00z Models pointing to a potential quick hitting snowstorm between 06z Saturday morning and 18z Saturday afternoon. Models are still different in the track of the surface reflection as an intense vorticity maximum moves through the base of the 500mb long wave trough that moves through in the progressive zonal flow across the northern US. Models differ on the track of this vorticity maximum and surface reflection as well as potential convective nature of the system. If the short range hi resolution models are more accurate cities of Hyannis, MA through Providence, RI will end up with a quick hitting 3-6" of snow, however if the GFS is correct then the heaviest bands will move to the north of the region, north of BOS through Portland, ME. This difference of 200 miles is a lot in such a mesoscale fine system. This surface reflection does not intensify much until it reaches Atlantic Canada. However if models trend stronger with this system, then snowfall amounts could increase with time. We will have to see how the next 12z and 00z cycles come through. I could see how a Winter Weather Advisory would be prudent for this system at some point. Although WSW or Winter Storm Warning could be prudent should models trend stronger with the convective nature of the system. Short range NMM and ARW show an intense convective nature to the system dropping 12h amounts of 0.5-1.0" of QPF, equating on a 10:1 ratio of 5-10" of snow. Again lets see how trends continue throughout the rest of today before jumping to conclusions as surface temps will become somewhat of a strong factor in determining snowfall amounts at this time. Thanks for your attention.
12z model update:
Models favor more of a northeastward placement of the primary snow band, favoring SNH and SME with the heaviest snows, with little to no accumulations for SE MA/RI. Time will tell, as we have another model cycle or two before we get a better handle with these types of troughs. Models are hedging towards a closed off H7/H85 low, but probably overdoing it in this scenario. This will likely give someone 2"+.
Updated: 20:22:GMT den 09. mars 2012
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