After a prolonged hiatus from making the lives of many across the United States miserable with cold and snow, winter has arrived once again. As if the cold temperatures of the last week across the eastern half of the U.S. weren’t enough, a moderate snow will fall along and east of the Appalachian Mountains beginning this evening in Tennessee and finishing up in the Northeast later Sunday.
All things must start from somewhere, and this winter event is no exception to the rule. A weak wave along a cold front over Louisiana and Arkansas will strengthen quickly with the help of positive vorticity advection (yes, it technically is differential positive vorticity advection that gets things going, but I like to make things simple) and a nice temperature gradient over the Gulf Coast states. Thereafter, the low will track northeast, steered by a strong jet aloft. Snow and mixed precipitation are expected throughout the watch areas on Bryan’s post below.
I am slightly disappointed with this storm since it could be so much more with the right ingredients. It seems as if everything will come together at the wrong time for this system to really get its act together and dump large amounts of precipitation by the time it gets to the Northeast...we’re talking about 0.50-1.00 inches of QPF maximum here. The only reason why forecasters are talking about such high snow totals (on the order of feet) is because the cold temperatures in place will allow for snow to liquid ratios of 15-20 to 1 in areas. Due to a quick pressure drop with the low and a moderate pressure gradient it induces, we can expect windy conditions at the coast, which leads me to the Blizzard Watch.
When I first learned that a Blizzard Watch was issued for coastal areas of Connecticut, I called Bryan (read his post below) and immediately started criticizing the Weather Service. I have never heard of a Blizzard Watch being declared 36 hours before a storm as it leaves too much time for error (ala KBOX a couple of years ago in a similar winter event, leading to a reprimand from the higher powers). While it looks as if this area will indeed experience blizzard conditions for some time, the Weather Service, most notably KOKX, will look awful if something were to go wrong with the current forecast.
Our not-so-trusty weather forecast models have been indicating this winter weather event for a while, and as of a couple of days ago, they came into agreement (in the weather forecasters perspective), but not so fast! The last couple of runs for the NAM and GFS have shown some variation in the track and timing of the system once it makes its way offshore. What would a winter storm be like if it were correctly forecast well in advance?