Carvers Gap

They hit -44F south of Cokeville, WY, this morning and -35F in Afton, WY.

I think spring will be ok. Cosgrove seems to think we have that last cold shot, and then make a break for spring. The transition to Nino is what give me pause(usually spring is late w those). About the time we are all tired of rain, cold weather....Nino doubles down! LOL. Hope the soccer is going well!

I would give it about a 75% of doing a full rotation through the warm phases at relatively low amplitude and be back in the cold phases by the last week of the month. Some plots take it into 4 and then it goes into the COD. But given the actual precip plumes in Indonesia....the warm phase rotation looks likely. Feb10-24 for that roughly.

Just looking at weather underground obs for Smyrna, looks like freezing temps are right at the I-65 corridor. You all have an ESE wind. Theirs is from the northwest. If your wind switches and comes out of the west or north....that might be telling.

Icicles add effect, eh? And no, I didn't add those. LOL. https://www.weatherbug.com/traffic-cam/memphis-tn-38111

So, just for folks working back though these threads during later years(me included), ice storm warnings envelope west TN and WAAs extend to the eastern Plateau, Arkansas, northern MS, KY, and SW VA. Models are trending colder with the storm. The cold air is pressing vs getting warmer. There is a separate thread regarding this winter weather event.

Radar is lit.

I noticed how cold it was in Memphis...much colder than modeled for today. They aren't even sniffing 32F during the middle of the day there. So, that tells me that air mass is very cold and very low to the ground likely. I also noticed WWAs were extended to the very eastern edge of the Plateau and just to my north. So, I decided to read the afternoon discos...and low and behold, modeling has trended much colder for the northern valley. The big show is stilll west and middle TN. What is coming in right now is moderate to heavy ZR there. I hope for their sake it is sleet. For our region, we are the very last wave regarding the snow. Though, tonight it could flirt light wintry precip(nuisance stuff here). That last wave is pressing east and south with each passing run.

The 12k NAM is picking up on frozen precip on Thursday. It has 3-4" of snow in TRI for that timeframe. And that has been on that model for several runs. I just never went to the middle of the run. Sorry to the middle and west folks for posting meager amounts here. I won't hijack the thread w/ E TN stuff. If it gets more realistic, I will just build another thread. This is Thursday night. Incoming RGEM has frozen precip as well...

It looks NASTY! Keep us updated.

Even MBY is now getting a mention for some freezing precip tonight and tomorrow. Man, it is straight nasty out there right now. From MRX and pay special attention to that big middle paragraph if you live in E TN: National Weather Service Morristown TN 312 PM EST Tue Jan 31 2023 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Wednesday) Issued at 311 PM EST Tue Jan 31 2023 Key Message: Light wintry precipitation, especially in the form of freezing rain, is becoming more likely for the northern Plateau and portions of southwest Virginia. Light ice accumulation expected in these areas. Discussion: Currently the gloomy weather is continuing across the area, even though most of the precipitation has diminished or moved east of the Appalachian Mountains. We`ll have a break in precipitation this afternoon before more isentropic rain begins to move in from the west/southwest this evening. With this next round of precipitation coming overnight the temperatures will drop to near or below freezing along the Cumberland Plateau, and parts of NE Tennessee, and SW Virginia. Atmospheric soundings continue to show a moderate warm nose overnight leading to somewhat favorable conditions for light freezing rain in parts of the area. Have remained close to NBM/WPC/HRRR/HREF forecasts with regards to total ice accumulations. Most favorable areas for ice to accumulate will be in the northern Cumberland Plateau over into SW Virginia where the shallow layer of cold air will penetrate the most. Some models and guidance have the cold air making into the eastern TN valley, but local research and historical trends indicate that this shallow layer or near surface cold air really struggles to make it up and over the plateau and local mountains/ridgetops. Forecast soundings seem to indicate this shallow layer of sub-freezing air stops less than 2,000 above the valley surface. Traditionally we need sub freezing temperatures in place already to see decent freezing rain accumulations on the ground. With temperatures currently in the 50/40`s this seems unlikely at this time, but can`t rule out some very light isolated icing on trees and other elevated surfaces in the northern Valley. With that being said, places along and west of the plateau have a much better chance to see accumulations, but based on QPF amounts it it looks likely that amounts hopefully remain less than 0.10" with isolated higher amounts. With that being said, will go with a Winter Weather Advisory for several counties on the Plateau, up into SW Virginia where there is the highest chance to see ice on the ground.

@1234snow, looks like you all are under a WWA now as well. That is only about 5-7 miles from MBY.

Looks like @John1122's area is now under a WWA.

Nashville is reading 32F and Clarksville 27F at this hour w/ heavy precip inbound from the SW.

There is lightening incoming with this next round of precip into west TN. Take a look at these temps. Wind chills in the low teens. This is a fairly significant event. Let's hope the lights stay on... That is as nasty as it gets.

Normally, us folks in the east refrain from wholesale rants about winter events to our west(i.e "it missed us" posts). I think that is one of the great things about our forums. It doesn't descend into chaos. So, we just sit quietly. We all know that middle and west TN folks had to endure our shouts for joy during the many winters prior to these three Nina events. So, out of tradition, we either chime in w/ info about the event or just watch. And trust me, we can go a week in here w/out a single post during boring weather! LOL. Also, I don't see any huge changes to modeling. I could post some ice and sleet maps, but they generally look the same. Tonight will tell the story one way or the other. So, really just hoping to see some reports from the gang in middle and west TN once the sun sets and precip moves in.

Main wave comes into tonight. That is when the boundary presses SE on modeling. Boundary temps are not fighting sun angles.

Winds in that region are directly out of the north...just feeding the cold air into the storm. I don't see any winds from a southerly direction. As soon as precip hits those temps, I think it will drop.

Yes, the Plateau is the barrier. That said, even the 12Z Euro is bringing down temps in NE TN and SW VA. I doubt it gets here, but that boundary continue to press. I need to go look at the run2run temp changes.

12z modeling has decently upped the ZR totals for middle and west TN. The 12z RGEM now has the event lasting into Friday. The 3k NAM has some very light amounts creeping into NE TN and SW VA on this run. So message at 12z so far....increasing totals for the 72 hour time frame.

It is fairly amazing to see the GFS bend completely to the CMC on this ice storm. I think most assumed(me included) that the CMC had overdone the boundary, and maybe will once it verifies. But that is pretty solid and tight cone for the ice even this week. This should be a 48-72 hour overrunning event. Modeling has done a really good job up to this point with that.

There are definitely some oddities to the pattern...the NAO connecting to the eastern ridge for a time was one for me. That isn’t unprecedented, but it was odd. Yeah, I was just spitballing myself. So an Aleutian low should produce HP in the eastern GoA, right? ...which is an EPO ridge. Boone did mention early on that the low around Alaska was a problem. I think a hostile PAC in combo with a SER is just part and parcel Niña climatology for Jan/Feb. I don’t have an answer for most of that. Good thought provoking set of posts....

The quintessential La Nina pattern signal is heavy snows in Montana, Wyoming, and the Mountain West....and a very hostile Pacific for eastern NA in regards to snow during Jan/Feb. We have had all of that in spades. Nina winters also begin very cold and often end warm. Nov/Dec were decent months temp wise...but early snows at lower elevations are not common prior to Christmas regardless of ENSO state. The dominant storm track has been a cutter, and that is definitely La Nina....textbook La Nina. The lack of coastal storms is another signal for La Nina. As for the Aleutian low....I have seen it in place more in LR modeling than in actuality. That last 500mb map actually has an Aleutian HP paired w/ a -NAO(which saved us). I think right now, we are in transition in terms of ENSO, but La Nina is dominating the storm track. The West is just getting pounded w/ snow. They had to shut down Teton Pass over the weekend. That might sound like a big deal, but the folks who work in Jackson...a lot of them live in Driggs, Idaho.

Once reason people like El Nino winters is that the STJ is very active. And one can see that on LR modeling. They aren't necessarily super cold, but active. So, in a sense, the hitter gets a bunch of pitches - bad pitches but lots of them. Whereas, La Nina winters have far fewer pitches, but many are over the plate early in the count. When I look a the LR pattern (warm for sure), the STJ is just ripping. There is enough cold to our north for a system to cut under us and tap it. Does it happen? IDK, but it is plausible w/ the very short wavelengths.