1/10-1/12 Southern Slider

[Holston_River_Rambler]

Past 3 EPS means:

[fountainguy97]

8 minutes ago, Holston_River_Rambler said:

Welp, still over an hour for the SREF, so might as well look at the EPS:

 

10th through 90th percentile snowfall (this is NOT an increasing Mean)

 

 

 

Here is a SREF control I assume for 09z. I was just watching them for hints of what the NAM may do. To me the trend is for a more consolidated southerly low.

 

also seems to be more precip this run across NE areas

 

[Carvers Gap]

9 minutes ago, tnweathernut said:

Kind of like the school system in middle TN sending texts to parents yesterday telling them to have a ride prepared for their children Friday, they were going to attempt to start school.  Why?  From the first 10 minutes of flakes you are certain to have road problems and the start time has been well modeled between 8-10 am for the last 48 hours now.  Hopefully they backtrack and don’t meet at all tomorrow in northern middle TN.  If they do I’d question the sanity of the people making these high level decisions.  

I don't want my comments to come across as prideful.  I know they have a model which has gone rogue(3k NAM).  If I got paid to do this, it would give me pause as well.  (The 12k NAM at 6z is now back in the winter storm camp).  I understand the call, and respect them as professionals.   A watch is appropriate(for now) for the eastern 1/3 of the state - for now.  However, they need to understand that they have already busted twice this week with little acknowledgement (that I know of) of those errors.  And yes, errors do happen in weather.  It just goes with the territory.  But the morning disco today seemed a bit preachy in spots, bordering on talking down to folks.   I could do without that.  They also need to understand there are many, many decisions made with their products(timing, impacts, amounts, significance) in mind.  If they are right on this one, they will be 1 for 3 this week.  

I say this often.  Luck cannot be part of effective safety protocol.  

[tnweathernut]

20 minutes ago, matt9697 said:

Here is the most recent statement on the Sumner County Facebook page.....

When I went to high school in Sumner County we had a smoking section outside for the kids and teachers.  Times have changed.  lol

[Carvers Gap]

Anyone can make a correct forecast if they wait until the event is under way.  At that point it really isn't a even a forecast product, but a statement of the obvious.  

[housemtnTN]

I would rather be wrong and everyone be prepared than the latter.

[Carvers Gap]

24 minutes ago, matt9697 said:

Here is the most recent statement on the Sumner County Facebook page.....

I just want to know if we can incorporate that sensor data into our weather models. 

[Carvers Gap]

9 minutes ago, fountainguy97 said:

Here is a SREF control I assume for 09z. I was just watching them for hints of what the NAM may do. To me the trend is for a more consolidated southerly low.

 

also seems to be more precip this run across NE areas

 

Man, I could easily be wrong, but with the 6z 12k NAM coming back onboard....the 3k might come back around as well.

[matt9697]

5 minutes ago, Carvers Gap said:

I don't want my comments to come across as prideful.  I know they have a model which has gone rogue(3k NAM).  If I got paid to do this, it would give me pause as well.  (The 12k NAM at 6z is now back in the winter storm camp).  I understand the call, and respect them as professionals.   A watch is appropriate(for now) for the eastern 1/3 of the state - for now.  However, they need to understand that they have already busted twice this week with little acknowledgement (that I know of) of those errors.  And yes, errors do happen in weather.  It just goes with the territory.  But the morning disco today seemed a bit preachy in spots, bordering on talking down to folks.   I could do without that.  They also need to understand there are many, many decisions made with their products(timing, impacts, amounts, significance) in mind.  If they are right on this one, they will be 1 for 3 this week.  

I say this often.  Luck cannot be part of effective safety protocol.  

I know there were a couple times in the 1970's when schools in the Nashville area got caught with wrong decisions. A few times, kids spent nights on buses instead of at home; since then they typically call school when snow is even mentioned. The most recent time, I believe, was in 2003 when the NWS was calling for a few snow showers and we got several inches. The problem was that there had been no pretreatment, everyone was at school/work; then when it started snowing, when it became obvious the forecast had failed, everyone hit the road at the same time, only to have mass gridlock, kids spending the night at schools, it was a mess. 

 

https://www.newschannel5.com/news/taking-a-look-back-on-past-major-winter-weather-days-in-tennessee

[Holston_River_Rambler]

One thing I have noticed (now that I can look earlier than thought at the SREF thanks to fountain) is that he SREF cores seem to have been overestimating ZR over AR and TX:

5 run trend:

ARW core

NMB core:

 

They are also too far north with the mixing line:

 

 

 

[Carvers Gap]

The HOT donuts sign has returned for this thread.

Now, back to model watching for me.  I really don't see a ton of changes from overnight modeling.  There is an ebb and flow with each model run.   We have seen that overnight.  MRX correctly noted (as did all of us as we watched it roll in!) that the 3k NAM is a notable outlier.  But it scores a coup enough of the time that it probably should be factored, especially if you make money doing this for a living.  The 6z 12k NAM is noticeably less amped, and thus, its snowfall totals sharply increased.  

It is now the 3k NAM vs all comers.  Get your popcorn ready.  Who knows what this day will bring or what model trends will be presented?  But at least the answer to that question is that today has promise in that it won't be boring. 

[fountainguy97]

5 minutes ago, Holston_River_Rambler said:

One thing I have noticed (now that I can look earlier than thought at the SREF thanks to fountain) is that he SREF cores seem to have been overestimating ZR over AR and TX:

5 run trend:

ARW core

NMB core:

 

They are also too far north with the mixing line:

 

 

 

Yep. Good signs for downstream adjustments! Optimistic for a better 12z high res suite.

 

one thing that is weird is how different the rgem is. I guess it's taking the euro approach with much less qpf.

[Carvers Gap]

5 minutes ago, Holston_River_Rambler said:

One thing I have noticed (now that I can look earlier than thought at the SREF thanks to fountain) is that he SREF cores seem to have been overestimating ZR over AR and TX:

5 run trend:

ARW core

NMB core:

 

They are also too far north with the mixing line:

 

 

 

The trade right now might be snowstorm for ice storm for some areas.  Oof.

[Holston_River_Rambler]

3 minutes ago, Carvers Gap said:

But at least the answer to that question is that today has promise in that it won't be boring. 

Maybe Powell will ride in like Gandalf at Helm's Deep to usher in the 18z runs? 

[matt9697]

Obviously this thread is for the current storm, however, I am still seeing signs of a bigger cold shot around the 20th, I believe @Carvers Gaphad mentioned an overruning situation? 

[Carvers Gap]

Just now, matt9697 said:

Obviously this thread is for the current storm, however, I am still seeing signs of a bigger cold shot around the 20th, I believe @Carvers Gaphad mentioned an overruning situation? 

Yes, we have some commentary in the January thread.  As of last night, that signal was there.  I haven't checked this morning. I would suspect that is still there unless there has been some sort of overnight flip(which could happen at this range).

[fountainguy97]

12z hrrr rolling. Looking better for eastern areas regarding precip early on.

[fountainguy97]

Hrrr has doubled precip for most of ETN. Looks like the 12km nam. 
 

seems like the shadow still exists but just way more QPF in general across the area.

 

[TellicoWx]

HRRR caved....for those in southern valley check the soundings. Sharpy is putting way too much emphasis on the temp line crossing 32 for an extremely brief second (that's a snow sounding not mix)

[Holston_River_Rambler]

I don't know which is better on the HRRR, the Kuchera or 10:1 lol. 

[Holston_River_Rambler]

 

 

[Holston_River_Rambler]

Ron to run trend:

[matt9697]

1 minute ago, Holston_River_Rambler said:

 

 

Cash it in! 

[TellicoWx]

Chatt sounding (Sharpy spit out rain)...there is only 1 1hr frame where a legit mix would be possible.

[Reb]

5 minutes ago, Holston_River_Rambler said:

Ron to run trend:

These are the trends I was hoping for! Sheesh. If other models follow suit, game on. Still don’t trust the HRRR though 

[Holston_River_Rambler]

I wasn't sure what Tellico was talking about with SHARPY, so I looked it up and thought I would share:

https://sharppy.github.io/SHARPpy/

 

 

[TellicoWx]

Just now, Reb said:

These are the trends I was hoping for! Sheesh. If other models follow suit, game on. Still don’t trust the HRRR though 

Yeah, I'm still using it for trends only. Verbatim off soundings, it is where globals were couple days ago with the Sharpy issue. That's wht snow maps are pretty to look at, but always double check them. Old saying...trust but verify.

[Holston_River_Rambler]

Just based on 500 mb trends at 15 hours out, I think the NAM will have more precip this run, mixing or not remains to be seen. 

[TellicoWx]

2 minutes ago, Holston_River_Rambler said:

I wasn't sure what Tellico was talking about with SHARPY, so I looked it up and thought I would share:

https://sharppy.github.io/SHARPpy/

 

 

It's basically what websites use to generate their maps. It's the Grib data in visual form. Sometimes it will over compensate...usually not quite this bad.

[housemtnTN]

14 minutes ago, Holston_River_Rambler said:

 

 

Wow! This might actually be a possibility? This is a higher resolution short range model, correct?