and one trough in a latitude belt, while wave 2 means two ridge's and two trough's.

EURO 1hPa temp & heights day 7:



Now day 10:



Part of this may be due to the subsiding easterlies near the Equator to 20N (blue color). Westerlies are taking over in the upper Stratosphere, albeit not very strong just yet.



EURO 10hPa temp and heights Day 7:



Day 10:



You can almost see the wave 2 influence with ridges forming on both sides of the PV. However, it is not look strong enough at the moment to split the PV. I still think this is pretty unlikely just from what Iv'e been reading about -QBO years. We're banking on a strong wave 1 event to displace the PV out of the Arctic Circle.

What's key is to get the warm temperatures to propagate to the mid and lower levels of the Stratosphere. Despite the stronger wave 1 event compared to late November, it does not look like it's enough to penetrate the mid-levels just yet. 50hPa looks to remain very cold.



Judah Cohen posted this on his Twitter:



In a nutshell, it shows stronger vertical energy transfer of Rosby Waves between the Troposphere and Stratosphere between Dec 20th and 25th. This will should help warm the Arctic and weaken the PV.

Lastly, sunspot activity continues to trend downward. The Sun should not be much of a factor when it comes to Troposphere-Stratosphere interaction.



The trend the last couple of days has been for this wave 1 & 2 attack to get stronger. We'll see if this trend holds in the upcoming days.

[HectorO]

If this keeps up, hurricane season will start in March this year.

[HectorO]

http://time.com/4147776/warm-east-coast-weather/ I wonder why "EXPERTS" say next year will be hotter????

[Frank_Wx]

Dr Judah Cohen feels a SSWE is on track to occur around the 2nd week of January.

"

At AER we have developed a polar vortex model that predicts the strength of the polar vortex one month in advance. As we discussed in the blog last month, the model was predicting the polar vortex to become disturbed the third week of December, which is now being predicted by the weather models. The polar vortex model also predicts a similar perturbing of the stratospheric polar vortex in the first week of January and again an even bigger event the second week of January. In addition, the predicted temperature pattern of cold Siberia and warm western Eurasia is favorable for increased WAFz. Therefore, based on the polar vortex model and the upcoming atmospheric circulation pattern, we are anticipating more upward pulses of WAFz. If our expectations of more upward pulses of WAFz is correct, this should be sufficient to force a sudden stratospheric warming (SSW) sometime in January. One ongoing inhibiting background factor is the westerly phase of the quasi-biennial oscillation (QBO) that favors a strong vortex over a weak vortex. But if our expectations of a weakened polar vortex verify, this will likely favor an increased likelihood of severe winter weather across the continents of the Northern Hemisphere. On the other hand, if our expectations of an active period of WAFz is incorrect then the polar vortex will remain strong and likely the AO will remain positive and the weather pattern mild for the Eastern United States, Northern and Western Europe and East Asia."

[HectorO]

So best case scenario is another 2 weeks of winter gone next month, with the hope of it changin by the 3rd week?

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