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Interesting point about low level moisture Saturday. One huge challenge is not super moist above 700 mb. Dendrite growth temperature zone looks weak, but some moisture. Now if we were forecasting severe weather, I'm all about the extra ground moisture. Those concerns noted, It's a feisty little wave. Figure places with terrain help will be nice. More notes added later: The Euro for Saturday appears a little low relative to consensus. Others have more qpf and snow, from more WAA aloft. Just a little more moisture up to 600 mb would be enough. GFS looks too amped, but I said that about the Euro for Friday. We'll see. Moving to next week, the ECMWF and GFS remain in sharp disagreement. So do the weekly products. The issue is MJO forecasts. Unfortunately the (currently mild) Euro usually wins those battles. GFS has advantage in only 1-2 MJO phases, and these are not it. That said, I'm in ski weenie mode after what just happened today and will happen tomorrow. Fingers crossed the GFS scores a rare win on the Euro next week. .

Good news for the Plateau, Mountains, and maybe Nashville. Both waves appear to be night and morning timing now. Gosh, when did snow forecasting get as diurnal as severe forecasting? Anyway seems like a dusting to half inch along and north of I-40, except that ends on the Plateau (inclusive of course). Upper Plateau and into Kentucky looks like 1-2 inches, locally more Plateau. Bad news: Great Valley boundary layer is still a no-go. Even Nashville looks better than TYS and MRX. I have trouble taking out TRI, but the models are not friendly. Tonight looks like cyclonic flow plus short-wave hybrid, decent moisture left over. Friday night and Saturday morning looks less juicy now. Southern Apps may get their turn though.

Flooding might be worth a thread, or go ahead in the existing Flooding thread. Keeps this one winter. Then we got severe going too in that thread. Mississippi sup on the marine warm front as I type. 12Z Euro came in similar Friday and Saturday. Cyclonic flow aloft with short-wave Friday. Another wave from the southwest Saturday. Both look cold enough Plateau and Mountains.

Lookout Valley west of Chattanooga, flooding on I-24 per Covenant Transport Met. I-24 was closed as of 3pm Eastern Wednesday.

Enhanced risk for central Mississippi into northwest Alabama! Well Dixie has a funny idea of how to do an overnight rave. Jokes aside, I'd ditch the hatched but 10% might be OK. I'd introduce 30% wind though. But the HRRR! But the SFO run? OK back to weather. Both versions of the NAM temper things compared to the HRRR. NAM looks believable given all the cloud cover. However the marine warm sector has made it well north in Mississippi. North Alabama is still conditional on precip. I actually like the wind fields not pegged out, just seasonably strong. However the low level CAPE lacks. Don't take much at night in Dixie, but it needs to be more than 50. LI looks good because it is above the warm layer aloft. Figure storms can root for a couple Mississippi tornadoes this afternoon. Alabama might get to sleep well with just wind if it does not destabilize in the low levels. Believe the sounding is a bigger problem than upper level wind directions relative to the boundaries. It's a quasi-lifting boundary not a CF in the risk area. Either way, I think it's mainly wind. 2pm Central Update: South Mississippi supercell rooting on the marine later warm front. Other cells coming out of Louisiana may root in Mississippi.

Friday seems to have perked up on cyclonic flow aloft, lingering moisture, and a little short-wave. Upper Plateau to Mountains is favored, along with well north of I-40. Boundary layer struggles continue. Saturday downshifted some models, probably because that short-wave fills with time. However the column is forecast colder than it was yesterday. Saturday looks better along I-40. Thickness, partials, 700 mb are all colder. OK it might snow a little in Chattanooga, but boundary layer likely denies sticking. GFS totally trashed the 6-15 day. Dammit! Hopefully that convection over Indonesia is just diurnal. If so the GFS got tricked like SFO celebrating early! If not, we are SFO and the MJO is the relentless Chiefs offense.

Saturday has downshifted a bit, but Friday looks good NWF. Two small events, NWF and clipper ain't bad. Arguably it's even better skiing. Friday looks juicier behind the main rain. Plus a short-wave is forecast so it is hybrid NWF and cyclonic flow aloft. Saturday that short-wave is filling a bit, but the temp profiles look colder compared to forecast yesterday. Despite lower QPF, snow amounts are not that degraded mountains. I'm not sure about a big time snow chase; but, I definitely like the skiing. These NC ski areas are specialists in artificial snow augmentation after rain. It'll be fine. Still early on the track, Catty/Maggie vs Avery Co. Hopefully ALL!

ECMWF both 00/12Z stays friendly for mountain snow lovers. Weekend mountain snow event might not be getting much NWS or media attention since they have to deal with the heavy rain first (over a wider area). Day 5 is a crap shoot in the South, except in the Mountains where terrain can forgive tracking errors. Vort max dives through the Plains and pivots Tenn Valley, not bad if you want a juicy clipper hybrid. 500/700 vorts are both at/north of I-40; so, lower elevations probably will be disappointed by a warm boundary layer. (Partial thicknesses are not as cold as total 1,000-500 mb). However temperature profiles and partial/critical thicknesses look great at elevation. It is a little early to drill down those charts, but again mountains offer a forecaster some cushion. 12Z Euro finally got to Saturday. Its vort max is slightly south and surface Ts slightly colder mountains. Hope this turns out to be great news for ski areas, both the operators and the skiers / riders. Snow conditions should be good, in contrast to other cold following rain fronts. If 3-8 inches of new snow accompanies snow-making overnight, it'll be pretty nice skiing and riding this weekend.

Weekend snow north of I-40 (and perhaps along parts of I-40) looks decent this morning. Euro remains on board, and even ticked south overnight. Still awaiting 12Z Euro. I still think snow will not make it south to the 540 thickness line / 0C at 850 line. Low levels look warm and much of the event is Saturday daytime. 500/700 mb vort max still along/north of I-40. Finally, who believes Chattanooga will get snow? Shows 540/0C over town, but nah. OK, serious again, the more reliable output still keeps snow an elevation event for the Plateau and Mountains. However snow levels are a touch lower, and accumulation at elevation a bit higher. Surface HP comes in behind the system. Might get some cold enough air for BNA/TYS/MRX but it's tough w/o HP already in place and/or dropping from the N/NE. Tri Cities has a slightly better shot at snow, esp if some wrap-around. While it's a little early to drill down partial thicknesses, they are not as bullish as the total 1,000-500 mb thickness. They are almost as far south, but not quite. The 1,000-850 mb hints at warm boundary layer. The 850-700 mb hints at the vort max a bit north. Again it's early for that tool, and I only have it on the GFS. Looking ahead. Carvers offers a path to a nice encore. It could happen given IO Pac convection. Some is in a decent spot. However the IO is firing too. Depends when/how long that meanders over warmer phases of Indonesia. Also if any northern stream TPV energy fails to catch the West trough, SER will be stubborn. Euro is with Carvers. Fingers crossed.

Saturday looks like an elevation snow north of I-40, perhaps limited to just the Upper Plateau and Mountains. TRI might get lucky, but currently looks like too much WAA up the Valley. That and concerns Carvers notes above. Thickness and 850 mb look right, but that darn boundary layer spoils again. Upstairs one sees the 500 mb and 700 mb vort maxima go at/north of the area. It's cookbook meteorology, but pretty reliable, that sucks.. the life out of the system. Sure enough 2m progs are too warm to stick. Exception would be a narrow moderate to heavy snow band. Always possible cool air gets trapped MRX north - even better for TRI. Current progs show nothing like that, but it's day 6. Unfortunately I'm fairly confident taking out TYS and BNA. I'm not even thinking about CHA. Looking farther out, watching the SER re-appear after some weekend modeling feels like probably how SFO fans felt 4Q. Too early? On the bright side, we KC fans felt like when a TROWAL surprises with big snow after starting as rain. Might be my only chance this winter to write TROWAL.

Despite all the advances in numerical weather modeling, that hybrid in-situ (local surface ridge vs huge high) CAD with dry then saturate column keeps surprising. Congratulations to those who received snow today! And to the ski areas! The need it going into a weekend.

I agree with Carvers that we are hunting for a quick break within an awful pattern. The coveted 2-3 weeks of cold is almost off the table. The freak storm on a sharp baroclinic boundary? Heck, that can happen into March historically. Seriously, I think in the current regime we have February to get lucky. Normally sustained cold is hard to come by after February 15. However a one-off snow can happen almost as easily in late February as in early Feb. Even if the troughs do not reshuffle (see Carvers previous pages too) the other path is a stout system ginning up on that (forecast) tight temperature gradient early to mid-month. Upstairs the jet stream will probably be strong too. Miracles can and do happen on sharp baroclinic zones. Of course it could be heavy rain or severe too. Despite my rants, look for me in the severe thread, I still hope for something winter. Forget the charts for just a minute. January and February I consider the snow months. It's only half-time. November and December are dark cold months, less daylight than here at the end of January, but also less snow. While starting 3rd period (hockey) for cold temps / met winter, it is just half-time for snow. Of course it needs to be below freezing to stick daytime after 15 Feb. And we need some really big breaks!

An even bigger version around the Smokies. If south or southeast low level winds accelerate around mountains it would enhance low level inflow. Then farther off the ground south to southwest winds could be guided to turn with height due to the direction of the Valley. I'm just speculating on a hypothesis. Similar debate is ongoing for central Oklahoma (Moore/Norman) and the southeast facing Canadian River Valley. That's low levels only of course. The Plains can take care of its own mid-levels. In both cases it is hard to prove causation, but correlation is notable. They have tried to model the OK case.

So up there you get snow and tornadoes! Jealous, haha I wonder if low level winds whip around the ridge southeast of town. Accelerate a bit per Bernoulli effect? And a little farther off the ground I wonder if ridges nudge winds a little veered relative to below. On the other hand it could be random luck.

Questions remain in Alabama due to morning rain on Saturday. Euro has consistently hammered Mississippi and the GFS has now slowed down to do the same. NAM going nearly unidirectional upstairs is a real party pooper for fans of intense severe weather though. Saturday is still the back half of the NAM (as of Thursday writing) where NAM accuracy falls off. However the accuracy issue is usually on mesoscale details. Upper wind fields is a larger scale issue. I'm afraid the GFS/Euro will trend toward the semi-unidirectional NAM. Sure it has helicity off the charts, but that is mostly speed shear. Turning is meh on the NAM. It would be a strong but sloppy line. Now the GFS and Euro (globals) both still have a classic winter Dixie outbreak. Globals start turning 700 mb wind, with 500 mb southwest or better. NAM has 700 mb barely west of south and 500 mb still SSW. They all have a mess at 200 mb, but the globals have enough turning up to 500 mb for a lot of severe wx and some tornadoes. Plus they all have robust LLJs. Instability is marginal, but that is normal in winter severe weather. Tonight or Friday morning, one could check fcst soundings for where that instability lies Saturday; low level or mid-level. If low level (just a few thousand ft AGL) it only takes a few hundred CAPE for severe. If mid-level only it's tough to light the candle. Such mesoscale detail isn't clear until about a day to 36 hours ahead. If everything comes together, one would expect that secondary warm front, originating from the Gulf Coast front, to lift north of I-20 or even US-82. Worst action would be from there south. Otherwise it's a sloppy rain-out except down on the Gulf Coast. Most of this was copied from my Tennessee Valley post. However it looks like the worst of it will be this Southeast Region, because of central/southern Mississippi and Alabama. Even there it could underachieve if the NAM is right.

Yes at one point Alabama looked capped on the Euro following stabilizing Friday night rain. Euro has consistently hammered Mississippi Saturday. I'm less concerned about caps now. NAM going nearly unidirectional upstairs is a real party pooper for fans of intense severe weather though. Saturday is still the back half of the NAM (as of Thursday writing) where NAM accuracy falls off. However the accuracy issue is usually on mesoscale details. Upper wind fields is a larger scale issue. I'm afraid the GFS/Euro will trend toward the semi-unidirectional NAM. Sure it has helicity off the charts, but that is mostly speed shear. Turning is meh on the NAM. It would be a strong but sloppy line. Now the GFS and Euro both still have a classic winter Dixie outbreak. Still sloppy, but it's relative down here. GFS/Euro start turning 700 mb wind, with 500 mb southwest or better. NAM has 700 mb barely west of south and 500 mb still SSW. They all have a mess at 200 mb, but the GFS/Euro have enough turning up to 500 mb for a lot of severe wx and some tornadoes. Plus they all have robust LLJs. Instability is marginal, but that is normal in winter severe weather. Tonight or Friday morning, one could check fcst soundings for where that instability lies Saturday; low level or mid-level. If low level (just a few thousand ft AGL) it only takes a few hundred CAPE for severe. If mid-level only it's tough to light the candle. Such mesoscale detail isn't clear until about a day to 36 hours ahead. If everything comes together, one would expect that secondary warm front originating from the Gulf Coast front. Worst action would be from there south. Otherwise it's a sloppy rain-out and I'm watching college basketball all day Saturday.

And 30% is posted for our parts of our Forum Region! Where's the siren emoji? My thoughts are similar to those from Monday. GFS is a bit fast, ECMWF is slower, truth may be in between. Regardless the 12Z Euro is total eye candy. Still early for soundings*; but, the constant level plots are lit. So is the surface. * Friend reminded me it's also too early for meso-scale forecasts (outflow, cap, etc) and that's right. However it is my decision point, more than a forecast. Mesoscale will determine my chase status. If not, plenty of college basketball on Saturday. KU hoops is on on CBS! As for my snow post from Monday, I'm sorry if I raised false hope north of I-40. What a disaster! Guess I was jacked up on severe wx thoughts.

The 12Z ECMWF is pretty lit (verbatim) Saturday. Oh I'm glad I saved the best for last. Winter is choking, so I'm ready to talk severe! Most notably, the Euro has a southern stream system to spark convection in the Deep South. Surface low going into the Midwest may have unidirectional winds aloft. The South, on the other hand, should have veering with height. Next feature is a long-shot in January, but the Euro shows a secondary boundary in North Mississippi to North Alabama, south of the synoptic WF. Should the coastal warm front merge with this boundary, it'll be more believable. At any rate Friday night rain sets up the possible outflow boundary OFB I'm talking about. Winter set-up means an even higher than usual possibility of a morning rain induced stable bust Tenn Valley. I'd need the coastal front to merge with the OFB to give it more spark. Now Alabama may be capped. This whole OFB and moderate cap would be wonderful in the Plains in May. Dixie in January? It could work, but I'm not holding my breath. Few more days to watch this. Mississippi looks less capped as the southern short-wave induces cooling aloft. Still great wind profiles ahead of the trough. Mississippi is also favored in winter climo. Alabama is more February and later. We'll see though. 30% generates a lot of social media hype, but this is typical Dixie in winter - very conditional. Wind fields are there but instability is always TBD. While I'm eagerly watching (though not holding my breath) chances are I end up watching college basketball most of Saturday in my nice dry living room.

Oh the weather outside is frightful, literally! Midday was robust in Louisiana including that tornado emergency for Alexandria. This afternoon looks a little more linear for North Mississippi. Strongest shear is ejecting away from Louisiana and southern Mississippi; however as of 3pm Central those south cells remain robust. Greater and forecast instability allowed this event to escalate day 1. Also it appears the LLJ was a little less veered through midday, compared to progged over the weekend. Little details make a big difference in Dixie. Y'all be safe!

SPC still has Monday highlighted. Lots of kinematics including close to the surface, so a little straight line wind would not surprise me. However now the 850 mb level is veered off and precip may be sloppy. 925 mb is trying not to veer off and surface to just aloft is south. Still I think given the frontal orientation along the upper winds, it's a mess. Models continue to trend more positive tilt on the trough. At one point a few days ago it was almost neutral, but that's long gone. Can't imagine anything more than 15% even on game day. Not all D4-8 go big. This one was just evident on the synoptic scale, but slight all the way.

Always fun to saber rattle severe in December, a holiday tradition for me, though I enjoyed the snow yesterday. Moisture looks a little JIT and the wave has a slight positive tilt on the ECMWF. I can see why SPC waits. However the upper level wind fields are robust. Currently no VBV issues and 500 mb is nearly straight west. Things like this can work out in December when it's more about dynamics than thermodynamics. We'll see... If Monday does not work out there's always Christmas severe saber rattling. Big warm-up is forecast that holiday week before a front. Little more of a West trough is forecast for a few days before advancing into the Plains and Mid South. Funny a few days ago one GFS run had snow for Christmas. Anything is possible 2 weeks out!

I infer from Lezak's public forecast that the dominant pattern is the trough Plains, which gives 3-4 winter storms for KCMO. Secondary pattern is not discussed in the public forecast; however, the LRC usually has one. I don't have access to the subscription, though maybe I should. Anyway I figure the secondary pattern is northwest flow. That's less juicy your way but probably my only hope over in Tenn.

I'll put in an order for Trans Nino by spring. Thank you!

Saturday has more instability than Tuesday night's debacle. However Saturday low level winds look a bit veered. Probably be more interesting Friday in the Plains. At any rate Saturday would require some sort of meso-scale boundary set-up if those 850/925 winds don't back a bit on the models. I'm not counting on that. Good thing we have plenty of football, basketball and other sports this long weekend. Happy Thanksgiving!

If the IOD stays on full-tilt, it does kind of promote a Modoki shadow/imprint. However like pointed out above, sub surface is warm east. Perhaps most important, will be weaker convection when it's over/near Indonesia - thanks to cool SST anomalies. That's typically the warm phase, so muting it could help keep colder MJO phases.