Christmas day/night storm 2010

A significant winter storm for the Triangle is looking more likely on Christmas day through the Sunday. The 12z GFS trended closer to the ECMWF with the ECMWF holding nearly steady... just a bit further west and stronger than 00z...

HPC prefers a 50/50 blend of the GFS/ECMWF with nam being a bit of an outlier at this time, which is not unusual in the 84 hr range. Agree with HPC to mix the GFS and ECMWF despite the impressive consistency of the ECMWF... But caution tells me to not side with a historic snow storm this early. A blending of the GFS/ECMWF is a great track for heavy snow fall in the triangle... A pure ECMWF solution shows a historic bombing low just of the coast dropping warning criteria snow for a large chunk of the deep south. GFS is further east and weaker and thus most of the precip stays along the coastlines.... although GFS likely under doing precip amounts to the NW of the low.

Accumulation rates will be on high side of a 10:1 ratio due to very cold temps aloft. Am thinking that high snowfall amounts is a good possibility. But at this time will stick with only warning criteria amounts for the triangle... will hold off on higher amounts due to model discontinuity this far in advance of the low... intensity and exact location are still in question. Taking qpf literally from the from the EURO gives the Triangle 2 feet of snow with blizzard conditions lasting through Sunday night! This has the potential to not only be a strong phased storm, but a slow mover as well.


Forecast:

Christmas Day: Cold with a slight chance of snow in the afternoon.

Christmas Night: Occasional Snow... the snow could be heavy at times...

Sunday: Snow likely... the snow could be heavy at times especially in the morning... Windy with frigid temps

Sunday night: A chance of snow... windy and very cold

Monday: Decreasing clouds and very cold.

Total accumulation 3 - 7 inches possible.... May forecast higher accumulation amounts as Christmas nears.