tnweathernut

Just now, TellicoWx said:

NAM has an 80' deep warm nose (925-950)...unless that nose originated from Hades think it's overdoing the frz ra 

It doesn’t make sense for the setup we have.  I would think it’s likely wrong, but living where I live I never feel totally comfortable until the event has passed.

2 minutes ago, John1122 said:

Even though it benefits me the most, I truly hope the NAM isn't right for everyone else's sake.

It’s been a thorn for a couple of days now…..  good test of it coming up.  It’s definitely on an island.  Hope the rest of the 18z models don’t follow.

8 minutes ago, TellicoWx said:

Whiteout conditions being reported in NW AR

Thanks for mentioning surface conditions.  Just checking the radar to the NAM, precip is breaking out faster than modeled.  For everyone following, this is typical in overrunning situations.  We can almost discard the globals at this point and go to the short range models.  Even beyond that it's time to compare the actual surface to see if those short range models are initializing correct.  Good luck everyone, hope the overrunning shield is a bit more robust than models indicate and hope we can keep any thermal issues down for those along the west side of the apps and especially for our brothers and sisters down toward Chattanooga.

12 minutes ago, Daniel Boone said:

If this thing turns out as modeled now, a big win for the Icon irt Medium range Models.

I never thought I’d live long enough to see it……. lol

7 minutes ago, nrgjeff said:

Some downslope warming is possible on the front side of the system. However I don't think it'd be a deal killer. Maybe cut rates for a couple hours. If it even happens, start snowing, ease up, then get back at it second half. Kind of like Tennessee basketball, ha!
Otherwise, box to wire snow.

Thanks, that makes sense.  Good to see your Jayhawks get the train back on the tracks today.

7 minutes ago, Carvers Gap said:

Models once inside of 36 hours which I normally use in this order for E TN....RGEM, HRRR, 3k NAM.  I do watch trends on deterministic models, and ensembles still have a place.  NBM of models is good until it can't keep up with trends.

We haven't discussed this much, but where does the FV3 fit into the equation?   I honestly have NO clue.  

18 minutes ago, nrgjeff said:

NAM seems a little off this setup. We got the gentle isentropic upglide we all been wishing for since 2015.

Energy for our system is just getting onshore in the Pac NW. Looks like the 18Z NAM is a little south (John, Carvers posts above) and the NAM will get more of the Pac NW wave on the 00Z run. Hopefully the NAM will settle in with the Globals.

I'm cautiously optimist about Chattanooga. Cold air should be in place. A brief mix is possible due to low level temps, but this feels like an all snow event. Energy sliding up from the Deep South with isentropic lift is hard for even KCHA to screw up. Fingers crossed

Little concern elsewhere. Looks like a gem coming for much of us!

I agree this is the setup where most should score with little harm from thermal layers off a setup we have waited for ...... for a LONG time.  It's not like we have a wrapped up negative tilt system coming at us.   What do you think about the modeling consistently showing a warm nose/downslope up the western side of the apps into NE TN?   I don't want to assume, but would guess you think this is overdone, solely based on the setup?

RGEM gives southwest NC 1.2 inches of QPF.  NAM gives at most .4   Pretty crazy difference 

1 minute ago, Carvers Gap said:

Maybe, but don't base that on a the NAM which is possibly dealing w/ feedback issues.  RGEM should roll in a minute.  The NAM was so amped it tried to bring a slp into the Apps - only the CMC from a few days ago had that.  Could it happen?  Sure.  But for now, no other model has anything even remotely close to its recent solutions.  

I thought the RGEM and Euro both popped a less side low in SW NC.  I figured this was the root cause of thermals getting screwed up in NE TN.

11 minutes ago, John1122 said:

When we start out that cold we often get a front end thump before it rains. Happened several times in 2015. 

Yeah, you are correct.  I shouldn’t discount that possibility.  From a progression standpoint front end stuff can happen before a changeover.

1 hour ago, John1122 said:

The CMC has us in the single digits and a monster winter storm brewing over Oklahoma and Texas at the end of it's run.

FWIW.  That one at the end of the run (if you look at 500) has no chance to be wintry…..  should cut straight to the Midwest.  Would make sense we relax after the next week.

Euro is trolling us at this point.  This system and the next. Poof.  lol

10 minutes ago, fountainguy97 said:

Mountain counties are warm nosed. Rain/freezing rain. On rgem atleast. It's not a qpf problem or anything. It's temps.

 

In fact, the rgem warm noses a larger portion of ETN this 12z all the way through Johnson city.

I feel attacked here……. lol

I'm not sure who remembers AM Weather (really showing my age), but it was primarily an agricultural/aviation weather program I'd watch before school every morning in the winter time.  This map is a fancy version of what you'd see on that program.  I like it because it's old school.  lol

2 minutes ago, PowellVolz said:

Chicago got absolutely screwed and the NAM had it right?


.

That was my understanding, but I'm not sure what lead time the person was talking about.  If it was less than 24-36 hours that's a lot different than NAM had it nailed from 84.

Yesterday, I was reading some on another forum covering the Chicago snow (can’t remember where I saw it), but was talking about the NAM being the only one not on board with a major snow). It ended up beating all the other models.  
 

It’s interesting because our system is projected so much further north than other modeling on the NAM.  If it continues to stay north, will be fascinating to see if it can score a similar victory.

I will say I have seen numerous overrunning setups in the past be further north and/or have that SW to NE trajectory vs the WSW to ENE trajectory once it starts developing.  The good thing is, we don’t have to wait too much longer to find out.  

Those snow weenies in the mid Atlantic forum might be about to lose their minds seeing this thing just roll out to sea on the GFS.

0z GFS really does complete the picture by giving everyone in TN something to cheer for.   I see you Chattanooga with those 5 kuchera inches…….

Pretty normal oscillations happening, IMO.  In the overall scheme of things we see models waffling back and forth about 75-100 miles.  Probably not unreasonable.  We can all hope the overrunning is a bit more robust when we get to game time.

1 minute ago, John1122 said:

I honestly would've thought downslope wouldn't be a thing with this particular set up. 

It shouldn’t be, but I have learned to never discount it completely.

The ICON seems to be putting less emphasis on the low in the Atlantic and more on the low in the gulf.  I don’t think it really matters as it relates to the overrunning which spreads across the state, but I did find it interesting.

1 minute ago, John1122 said:

It's rocking. So far the 12k NAM was the outlier at 18z and looks like it's 2 to 1 against it at 00z. 

The positive, someone is getting a big snow. The Memphis to Nashville are just about locked in across all modeling. The Plateau is close to it as well. NE Tn, SETn and NW Tn SWVa seem to get less on various models. 

Agree.  I was waiting for the heavier snow bands on the icon to pivot through NE TN.  For some reason they just dissipate.  Not likely, but I suppose it could have been downslope aided.

ICON spreading the overrunning love here at 0z

1 minute ago, John1122 said:

RGEM.

 

Long duration event in east TN.  Likely 2-3 more hours of snow left to go past 84

At least there’s a model for everyone in the state tonight….