Feb 10, 2013: Ice/Rain Monday, Thurs Storm Possible

Forecast Highlights:

Mainly sunny skies were observed today aiding in the clean-up after the blizzard in Long Island and Connecticut, with high temperatures in the low to mid 30s. Stormy conditions will make a brief return on Monday, however, with light ice accumulations for interior parts of the area in the morning followed by moderate rain for the rest of the area as temperatures rise into the 40s. Seasonable temperatures will continue for the rest of the week with storm potentials on Wednesday night and a potentially larger storm for the weekend.

---

Tonight - Monday: Ice, Rain Expected

A strong low pressure currently producing a blizzard in the Midwest will track towards the Great Lakes and into Canada, bringing widespread precipitation into the region ahead of a warm front. Temperatures aloft will be above freezing, but will remain near to slightly below freezing initially at the surface, especially north/west of NYC, resulting in a period of freezing rain on Monday morning north/west of NYC and into parts of southern CT away from the coast. Any freezing rain is expected to remain light, under 0.10 inch, but even minor freezing rain accumulations can cause hazardous conditions. As the warm front moves through the area later in the morning, any freezing rain will change over to rain as temperatures warm into the low to mid 40s for highs, with widespread moderate rain expected across the area for the late morning into early afternoon, gradually ending from west to east towards 3-6 PM with scattered showers lasting through the evening. At least 1/4 to 1/2 inch of rain is expected with locally higher amounts.


Tuesday - Thursday: Seasonable, Then Snow Possible

Partly cloudy skies are expected to return for Tuesday and Wednesday with temperatures near to slightly above average, generally in the low to mid 40s across the area. Towards Wednesday night, uncertainty returns into the forecast with a storm expected to affect the region. Last night's update mentioned that although most models kept the storm south of the area, the possibility was there for a further north track with more impact in the area. Today's model guidance had roughly the same scenario; most models kept most, if not all of the snow south of the area, with the GFS initially showing snow accumulations before trending south with its 18z run. The NAM is currently the northernmost model with widespread snow in the area and New England, although at this range it is not very reliable, as also shown with the recent storm when it was among the last models to catch onto the idea of a major snowstorm.

A marginal cold air mass will be in place during this time frame with surface temperatures overnight not much below freezing, suggesting temperatures will be marginal for a snowstorm to occur, with the possibility of a wet snowstorm in locations that do receive accumulating snow. At this time, I am siding closer to a further north scenario where this does affect the area with precipitation. No significant snowfall is expected out of this, although light to moderate wet snow accumulations would still take place under the axis of snow, with the main question at this time where it sets up, whether it's further south towards southern PA/NJ or over the NYC area; at this time, I am leaning towards the former, with the heaviest wet snow southwest of the area. This is not certain at this time, however, and the potential still remains for this to end up mostly south of the area. Stay tuned for more information on this potential storm.


Longer Range: Colder Weekend, Storm Possible

With a lack of a strong cold air mass in place, temperatures will remain close to seasonable on Thursday and Friday, generally in the upper 30s to mid 40s again with drier conditions expected. Then a stronger trough is expected to drop into the region for the weekend with colder temperatures returning, dropping back to below average. Along with this setup comes the potential for a coastal storm; almost all of the medium range model guidance currently shows either a weak frontal passage or a low pressure well offshore, although the potential remains for a more significant storm closer to the region considering the pattern, consisting of a strong trough over the region and a ridge in the western US, along with transient ridging near Greenland, and there have been some hints of this showing up from the GEFS ensemble emembers and to a lesser extent the 12z ECMWF. More information will be posted on this potential as details become clearer, but the potential is there for a storm, potentially significant, to affect the region this weekend.