A slow moving upper level low pressure area moved from the Great Lakes towards the Northeast between Wednesday, August 20th and Friday August 22nd.  Several rounds of showers and thunderstorms occurred across the entire region during this time period.
During the evening on Wednesday, August 20th, slow moving thunderstorms produced two to four inches of rain across parts of the Mohawk Valley and Sacandaga Region.  Despite this rainfall, no flooding was reported, but this rainfall led to ponding of water on roadways and helped to moisten up the ground conditions.
Another batch of heavy rainfall due to slow moving thunderstorms occurred the next day on Thursday, August 21st during the evening hours.  Once again, several inches of rainfall occurred across the central Mohawk Valley.  With the ground saturated due to the recent rainfall, small streams and creek quickly overspread their banks.  This led to flash flooding across parts of west-central Montgomery and northern Schoharie Counties, with many roads washed out and closed.  At least 15 roads were closed in Montgomery County, including an onramp for the New York State Thruway, and a State of Emergency was issued for the county due to the flooding.  The flooding caused sewage treatments plans to be inundated with water and a boil water advisory was issued for several days due to the local water supply being compromised.
Some lighter rain showers occurred on Friday, August 22nd.   Most of the damage was already done, although another minor mudslide occurred due to the already weakened ground conditions.  Once showers ended by the afternoon of Friday, August 22nd, the water was able to recede and the ground conditions started to finally dry out.  All road were reopened by Monday, August 25th at 9 am and the State of Emergency was lifted on the 25th as well.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:00:00 to 22-AUG-14 01:15:00 (EST-5)
Location: STONE ARABIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

State Route 10 at Groff Road in Stone Arabia was closed due to flash flooding from thunderstorm heavy rainfall.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 19:45:00 to 22-AUG-14 01:15:00 (EST-5)
Location: CANAJOHARIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rainfall from several rounds of slow moving thunderstorms led to flash flooding in the Palatine Bridge Area.  State Route 5 was closed at State Route 10 in Palatine Bridge due to high water.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:30:00 to 22-AUG-14 01:15:00 (EST-5)
Location: SPRAKERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rainfall from repeated rounds of slow moving thunderstorms led to flash flooding in Montgomery County.  A mudslide along Route 5S closed the roadway between Canajoharie and Route 162 in Sprakers.  Sprakers Road was also closed between Jump Road and the village of Canajoharie.  The New York State Thruway was also closed at Exit 29 (Canajoharie) due to high water on the roadway between Exit 28 (Fultonville) and Exit 29 (Canajoharie).

Flash Flood in SCHOHARIE, NEW YORK
From 21-AUG-14 20:32:00 to 22-AUG-14 02:15:00 (EST-5)
Location: LEESVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

U.S. Route 20 was closed in the village of Sharon Springs due to flash flooding from heavy rainfall due to slow moving thunderstorms.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:34:00 to 22-AUG-14 01:15:00 (EST-5)
Location: FONDA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rainfall from thunderstorms led to flash flooding Fonda.  Excessive flooding occurred on both Main Street and Broadway in Fonda.  Flooding was also reported at the intersection of Route 5 (Main Street) and Route 334 (Cayadutta Street).  A State of Emergency was issued for the town due to extent of the flooding.

Flash Flood in SCHOHARIE, NEW YORK
From 21-AUG-14 20:45:00 to 22-AUG-14 02:15:00 (EST-5)
Location: SHARON SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous basements were inundated with water due to flash flooding from thunderstorm heavy rainfall in Sharon Springs.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:30:00 to 22-AUG-14 01:15:00 (EST-5)
Location: SPRAKERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Route 162 at Flat Creek Road in Sprakers was closed due to flash flooding from thunderstorm heavy rainfall.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 21:00:00 to 22-AUG-14 01:15:00 (EST-5)
Location: FT JOHNSON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Route 67 was closed between Fort Johnson and Johnstown due to flooding and a mudslide from thunderstorm heavy rainfall.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:30:00 to 22-AUG-14 01:15:00 (EST-5)
Location: SPRAKERS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Monk Road was washed out and closed in Sprakers due to flash flooding from heavy rainfall due to slow moving thunderstorms.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:30:00 to 22-AUG-14 01:15:00 (EST-5)
Location: AMES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding occurred in Ames due to repeated rounds of heavy rainfall from slow moving thunderstorms. State Route 10 was closed at Old Sharon Road in Ames due to high water.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:25:00 to 22-AUG-14 01:15:00 (EST-5)
Location: AMES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding occurred along West Ames Road in Ames between White Road and Bueld Road.  The Canajoharie Creek overspread its banks due to heavy rainfall from repeated rounds of slow moving thunderstorms.  A large hole was formed in the roadway as a result of the flooding.

Flash Flood in MONTGOMERY, NEW YORK
From 21-AUG-14 20:45:00 to 22-AUG-14 01:15:00 (EST-5)
Location: CANAJOHARIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash flooding occurred along the Canajoharie Creek in Canajoharie due to thunderstorm heavy rainfall.  Old Sharon Road was closed between Carlisle Road and Maple Hill Road due to high water.

Flood in MONTGOMERY, NEW YORK
From 22-AUG-14 09:15:00 to 22-AUG-14 09:15:00 (EST-5)
Location: NELLISTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A mudslide occurred near the intersection of Happy Hollow Road and Old Fort Plain Road due to recent heavy rainfall from slow moving thunderstorms.