nrgjeff

Yeah it's nowcast time and the models add less incremental value. Knowing climo is why I'm so cynical in KCHA. We have a nice baroclinic leaf on both satellite and radar. It's not moving terribly fast either, since we are still pre-pivot. Except for Chattanooga proper, I think all systems are go. Signal and Lookout will definitely have snow. Last post of the night. Best to all!

SPC is licking the column in Chattanooga after the triple dare. Best thing about a Christmas Story is they did a good job with all that snow outside.

SPC Mesoscale discussion does not account for the Great Valley. I don't expect a micro-scale map, but that broad brush is pretty bad to be honest. Chattanooga in the heart of the heavy sticking snow? Um, no. That aside, SPC seems to be with the local WFOs. They see the trough pivoting negative. That will indeed cool the column in a hurry. Lower Great Valley won't benefit much due to typical downslope and oh my it's still warm! Still SPC makes good points about the rest of the system. More than Feb. 2020 it reminds me of an event back in Kansas during October. Don't ask how long ago, haha. Tight low came in while temps were above freezing. Low pivoted negative and dumped 1-2 inches per hour snow.

Yeah grassy areas are not melting if it's in the 20s, even if the soil is still 40s. Roads will probably quickly improve after it ends though. Obligatory back deck and grill pictures will be preserved most of the morning. Looking forward!

Arctic fronts are good at coming in quicker west of the Plateau. I think you're right. Unfortunately the Great Valley can not escape downslope, esp below Maryville, Tenn. Chatt temps are still nutty warm. Plateau blocks low level cold. Smokies double down with sinking motion out of the East. I'm not sure why MRX is so optimistic. I always love mention of the T-word though. Good for points north and east and west and even south. TROWAL!

Here are screenshots of video from near Muscle Shoals on New Year's Day. Two separate supercells produced rotating wall clouds, but I could not discern any touchdown. A middle second sup is not pictured because it was garbage. Thanks to @Fred Gossage excellent TV and radio commentary. First supercell near town about 3:30 pm Third supercell just south of town 5:00 pm

In Chattanooga we remember all the big strike-outs. Bottom of the Ninth Game 7 WS with RISP. All we need is a blooper. WhifX3! There was the Chattanooga Saturday miracle February 2020. Nice things before the Pandemic, lol!

Lock in that RAP. See Chattanooga forecast. Rest of y'all are good to go!

It's just the HRRR. In all seriousness probably some sleet. Eventually it's changing over and snowing for a few hours. DGZ ain't bad either. Can't always be perfect saturation. Hopefully inside 12 hours a Red Tag does not jinx it. Still thinking warm nose hell dusting or less KCHA. I like almost every other forecast point in our region.

So Tornado Warnings and Watches improve the effect over general thunderstorms. Just kidding! Regarding the Great Valley, it's definitely downslope. Cold air likes to get trapped. Warm air would rise through cooler air (instability) or just be static stable (all else equal). Of course with terrain it's not equal, and we get downslope instead.

Yes it was an excellent bowl game. Very entertaining for neutral fans and the national audience. Now I'm ready for basketball and other winter things. Red tag can't say the word for risk of a jinx.

Well @Holston_River_Rambler we might be able to enjoy some SREF plumes. I just saw the 12Z stuff for Sunday snow. So we can be disappointed on both the storm and winter side? I'll check that snow stuff later. Yes @Carvers Gap you make good points about UT. I was just stomping around the living room and barking at my TV.

Saturday will depend on the prefrontal trough. Main front is veered off with parallel upper level flow, not really a tornado machine. Mississippi and Alabama will start Saturday capped. However the cap will gradually erode. Prefrontal trough is forecast and will be there. Question is the cap. If the cap breaks down there, discrete supercells will bring their usual threats. They would probably go from rooted to tornado in an hour. That kind of shear, this time with low level flow, would spin up tornadoes rapidly. Would be MDT but too early to make the call now. That's only if the cap breaks. If the cap holds then it'll look a lot like Wednesday - which still had Sand Mountain tornado(es). However that's not a huge day across the region. SPC should hold with ENH on this afternoon's Day 2.

Always Sand Mountain @SmokeEater Also saw a report from Rainsville, another common event. It's almost the Cullman of the Mountain.

Well Tennessee is a sports betting state. ACC Refs could do it under the radar. Also UT play calling was atrocious late. Why pass when you can run up their gut? Unbelievable! @Bigbald we pulled off a Christmas miracle and skied Cataloochee, NC before these closures. I believe this is uncommon. They can usually make snow a majority of nights even in mild wx. The string of well above freezing nights is a deal killer. Good news those snow guns can make a ton of snow at night. What we see during operating hours is nothing. They can be open very quickly this week after just a few cold nights.

Boundary, clearing skies, and increasing surface winds has reached the Tennessee border with Mississippi and Alabama. Watch is valid. Another Southern event looks poised to over-achieve relative to 36 hours out. Still think Enhanced 10% hatched covers it. Not quite Moderate material, but it's getting close. I'd keep Enhanced. Word watches bluntly, but not strongly. In addition to the lifting boundary, appears a pre-frontal trough runs north to south in Mississippi. Could be a focus for robust new development.

Thanks MRX I'll look forward to that sh!t after dark. At least it'll still be evening, not late night. Remember even storm chasers don't like that crap after dark. Virtual chase target is northeast Mississippi to northwest Alabama, into southern Middle Tenn. That's hideous chase terrain so no real chasing. Lunch in Corinth, Miss. would offer options south into Miss. or back east into Bama. However the immediate tri-state (with TN) is completely unchasable terrain. Punt! Oh yeah, lots of college football on today too. Cheers!

My take of the 12Z Tuesday guidance is after dark, but not super late. Short wave looks a little clumsy. I guess that's non-technical talk for odd ejection with poor low level wind fields. CAPE is high for this time of year, so any uptrend in low level wind fields would have to be watched closely. Look for heavy rain and some severe, but I don't think Wednesday evening will be too bad (if low level wind field forecast holds meh).

I was actually going to take Tennessee. I heard Bama rebounds poorly this year. Day of news check, I'll see if Tennessee tall guys are back before wagering. Not investment advice. Oh yes @Carvers Gap Tennessee will be well prepared for March!

We'll go storm chasing if you're here through the weekend. I will opine on the January cold after forecasting Wednesday and weekend severe. Feeling the latter gets muddled with Arctic air in the equation. Wednesday on the other hand features a spring-like stalled boundary.

Tennessee at Alabama a Yuge game coming up. It's basketball! Hopefully the game is played this week. Merry Christmas and Happy New Year!

Good call. Locking the previous thread also saves the December 10-11 outbreak as the most recent material. 12Z Monday Euro and GFS (globals) have more of a surface low than the NAM for Wednesday. At 60 hours the globals are more trusted than the NAM. Regardless of what the NAM does overnight to 48 hours, SPC should go Enhanced for Wednesday as Day 2. Additional strengthening of the low level wind forecast could open the door to higher probabilities, but we're not there at this time. Wednesday soundings have eerie similarities to those of Dec. 10-11 in that they have more low level CAPE than recent April setups. Any strengthening and backing of low level winds could be trouble. Also we have the instability to promote another around of activity along the east-west boundary (as opposed to needing a prefrontal trough) IFF the low level wind forecast strengthens. Saturday could be big, or trash out with an Arctic front surge. This reminds me of a big week in the Plains. Saturday oh Saturday! Prior Wednesday ends up the big day.

I fell way behind on this thread, but here is my still semi-bearish outlook. If something can go wrong in the West Pac, it will. Typhoon is dying in the South China sea, no phase. Models have remnant low hooking up with a Japan system, but that's no phase. Per Carvers (my negative take at least) it just jacks up the +ABNA... Which might hook up with the raging -NAO forecast by January. Except the damn -PNA is relentless. We've seen this rodeo before. Models will struggle much worse than normal (both directions) as Arctic air enters the central US. Now the -NAO is amped up on tilt both CFS and GFS weeklies, with some handoff to West Coast / Southwest ridge; however, we've also seen those false alarms before. I simply don't believe it. SER remains stubborn, and it jives with a locked in -PNA. Worse yet, MJO convection wants to reset over that dreadful Maritime Subcontinent. Color me skeptical of a cold pattern change. My interpretation of the West Pac satellite image

Just wait and see how it shakes out. I agree models are trying to figure out a cold shot. MJO continues to look favorable. TC is forecast over there, but other convection should continue - vs TC saps all energy. Yea Grit is in a whole other weather universe east of the Apps. He can have his ice storm. Ice requires such a specific set of circumstances here that there's no reason to forecast it outside of 3 days. Over there, different story with CAD pattern recognition. As for blocking yes a west based -NAO is required, esp with this stubborn -PNA. Yeah a Rex in the GOA would change things.

NWP has turned less hot for the 11-15 day. Do we want to ride the emotional roller coaster? Convection is all over the West Pacific. Couple invests; however unlike last time, other deep convection is present. Maybe it will shake out well for some cooler temps in the Southeast US. Blocking tendencies are noted in the extended guidance, but it's probably a function of the MJO. Can it verify?