Carvers Gap

The 12z GEFS and GEPS(and prior runs) have roughly 6" of snow for their NE TN ensemble means. Usually, that is a good sign. No idea if those numbers will verify, but I am optimistic that we see some winter weather over the next couple of weeks.

Here are the full run ensemble clown map members...

The 12z GEM para is again the model which I "think" simulates the next ten days in a sensible fashion. As Boone noted, lots of light events are embedded. Systems don't look overly amped, but looks sensible in terms of its QPF and track given cold air in place. This is what "should" be occurring at the base of a highly amplified trough. Beginning the 17th, there are several small events which rotate through.

May be something but probably not a big deal in regards to map features. I am seeing a little lee side low pop for the 15th. Time of day is the deal killer, but interesting nonetheless.

Wonder if @Mr Bobis in this or any of our other met folks? https://www.amazon.com/Weather-Channel-Pioneers-Joseph-DAleo/dp/1986184161?asin=1986184161&revisionId=&format=4&depth=1

Yeah, so that flattens out from time to time. I doubt modeling has the details correct. Could be a brief warm-up and rain or could be even as severe as over-running. I am interested to see how the models react to the phase 8 and HL blocking combo. That could get severely cold, but I have been burned at this range too many times to count. But yes, the trajectory(for now) favors either a cutter or over-running or both!

The 12z EPS 10d 500 map from d 3.75-13.75. I didn't run it to d15 as the run isn't over. The 12z GEFS is almost identical. The 12z GEPS doesn't have a 7d map...but kick the base of the western ridge slightly eastward....but still cold.

And I haven't even talked about the weekend and the 12z Euro run. Nothing huge, but lots of bands of light snow rotating through on the 17th, 19th, and possibly the 21st. Snow flurries could reach all the way to the Panhandle of Florida. That WWA for the mountains (which was shared earlier) could easily be a blizzard warning above 5000'. 40mph winds w/ accumulations of 6" and that is for Jan 13th. Ski slopes may score big during the next two weeks. Lots of windows to track right now...

This is a 10-day(!) map. This isn't just the d10-15 map. This is d5-15 map. I am not guaranteeing this verifies. But if I showed you this during August, and said that temps are going to be BN during our coldest climatology w/ blocking over the top and out West...would you have taken this map? You bet!!! The risk is that this pattern is dry. For many of our good snows, we need cold in place and good source regions.

What a run of the 12z Euro just speaking from a 500 pattern perspective. If snow is on the ground, this is how record lows are broken. Below is a textbook, high latitude blocking pattern. As long as that cold air pool is sitting and spinning over Manitoba, Ontario, and Quebec....that trough will have a hard time being anywhere but the eastern half of North America. The trough will try to go west from Jan 22-24, but it "appears" there is a very strong Arctic air mass poised to descend well below the 49th parallel. IF THIS IS REAL, many boxes are check for a pattern which would support a winter storm(s) over eastern North America. Trough east of Hawaii, phase 8 MJO, EPO ridge, block over Alaska, -AO, -NAO, and western Europe trough. IF REAL, I would expect there would be a potential storm run an impressive temperature and pressure gradient between cold and warm air masses. That gradient would stretch southwest to northwest. That potential storm could could be a cutter, or over-running event(probable), or EC storm. But when you draw up a pattern for winter weather....this is it. I do NOT know if this will verify, but this look is present across modeling right now in some iteration or another. I pulled the apparent temperature map as this rolls through at 306. And you all know the rules at this range, especially when looking at detailed maps at range. But this is just wild and worth a share IMHO. Those real feel temps. One end of the state is 27 degrees AN, and the other end is 20 degrees BN. That would be an all timer in regards to cold fronts.

Great find. 6 inches of snow and 40mph winds. Wow! Not a good time to be above 5000'. Almost seems like a WSW is applicable at higher elevations for this one?

Yeah, man. Big ol' banana over the top in the medium and LR. EPO -> AO -> NAO.

And who knows if it is correct, but the 12z GFS does have some support from both ensembles and other deterministic runs...the 12z GFS does amplify the pattern after the 25th w/ very cold air getting trapped over NA...just look at the 500 heights. The 0z Euro just about went to the extreme. Big story for 240+(proceed at your own risk...) is the movement of very cold air into NA. Can it get to our latitude? I think it has a chance. Feel better, @John1122! Hopefully @Daniel Booneis on the mend. I haven't seen him post as much recently.

That 25th-28th timeframe does coincide w/ the MJO potentially trekking into phase 8. Yeah, I looked, but kind of felt like it might impact EC weather. With HL blocking in place, a phase 8-1-2-3 of the MJO circuit, and it being mid-winter....I have seen A LOT worse at this time of year from both teleconnections and modeling.

And the 12z GFS shows the risk around the 25th or just after. The 0z Euro was more of a cutter type of system...but both kind of slide across w/ very cold air just to the north. The 12z GEM likely got lost late in the run w/ the weird West Coast stuff that models have had all winter - and yes, the West Coast does get precip during winter, but maybe not quite like that. Models are going to struggle a little bit as very cold air is potentially going to get trapped around the 25th(see my recent posts on the matter). How far west that cold goes will depend on the strength of the SER in the East. If it drops into the central or eastern Plains, we likely would be in business.