Albany National Weather Service Doppler Radar Base Reflectivity Image Series of the February 14, 2007 Nor'easter

Image #1: ENX Radar (Albany, NY) base reflectivity lowest tilt at approximately noon on February 14, 2007: The distinct high reflectivity band (bright reds and yellows) extending from eastern Delaware and Otsego counties on north into western Schoharie and Montgomery counties is the radar representation of large snowflakes mixed with sleet and graupel aloft with snowfall rates at the ground of up to an incredible 6"/hour. During this period an exclusive WeatherNet observation from Worcester in eastern Otsego County along I-88 indicated 6" of snow between 11:40am and 12:40pm, confirming the radar representation. The brighter reflectivity (The reds and yellow colors) in the Capital Region from Albany to just north of Bennington,Vermont indicated snowfall rates of 1"-3" per hour, lighter due to the presence of more sleet. Sleet appears very bright on a radar and therefore can be mistaken for heavy snow during major storms in the absence of critical ground spotter reports. Similarly, the brighter areas on the display over Berkshire county and Ulster and Dutchess counties is a representation of a mixture of heavy sleet and some snow.

ENX (Albany, NY) Base Reflectivity Radar Display at approximately 12:00pm February 14, 2007

 

Image #2: ENX Radar (Albany, NY) base reflectivity lowest tilt at approximately 1:00pm on February 14, 2007: The snow band remained very intense at this time continuing to produce snowfall rates ranging from 4"-6" per hour. The zone of heaviest snow at this time extended in the area of brightest colors from Delaware and Otsego counties on north through the Mohawk valley to northwest Saratoga and northern Washington counties. The bright banding on the radar south and east of Albany continued to represent extensive sleet mixing in with the snow. Snowfall rates in the Capital Region at this time ranged from 1"-2" per hour.

ENX (Albany, NY) Base Reflectivity Radar Display at approximately 1:00pm, February 14, 2006


Image #3: ENX Radar (Albany, NY) base reflectivity lowest tilt at approximately 2:00pm on February 14, 2007: The snow band at this time had continued to track to the northwest. The band also had weakened but was still quite intense with snowfall rates ranging from 2"-4" per hour. At 2:30pm, an exclusive WeatherNet 6 report from Speculator in Hamilton County, indicated 3.5" per hour snowfall rates between noon and 2pm, confirming the radar signature. Snowfall rates around the remainder of the region pulsed back and forth between an inch to two inches per hour with sleet still occurring in parts of the mid Hudson valley and Berkshire county, MA. Of additional interest on this image is the area from northern Berkshire county, MA, near North Adams, north to Bennington, VT, to southeast Washington county, where the radar colors turn light green. This is an area of low reflectivity indicating very light snow, a result of the air flowing down the mountains located directly to the east. (Downsloping is a process that warms and dries the air through adiabatic compression, reducing precipitation amounts in the areas affected) The downsloping effect, due to the local terrain, is common in major east coast storms that produce a strong easterly flow over the region. In this case, the downslope was very localized to these small areas with relatively minimal impacts throughout the rest of the region in lowering snow totals.

ENX (Albany, NY) Base Reflectivity Radar Display at approximately 2:00pm, February 14, 2007

 

Image #4: ENX Radar (Albany, NY) base reflectivity lowest tilt at approximately 3:00pm on February 14, 2007: The radar imagery continues to show weakening of the main snow band with most of the bright reds and yellows being displayed a few hours earlier almost gone. However, the zone of dark green extending from the Adirondack through northwest Saratoga county south through Otsego county was an area of 2"-3" per hour snowfall rates, based on ground spotter reports. This banding generally remained in the same general area through much of the duration of the storm with a cycle of weakening and strengthening. The net result was the immense snow dump in this region, clearly depicted on the WeatherNet 6 snowfall distribution map.

ENX (Albany, NY) Base Reflectivity Radar Display at approximately 3:00pm February 14, 2007