Weathertree2

Had a few lightening flashes claps thunder this am.

10 hours ago, Daniel Boone said:

I still think so. Hope I'm wrong.

Already turning that way here in and around Middle TN 

000
FXUS64 KOHX 112030
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
230 PM CST Fri Mar 11 2022

.DISCUSSION...

Models have sped up this system for tonight a bit, and the cold
front is a few hours ahead of previous forecast. But, snow timing
remains roughly the same. Amounts have changed slightly, with more
of the east possibly getting into the 2 to 3 inch range if the
cold air continues moving in a little faster. Rest of the forecast
remained mostly unchanged, with snow starting in the northwest
around 6 pm and spreading across the mid state through the
evening. Advisory area still looks to get 1 to 3 inches, and the
Warning area 3 to 6 inches, with those higher amounts at higher
elevations and on the Plateau.

Upper trough continues to dig southward and strengthen as it
approaches from the west, and the cold front has nosed its way
into the northwest part of the mid state already this afternoon.
Rain will start in isolated locations this afternoon ahead of the
main band but precip chances increase from the northwest late this
afternoon, and after a brief period of rain, a rain/snow mix and
finally all snow will make a quick transition this evening. Some
sleet will be possible mainly south and east of Nashville this
evening, but it appears to be very brief as heavy snow bands will
quickly cool any remaining warmer layers aloft. Isentropic lift
remains strong ahead of the front, bringing plenty of moisture in
the low to mid levels. Frontogenesis remains extremely strong also,
and will support the very strong omega values that are clearly
seen on soundings and cross sections. Cross sections also indicate
some areas of weak instability, and combined with strong dynamic
support in the mid to upper levels, heavy and potentially
convective snow bands will be possible. These bands can easily be
capable of bursts of 1 to 3 inches per hour, which is why the
surface and near surface cooling a bit earlier has resulted in a
little more accumulation in the northwest. The faster moving
trough looks to exit sooner, with most of the mid state done with
heavy snow before sunrise and lingering snow on the Plateau
Saturday morning. Adding to the snow issue will be the strong
northwest winds of 10 to 25 mph and gusts as high as 40 mph which
could result in some downed power lines/trees when combined with
the heavy snow.

This still remains a challenging forecast as CAMs are the ones
dialing back accumulations a bit, likely due to the increased
speed of the system and more accountability for warm surface
melting with initial snow compared to larger scale models.
Upstream, there are reports of heavy snow, but mainly sticking to
grass, cars, etc and leaving roads wet with the initial onset.
Depending on how long temps can hold out on the surface, the warm
pavement will rob some of the accumulation potential early on
especially if snowfall rates are slow, but will still accumulate
on cold surfaces. Should convective snow bands develop, or even
within heavier snow bands, rapid cooling will result, and can
easily start accumulating on area roads. Bridges and overpasses
will be the first to start, but it is possible that slower
snowfall rates in some areas will result in accumulations only on
cold surfaces, and roads stay wet/slushy with slick spots in the
western half of the mid state. On the other end, should heavy snow
and convective bands last longer and be more frequent across the
area, they can put down heavy snow amounts very quickly, and we
may wake up with more snow than currently in the forecast.
Definitely a challenging scenario with a quick moving, highly
dynamic trough with convective snow potential.

Models are still quick to bring clear skies on Saturday, but kept
clouds in a bit longer. There is still a chance that a stratus
deck lingers longer into the day Saturday preventing the sun from
clearing the roads. Even though temperatures will be in the upper
20s to low 30s for highs Saturday, the March sun is still very
powerful and can even get some melting done with a thin cloud
layer. But, clear to partly cloudy skies in the afternoon would be
ideal to help clear roads, especially with below freezing temps
returning Saturday night and re-freezing any wet areas. Sunday
will be much warmer, and likely get more of the snow melting job
done with highs in the low to mid 50s. 60s return on Monday.

Next chance at rain will be Monday night into Tuesday, but looks
like this system will clip the south for the most part and doesnt
look like a soaker at this time. Temps will continue to warm
during the week and we will be back in the 70s by Wednesday.
Another strong trough is possible next Friday into Saturday but
this one will be warm enough to avoid any snow.

&&

.AVIATION...
18Z TAF DISCUSSION.

A strong cold front has passed through CKV and will shortly move
through BNA/MQY shifting winds to the NW. Frontal passage will
occur late this afternoon at CSV. Precipitation will move into the
terminals this evening which could begin as rain showers but will
quickly transition to snow. Snow will reduce vis to IFR and even
LIFR during heavy bursts. Snow will move out of CKV around 08z and
out of BNA/MQY around 09z. Snow will linger at CSV longer with
some light snow showers possibly lingering after 12z. Models are
quick to return VFR cigs after the snow pulls out, but with snow
on the ground and steep low level lapse rates, MVFR cigs were left
in the tafs for the remaining forecast to account for a likely
stratocu deck. After frontal passage, winds will be out of the
NW/NNW around 10-15 kts with gusts around 25 kts.

So, anyone have an early thoughts on the Spring/Summer? A continuation of a week of flood a week of dry? 

1 hour ago, Holston_River_Rambler said:

Euro was still a little bit south with the firehouse, so yeah somebody in the TN Valley watershed is going to get it. Hopefully nothing like the 14" amounts come to fruition anywhere. 

Me too but it is setting us up for a Spring that could be bad as far as flooding goes 

5 minutes ago, Holston_River_Rambler said:

GFS seems to be trending a bit north with the worst rainfall this week. 

WPC seems to like that solution:

 

Looks pretty much like the NBM, but hedging on the higher side. Seems reasonable to me. Will be interesting to see exactly where the firehose sets up. 

Does not look good any way you slice it honestly; essentially all of the rain we got last week ran off; any amount of rain will not be  good for my area, north of Nashville

2 minutes ago, Holston_River_Rambler said:

The Euro is, I think, about to make up those couple hundred miles with a triple phaser for Valentine's weekend. 

Pix?

48 minutes ago, PowellVolz said:

 

This must be highly localized; I drove into Nashville from rural Sumner County, north of Nashville and had absolutely no issues; roads are wet that is it. 

 

.

 

 

1 hour ago, nrgjeff said:

Little birdie told me Nashville knows they have a higher ice accumulation risk. They are trying to manage flash flood messaging first. I get don't confuse the public. However if there's a chance of meeting ice storm warning criteria, a WS Watch needs to be out. Advisory upgrade last-minute will make grocery stores comical tomorrow. 

And Memphis to Paducah. Nothing but pain. Cue up Mr. T / Clubber Lang gif. He just says one word to Rocky. Pain!

Especially north and northwest of Nashville 

22 minutes ago, nrgjeff said:

Surprised how quiet the thread has become. We don't do ice? I certainly agree ice is by far the worst kind of weather.

Arctic front may surge more into Middle Tenn. OHX has been hinting at teeing up stronger winter / ice messaging after getting the public aware of the flooding first. 

Saw MEM occasionally above 32 on CAMs. Overmixing. Little CAD east of the Ozarks is going to keep the Delta freezing and probably also the Memphis metro. 

Pain. Pain. Pain.

Yea, seems kind of odd looking  at the watch/warning map to see the break in OHX territory 

12 minutes ago, John1122 said:

I've often found in these situations the cold creeps further S/E than modeled. JKL crept a little south with their winter storm watch this update. I think OHX will eventually have to issue winter products and that MEG will have to move theirs east. Hopefully our western forum guys aren't in the dark for days on end like some of the big 90s ice storms.

I personally agree with you but OHX is so so hard headed - according to their discussion, main thing to be concerned about is possibly ponding water in areas....

000
FXUS64 KOHX 012040
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
240 PM CST Tue Feb 1 2022

.DISCUSSION...

Today turned out to be a very nice day. Temperatures warmed a bit
more in some place than what was in the grids with some locations
getting to 65/66 degrees across middle TN. This is going to change
as we have been advertising. Rain moves in tonight close to
midnight for the west and will spread east overnight. Rain becomes
definite by tomorrow and heavy at times on Thursday. QPF amounts
have came up a bit at this time from WPC guidance. Still expect
2.5" to 4" from 06Z Wednesday through 12Z Friday. Some locations
could receive locally heavier amounts. Hopefully with it being so
dry lately there will be no real flooding concerns outside of low
lying areas and locations that are prone to flooding. Since the
rain will be falling over a long period of time no type of flood
watch will be need. Middle TN tends to have some flashy
rivers/stream so advisories might be need by Thursday.

As the system is pulling out Thursday night into Friday winterly
weather is still expected. The GFS is the most aggressive with
the cold air...and the other global models not as much. The
northwest will have the best chance for mixed precipitation. The
main concern is freezing rain. With the ground currently warm and
a large warm nose /8 to 10C/ that is a lot of warm air to fall
through. Freezing rain the greatest threat.

It stays cold through the weekend with lows on Saturday in the
teens to low 20s. Highs will climb to around 40. Not quite as cold
Sunday morning...but still below freezing. A short wave moves
across the south Sunday morning and this could bring a very small
chance for rain/mixed precipitation for the plateau.

Once we get through the weekend it will be dry for the beginning
of the next work week with temperatures below climatology for this
time of year...but warming through the week.

33 minutes ago, Carvers Gap said:

It looks pretty locked in...I could be wrong.  I could see the transition line between rain and ZR move around 50 miles or so.  I think the threat to western areas is fairly dialed in.  Now, if that line pushes into BNA...that is the question.

Yea, i am closer to the KY than i am BNA has me cautiously optimistic that we miss ice but going to be close

59 minutes ago, Carvers Gap said:

The NWS has added more counties in western TN to the WSW.  There are now some counties in NW MS in addition to the northern 2/3 of Arkansas.  I wold suspect there will be more counties in TN added.  For folks in those areas, time to make sure to have a backup heating source and power source.  Looks like the ice portion of the storm will run the Mississippi River and also along the Ohio.

I would imagine that there will be more changes with the 12z model suite

5 minutes ago, jaxjagman said:

Not sure yet.CFS is parking the signal into the Maritime and Euro seemingly,that should possibly be severe leading into or around Met spring.

Gotcha

19 hours ago, jaxjagman said:

Rossby wave is going to work its way into the IO the next few days and a Kelvin Wave coming off Africa during the same period,plus you have a TC,MJO signal could and should get stronger into the IO

This implies a continuation of the current pattern?

1 hour ago, Carvers Gap said:

Sever ice event is back on the 6z GFS for middle and west TN.

The thing that is concerning to me is that the GFS has been creeping the line of ice slowly south with each run while other models have been showing it for a few days now 

30 minutes ago, Carvers Gap said:

The 18z GFS sure likes like a multi-day over-running event.  It looks like a more traditional event than last year.  The front pushes and the firehose is pointed at the boundary as it presses(vs stalls like last year).

I must have missed that hardly seeing a thing for my area. You mean pattern wise?

24 minutes ago, Carvers Gap said:

The 12z GFS is loaded for bear yet again.  

That is some real-deal vodka cold in the Northern Plains, -45 wow, just one good system could pull that down right?

LR still looks cold; if we manage to put snow on the ground, we are going negative, those are some cold numbers! 

GFS advertising a pattern that just keeps giving lol 

Huge model swings  from  run to run  for sure! 

31 minutes ago, Carvers Gap said:

12z Euro has that system as well, but further to the west.  I am guessing that is going to be a cutter for the Plains, but it has trended better for middle and western areas of the state.  If it comes to pass, the GFS nailed this from d16.  I think there is a pic of it in the banter thread.  Regardless of that storm, he pattern that comes after that looks really good.  That 6z GFS run looked a lot like last winter's overrunning event.  

The GFS has some DGEX DNA in it.  It has been over-amping stuff this year in crazy ways, but generally getting the placement of the features reasonably correct on a large scale.  It seems to have feedback issues when a slp turns to the NE or when it phases.  It has done that all winter.  I will say this though as a counterbalance to that last opinion, February systems tend to over-perform in my book.  Modeling often overestimates how far south those storms will be suppressed and underestimates the strength and precip.  

In the LR, modeling(ensembles and operationals) look really good.  What looked to be a pattern change, now looks like an EPO ridge which has ideal placement.  I am a little wary of this flip back to a colder look(after several days of a flip to warm after Feb2).  If you remember back during late December when we flipped cold, for a time modeling only had the monster cold front on Jan3rd, and then turned warm after the front.  In reality, that was a pattern change.  We had a slight warm-up after that front, and then the hammer dropped for good.  Right now we have a similar (but opposite) look where a strong cold from drops into the West during early February.  At first, modeling had that as the pivot to a warmer pattern over the East.   For the past 3-4 days, modeling has trended much colder for the East as it rolls that rough out of the west right back into the East, and then locks it into place.  The 6z GEFS is now a complete flip to a very cold look, and its look is one that could deliver a very cold air mass into the US.  The 0z CMC has something similar.  The EPS has been a few days behind @Mr. Kevin, but it is almost there.  The EPS has been less than consistent in the LR.  Again, GREAT looking pattern.  And again, I am wary of modeling perpetuating the current pattern.  

For you LR model watchers, does that pattern after the cutter look like a return of the current pattern or is it a new pattern?  It looks to me like a variation of the same family of EPO ridges, but the center of the ridge looks further south than the previous pattern.  The reason I ask, the current pattern is due to break 4-6 weeks after Jan 3.  That would mean that look in the LR is very temporary.   If it is a new-is pattern, we may see much of February get cold.  

I was thinking same about the overrunning likely will be different next run but as you pointed out indicating the pattern general 

Great eye candy on the 6z run of gfs, my new screen saver

Looks like models are still struggling. 0z & 6z of gfs wildly different in long range. I think, for what's worth, the forum has chance for another couple ststem s before spring. Is this one of them? Perhaps.

Looks like a great run by 6z GFS for west/middle areas of forum