Dec 8, 2014

Major Winter Storm Heading Our Way

A complex , significant, slow moving and muti-hazard winter storm will affect the region from Tuesday through (at least) Thursday night. Even though the start time of the storm is now less than 18 hours from starting, weather data regarding the actual evolution and track of the storm is still uncertain.

The uncertainty in the storm's track will be VERY CRUCIAL in determining precipitation type. If the low tracks right along the coast towards New York City and western Long Islnad then precipitation, while initially starting as snow could mix with or change to sleet and rain in the Hudson Valley and points east late Tuesday and Wednesday; a slightly more east or offshore track to the storm will allow for colder air to remain in place and a mostly all snow will then fall.

One thing is certain about this storm it will have a lot of moisture associated with it thus precipitation amounts will be heavy. Where this precip falls as ALL snow, snowfall totals will be very high likely exceeding a foot with perhaps some areas near 2 feet possible. Right now the central and northern Catskills and the southern Adirondacks as well as the higher terrain to the west of Lake George appear to be mostly snow.

Elsewhere, snowfall amounts will range from a few inches across the lower Hudson Valley and northwest Connecticut to as much as 6-12 inches from about Hudson north (including the Capital District) to Glens Falls. Expect similar amounts to the east across Southern Vermont and the Berkshires. Its over these latter two locations where a better chance for snow changing to or mixing with rain or sleet could occur as temperatures here will be warmer.

The Hudson Valley region may be subjected to the snow mixing with or changing to sleet, freezing rain or rain. In addition "downslope" easterly winds may cause a “precipitation” shadow to develop here. If this were to happen then the air would dry and warm lessening the amount of preciptation. However if the shadow is NOT strong and warmer air doesn't allow for the snow to mix or change to rain or sleet then snowfall amounts here will be much higher.

The above map shows most of Western New England, Eastern and Central New York State under a Winter Storm Watch (WSW). In addition the Lower Hudson Valley and Connecticut while NOT under a WSW ARE under a FLOOD WATCH


Heavy precipitation

Heavy snow: across the Catskills and Hilltowns and Southern Adirondacks where accumulations will exceed 12 inches.

Heavy Rain: Lower Hudson Valley and NW Connecticut after a period of accumulating snow. Potential small stream and urban flooding


Periods of gusty East winds with gusts to 40-50 mph possible across the higher terrain of the Catskills, Taconics, Berkshire and Green Mountains during Tuesday could cause blowing snow and perhaps some sporadic power outages.

START TIME: Daybreak Tuesday over the Lower and Mid-Hudson Valley, Capital District between 9AM and Noon with areas north of the CD between Noon and 3 PM

END TIME:  When its finished...seriously very Late Thursday night.

I'll have more on the storm this evening as well as maps including a snowfall forecast, too.