Nov 7, 2010: Storm Forecast For Tomorrow

Today was another chilly day for the area, along with mostly sunny skies. Temperatures this morning were in the mid to upper 20s inland, upper 20s to lower 30s north and west of NYC, and in the mid to upper 30s for NYC. High temperatures, meanwhile, were in the upper 40s to lower 50s in most of the area.

Cloudy skies are expected for the eastern parts of the area tonight with increasing clouds for the rest of the area as a storm approaches the area, which has the potential of bringing the first flakes of the winter to southern Connecticut.


Tomorrow's Outlook: Cold, Rainy


Storm Scenario: Currently, there is a long line of moisture and very heavy rain extending from the remnants of Tropical Storm Tomas to a low pressure well southeast of the region. As seen on the radar to the top left, precipitation is already falling in eastern New England, some of it in the form of sleet in places such as Massachusetts. Throughout the day, the line of moisture became more negatively tilted, with a low pressure expected to rapidly intensify overnight while moving NW, ending up near Boston in the morning hours as a 985 to 990 mb low pressure.




This storm will run into a cold air mass currently present over the region, and with the best dynamics focused to the west and south of the storm track, it will be able to produce snow/sleet for much of southern and central New England tonight. Slushy accumulations of at least 1 to 3 inches are likely in the higher elevations from parts of northern Connecticut into Massachusetts and Vermont/New Hampshire, though the lower elevations of southern New England, including Boston and southern Connecticut, could see some non-accumulating snow/sleet tonight as the precipitation runs into the cold air mass and temperatures in the lower to mid 30s across most of the area. While producing snow over that area, the storm will pull in a warmer air mass into Maine combined with heavy rainfall, which could lead to 3-4 inches of rain for southern Maine by the time that the storm ends.

The storm is expected to peak in intensity tomorrow morning and weaken throughout the day, but will then do an unusual movement by heading southwest, from Boston to Long Island. As the storm will weaken, so will the precipitation and the cold air support. With the precipitation only expected to move into NYC by 10-12 AM, the 850 mb and surface temperatures will be too warm to support snow/sleet falling in NYC and the rest of the area even though some snow/sleet is possible north and NE of NYC, leading to a case where snow/sleet could fall over places such as southern Connecticut but not in places such as the higher elevations of NW NJ.


Forecast for the area: Whether it snows or not tomorrow morning in the immediate NYC area, tomorrow will be a very cold day for the area, with high temperatures only in the lower 40s for southern Connecticut and in the mid 40s for the rest of the area, though some upper 40s are expected in the southern and western parts of the area where most of the day will be dry.

The rain will likely mix with sleet and/or snow in the morning hours for parts of southern Connecticut, changing to rain by the late morning as precipitation spreads from NE to SW, reaching NYC around 10 AM. Light rain will fall in the central and western parts of the area, with rainfall amounts up to 1/4 inch, with rainfall amounts in the eastern parts of the area between 1/4 and 1/2 inch with locally higher amounts.