Flood Watch
National Weather Service Buffalo NY
327 PM EDT Sat Sep 8 2018
...A long duration rain event expected for the region...
The remnants of Tropical Storm Gordon will move from the Upper Mid
West to the Lower Great Lakes later Sunday into Monday...and this
will result in a relatively long period of moderate to heavy rain over western New York. While the tropically enhanced rain will begin Sunday morning...the steadiest and heaviest rains are not expected until later Sunday afternoon and night. The rain will then taper off as we progress through the day Monday.
Rainfall amounts across the Southern Tier will range from two to three...with higher amounts likely south of the Pennsylvania
border. This will result in significant rises on area tributaries...with areas of higher rainfall amounts pushing some to bankfull. The risk for flooding may be exacerbated by higher rainfall amounts over the northern tier of Pennsylvania...as some of this rainfall will flow into the Genesee and Allegheny River basins. The main stems of the Allegheny and Genesee Rivers will not crest until well after the rains end on Monday.
Cattaraugus-Allegany-
Including the cities of Olean and Wellsville
327 PM EDT Sat Sep 8 2018
...FLOOD WATCH IN EFFECT FROM SUNDAY EVENING THROUGH TUESDAY
MORNING...
The National Weather Service in Buffalo has issued a
* Flood Watch for a portion of western New York...including the following counties...Allegany and Cattaraugus.
* From Sunday evening through Tuesday morning.
* Two to three inches of rain will fall over the region Sunday into Monday, with the steadiest and heaviest rains expected Sunday night. Higher rainfall amounts will be possible. While the heavy rain will end well before Monday evening...it will likely take several hours for the larger basins to crest.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Flood Watch means there is a potential for flooding based on current forecasts. You should monitor later forecasts and be
alert for possible flood warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop. Stay tuned to weather radio or other radio and TV stations for further details or updates.
.HYDROLOGY...
In general expect a total of 1-2 inches of rain from Buffalo to Rochester north with 2-3 inches in the western Southern Tier and
upper Genesee Basin. This will be a prolonged moderate to heavy rainfall event with river flooding the main concern. Current flows are low, with these rainfall amounts marginally enough to result in
flooding. However, an axis of heavier rainfall will be just to our south and any northward shift in this would impact river forecasts significantly. Also, a portion of the headwaters of the Genesee and
Allegheny river extend to our south where there will be more rainfall.
The main concern is for the Wellsville forecast point on the Genesee
River and Olean and Salamanca forecast points on the Allegheny
River. MMEFS ensembles show a wide range for these points, from no
flooding to moderate flood stage depending on how far north the
heavy rain reaches.
