1-30/2-1-26 Arctic Blast, ULL Snow Event

[Holston_River_Rambler]

Cheer up fellers! Sunset is in only three hours! 

 

Kidding aside, upper low is still up north Chicago and all we have is some broad divergence ands little bit of a leeside low for now.

 

 

 

[Stovepipe]

No model that I saw leading up to this had snow starting before around 7pm in the central valley.  Temps were shown to creep up to around 36 and then crash down hard by the time snow starts.  So far it looks to me like we are about on track for that.

[fountainguy97]

1 minute ago, Holston_River_Rambler said:

Cheer up fellers! Sunset is in only three hours! 

 

Kidding aside, upper low is still up north Chicago and all we have is some broad divergence ands little bit of a leeside low for now.

 

 

 

yep when that ULL forcing arrives it'll be hours of .5 hour rates all night into the day tomorrow.

[TellicoWx]

The gusts to 35mph wording has me curious if at some point part of the WSW is upgraded to a Blizzard Warning due to whiteout conditions. Low chance I think.

[John1122]

The 18z HRRR snowfall output looks almost exactly like the Euro but with a little less in the southern valley around downtown Chattanooga.

[Carvers Gap]

15 minutes ago, fountainguy97 said:

This thing hasn't even started yet. Latest HRRR lays it DOWN across ETN tonight. Temps crashing from 20s down into the teens with a deform band just rocking. 

 

Accumulations don't start until 6-9pm. That's always been the case. at least the last few model runs

Areas that have orographic lift, you should do really well.  My concerns for west of I81 in TRI are readily apparent w/ that map.  MRX downgraded Bristol's and Kingsport's max to 1-3" - lower than Knoxville's.  OTH, Gatlinburg has a max of 16".  There are going to be some very strong gradients over TRI...potentially comparable to the storm of the late 90s.

[Carvers Gap]

14 minutes ago, Stovepipe said:

No model that I saw leading up to this had snow starting before around 7pm in the central valley.  Temps were shown to creep up to around 36 and then crash down hard by the time snow starts.  So far it looks to me like we are about on track for that.

They showed 2:00PM for MBY here in TRI and started about an hour early.  I am THANKFUL for Knoxville not having snow yet.  I have one who has to commute home....selfishly, I want it to wait until after 4:00PM.  Knoxville could potentially do well.  I think Knoxville's totals could resemble the west side of TRI.

[Kasper]

1 hour ago, bearman said:

Not to say anything like this is going to happen, but I remember one event or rather non-event when I lived in Athens.  We had super cold air, i think it was a week or so before we got the big sleet storm.  We had a Winter storm warning out for multiple inches of dry snow. That morning I woke up and watched Bill Race, and he was saying it would not be long until the snow saturated the air, and we would be getting snow at a good rate.  I remember looking out and seeing a snowflake fall and thought it's starting.  It was the only flake I saw all day. We ended up getting zilch. It was the biggest bust I can remember.

I remember that well lol

[Tucker1027]

Still snowing at the end of this, but a big jump for Chattanooga on 19z RAP 

 

[TellicoWx]

Hello NAM nice to join us in Monroe co 

[BlunderStorm]

23 minutes ago, Holston_River_Rambler said:

Cheer up fellers! Sunset is in only three hours! 

 

Kidding aside, upper low is still up north Chicago and all we have is some broad divergence ands little bit of a leeside low for now.

 

 

 

I appreciate the synoptic maps you and Scottie posted. Keeps things tangible and allows comparison with the models when nowcasting. Wish we had more posted more often. 

[Carvers Gap]

The northwest side of TRI has to score early with this.  The southwest side(west of I81) has prolonged and strong forcing due to orographic lift on northwest flow.  The snow(as I mentioned to Stove) started here in Kingsport about 1:00PM which was early for most modeling by about an hour.  The original timing was....19z -12 - 5 = 2:00PM.  Though the storm is unusual w/ its dynamics...the stronger accumulations near the mountains are common when the incoming system has a northwest flow forcing component.  Kingsport does better when there is backing of any kind and especially if there is Atlantic input. I would think any NW facing area could score well.  I have my investment low for KPT, but am pulling for the Euro w/ the same fervor that I pulled for the GFS during the last storm...and maybe a little bit of "little engine that could" embedded in there.  Good luck to you all in the foothills...we will live vicariously through you!

[John1122]

4 minutes ago, TellicoWx said:

Hello NAM nice to join us in Monroe co 

It took me from 1 inch to 4 inches.

[TellicoWx]

Low res NAM splatted my area

[John1122]

The 3k has a 6 inch dot close to me now.

[Carvers Gap]

18 minutes ago, TellicoWx said:

The gusts to 35mph wording has me curious if at some point part of the WSW is upgraded to a Blizzard Warning due to whiteout conditions. Low chance I think.

Yeah, that is very close.  I would think mountain communities might meet that criteria, but they guard that designation with their lives in E TN.  

[GBOVolz]

I wouldn’t pay attention to Matt lol

This is my point about Matt. He doesn’t look at the mods like he acts like. He made a post 30 min ago saying the euro has blown up its totals. The euro has been pretty consistent the last 48 hours. He obviously hasn’t looked at anything other than the NAM or NBM.



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[Tucker1027]

[fountainguy97]

wow these 18z models are hitting hard. Johnson city over 15" on 3km NAM

[fountainguy97]

 

 

The big 3

 

RRFS

 

 

HRRR

 

 

3km nam

[John1122]

Gonna see who wins the war, all models (except maybe the NBM) or my point forecast. (my high today has been 29)

This Afternoon

A 40 percent chance of snow showers. Cloudy, with a high near 34. North wind around 5 mph.

Tonight

Snow showers, mainly before 3am. Low around 11. Wind chill values between 1 and 6. North wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.

[Windspeed]

The RGEM crushed our souls last week once it got into range. Everything quickly followed suit, so I'm going stubbornly stick with it through the evening. The 12z run doesn't have my location with an inch of accumulation at 10:1 until around 0z / 7PM. That seems reasonable, given the melting occurring with the sun. I figure we won't see heavy returns until sunset. As the temperature drops that ratio should also increase with the cold column in place.

[Silas Lang]

Man all mods are consistent Knox getting the sharp cutoff with an average of around 5 inches. 

[housemtnTN]

Just now, Silas Lang said:

Man all mods are consistent with Knox getting the sharp cutoff with an average of around 5 inches. 

Glad I am far out east!

[Holston_River_Rambler]

2 minutes ago, housemtnTN said:

Glad I am far out east!

Are you north or south of house mt? 

[Wurbus]

I think I'm right on that cutoff line near Walker Springs so it'll be interesting to see what happens.

[Tucker1027]

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[housemtnTN]

6 minutes ago, Holston_River_Rambler said:

Are you north or south of house mt? 

Just south of it. Maybe 1 mile if that.

[nrgjeff]

Shifting from forecast to nowcast. Have to decide whether this is stay up late or get up early. I'm gonna need a rave for the all-of-the-above all-nighter option. 

Wetbulbs are probably in the mid-30s everywhere. With below 0C temps aloft it's all snow. Any initial sprinkles should goto snow.

Plateau clearly has multiple rounds. This is the appetizer. Main course is tonight into early Saturday. Saturated profile snow goes on into Saturday night. Mountains is even better.

Chatty looks mostly overnight. Everywhere around us will go through Saturday morning, but it'll cut off fast in Chat-town. Enjoy it while it's here!

Everywhere else looks good on MRX charts. Upper Plateau will almost certainly over-achieve though. 

[Silas Lang]

4 minutes ago, Tucker1027 said:

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First time I have seen this issued before. I know they have released maps with probability numbers but I really like this layout. Feels like a good way to message snow amounts.