January 20-22nd Updated Thoughts

Guidance is coming into somewhat better agreement as of the 00z models last night. They all are pretty similar in tracks with the exception of the ECM which ends up in the same location at 96 hrs as some of the other guidance but its further off the coast in the 72-96 time frame. Lets look at the guidance that was offered..

The 00z GFS ends up phasing the two streams together ..northern and southern stream and ends up producing a moderate snow storm across the region.

GGEM continues with the more AMPED up system and has a good amount of moisture with it and probably would produce snowfall totals in the range of 6-12 inches perhaps slightly more. It could bring precip issues to places like NYC as it virtually passes over top of them.

UKMET takes a track that is more to the west of the ECM during the time frame of 72-96 hrs but ends up in the location where the ECM & GFS end up.

00z NAM ends up phasing the two streams together as well and slightly earlier then the other guidance and ends up taking the low pressure at 84 hrs just south of PA with a warm surge at 850 and also slightly at the surface. However..north of the big cities would be all frozen and cities would change back to frozen once the low passes as the heights would crash. 6 Z NAM continues the same general theme with a slightly slower timing on the phase and brings the low pressure actually more to the N where it appears to go over SE PA and Over NYC as well and end up over SNE inland.

The above is the ECM..as you can see it has a more disorganized low at 72 hours and the ECM does not phase the two streams together so this allows the storm to go further east then all the rest of the guidance.

The other difference between the ECM and the rest of the guidance is the ECM only brings enough QPF to deliver 1-2 inches of snow to the the KPHL to NYC region.

All other guidance brings at least a moderate event and in some cases more. All other guidance is either phasing the two streams together or trending towards a phase which previously were not trending that way.

So, it appears that as of right now…while some may consider the ECM model the more consistent model it appears to be an outlier..despite HPC using it as there prelim fronts and pressures. If a model is different from the rest of the guidance then it raises the percentage of that model being inaccurate.

So at the present time we will continue to watch the latest trends within the guidance and keep you updated as usual!

Remember the two most important points when looking at the models is:

1.What model best represents the pattern and teleconnections?

2. The area of the greatest thermal gradient would be where this storm wants to go.

Stay tuned for further updates!