February 25, 2010
Radar Images

#1 Albany NEXRAD base reflectivity image, lowest tilt, 1:16 pm Thursday February 25, 2010
The yellow line drawn on the radar map is a close estimate to where the sharp rain-snow line existed at this time. The enhanced reflectivity in the center of the image, around the Capital Region, was largely produced by the radar beam hitting melting snow as it fell. Melting snow is highly reflective to a radar and thus shows up as an enhanced area of brighter colors on the screen, leading a casual observer to believe that heavy precipitation may have been falling at the time. In reality, light to moderate rain was occurring on the ground. Another area of interest on this image is the zone of light or little reflectivity in Washington, northern Bennington, and Rutland counties. The easterly flow around the low pressure system produced a considerable shadow or downslope wind effect in this region where the air, as it descended down the western slopes of the higher elevations in Vermont, dried a bit as it compressed. Much lower storm total precipitation amounts were recorded in this area through this first phase of the storm.

Albany NEXRAD base reflectivity image 1:16pm February 25, 2010 

#2 Albany NEXRAD base reflectivity image, lowest tilt, 4:32 pm Thursday February 25, 2010
Little change in the structure of the precipitation shield over the region was noted at this time with the rain-snow line remaining essentially stationary just west of the Hudson river. Moderate to heavy snow was falling west of the line, with moderate rain to the east of the line, except in Washington, Rutland, and northern Bennington counties where rainfall was much lighter and more intermittent due to the shadowing.

Albany NEXRAD base reflectivity image 4:32pm February 25, 2010 

#3 Albany NEXRAD base reflectivity image, lowest tilt, 5:41 pm Thursday February 25, 2010
A tighter view of the ongoing precipitation across the region. The widespread yellow enhancement to the radar returns in this case was an indication of both moderate rain at the surface and melting snow. In fact, the north to south oriented band extending from Kingston through Albany, north to Glens Falls clearly marked the rain-snow snow line at this time, where snow melting on its way down to the ground served to light up the line with a bright band of reflectivity. In Berkshire County, the yellow radar returns indicated moderate to heavy rainfall. Shadowing remained quite apparent in parts of Washington, Rutland, and Bennington counties.

Albany NEXRAD base reflectivity image 5:41pm February 25, 2010 

#4 Albany NEXRAD base reflectivity image, lowest tilt, 7:43 pm Thursday February 25, 2010
The rain-snow line at this time had pushed west into parts of the eastern Mohawk valley and southern Adirondacks where WeatherNet 6 ground spotter reports made the confirmation. The darker greens and yellows over Saratoga, Montgomery Fulton, and Hamilton counties was the radar signature that in fact the rain had pushed west into this region as melting snow on its way down served to increase the reflectivity marking the boundary. Considerable bright banding persisted over the Capital Region as melting snow continued to fall, but fall short of reaching the ground

Albany NEXRAD base reflectivity image 7:43pm February 25, 2010 

#5 Albany NEXRAD base reflectivity image, lowest tilt, 9:27 pm Thursday February 25, 2010
The rain snow line appeared on this image as the diagonal line of dark green with patches of yellow extending from Hamilton County on south through eastern Fulton, Montgomery, Schenectady, Albany, eastern Greene, and central Dutchess counties. West of the line, moderate to heavy snow continued to fall. East of the line it was rain. Significant drying due to increased downsloping was now evident in eastern Warren, Saratoga, Washington, northern Rensselaer, western Rutland, and western Bennington counties. The flow around the now very intense low pressure system had increased considerably causing an enhanced dry shadowing effect in this region. WeatherNet 6 ground spotters at this time were reporting either no rain or drizzle in the shadow zone.

Albany NEXRAD base reflectivity image 9:27pm February 25, 2010 

#6 Albany NEXRAD base reflectivity image, lowest tilt, 11:46 pm Thursday February 25, 2010
The character and location of the rain and snow across the region remained about the same at this time with the northwest to southeast oriented rain snow line still extending from Hamilton County south through the eastern Mohawk valley, Capital Region south into Dutchess County. Of interest on this image is the marked drying that was occurring in New Hampshire and central Massachusetts. A significant dry slot was working up around the north side of the storm center as it tracked northwest towards New York City. This dry slow moved into and through the local area roughly between 1:00 am and 4:00am on the 26th shutting the steady moderate to heavy rain and snow down.

Albany NEXRAD base reflectivity image 11:46pm February 25, 2010