Carvers Gap

Snow is falling on Mt Leconte this evening.

The pattern change to a much cooler pattern is likely at hand. I think this lasts through early to mid-Nov, and then flips back warm for 6-8 week to close out the calendar year. While not exactly rocket science, that is fairly textbook Nino climatology if it happens in that order. My guess is the first winter time air masses will arrive mid-late January - nothing earth shattering. Again, I would not be surprised to see snow flying in the mountains early next week, but likely during the next 4-6 weeks.

New drought map should be released at 8:30 this morning.

14-15 looks like it bottomed out during winter at roughly the same time this one might. 09-10 looks like it paused during winter and then continued down. Are you seeing evidence of a head-fake? Just skimming the data sets, it looks like the QBO loses some downard trajectory between months 3-5 once it is negative, and then continues downward.

Jeff, do you think the QBO can stay falling through winter? Looks like we are three months into the (negative side of things)drop and already at -13.58. Guessing we "bottom out" around January-ish as we hit negative during July. I am just using the 6-7 month rule from when it hits negative. To me, it starts coming up during Feb????

I do believe the mountains have a decent chance of seeing snow above 5000' early next week on the GFS (12z and 18z). Some upslope rainshowers in the mid 30s. That often translates to frozen.

The 1970s analogs are just awesome. The late 60s "I think" had a Thankgsiving snow or very early 70s. My parents talk about traveling home during that break and having a lot of trouble.

I think flurries and snow showers during late October are perfectly normal. Early season snowstorms IMBY usually mean the Arctic gets "emptied" early and may or may not rebuild its strength. The pattern on modeling right now does not look anomalous. Just looks like a cool-ish weather pattern. I think anomalous snows in October are what is sketchy. I am just used to winters starting early out West during the past decade - and I think that is already under way again. But really, a feaux start to winter is somewhat normal for El Nino, and then December rocks warm.

The 6z GFS this morning is wild.

Both the CMC and GFS at 12z show what appears to be at the very least a relaxation in the current pattern if not a complete reversal - back to chilly temps. Snow is on the 12z GFS for the mountains, and that set-up would likely get frozen precip into the foothills if that verified.

Yeah, I hate to even discuss it. I have alluded to it. Fountain mentioned the NE TN mountains have had more rain than the valleys. That is fortunate. Worried about other areas as you note. With temps cooling off, that is a HUGE plus. Looks like first legit rain chances will be next Saturday. At that point, maybe some minor relief is on the way in the long term. What is crazy is LR modeling pretty much nailed the spigot being cut off. Today's CPC 3-4 week forecast has normal to AN rainfall for that timeframe.

The force is strong w/ the +PNA re: this afternoon's ensembles.

Now for some way-way-way out there ideas...I think the 24-25' winter would be similar to a composite analog of the past three winters(not including the upcoming one). We had better hope that El Nino has some hangover effect next summer...otherwise, July/August next summer could be very hot against the norms. I would likely say that next summer is of the "endless" variety unless the Nino unexpectedly hangs on. Next winter could flirt with strong Nina status.....and that is torch city. But who knows, it could do exactly the opposite!

Good to see the PDO getting more press. My drivers this winter are probably still the same. 1. El Nino shifting to basing wide by mid/late-winter(completely reversed to Nina by next summer?) 2. MJO 3. PDO 4. QBO/potential for subsequent Atlantic blocking. Overall, no changes to my original ideas at this point.......One tweak which may be required is to add more wintry precip to the far western areas of the forum (if the Euro seasonal is correct). For now, I am not going to "bite" on that look quite yet. I have noticed seasonal modeling often trends to whatever is in the 2-4 week range, and then just perpetuates it erroneously. Of note, a lot of great posters no longer place their ideas on public forums or websites. Why? One, accuracy is still very tough to come by w/ seasonal forecasting. Two, nobody likes being wrong so often! Generally, I try to go with large scale pattern looks, and steer very clear from detailed areas of particular regions. That said, I have tried to make sure there is a bit of added detail for our forum area, but that comes with the risk of being more inaccurate. I say this often...our forum area is affected by four bodies of water(Pac, Atlantic, GOM, and the GL), multiple mountain ranges, and the Great Plains to our West. Lots to juggle....this area is very tough to forecast even on a 5-7 day scale. On June 16 I hade this: This would be my overall winter forecast if pressed: Temps Dec: AN Jan: Much AN start/sesaonsal to BN to end the month Feb: Seasonal (If the Nino is classified as strong or super....much AN temps all months) Precip normal to AN. Snow.....BN for middle and west TN. E TN, especially NE TN/W NC/ SE KY/ SW VA will be dependent on a storm track which should favor the Piedmont or coast during late Jan to early Feb. Whether we get enough cold air in place to help is a giant question mark. Nino winters are often 1-2 big storms along w/ lots of slush during other events. The bitterly cold intrusions of last winter would be less likely. This is more track dependent w/ "just enough" cold in place. If this is a super Nino, warmth/zonal will potential overwhelm the pattern, and everyone strikes out. If the super/strong Nino can hold off until next spring, there should be a window for winter weather during the aforementioned months. And this is the more specific "forecast" from August 17: This wx pattern is one which often favors E TN. I made no bones about it when it came to last winter's forecast for NE TN and SW VA- it was going to be sparse, especially towards the mountains. At this moment, I would literally flip last season's forecast for all regions of the forum area. "Right now" the Nino is depicted by seasonal modeling as shifting to a basin wide event by Jan. I think we start as east based and transition steadily to a basin wide event. The 90s were Nino predominantly = snow dome for Nashville. The 2000s have had many more La Ninas = often a good pattern for Nashville and points westward. SST forecasts are notoriously fickle - I have been burned more times than I can count at this range. Temps/Precip/snowfall: Dec: eastern forum areas: normal to above/above/below middle forum areas: normal to above/above/normal to below western forum areas: normal to above/above/normal to below Jan: eastern forum areas: starts above and moves to seasonal/above/seasonal middle forum areas: above/seasonal to below(edit)/below western forum areas: above/above/below Feb: eastern forum areas: BN to much BN / above / above middle forum areas: normal / seasonal to below(edit) / below western forum areas: normal /above / much below March: Yes, March during El Nino's eastern forum areas: BN / above / above middle forum areas: BN/ above / crap shoot western forum areas: BN/ above / crap shoot Overall Season (Dec-March): eastern forum areas: normal / above / normal to above middle forum areas: above / seasonal to slightly BN(edit) / below western forum areas: above / seasonal to slightly BN (edit) / below Over-reaching ideas: When it snows, the storms could be big. El Nino seasons are often not nickel and dime stuff. The primary pattern is coastal storms with secondary as inland runners. There are always some cutters - we live in the South! Cold sources will likely be an issue, but the storm track for E TN could potentially be good. As others have noted, east based El Ninos don't favor a good winter pattern for all but the most eastern sections of the forum areas. A super Nino which is east based is a bust for all regions. Basin wide(which I expect from mid to late winter) favors E TN and the NC mountains. I don't foresee week after week of snow on snow - unless you live in the mountains. What I do think we see are big storms which bring us to average - maybe even just one storm. The pattern should be active. The trick is getting the cold to get far enough south while the STJ is absolutely ripping. I think the MJO will favor trips into colder phases as plots 7-8-1 should have active convection. The PDO is the wildcard...to repeat...the PDO is the wildcard. To have a banner winter, we need it to flip from its phase last winter. Of note: Seasonal forecast is often woefully inaccurate. I am basing my forecast on the Pacific driving the pattern - ridge out West, mean trough in the East. Get that trough east of Hawaii(per the Euro seasonals), that is a money pattern. As always, it is important to remember that we live in a place where it wants to rain for about 48 weeks out of the year. In Wyoming it is rare to see rain during DJFM. Here, it is quite the opposite in the sub tropics. It wants to rain. But...there are times when we can coax a decent pattern from the chaos.

Maybe frost on the horizon for the foothills? MRX morning disco... Behind the front, much cooler air will filter into the region through the weekend. Some areas particularly in the higher terrain will experience temperatures in the upper 30s Saturday morning. But by Sunday morning, those low temperatures will dip into the lower to mid 30s (higher terrain) to upper 30s and lower 40s across many areas. Be mindful of patchy frost developing Sunday morning and protect any plants that might be susceptible. The weekend max temperatures will rise into the mid 50s to mid 60s.

As usual, great stuff, Boone. Hope I didn't sound contrarian. Again, all great points.

Also, nice write-up by @GaWx, and the correlation of October to the rest of winter....

Just went over to the MA forum...here are the maps from Weather Will. Will noted, and I would concur, that the ECMWF seasonal has a warm bias at this range. If we aren't torching on those maps, generally that is a good thing. They are colder than lost month. If I get a chance I will post some comparison maps - side by side. Feel free to post the same if you don't see mine posted yet. Comparison maps are pretty powerful at this stage as one can see which way modeling is trending. Trend (for now) is a Pacific driven pattern which would be good news given the strength of the Nino. Whether we can get a ridge where the -PDO is...BIG question. One can see some PDO influence as the trough is slightly further west than it was the previous run. Very common to see winter start early during an El Nino winter out West...and then collapse during January and February.

October has some value on seasonal modeling for winter, but not near us much as November. Good run, but want to see that hold for one more run. November is the money run. The CFS seasonal this morning is also showing a warm December. That would make sense, especially IF the current trend to a cooler October is a pattern change. Cool temps from October to mid-November. Warm temps from mid-November to first or second week of January. Then, winter hits. That pattern fits a lot of what we have discussed here. I do think modeling is riding almost purely with analog packages right now, which is why November is important. November's run may well have some actual 3-4 week forecast rigor which will help. One thing about the Euro seasonal run which just came out...source regions for it would be cold unlike the previous run - coldest air on this side of the planet. NO IDEA IF THAT VERIFIES! Huge grains....

October ECMWF seasonal is out....looks good. Key takeaways: 1. Jan/Feb EPO ridge 2. Jan/Feb EPO ridge 3. Jan/Feb EPO ridge Cold dumps in the West for December. SER in the southeast also for December. Trough builds into the East second half of winter. Pretty classic Nino progression - textbook. Not saying any of that happens, but that is the general look. Much more Pacific driven pattern with less Atlantic blocking. BUT, the precip pattern definitely signals coastals as the primary storm track.

Remind me, do we like that year? LOL.

The fire hose is going to be cranking. I suspect(though am by no means certain) that we are entering an era of -NAO blocking(decade type stuff). I think the QBO will help. The further west one gets in the forum area, the worse the storm track IMHO. The drought(which was predicted quite accurately while it was still raining buckets here) is probably of more concern. If the drought breaks, I feel better about our chances. And yes, the PDO phase is the opposite of optimal. I do think we see split flow. Cosgrove notes that increased rainfall in SoCal would be a good sign this fall. With a strong Nino, no doubt warmth will overtake the pattern at times. I think we flip back and forth between zonal Pacific air and Canadian (not Arctic) in terms of air masses. E TN and the mountains "should" have the best shots." I do think the MJO will be the main driver this winter, and that should result in some phase 8 rotations(and slowly at that). We generally do better when the phase of La Nina or Nino is weak for sure.

Accuweather discussion which seems reasonable... https://snowbrains.com/accuweather-releases-23-24-winter-forecast-el-nino-could-bring-a-repeat-of-last-winter-to-the-west/?fbclid=IwAR3YZ6GRmfQ7wjhsI0gkYHMzBNy2C-35Su5_MtFWRgEcTbFz-EJoIf8deu8

And I should add Met, I hate trying to interpret shoulder season modeling. It is just so fickle. That said. The cooling trend seems to be mid Oct to the end of December. Again, HUGE grains of salt.

Seems to be d10-46 have cooled considerably. Could just be normal ebb and flow of cold in modeling. We saw that ebb and flow a 2-3 weeks ago, and then the warmth became more pervasive. edit...but the cooler solutions are likely going to verify from 2-3 weeks ago.