Strong and powerful low pressure, over the southeastern United States lifted northward, and combined with a strong cold front, to bring plentiful rainfall to the Capital Region on September 18, 2012. The circulation around the intense area of low pressure acted as a catalyst for the northward transport of abundant moisture into the Capital Region.
Unlike the squall line event experienced but ten days earlier, this event featured less in the way of atmospheric heating, as clouds were more plentiful in advance of the system. However, in comparison to the prior event, moisture-laden low and mid-level atmospheric wind fields were quite strong and energetic. A swath of moderate to heavy rainfall was the result, lasting for the bulk of the afternoon and evening hours of September 18, across the region.
The few thunderstorms that did form created enough vertical mixing to translate some of the energetic winds, just above ground level, to the surface during the event. That notwithstanding, winds gusted to between 25 and 45 MPH across the region just as result of the dynamic nature of the overall low pressure area and cold front. A wind advisory had been issued by the National Weather Service to account for the potential for strong and gusty winds. There were several reports of downed wires and tree limbs region wide as result of the chronically gusty winds.
Due to the rich and abundant amounts of moisture tapped by the system, copious rainfall was also experienced. Portions of the Catskills and lower Hudson Valley picked up almost 7 inches of rain in the 24 hour period from 12 midnight 9/18/12 to 11:59 PM 9/18/12. The Albany Airport picked up 3.27 inches of rainfall during this period. However, for the sake of comparison, right down the road from the Airport, in Latham, NY, observers reported 5.89 inches of rain had fallen during the same period! Radar estimates indicated that between one and eight inches of precipitation had fallen across the entire span of Upstate Eastern New York and adjacent Western New England, with a concentration of heavier amounts spanning the Hudson Valley and portions of the Catskills.
Reports of flooding were most numerous in Ulster, Dutchess, and Greene counties in New York where area roads were reported to have been flooded, and some flash flooding had occurred. In addition, portions of Route 5 in Colonie, NY, had to be closed, due to flooding, during the course of the rainfall.
Data for this article was obtained from the National Weather Service in Albany, NY’s assessment of this event. Link is available in the related links section below.
Additional Related Links…
National Weather Service Storm Summary 9/18/2012
National Weather Service Local Storm Reports 9/18/2012
National Weather Service 24 Hour Precipitation Totals 9/19/12