Model Scoreboard

GFS- 2-4" of snow for many in VA/MD/DE/NJ/PA/NYC/New England. We say throw this run out because of the progressive bias being dispayed. Check below for details

****Euro- Big hit for many again.  Heavier on qpf slightly and further north slightly.  But tracks of low are similar to 12z. Widespread 7-12" VA/DC/MD/DE/E PA/NJ/NYC/ New England*** Model of Choice

GGEM- Major Snow Storm. 8-12+" in Philly/DC/Northern DE/NJ/E PA/NYC (details coming shortly)

UKMET- Strong low inland. Big snow northern Middle Atlantic. Philly is questionable because of the increments being 24hours in this range and limited temp profiles.  We shave until tomorrow night until details for this model.

GFS Ensembles- Wetter than operational GFS. Widespread 4-7".

Euro Ensembles- Agree with operational Euro!

GGEM Ensembles- Check Back

The NAM is coming in now and we will entertain everyone with the result, but it is important to stress that the NAM is not a model to look into at this range.  Between 60-84hrs on the NAM the model will probably start off way north and adjust towards the other global models at 60hrs.  It does this with every storm so we will take it off the scoreboard until we are within 60hrs.  

Previous runs of the 12z suite showed a split between a more northern track of the GFS and GGEM and the southern track of the Euro.  The Euro was a big time snow event for VA/DC/DE/MD/NJ/E PA/NYC/Southern New England.  Euro ensembles supported the operational run and to some extent the GFS ensembles did also (south of op GFS).  So tonight we are going to be looking for the models to shift south towards the European.

***South trend in this blog is referring to the global models coming around to a colder European solution.  A south trend still brings very good snow to VA/DC/DE/MD/NJ/E PA/NYC/Southern New England.****

NAM

As Expected the NAM is trending towards the European model and the south trend. We can see this clearly when comparing the 12z NAM to the latest NAM.

NEW NAM

OLDER NAM

Final Thoughts on the NAM: The change in the 12hrs from the previous run are expected from the NAM.  The system is much further south on the newer run and coming in closer to the European model.  This would mean a much colder solution with more snow across much of the area.

The PV is stronger and more defined in the new run showing the presence of colder air in place. The NAM is seeing the cold air and not kicking it out as quick. This makes sense and we expect the other models showing a warmer solution to come around also in tonight's run.  

GFS

The GFS comes around on one aspect of the 00z's and that is the cold air winning out.  However, the system is north and this is because the northern stream does not dig down.  The ridge out west needs to be amplified to bring down the northern stream system and meet with the southern low.  Without this the southern low gets sheared out and the northern low is the primary.  The GFS hasshifted the other way on this and the European was favored because of its strong ridge.  In a MJO phase 7 the signal is strong for an amplified ridge so we are not puttin gtoo much into this run.

The reason why we are not believing the GFS is the MJO composite for a phase 7:

Conclusion on GFS: Progressive bias is showing up on GFS.  If all other models come in with this solution than we will change our tune, but that is unlikely.  A lot of observations currently support a strong ridge and more amplified northern stream.  The progressive GFS shears out the southern low.  The GFS does fix its idea of the cold and does not show it budging much.  A correction to the ridge will allow a much bigger snow storm than the 2-4" modeled.  ***Throw the GFS out**

UKMET

UKMET is very strong and looks warm.  We cannot tell since the 850mb temps only go to 72hrs! But notice the confluence in New England.  This will force a redevelopment situation with a low over NC/VA most likely.  If I had to interpret this further I would say a big snow event for someone near Philly on northward.  With that strong of a low warm air would come in but the arctic air is not budging that much and confluence will keep cold air in at lower levels.  This model has been overdeveloping this low inland and it seems like models are trying to steer away from that, so will see where the GGEM and Euro take us tonight.

GGEM-

Wow!  Major Snow Storm for the Middle Atlantic into the Northeast.  This could be 12+" for some areas in NJ/LI/E PA/N DE/DC.  The major difference from the GFS is the ridge out west.  The ridge is very amped and as a result we see a much bigger system.  The cold air not budging is key here again as the 540 line shifts south and redevelopment is forced off the coast.

GFS ENSEMBLE MEAN QPF FOR STORM

Ensemble mean has come in a lot wetter than the operational GFS.  I am sure we will still see a big amount of disagreement amongst individual members but the theme continues that the operational is not getting support.

EURO

Widespread 7-12" snow storm for DC/VA/MD/DE/NJ/E PA/NYC/New England

Euro Ensemble

Agrees with the operational Euro!