Carvers Gap

@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.

Very definition of an over-running event if it lasts that long.

For E TN and W NC, there is still some passing interest in the system on Feb 6. Interestingly, when we first starting this forum, Memphis rarely had any opportunities at anything frozen outside of hail. For the second time in three years, an ice storm warning has been posted for the western areas of the forum. I think it is a textbook example of La Nina climatology. I certainly see aspects of El Nino starting to take over, but western areas of the forum getting wintry precip such as ice is La Nina. In the LR, the longwave pattern still looks warm after the 10th(maybe even earlier than that). However, details matter. The 6z GFS portrays a patterns where 2-3 storms press the boundary eastward and cause a system or two to take the low road during the middle of that warm-up. There is plenty of cold air in Canada by that time, so a couple of storms pressing the boundary is a plausible scenario. Again, we are just looking for windows for winter. If Nino is legit taking over, we should see weakness(BN heights) in the SE as a steady pattern. Not sure we are there yet, but that pattern on the GFS is close.

If this comes to fruition, this is a coup for the Canadian RGEM and CMC. They had this from the word "go," and never budged.

.DISCUSSION... (Today through Sunday) Issued at 530 AM CST Mon Jan 30 2023 00Z model guidance consensus trended significantly higher with respect to ice accumulation, following days of relative stability of depicting 0.1 to 0.2 inches of maximum ice accumulations. Model spread remained less than ideal 24 hours out from event onset, with the Canadian ensemble members on the high end, and GFS members on the low side. Overall, the 00z consensus signal is clear for greater than 0.25 inches of ice accumulation. The WPC Super Ensemble mean showed 0.30 inches for Memphis through Wednesday - among the highest amounts depicted for the Midsouth. For reference, Ice Storm Warning criteria is 0.25 inches. The primary reason for the bump in ice accumulations are the downward trend in temperature guidance through Tuesday night. 2 to 3 degrees makes a big difference when temperatures are near freezing. Higher sleet ratios are expected over far northeast AR, the MO bootheel and far northwest TN through Wednesday. This would reduce forecast ice accumulations below Ice Storm Warning criteria. However, if more than 0.5 inches of sleet becomes likely, areas north of the Ice Storm Warning may be upgraded to a Winter Storm Warning. As mentioned in previous discussions and in the recently issued Ice Storm Warning, partial melting will be possible Tuesday afternoon, which may relieve trees and powerlines from the ice load that accumulated Monday night. Based on forecast surface temperatures, this partial melting would be most likely to occur southeast of a line from West Helena to West Memphis AR, to Covington and Camden, TN. This includes Shelby County, TN. As always, forecasting shallow Arctic air is a challenge. The official forecasted temperatures for Tuesday morning and afternoon follow the NBM, which was colder by 1-2 degrees than the mean of the NBM ensemble members. In other words, the NBM and the official forecast are on the conservative (cold) side of the model guidance envelope for temperatures Monday night and Tuesday. A second round of ice is expected Tuesday evening, as midlevel subtropical moisture continues to stream into our region from Texas. Low level moisture transport will increase above the shallow Arctic air, under the right entrance of a strengthening upper jet core over the Ohio River Valley. Total precipitable water values will reach 1 inch as far north as the TN/MS border Tuesday night. At the surface, Tuesday night temperatures will cool into the upper 20s along the I-40 corridor, and the mid 20s over northeast AR, the MO bootheel and northwest TN. By Wednesday morning, the center of the Arctic surface pressure ridge will move to the upper Ohio River Valley, with near neutral surface pressure and temperature advection over the Midsouth by daybreak. Under building heights aloft, temperatures should slowly warm above freezing Wednesday afternoon over all the Midsouth. As with Tuesday, official temperature forecasts for Wednesday followed the NBM, which remained a 1-2 degrees cooler than NBM ensemble mean. Rain will continue Wednesday night, with some threat of a changeover to light freezing rain over far northeast AR and the MO bootheel. At this time, QPF and temperature trends suggest less than 0.10 inches of ice, before temps warm well above freezing on Thursday. This may need to be addressed in a future Winter Weather advisory. A welcome change will arrive Friday and Saturday, as shortwave ridging aloft brings sunshine, and mild temperatures.

Ice storm warnings have been posted for much of west TN, NW MS, NE Arkansas. WWAs all the way to Nashville. URGENT - WINTER WEATHER MESSAGE National Weather Service Memphis TN 321 AM CST Mon Jan 30 2023 ARZ026>028-035-036-048-049-058-MSZ001>003-007-008-TNZ003-004- 019>022-048>055-088>090-301800- /O.NEW.KMEG.IS.W.0001.230131T0000Z-230201T1800Z/ Craighead-Poinsett-Mississippi-Cross-Crittenden-St. Francis- Lee AR-Phillips-DeSoto-Marshall-Benton MS-Tunica-Tate-Weakley- Henry-Dyer-Gibson-Carroll-Benton TN-Lauderdale-Tipton-Haywood- Crockett-Madison-Chester-Henderson-Decatur-Shelby-Fayette- Hardeman- Including the cities of Jonesboro, Harrisburg, Blytheville, Wynne, West Memphis, Forrest City, Marianna, Helena, West Helena, Southaven, Olive Branch, Holly Springs, Ashland, Tunica, Senatobia, Martin, Dresden, Paris, Dyersburg, Humboldt, Milan, Huntingdon, Camden, Ripley TN, Covington, Brownsville, Alamo, Jackson, Henderson, Lexington, Parsons, Decaturville, Bartlett, Germantown, Collierville, Memphis, Millington, Somerville, Oakland, and Bolivar 321 AM CST Mon Jan 30 2023 ...ICE STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO NOON CST WEDNESDAY... * WHAT...Significant icing expected. Ice accumulations of a quarter to one half an inch. * WHERE...Portions of East Arkansas, North Mississippi and West Tennessee. * WHEN...From 6 PM this evening to noon CST Wednesday. * IMPACTS...Power outages and tree damage are likely due to the ice. Travel could be nearly impossible. The hazardous conditions could impact the morning or evening commute. * ADDITIONAL DETAILS...Partial ice melting may occur Tuesday afternoon before freezing rain returns Tuesday evening.

The 0z 3k/12k NAM depictions push the ice line southward with each run.

So, two things I could have done to help us...predict a warm-up and put up the hoop house. I have been looking at NA temp anomalies, and they are not warm for most of the GFS run. The SER tries to flex per the MJO, but I do wonder if the cold is going to push into the east more than LR modeling is sensing. A great example(no idea if it holds), is the GEFS finding another cold front around the 11th. This is right around the warm-up I as talking about. If it snows and is cold during this time...you can send me a Christmas card. Run2RunChange from 12z to 18z.

I think I have been in Knoxville like 3x during the past 5 weeks! LOL I like Yassin's in West Knoxville. Anyway, I look at real estate in Roan Mountain regularly. That is where I want to be. Wears Valley is awesome though, and I watch that market as well. The Harmon's Den area(Beauty Spot) to Del Rio is a good area for snow. I would like a higher elevation farm.

Great insight. For sure, I lived about half my life in Knoxville. I am getting ready to send one to UT next year. I spent my entire childhood jealous of Crossville where it seemed to snow every day during the 70s. Margie Ison is who I grew up watching on TV. Here is what is crazy, my elevation(Kingsport) is only about 350' higher than downtown Knoxville. Kingsport is right on the Holston River where JC and Bristol have more elevation. Latitude is about my only advantage here re: spring. Definitely when I lived in Knoxville, I always looked as TRI as a different climate. The rain shadow up here is what is the worst. Knoxville, ironically, has probably received more snow than I have during the past three years.

Backend winters due to El Nino are almost unbearable. The pattern is usually terrible in December, and then it flips cold overnight sometime during January. We have been spoiled by some nice, cold(sometimes snowy) recent Christmases. If it is a super Nino, we will know by late summer or early fall I think. And if it is a super Nino, I will be the first to put the brakes on an speculation of a cold winter. The non-winters I have experienced are almost all exclusively super Nino winters. I am talking no measurable snow, lots of rain, and mowing lawns all winter. If the Nino is weak w/ the QBO dropping...that would be good.

Yeah, agree. I don't even know if there has been 4 straight Ninas since modern records have been kept. I don't foresee a fourth consecutive La Nina. I think its Nino...just the degree of the Nino is the question.