The snow forecasts for the weekend have converged on a 2 to 4, 3 to 5 inch mini-storm for Saturday during the day and evening.
Usually, my rule is a storm with more snow will take more time to be wrapped up in the jet stream and be delayed. Not working this time! This weak waves of weather were forecast to get to the northeastern corridor of the US by Saturday night, but yesterday the forecast models were starting to predict more snow inland, but also bringing the snow earlier than in previous computer model runs. This appears to be because an extra packet of energy is going to arrive from the west just in time to give the storm a lift and some extra spin.
So, here we are – looking at a couple to four or five inches of snow starting mid-morning on Saturday and tapering off early Saturday night. See your local forecast for details on timing (link to my location provided as an example).
From the National Weather Service Forecast Discussion for NYC:
Initially the low develops from southern
stream energy across the southeast, but another piece of energy
in the northern stream will help amplify the middle/upper trough
and thus intensity the low as it passes near or just to the
east of the 40N/70W benchmark. The low quickly lifts off the New
England coast Saturday night as the upper trough slides
Models have come into much better agreement with the expanse of the
precipitation shield as well as the overall timing.
How could the final result be different? Watch the forecast briefings from the NWS (found here for NYC), described in the forecast discussion:
While confidence is high on the above scenario, slight shifts in the
track of the storm could lower or increase snowfall
accumulations. A shift west with the low track could introduce
some mixing with rain across eastern Long Island and southeast
Connecticut. The latest experimental High End Amount shows a 1
in 10 chance for warning level snowfall from the Hudson River
corridor on east. Snow to liquid ratios may range from 8:1 to
10:1 with this event and could be a bit lower across the
southeast coast of Long Island.
Look at the national weather warning map from the National Weather Service, and see the long string of winter weather watches and warnings from the Gulf Coast to New England.
9:20am EST Friday Dec 8 map of weather watches and warnings for the United States. Click on the link above for an updated version.
There’s another storm, this time from Canada, on Tuesday/Tuesday night, now forecast to pass a bit too far north of us to be a significant storm for the NYC metro area and southward.
Another shot of energy, also from Canada, will whisk through the east coast next weekend, bringing colder air.