Monday, December 13, 2010

Pre Christmas storm(s) 12-19 tp 12-23

12-20 - post mortem - this was the day it was supposed to hit. After witnessing model flip flops from way ots to 30 inches in Millville and 26 inches at LGA, storm ended up out to sea, clipping cape cod. The major factor I saw was lack of energy - no vort maxes, jetstreaks or other upper air dynamics to really crank the storm. Instead, reliance on the warmer ocean, which resulted in the storm not even forming until it was already ots. No model fared well - likely due to the lack of energy. The pressure spreads across the country ranged from 1008 to 1020 - and it was fair here with pressure of 1007. It took until Friday, two days before, for the models to finally lock on an out to sea solution. If I had to pick a winner, it was either the GGEm or the JMA. Onto the next debacle

12-15

Busy day, not much time to post. Summary: 0z, 6z gfs shifted out to sea. All other 0z models, including ukmet now out to sea. 12z gfs pulled back just offshore getting most of the area. 18 z gfs pulled east, with just sne and ccod getting creamed as the storm stalls. Oddly, the 12z GEM came on board with the 12z gfs. The euro still stayed fairly consistent, perhaps a bit east crossing 40n at 65w. Most models do agree with the storm stalling at one point, its just a matter of where.

Interestingly, the ensembles for the GFS and Euro have a strong westward bias, so there is still plenty of debate going on there. But losing the ukmet, which had been consistent over the last few days, and not having much of a shift in the euro is not encouraging for a major snowstorm.

The problem I see is not with the upper pattern setup as the pv is fading west and there is some ridging off the coast. I just don't see any energy in the flow, and the storm forms mostly at sea. The trough goes negative as the low forms off NC on the 18z gfs. But its only a 1008 low (which is the pressure today and it was fair.)









12-14 afternoon
Models mostly shift west, except cmc and jma, which continue their straight ots. UKmet is very close, if not at BM. Euro is a degree east, but has shifted westward.

GFS has an all out 20 inch blizzard - see above. And it sits the storm there 24 hrs

12-14 Morning
All models look ots for the 0z runs. GFS ensembles are pulling west with spread, euro pulling sw with spread, cmc is light in spread and ots. The GFS and CMC ensembles each produce 3 inches of snow as is for this area, more to the east.
All operationals are out sea, but not by that much and will likely correct west with time, assuming they strengthen the storm.
Euro is at 68/40 6z sun
0z and 6z gfs is at 64/40 9z and 15z mon - much less amplified than euro
ukmet has the low moving from west NC at 96, due east to 72/35 at 120 - 144 looks to take it due north though
dgex doesn't even have a storm until way out to sea


12-13 afternoon summary
GFS - 0z,6z and 18z have all out blizzard for northern fairfield
Euro - 12z yesterday had blizzard, 0z today way out to sea, 12z just grazes just east of BM
UKMET - only up to 144, but has it in the carolinas by then heading our way - may be too warm
JMA - out to sea, but yesterday had big storm
CMA - morning out to sea, afternoon OBX to CCOd
dgex - just misses east

Fun! At least there is some consistency




12-13

0z GFS run has massive snowstorm pre Christmas, from hrs about 160-216, all snow and heavy.
Yesterdays 12z Euro run supported this, as did the JMA. But the 0z Euro loses it None of the other GFS runs yesterday supported this, with only southern sliders out to sea. Total output for the 60 hours ending 216 is 1.75 inches. UKMET may support as it has a strong southern low, but only goes to 144. DGEX supports idea of massive storm, but takes it to our East ots.

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