frd

Last couple years we had good gains and I believe record North America snow cover in early December . Then, after December 20th it starts to shrink due to Pac air and a warmer NA pattern. Last year, and the year before were very abrupt turn around. However, my speculation is that we at least may get an impact from this moving into mid to later November, in terms of colder air . The SAI and extent regarding a connection to the winters dominant ensuing AO phase has basically be proven false. However, we do need a healthy cryosphere to support significant cold in our region. We may get some a few -EPO intervals this winter.

Look at the winter thread I covered it there.

For those who follow the PDO , this is an eye opener. As bluewave noted, you do not typically see this in a Nina. Oh, and as you can see from the image below unless you are talking real time cause and effect, don't get excited just yet. Just look at last December 1 st and then the following Jan 15 th time period. We went from + PDO to negative PDO in a matter of weeks, with a two point deviation decline. < The PDO isn’t following the La Niña playbook this fall. This was one of the biggest PDO increases during a La Niña in October. But as we have seen since the record North Pacific warming in 2013, these monthly values can really jump around a lot. Last winter we went from positive in December to negative during January and February. It all comes down to how the North Pacific ridge behaves. >

Beach chase coming up !

Interesting https://www.osti.gov/biblio/1613223 Ural Blocking as a Driver of Early-Winter Stratospheric Warmings Abstract This study explores the early-winter atmospheric response to Ural blocking anomalies in November, using a nudging technique to constrain the temperature and dynamics in a high-top atmospheric model. Persistent Ural blocking anomalies in November are associated with a warm Arctic/cold Siberia pattern and increased upward planetary waves entering the stratosphere, leading to a warming of the polar vortex. This stratospheric response then propagates in the troposphere, leading to increased occurrence of the negative North Atlantic Oscillation in December and January. In contrast, simulations with perturbed Barents-Kara sea ice and Siberian snow in November do not reproduce a significant atmospheric response. In simulations including a slab ocean, the Ural blocking induces Barents-Kara sea ice and Siberia snow anomalies that resemble composite analyses from observations. These results highlight Ural blocking variability in November as a robust driver of early-winter stratospheric warming while questioning causality between sea ice/snow and Ural blocking anomalies.

A look at the latest CFSv2 and the GEFS 35 day forecasts we see overall the early season vortex still close to the seasonal ERA5 mean. The CFSv2 actually a little below the mean, with the GEFS slightly above the ERA5 mean. While the 35 day GEFS tracks the PV slightly above the seasonal ERA5 mean.

Speaking of the Ural High and the Scandi - Greenland pattern, maybe showing up in a more significant fashion for the month of November. Worth following, as the implications are significant, both short-term and long-term.

Many of those factors we have heard already, especially the possibility regarding the poleward Aleutian ridge. Wondering the effect of less sea ice, however, my thoughts focus on rapid snow cover up North along with a November enhanced - EPO / +PNA later November. Snow is indeed expanding now in week 42 up North. How long the SST configuration lasts off the West Coast / North Pac is up to debate. I am not so sure about a + NAO though, feel there may be a couple - episodes. Speculation on the Ural High connection. Keep an eye too on the Scandinavia–Greenland pattern . Although hard to predict beyond week 2. More about that on the link below. https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.3892

So true. Only with climate adjustments and weighting can you even begin to consider older analogs .

Speaking of analogs, take from this what you want. Both threads below have very interesting takes on climatology, analogs and SSTs . 1942 did happen during WWII.

As Anthony mentions, the weekly value does not define the strength of the Nina. However, it has joined a few others in the strong group, in week 42.

Interesting update. Do you feel those analogs you mention are still useful in our present climate regime? You must feel they have have some merit of course, as you stated they are the " best ENSO match by a combo of structure and intensity," but wondering whether you could comment further.

Pondering the Nina correlation to the ensuing winter's NAO and IOD, well.................

What once looked like a chilly air mass later this month has now turned into more of the same with cold fading and warmth returning. Some asked when this new era of less snowy winters and generally warmer weather started here, well this post by bluewave is an eye opener. I still feel that 2016 was a turning point. from bluewave < It has been the only cooler than average part of the US since the Super El Niño in 2016. >

Seems that Greenland ice melt effects ( has altered ) the Greenland ocean circulation/tripole that is used to forecast the winter's ensuing dominate NAO phase. Just started to research this and also read a few intriguing posts by HM. Some state the summer ice melt was not as bad in Greenland, but according to HM is still was not great when you target on his on his focus which is repairing the Greenland ocean circulation/tripole. As HM states, the ice melts throws a monkey wrench in the NAO forecasts of the upcoming winter. HM states it is better to look at the Spring's tripole for an indication of the ensuing winter's NAO versus the tropical season. Caveats apply though, in regards to Greenland ice melt and AGW. Some interesting things to consider here.

Mentioned we might get some interesting North Atlantic weather later in October, and it appears we may indeed get a deep bomb cyclone to form there near the 27 th., however, the exact outcome and lowest pressure are still uncertain. The 00Z GFS looks too extreme.

Looking ahead we go significantly above normal later this week. Anyone with flowers that did not have meaningful frost damage look to hang around deep into the month. Huge storm off the coast late week. but a phasing opportunity is lessening.

This was a surprise for my area, updated at 9:30 PM from MH AFD. With this update, have expanded the Frost Advisory to all counties where the growing season remains active, save for Philadelphia and Delaware Counties and the coastal strip. While the odds of frost will decrease closer to the urban corridor, there is enough potential in the more outlying areas to warrant an advisory throughout the CWA. Also, some areas within the advisory may get down to freezing, but not expecting it to be widespread enough to warrant a Freeze Warning in areas where the growing season remains active.

I have also scored relatively well with rainfall. Grass is green and lush. Tomorrow AM.looks like junior league Jebb walk weather. Looking forward to a walk with my greyhound trying on his new European sweater.

Appears that we go rain free for the next 7 days with moderating temperatures and beautiful weather for late October.

Nina results vary, but cool to see the various temp profiles going back to 1925.

From Met Walt Drag A fair amount of discussion about the 25th-26th... am considering a topic since it's amped with potential, but that this could still easily be a marine storm once past FL. I'd like to see more ensemble agreement on a storm up the coast, supported by 30% or greater prob for 2"+ along the E Coast. If that were to occur, it's probably a few days off but imo, little doubt (in my mind) the models are onto two more tropical systems 19th-26th in the W ATLC. One other thing...while most of the debate is about 1) whether a storm, and then 2) either out to sea or up the coast... I can visualize jet stream pattern adjustments that permit E GMEX and northward up the W side of Apps. Just very-very-very early. I think Epsilon may get named within 48 hrs. Am posting on tropical page a couple of graphics. It probably won't a direct influence on our area except for swells... however, its eventual development may strengthen the WAR, and provide an even more favorable flow pattern for the 25tth-26th? We'll see, Post goes up by 525PM, unless it's already done there by a tropics poster.

Looks like a black hole on the afternoon GFS.

Must be big axx squirrels !

Nina update