Christmas Eve Potential Major Winter Storm

[Money]

[Money]

[Money]

So, pretty much everything is on the table until this thing is completely on shore and everything is sampled. Phasing systems always give the models the most trouble, and I honestly don't think we'll get a consensus until 18-24 hours away from the storm. 

[Geos]

Well the PGFS is on it's own right now. You've got the NAM on it's own furthest East. Then everything else tracks the low through IN and MI for the most part.

[tim the weatherman]

i think that the low will track through indiana and michigan so that means chicago will be on the sweet spot with this one.

[Madtown]

Storm will be back on tonight's runs in my opinion.

[Money]

12z EURO has a 997 L in C TN area at HR 72. Way, way slower than 12z yesterday where it as in MI already.

[Geos]

EURO looks like the GGEM is several respects.

 

This is what we got through 12z the 25th.

 

[Money]

EURO was the step in the right direction though. Looked more amped than previous runs and wasn't too far off from going bigger. 

[tim the weatherman]

http://www.tropicaltidbits.com/analysis/models/gfs/2014122112/gfs_T850_us_14.pnghttp://www.tropicaltidbits.com/analysis/models/gfs/2014122112/gfs_T850_us_13.pnghttp://www.tropicaltidbits.com/analysis/models/gfs/2014122112/gfs_T850_us_15.pnghttp://www.tropicaltidbits.com/analysis/models/gfs/2014122112/gfs_T850_us_25.png

[Money]

12z GFS Ensembles:

 

http://mp1.met.psu.edu/~fxg1/ENSPRSNE_12z/f84.gif

[Tom]

When I took a look at the jet stream structure on 12z 24th it almost seems positively tilted and no where near as deep of a trough as previously advertised.  This doesn't make much sense.  Until this storm starts to take shape late Monday in the central CONUS, we are not going to see model consistency.  Most of the jet energy is coming onshore today and we should see some changes on tonight's 00z run.  With the ridge off the west coast, this should translate to a deeper trough than what this run shows. 

[Money]

Hm.

 

18z NAM taking the northern stream into N. KS/S. NE so far through 23. Way south than 12z at hr 29.

[Geos]

Hm.

 

18z NAM taking the northern stream into N. KS/S. NE so far through 23. Way south than 12z at hr 29.

 

Yeah that's way south...

[Money]

Still in S. IA/N. MO at HR 30 while 12z NAM had it in S. MN

 

Wonder what this would mean down the road. 

[tim the weatherman]

Still in S. IA/N. MO at HR 30 while 12z NAM had it in S. MN

 

Wonder what this would mean down the road. 

looks like it went west.

[Money]

Look where the 4km NAM takes the northern stream...

 

http://www.tropicaltidbits.com/analysis/models/nam4km/2014122118/nam4km_ref_frzn_us_8.png

[tim the weatherman]

according to the wgn tv's website that chances of the christmas eve storm is decreasing and mike hammernik said on this morning's newscast because of the models.

[Madtown]

Hmmmm

[Tom]

Look where the 4km NAM takes the northern stream...

 

http://www.tropicaltidbits.com/analysis/models/nam4km/2014122118/nam4km_ref_frzn_us_8.png

That is probably going to make the southern energy dig even farther and phase better.  Pretty big change in about 6 hours on the 18z NAM.  Through 60hr...

[Tom]

Notice how the 18z NAM digs the tough so far deep into the south near TX/Mexico border...southern energy developing on Gulf Coast near TX/LA border.  Probably going to go due north from here.

[Money]

Ends up in W. GA/C. TN at 72

[Tom]

18z NAM develops southern piece to far east....snow begins to break out towards SE IN/W OH towards end of run...now I've very curious to see what the 18z GFS will show.  That was a pretty big shift south with northern piece.  Might be because of better sampling.

[winterfreak]

Yeah that didn't go due north. Northern stream looks mildly interesting. January can't get here soon enough.

[Money]

18z NAM develops southern piece to far east....snow begins to break out towards SE IN/W OH towards end of run...now I've very curious to see what the 18z GFS will show.  That was a pretty big shift south with northern piece.  Might be because of better sampling.

 

Ends up really strengthening at the end of the run. Down to 990 in SE Ohio. Dropped like 5 mb last frame. 

[Iowawx]

Another dud, way too far south for my area. Also, latest GFS has little to no snow through January 6th.

[Money]

4K NAM has the low down to 1001 or so at HR 60. Nearly 6 mb difference from the regular NAM.

 

http://www.tropicaltidbits.com/analysis/models/nam4km/2014122118/nam4km_ref_frzn_us_20.png

[Tom]

4K NAM has the low down to 1001 or so at HR 60. Nearly 6 mb difference from the regular NAM.

 

http://www.tropicaltidbits.com/analysis/models/nam4km/2014122118/nam4km_ref_frzn_us_20.png

It really begins to take on a neg tilt shape towards the end of the run, which we all know, the model isn't as accurate at that range....

[GDR]

Another dud, way too far south for my area. Also, latest GFS has little to no snow through January 6th.

it could be one of the driest winters on record for Iowa.

[Madtown]

As far as dry the analog of the 70 ' s we aweful for snow here I believe 77 was 20" for the year.

[Tom]

When looking at the 12z Euro Ensembles 500mb pattern on 00zz 25th and see a positive tilted trough, you begin to ask yourselff questions, why?  Well, I think there could be an explanation to that.  The negatives you see near OR/WA are neglecting the trough in the east to be deeper.  This could be a model error or it could be right, but the Euro likes to hang energy in the west.  Also, notice the massive ridging in E CA.  This should slow the system down and could be a reason why we are now seeing a Christmas Day event instead of an earlier arrival on Christmas Eve morning like we thought yesterday.

[Money]

18z GFS brings the northern stream down into N. MO...stronger southern stream developing also 

[tim the weatherman]

the way i am hearing from this fourm that there is hope with storm.

[Money]

18z GFS should be stronger/nw than 12z. Already 2-3 mb stronger and west so far through 48.

[Madtown]

Still believe we are in the game by tomorrow mid day it will be a beast

[Money]

997 in S. TN pretty much going NNE last 2 frames. 

[Money]

Going to be a huge hit. Lot of QPF developing on the left side, and rapidly strengthening. Pretty much heading due north. 

 

995 in S. IN at HR 69

 

991 in W. IN at HR 72

[WildWisconsinWeather]

Going to be a huge hit. Lot of QPF developing on the left side, and rapidly strengthening. Pretty much heading due north. 

 

995 in S. IN at HR 69

 

991 in W. IN at HR 72

 

My head is spinning, each run is a different solution.  MKX commented that the models were converging toward a general solution, with this morning's PGFS being the outlier, but it doesn't sound like it to me.

[Yerf]

LOT mentioned the strength of the downstream ridge which will limit how far east the low will go

[bud2380]

hard to say if the 18z GFS will be a trend setter or go right back to the less phased/further east solution. This storm makes me laugh.