Feb 8, 2015

Update on Feb 8th thru 10th snowstorm


Fig. 1
It still looks like a long duration snowfall that will lead to a heavy snow accumulation for everyone. It won't be a textbook "storm" a la a Nor'easter or even a strong area of low pressure. Instead a combination of features surface and aloft will come together in both time (tonight through late Monday night) and place (over us!) to produce a heavy snow accumulation, even though the snowfall rates will only be briefly moderate to heavy at times in places during this snowfall. It is the expected duration of the snow that will cause it to pile up! The map in  (Fig. 1) is the surface map from 11 AM Sunday morning, 8 February 2015. To our north over Canada another arctic high pressure area and to our south a stalled front with "waves" of low pressure rippling along the front from west to east.

Fig.2
The front will remain stalled through Monday morning (Fig. 2) with an area of low pressure moving east along the front across the northern Mid-Atlantic States; extending north from the low will be an inverted trough (the dashed orange line) up across NY State. This trough will produce lift and result in a steady MOSTLY light snow to persist through much of Monday. Forecast data indicates that the temperatures from the surface to above the ground will be cold enough for ALL snow for everyone on Monday and once again with the temperature profile being VERY cold the snow should be powdery in nature.


Fig.3 

By 7 AM Tuesday February 10th (Fig.3 ) both the front and lows will have nudged off the East Coast and the cold arctic high will prevail with gusty North or Northwest winds and more below normal temperatures.

With the snow ending late Monday night or very early Tuesday morning here is what I expect (Fig.4) to have fallen across the region. (Keep in mind this is NEW snowfall on top of what YOU may have received during  the snow that fell during Saturday night through this Sunday morning).

Fig. 4