Carvers Gap

The first high elevations snows(light) are expected in the Smokies overnight. I wonder you will see some, John?

The closer we are getting to winter(and I can actually see some weeklies runs), the more I think we are playing with house money at some point.

I really like JB's rule that winter weather (snow, cold, ice) tends to show up where it rained a lot during fall. Just file that away.

The PDO is a decadal trend...haha. Sorry, had to. But.......we should be coming out of that crap trend sooner than later. 17-18 seems like when this current winter pattern began. Cold starts to winters, and meh ends to winter w/ the middle of winter being a crapshoot. Some extreme cold shots have been embedded. That PDO cycle is coupled with the La Nina which is normal I think. With the La Nina cooling things off a bit(nature's thermostat), the next weak(and it must be weak) El Nino should offer decent chances. The NAO appears to be trending more negative during winter after decades of dormancy. The AMO should flip within the next 3 years - debate as to its "realness" allowed.

Check out the 18z GFS at 156z.

I definitely like a cold November, but w/ La Nina's of late....that rule hasn't played as fairly as year past. Probably has something to do w/ less see ice over the Arctic region. As for Nov, I think we start cold, warm-up during the middle 10 days, and cool comes back(edit...that originally made zero sense). We may be able to get a normal month in terms of temps with that setup. Since months are kind of arbitrary in the grand scheme of things(30 day increments), I think if we can get a pattern of strong amplification w/ some troughs coming through...we should be good. Amplified patterns (as long as they aren't too crazy) work for much of the forum area. I just don't want the motherload of cold during November. That was kind of my main thought. I want a flip strongly to cold to begin winter. I think that is our best chance this winter(December). Then, we hope it returns. It is worth noting Cosgrove strongly favors a backloaded winter and patience. I tend to see that as a Nino pattern, but he has some sound thinking, and really supports his ideas. Regarding this winter, I think for coastal areas, La Nina is no bueno. West of the Apps, we can score and score bigly. Kind of feast or famine like that Tennessee defense. I think we see chances at winter. Right around November 4th...strong signs of a big coastal.

Starting to see AN heights rebound for November on modeling. That is a GOOD thing. We do not want the flip to be now. Looks like a 1-2 week bout of BN heights, and then a bounce back to warm. Euro Weeklies, and to some extent the CFSv2, are showing a stout western ridge (like into the Arctic Circle) along the West Coast by the second week of December. That fits climatology. And it looks frigid. The Weeklies actually have BN temps for that week at the surface, and that almost never happens at this range. Huge grains of salt, but winter is showing its hand every so slightly on Weeklies. The good thing is that I am not having to rely on seasonal modeling...the weeklies have the first two weeks of winter in range.

Thursday night Euro is just nastiness - cold rain, likely mountain mix w/ a low parading across the Gulf states. My kind of weather, but it isn't for everyone.

Just looking at Apple Wx on my phone, I still expect to see temps in the upper 70s w/ sun. Right now, all I see are 50s and rain chances. This looks locked in for a bit. Should get a brief respite of warm during mid Nov before getting cold again. Long range pattern really does not want to budge.

I am definitely interested in the time frame around Halloween. The 12z GFS gets VERY close to something good for NE TN. The CMC isn't that much different. The Euro never entrains southern energy.... I am going to guess that has an inland runner.

Ensembles are picking up a fairly strong amplification on October 30th.....GEFS and EPS both. It is a pretty strong signal.

Second morning in a row with heavy frost. Yesterday morning was much colder than expected. Today was cold but was expected.

Both the 12z CMC and Euro have some iteration of this boomerang effect where a tropical system gets caught in a strong cold front, gets pulled northeast, and becomes a monster of sorts.

Interestingly, long range operational models are flirting with entraining a tropical system into an eastern trough around or just after Halloween. That is not without precedent during that time of year.

Kind of looks like the 13-14 analog might be showing its hand....

After bouncing around and not being able to make up their minds, it does indeed look like ensembles are depicting a pattern change beginning with today - shock...not in a few weeks. There will be some ridges roll through, but the pattern (as John notes above) should grow progressively colder. It is shoulder season, but colder solutions on ensembles appear to be taking over. This is a bit early for La Nina fall flips, but it does look like that is at hand. It won't be as abrupt as I was thinking, but there could be some really cold days embedded. Halloween looks very cold on ensemble runs at 12z - like green and not blue for departures. I think that is like 6-8 degree below normal with flurries in the mountains possible in that time frame. What is the cause of this? I "think" the tropical activity in the Atlantic, even though it isn't hitting NA, is really shaking up modeling. I would even suspect it might shake up Weeklies runs as well.

The Euro Weeklies this evening are depicting a cold pattern to end October and begin November...transient type of pattern. By the end of November, they look quite cold and storm.

Just toggling between the (3) weeklies (American, Euro, and Canadian)....there is blocking showing up over Greenland or slightly west of it in the Davis Straits. That is usually a pretty good sign that cold is coming. One thing to watch for is what the Pac does. If it is meh...periods of zonal flow could persist w/ maritime air flooding the continent. If the EPO or PNA fires up, then very cold air could head south. Some runs have the AN heights over the northern Hudson Bay....to me that is a crapshoot as to whether that helps us or not, and that is not a true NAO. If coupled with a good Pac, that works. Otherwise, zonal.

Just and addendum to the post above....the Euro Weeklies(control) does have a sharp downturn in terms by week 2 of November. The Weeklies ensemble has this as well. The CFSv2 yesterday morning started to show some hints of this. Let's see where this goes. Obviously, this could be a head fake at this lead time, but this fits with what we know about Nino climatology. It would not surprise me to see snow in the air by mid November, especially for foothills and mountain locations. It appears that summer is finally on the clock! I mean it has to be by mid November, right?

I strongly encourage everyone to read @John1122's posts in the winter discussion thread. Why? Because what I am gonna say next kind of dovetails into those comments. Both the 0z GEFS and GEPS are depicting a pretty significant(?) pattern reset to begin November. That kind of fits the 4-6 week pattern cycle of the past many years. Ridge slides west, and a trough develops in the central and eastern part of the United States. That could be a SHARP change in temps given the summer like temps we are experiencing right now. We are talking 20-30 degree differences in high temps. The Euro weeklies don't see this just yet, but they often get roasted during shoulder season...before often locking in the winter pattern by mid Dec. The 13-14 analog also had a sharp change in temps by November....

What was the preceding fall season like? AN temps w/ some periodic rain chances?

La Nina is just HOT in my backyard during fall. It has not been as hot as some years, but it is still very warm. Nights have been cool. It is almost like living in the desert with such low humidity. Leaves here are definitely in a state of suspended animation after some cold days in August and early September. Now, that we have switched firmly back to summer...everything is paused. Leaf season will run into early winter here. There are some hints that cooler weather is coming. The CFSv2 has an outright flip at 500 while the Euro Weeklies are typically blind to it. That said, the Euro Weeklies control doesn't have the flip. Usually if a flip is about to occur, I like to see the Euro Weeklies control and CFSv2 both showing something similar. Until we see that, I look for at least 2-3 weeks more of very warm weather...maybe longer, but that is pushing the envelope as the pattern will be due for a change sometime around mid-November. Ideally, we want the pattern to flip during the last week of November or first week of December. Then, maybe we can get 4-6 weeks of a pattern which could yield winter weather. What we don't want is the pattern to flip cold in early November. If it does that, that means it may well flip back warm by mid December and hold through most of January. That is a concern and very much on the table.

I have seen that year mentioned as well. How did that winter look?

@John1122, heavy snow warnings for the summits of Mono Co. John, who is it that you follow in Mammoth Lakes?

Powell is coming out of hibernation. Can someone unlock his account for him?