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Pattern Nippy November

Fountainguy97 said:
Yeah our precip will come from that Shortwave. Need it to continue to speed up and get pulled into the northern stream. Need to see a lot of speeding up though. Idk if we will see that much.
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GEFS has made very good progress, look how much it’s sped up, also northern stream slowing down and looks a little bit better positioned 89E27C6E-C88C-46F5-904A-1A3A05A82A02.gif
 
EPS has fewer snow solutions but looks better at H5.
00z
1573624800-ogQ9tpUkpTw.png

12z
1573624800-zXgNamhHgyM.png
 
Webberweather53 said:
There's still some takers on the 12z EPS. Arkansas & Tennessee have more model support & are more climatologically favored to pick up snow/ice at this of the year.
View attachment 25458
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The moment you realize you have the same statistical probability to receive an inch of snow as Columbia SC..
 
To reiterate, this is actually the classic pattern you often see immediately preceding overrunning &/or anafrontal-type winter storms in the southern US w/ a big cold trough over the Lakes and southern stream shortwave over the southwestern US. If only it wasn't November and over a week away.

Details will make all the difference between cold & dry, a nice light-moderate impact early season winter storm or cold rain w/ a storm cutting up to the Lakes & OH valley. All 3 of these general scenarios are legitimately on the table but one of them is very likely to transpire.


gfs-ens_z500a_us_33.png

ecmwf-ens_z500a_us_9.png
 
^ not to mention on the nam quiet snow showery if anyone wants to drive up the NC mountains Friday morning. Moisture fades but should be enough esp western slopes
 
I hope this doesn't violate posting rules ... but with all the discussion about a cold November leading to a hot December, or not ... it's all models and history, which does not necessarily repeat itself (do not repeat themselves to be grammatical) ... but thinking about what's not supposed to happen, after 9 years of marriage and no kids and being told it was "impossible", suddenly 2 of the best boys you can imagine came down the shoot ... so there's always a chance for a blessing, and when they happen, they can come in twos ...
decipher this and you're not at happy hour ...
 
Good evening everybody, I hope all is well.
With our small chance of snow next week, I went ahead and analyzed all the data and created a graphic (see below)
*Disclaimer This data is based on model analytics and is no way includes model biases or any human forecasting*

Data: 12z EPS and GFS ensemble members, reflected from Weatherbell Meteograms
Region: KGSO (Greensboro) Most Triad regions apply, even triangle regions wouldn't be too far off

Section 1. Mean
What I did with this set was as I created my excel spreadsheet, I set up the members and found their averages separately. The second thing I did was, weigh the members seperately. The GEFS was weighed 40% of the total; 1.1(mean) was multiplied by .40 and I got .44 The EPS was weighed 60%, I multiplied .29(mean) times .60 and got 0.171. I then added the total and got my average in which see below which is 61". Nothing Incredible

Section 2. % of members show snow
A bit more self-explanatory, I turned the members that showed snow into a percentage.

Section 3. Consistency.
What is did here was to use the mathematical formula, Mean Absolute Deviation, or for short MAD. Essentially It's the average distance the ensemble members are away from the mean. The process would be finding the original average, subtract the average from each member and find the average of that product. It is helpful because it lets you know whether a model is much more or less likely to verify. So essentially the smaller the number, the more likely that model set will verify and vise virsa, you could have a mean with 100 inches of snow, but will a low number, that would most likely verify, a high number and that means that 100 mean probably has a couple 50" members and a few 200" members.

Summary: This snow chance at the moment is very low right now, however, bears watching. As we head into the week, I hope to keep track of all these variables.
ncwx chances.PNG
 
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Ollie Williams said:
Good evening everybody, I hope all is well.
With our small chance of snow next week, I went ahead and analyzed all the data and created a graphic (see below)
*Disclaimer This data is based on model analytics and is no way includes model biases or any human forecasting*

Data: 12z EPS and GFS ensemble members, reflected from Weatherbell Meteograms
Region: KGSO (Greensboro) Most Triad regions apply, even triangle regions wouldn't be too far off

Section 1. Mean
What I did with this set was as I created my excel spreadsheet, I set up the members and found their averages separately. The second thing I did was, weigh the members seperately. The GEFS was weighed 40% of the total; 1.1(mean) was multiplied by .40 and I got .44 The EPS was weighed 60%, I multiplied .29(mean) times .60 and got 0.171. I then added the total and got my average in which see below which is 61". Nothing Incredible

Section 2. % of members show snow
A bit more self-explanatory, I turned the members that showed snow into a percentage.

Section 3. Consistency.
What is did here was to use the mathematical formula, Mean Absolute Deviation, or for short MAD. Essentially It's the average distance the ensemble members are away from the mean. The process would be finding the original average, subtract the average from each member and find the average of that product. It is helpful because it lets you know whether a model is much more or less likely to verify. So essentially the smaller the number, the more likely that model set will verify and vise virsa, you could have a mean with 100 inches of snow, but will a low number, that would most likely verify, a high number and that means that 100 mean probably has a couple 50" members and a few 200" members.

Summary: This snow chance at the moment is very low right now, however, bears watching. As we head into the week, I hope to keep track of all these variables.
View attachment 25474
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Nice break down ollie. Nice.


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SimeonNC said:
Is the NAM known for having a cold bias like the GFS/FV3?
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In my memories, the NAM is pretty good to use for thermal profiles and not so much for precipitation. So many tend to take it's thermals and apply it to a blend of other modeling's precipitation, regardless of type. Many think it does okay with CAD, while like other modeling, slightly under doing it's duration and strength too, but gives a better picture of the intricate details.
 
The way the ridge is oriented out west, systems are getting shredded when they try to come east or extremely suppressed. Too much positive pna imo.
 
While we like these trends and that NS energy slowing down, we don’t want that to happen to much, WAR starting to make its self known, at this point tho it would just increase the moisture so it’s not a bad thing right now 47E5DB54-D4B7-4706-B986-032925249243.gif
 
I don't think we've ever had a winter storm in November to my recollection this far south. It would be fitting after we got stuck in the oven through early October though.
 
WxWatch said:
Okay, I think we need to fire up the storm thread! I'm excited now, my predictions are actually coming true!
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Slow down fella, It’s wayyyy to early. I posted some percentages above, we have a 31% chance of seeing snow in the Triad area which would be the most likely area. I would wait until the Euro data and most of It’s ensemble members show something. Plus you don’t want to Jinx us
 
This GFS run is kind of what I'm thinking if this thing happens. Overrunning with a winter storm in parts of the western SE and upper south.

The BAD news however, is honestly this appearing this soon. Is there still a major suppression problem? If so, then buckle up as we're going to see some more north corrections.
 
Lets try to save this snow map (10:1 ratio). Do we see anywhere in the ballpark of this?

1573014425952.png

I'll give the GFS some credit, it's snuffed out a few things I think in the last month or so, just has been too cold in doing so. I have a feeling in the back of my head that the suppression issue is still a major problem.

Otherwise, I'd be like *tries to think of a way to get up to NC*.
 
Is it January or is it November?

1573014720409.png

I should also say that I showed to my dad a HIGH temperature map for next week from the Euro earlier today and it spawned him calling up his HVAC mechanic for maintenance this week.
 
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