Sunday-Monday August 22-23, 2010
Excessive Rain-Fort Plain Area Flash Flood Event

A brief breakdown in the summer's prevailing hot and dry weather pattern occurred during this stretch of days with the buckling of the jet stream over the eastern half of the country. A sharp low pressure trough formed over the region ultimately developing into a closed or "Cut-off" low pressure system at the jet stream level. Cut-off low pressure systems are much more common during the cold season rather than the warm, but nevertheless do on occasion develop in the summer, where they characteristically generate huge amounts of rain due to the slow moving nature to the pattern and the availability of rich supplies of moisture.

The combination of the low cutting off at the jet stream level caused a slow moving cold front to further slow as it moved into the region on the 22nd. That front, along with a strong flow of Atlantic moisture being funneled into the region around the storm's circulation aloft and at the surface focused heavy rain over the Adirondacks, Mohawk valley, and upslope regions of the Catskills where 4" to 5" fell on average, with locally up to 6.5", over the two day period. Significant flash flooding occurred in Fort Plain, Minden, Palatine Bridge, Canajoharie, and St. Johnsville from late Sunday into Monday due to rainfall up to five inches in approximately a 12-18 hour time period.

In the Catskills, strong easterly upslope flow, created by a tightening pressure gradient around a surface storm along the coast, drove moisture into the higher terrain leading to rainfall totals ranging from 3"-6" on average along terrain favored east facing slopes. Flooding, however, was minor in this region due to antecedent dry conditions. Rainfall amounts in the Hudson valley and other north south valleys like the Housatonic in Berkshire County were significantly lighter, generally ranging from 1/2" to 1.5" as mountain shadowing occurred due to a period of strong easterly downslope flow. That strong easterly flow, however, was low enough in the atmosphere to buffet the higher terrain in western New England for a time Sunday evening with 40 mph wind gusts which lead to scattered tree and power line damage.

The majority of the heavy rain with the system fell on the 22nd. The storm, however, parked itself over the Northeast through the 23rd, which lead to periods of additional rain through the day. The rainfall on average on the 23rd, however, was much lighter and more scattered in nature. Widely scattered showers and drizzle in fact lingered over the region into Tuesday the 24th with additional amounts of a trace to a few hundredths of an inch.

WeatherNet 6 Event Total Rainfall reports (Sunday-Monday, August 22-23, 2010)
(A time notation next to a rainfall report indicates rainfall through that time and is therefore not an event total)

Town County Rainfall Report Town County Rainfall Report
Savoy, MA Berkshire 1.61" Clarksburg, MA Berkshire 1.00"
Alford, MA Berkshire 0.75" Pittsfield, MA Berkshire 0.70"
North Adams, MA Berkshire 0.76"      
South Berne Albany 3.50" East Berne Albany 4.30"
Colonie Albany
Feura Bush Albany 3.50"
Albany (Airport) Albany 1.00" Cohoes Albany 0.80"
Ancramdale Columbia 1.45" Chatham Center Columbia 0.82"
Germantown Columbia 1.72" Livingston Columbia 1.27"
Roxbury Delaware 2.00"      
Poughkeepsie Dutchess 4.02" Red Hook Dutchess 3.74"
Rhinebeck Dutchess 3.30" Millbrook Dutchess 2.60"
Northville Fulton 2.13" Broadalbin Fulton 2.40"
Peck Lake Fulton 4.82" Gloversville Fulton 2.75" (6am/23rd)
Johnstown Fulton 4.18" (5am/23rd)      
Catskill Greene 3.45" Tannersville Greene 5.50"
Athens Greene 3.80" Lexington Greene 2.86"
Purling Greene 4.50" (7am/23rd) Haines Falls Greene 5.46" (6am/23rd)
Greenville Greene 3.72" (5am/23rd)      
Wells Hamilton 5.45" Old Forge Herkimer 4.57"
Speculator Hamilton 4.50" (7am/23rd)      
Fonda Montgomery 3.26" Amsterdam Montgomery 2.25"
Glen Montgomery 3.69" Fort Plain Montgomery 5.21"
Palatine Bridge Mongtomery 4.14" Tribes Hill Montgomery 2.86"
Worcester Otsego 2.78" Cherry Valley Otsego 6.50" (6am/23rd)
East Worcester Otsego 3.26" (5am/23rd)      
Melrose Rensselaer 0.94" East Greenbush Rensselaer 0.83"
Brunswick Rensselaer 0.74" Stephentown Rensselaer 0.70"
Speigletown Rensselaer 1.00"      
Charlton Saratoga 2.50" Clifton Park Saratoga 1.62"
Gansevoort Saratoga 3.32" Ballston Spa Saratoga 3.09"
Malta Saratoga 2.35" Saratoga Springs Saratoga 2.39"
Round Lake Saratoga 1.28" Edinburg Saratoga 2.74" (6am/23rd)
Wilton Saratoga 2.08" (6am/23rd)      
Jefferson Schoharie 2.30" Summit Schoharie 2.50"
Fulton Schoharie 1.60" Cobleskill Schoharie 3.54"
Charlotteville Schoharie 2.98" Schoharie Schoharie 2.40"
Scotia Schenectady 2.05" Delanson Schenectady 2.65"
Duanesburg Schenectady 2.50" Niskayuna Schenectady 1.31"
Kingston Ulster 4.00" Phoenicia Ulster 6.91"
Whiteport Ulster 3.68" (5am/23rd) Esopus Ulster 3.74"
West Shokan Ulster 6.86" Saugerties Ulster 4.21"
Lake Luzerne Warren 2.35" Warrensburg Warren 3.20"
Glens Falls Warren 2.14" Brant Lake Warren 3.67"
Granville Washington 2.00" Cossayuna Washington 1.40"
Whitehall Washington 2.75" Hudson Falls Washington 3.10" (5am/23rd)
Landgrove, VT Bennington 1.31" Woodford, VT Bennington 1.61"
West Rutland, VT Rutland 3.10" Bennington, VT Bennington 0.53"

Flash Flood/Wind Reports

Town County   Time
Little Falls Herkimer FLOOD: Route 5 near Gun Club Road and Route 5S near Lower Paradise Road flooded and closed 6:55pm
Dolgeville Herkimer FLOOD: Numerous roads closed in the vicinity of Dolgeville, along with basement flooding. South Main Street flooded in Dolgeville 6:55pm
Little Falls Herkimer FLOOD: Finks Basin Road off of Route 167 in Danube Flooded 6:55pm
Dolgeville Herkimer FLOOD: Standing water on I-90, between exits 29A and 30 7:15pm
Fort Plain Montgomery Otsquago Creek overflowing its banks onto Route 80 and through the entire village, 50-60 houses along Abbott Street, Reid Street, and Main street evacuated, significant damage on Abbott street with several garages and sheds washed away, state of emergency declared for Fort Plain, Minden, Palatine Bridge, Canajoharie, and St. Johnsville due to flooding 8:59pm
Sunderland, VT Bennington Trees blown down from strong non-t-storm easterly gradient winds
Bennington, VT Bennington Trees and wires blown down from strong easterly gradient winds 9:45pm

#1: Photographer: Mike Saracino. 4pm Monday August 23, 2010, Salisbury, NY, Herkimer County. The Spruce Creek just below the historic covered bridge

The raging Spruce Creek, Salisbury, NY, Herkimer County, 4pm on Monday 8/23/2010 

#2: Photographer: Mike Saracino. 4pm Monday August 23, 2010, Salisbury, NY, Herkimer County. Another view of the Spruce Creek just below the historic covered bridge.

The raging Spruce Creek, Salisbury, NY, Herkimer County, 4pm on Monday 8/23/2010