Wednesday November 14, 2018 Noon – Sorry for the lateness today. I am leaning toward the GFS solution below for snowfall across the Northeast into the Midwest. I think the model is doing a better job understanding the warm layers but might be too high on snow amounts as snow ratios will be 8:1 on average. The ECMWF solution seems a bit high in snow amounts given the early season and warmth so taking the model snow maps, one must deduct some of the snow accumulations based on melting and lower snow ratios.
Another issue with the the upper level low. Currently, that upper level low is producing snow across southern Arkansas and should produce light to moderate snows up the Ohio River into Illinois, Indiana and Ohio. Eventually, the upper level low meets up with the surface low along the Mid-Atlantic and intensifies the low Thursday night. Now the upper level low is predicted to open up as it crosses the Appalachians but there may be a time when the upper level low produces upslope winds into the Appalachians producing heavy snow bands and rates of 1-2 inches per hour Thursday night into Friday morning. I think that is why we are seeing higher amounts from southern New York into West Virginia with central and northern Pennsylvania in the center of the that heavy snow banding. So simply, for some it’s a two shot process with front end snow and sleet going back over to heavy snow before ending. I can even see heavy bursts of snow all the way into Philadelphia, New York City and southern New England Friday morning.
As I mentioned before with trees still retaining their leaves in some areas, the heavy, wet snow may result in power outages.
PSU EWall Snowfall
Things are tight and I like to keep the blog going so anything helps.
Tuesday November 13, 2018 8pm – The models all seem to be in agreement this evening on the evolution of a major winter storm. While the 10:1 ratio maps below show a lot of snow, one has to be concerned about snow ratios more like 8:1 and sleet/rain mixing in with snows.
The storm should track up the coast then take a right turn out to sea which will allow for a collapse of the snow into the I-95 corridor. I am not expecting a lot of snow, just enough snow to remind the city folks that winter is not that far away.
As for the big snows, it seems the models are showing two areas. One in the southern Ohio Valley i.e. southern Illinois and parts of southern Indiana and western Kentucky where 2-6 inches of snow may fall under the upper level storm. The other area will be in the Appalachians from Virginia into New York and western New England where 2-6 inches with locally 10 inches will fall.
Now given that in some areas the trees are just finishing with their leaves, one has to be concerned for heavy snow wit produce power outages by tree limbs falling on power lines.
Tuesday November 13, 2018 6am – Latest model runs seem to be in agreement that the second storm will be a heavier snow event for many areas of the Northeast and Appalachians. Even the big cities along the I-95 corridor may see some wet snow from the storm as the storm track maybe close to the benchmark for some. I like the fact that the GFS model and ECMWF model are in agreement on the snow but I am concern that some mixing will occur which will hold down the amounts. The raw data and soundings does show some warm levels sneaking during the middle of the storm which will mix things over to sleet and rain. So while the models do show a lot of snow, amounts could be a little lower due to mixing.
Monday November 12, 2018 9pm – The models are going crazy for the second storm the end of the week. Below are the GFS and ECMWF snowfall maps. I am little more excited to see the ECMWF shift the snows so far to the East and bring big snows but given the tropics are forcing the storm to stay along the coast, I see how this all comes about. While the first one will bring snow the second could be the big Daddy of the two as it produces a swath of heavy snow.