Winter 2021/2022 January Thread

[Holston_River_Rambler]

In all seriousness, if that western piece of energy holds together better than modeled and we still get shortwave interaction like the above...

 

[Carvers Gap]

Here are the comparison maps of the 12z Euro and GFS.  Just watch the energy in the southwest.  Notice how it feeds into the base of the trough on the GFS at 114 vs being strung out on the Euro.  Then, take a look at 123.  That energy on the GFS turns that trough natural tilt.  At the surface, there is almost nothing on the Euro over the SE.  

Look at the differences at the surface at 111 in terms of precip over the SE.  The Euro holds back that energy and strings it out. It then consolidates along the front piece of energy while the second piece heads to the Yucatan. 

 

 

 

 

[Carvers Gap]

One more note about 12z....The CMC has not run, but its ensemble has as Holston notes.  Both the CMC and GEFS ensembles have that energy over the GC and SE.  The Euro is the only one without it.  If we take into account known biases, the 12z suite is a storm signal for the EC.  Time will tell just how involved E TN can get.

[Carvers Gap]

But honestly as weird as this might sound, that Euro run is an improvement since it finally depicts the northern jet being organized.  It looked like hot garbage at 0z.  Get that energy feeding into a more organized northern feature, and that is not a terrible look.  We need some fire injected into the base of that trough to force it to go into beast mode earlier.  I think the general progression/timing/location of the trough looks pretty well set - and that likely won't help us.  We need that low to fire a bit earlier in the run.  With no blocking over the top, a strong storm would back west IMHO.  The more strung out it is...the more it waits to turn northward.  

[Carvers Gap]

I picture these troughs like a pendulum swinging.  We want it neutral over Alabama and not the Carolinas.  Not sure that is going to get fixed.  To continue what I said above, we just need that base of that northern stream trough to get hit with the STJ turbo boost as seen on the GFS.  Without that, the storm fires later which equals a later turn/recurve.  The formation of the slp earlier would likely allow/force the northern stream to buckle and pull back on the slp, thus lifting its almost due north.  If that won't work, we want a strong  northern feature in order to get some clipper snow. 

GFS/GEFS/GEPS vs Euro cage match.

CMC is injured and in the locker room for evaluation. 

[Carvers Gap]

On another note, the 6z GFS and 12z GFS are flirting with a multi-day, over-running event after the cutter which follows the potential weekend storm.  Not even going to get into details, but that has been on modeling off-and-on for 5-6 days I think.  It is still there.

[fountainguy97]

20 minutes ago, Carvers Gap said:

Here are the comparison maps of the 12z Euro and GFS.  Just watch the energy in the southwest.  Notice how it feeds into the base of the trough on the GFS at 114 vs being strung out on the Euro.  Then, take a look at 123.  That energy on the GFS turns that trough natural tilt.  At the surface, there is almost nothing on the Euro over the SE.  

Look at the differences at the surface at 111 in terms of precip over the SE.  The Euro holds back that energy and strings it out. It then consolidates along the front piece of energy while the second piece heads to the Yucatan. 

 

 

 

 

Honestly, I have not been impressed with the EURO at all this winter.  It has rarely if ever really led the way or won a battle vs other models.  Its GFS/GEFS/RGEM/HRRR for me until proven otherwise.

 

I don't really favor the GFS 12z run of stringing it out as an extremely likely solution. 12GEFS members most of them but a few are consolidated storms. Just depends on track for where the snow ends up.  I think we see that consolidated look. Just not sure where at yet.

[Holston_River_Rambler]

Not so great at reading the stormvista maps yet, but it looks like there are quite a few members of the EPS west of the OP:

Obviously still not great for us, but I think we would like that western trend to continue as long as possible. 

 

 

[Silas Lang]

Honestly feel better about the GFS picking up the storm than the Euro. 

27 minutes ago, fountainguy97 said:

Honestly, I have not been impressed with the EURO at all this winter.  It has rarely if ever really led the way or won a battle vs other models.  Its GFS/GEFS/RGEM/HRRR for me until proven otherwise.

 

I don't really favor the GFS 12z run of stringing it out as an extremely likely solution. 12GEFS members most of them but a few are consolidated storms. Just depends on track for where the snow ends up.  I think we see that consolidated look. Just not sure where at yet.

I agree. Seems the GFS has been pretty great this winter. I don't know if it is the particular pattern that's difficult or if the Euro had an "upgrade" at some point, but has not been that consistent this season. Really impressed with the GFS. It has caught trends on the other snows this year before the other models. 

[Windspeed]

Interesting take by Webb....

[John1122]

The NAM at 84 is similar to the 12z GFS with the 500mb vort in the SW. Probably going to see the 18z GFS evolve in similar fashion. 

[Holston_River_Rambler]

The western ridge is once again coming in slightly taller on the 18z GFS. 

[Holston_River_Rambler]

It's gotten so far west, that the GFS is trying to cut it off this time:

[Holston_River_Rambler]

Happy hour is filled with northern stream sadness. The vort gets so far west it can't manage to get east enough to phase with the secondary s/waves coming in from canada:

[Holston_River_Rambler]

In that set up we can hopefully get one of the northern shortwaves to be an over performing clipper. 

[Carvers Gap]

That is a 100% cave by the 18z GFS to the Euro.  Both solutions still look wonky as all get out...and not sure I buy either.  Euro is king today.

[John1122]

Wait until 0z and it will change again I suspect. 

[Holston_River_Rambler]

1 minute ago, John1122 said:

Wait until 0z and it will change again I suspect. 

I hope so. Some chunk of that 4 corners shortwave has got to kick out, or everybody loses accept for down east Maine and Nova Scotia, lol. 

[Holston_River_Rambler]

Just a quick glance at the GEFS and it looks like it is east of the OP, with the mean vort maps out to around hour 78. 

[Holston_River_Rambler]

18z Euro looked better with the southwest shortwave than the 18z GFS and the 12z Euro, IMO:

Brings a more consolidated shortwave out. 

 

[John1122]

4 minutes ago, Holston_River_Rambler said:

18z Euro looked better with the southwest shortwave than the 18z GFS and the 12z Euro, IMO:

Brings a more consolidated shortwave out. 

 

That definitely looks less strung out and more tilted that those two runs. I'd love to see it slightly ahead of the northern energy and let it tug it back some. 

[John1122]

GFS whimpered again. I guess the ultra dry runs are going to come to pass. 

[John1122]

In model mania, the Euro bounced back a little for Eastern areas. Pretty good upslope in the mountains and around an inch or so elsewhere. 

[Carvers Gap]

13 hours ago, Carvers Gap said:

That is a 100% cave by the 18z GFS to the Euro.  Both solutions still look wonky as all get out...and not sure I buy either.  Euro is king today.

And then the Euro goes back to the old GFS runs.  I have noticed this winter that the Euro seems(at times) about 24-48 hours behind the GFS this winter with trends.  Seems like it is almost where the GFS was yesterday morning.  Models leaning towards a clipper event for the weekend for northern areas with only the fair coastal cities having potential for significant snow.  If things don't move by 0z, there is really little room or time for the system to work its way back west.

[Carvers Gap]

The 0z Euro absorbs most of the energy from the southwest where it didn't during prior runs.  The GFS leaves it behind over the southwest.  It "appears"(my two cents and not the gospel) that when that energy actually moves eastward....the storm occurs close enough to the coast to have meaningful impacts in E TN. Maybe the 6z Euro will show some consistency.  Maybe not.   If the storm is going to occur two things have to happen:

1.  The energy can't be left behind in the southwest.  It can be strung-out some, but not completely sheered and left.

2.  Phase has to occur early.

The 0z Euro had both of those.  Even still, it needed to phase a bit earlier.  I wondered this yesterday, and still wonder today....are models erroneously leaving that energy back?  I don't know the answer to that, but it is something to watch.  We have seen that verify at times, and also be an error at times during the past decade.

[Carvers Gap]

It is on an island right now, but the Euro (again at 6z) appears to get most of the energy clear of the southwest at hour 60.  I can only see it in the front range right now, so we will see where it goes from there.

[Holston_River_Rambler]

Yeah it was a little better than 0z:

looked to me like it tried to phase over western TN and AL

[Carvers Gap]

Indeed the 6z off-run Euro would be a widespread light snow event for E TN.  Turns neutral tilt right on time - northern stream dominated event.  

[Carvers Gap]

Morning disco from MRX.  Good write-up and similar to discussions here:

With the approaching trough, significant 12-hour height falls of
200+ meters are expected, which will provide synoptic-scale ascent
on Friday, more notably to our southeast closer to the surface low
that eventually becomes a nor`easter. With the increased NW flow in
the lower levels, the focus for increased PoPs and longer
precipitation windows will be in the higher terrain. While there
does remain much uncertainty, current indications of the vertical
atmospheric profile suggest mainly a rain/snow mix with 850mb
temperatures to stay below freezing. This also could be accompanied
by sleet, depending on the depth of the saturated layer. Based on
the latest model guidance, it still appears that the best potential
of accumulating snowfall remains in the higher terrain. This is
given the continued uncertainty for residence time of moisture in
the region, dynamic cooling efficiency, and the overall timing in
general. It is also noted that the latest ECMWF and many ensemble
members are more aggressive on widespread light snowfall
accumulations due to a later exit of moisture and better forcing. In
any case, the overall message remains the same with potential for
widespread impacts remaining fairly low. By Friday night, strong low-
level CAA will be in place with the trough having moved just east of
the region.

Saturday through Monday

The main story for Saturday continues to be the likelihood of far
below normal temperatures, potentially colder than any seen so far
this season. The ensemble and deterministic consensus is for 850mb
temperatures to fall into the negative teens (C) after 500mb heights
fall to 5300-5400 meters, normal January values in the upper
Midwest/Great Lakes. This could mean much of the area will stay
below freezing for 48 hours or more, not to mention subsidence from
the surface high likely allowing for significantly cold overnight
lows Friday and Saturday nights. Depending on the strength of low-
level winds early in the weekend, wind chills could drop to the
single-digits area-wide to below zero in the higher elevations. The
remainder of the period will likely experience a warming trend as
height rises are indicated.

[Carvers Gap]

An interesting move by the 0z EPS last night.  It has some support from the GEPS regarding the EPO ridge.  This is the last 5 days of the run.  All three global ensembles are BN or temps in the East.  There is one trough amplification in the West around 180, and then the EPS firmly entrenches the trough in the East again.  If you go look at the historical thread, take a look at the 0z EPS and compare.  The GEFS holds the trough centered mid-section/west.  It has done better with transitions, but seems to have been left to its solutions...both the EPS and GEFS had similar looks.  The overnight and 12z(yesterday)EPS run is substantially different than its Weeklies.  The EPS made a move at 12z yesterday in the LR.  Weeklies were derived from 0z.  The 0z run continued that trend.  That pattern on the left would be quite cold here w/ some hints of split flow(see the low underneath).