The Flood Potential Outlook updated Thursday by the National Weather Service has good news and bad news for the Capital Region.
The good news is there isn’t enough snow surrounding oft-flooded rivers and streams to cause concern in the event of a quick warm-up.
The bad news is there isn’t any warm weather on the horizon for the next two weeks covered by the forecast, and that means ice on the Mohawk River will continue to build up.
“It’s been cold, but we’ve been relatively dry,” Steve DiRienzo, a warning coordination meteorologist for the weather service, said Thursday.
The weather service develops the outlook each winter, detailing factors that contribute to the amount of water within or bound for streams, creeks and rivers. Updated every two weeks until the snow is gone, the outlook takes into account the snowpack surrounding waterways, measured as “snow water equivalent.” It also reviews soil moisture conditions, current river flow and ice, reservoir and lake levels and temperature and precipitation, both past and forecast.
This week’s snowstorm boosted the amount of water in the snow surrounding the Mohawk River, the Sacandaga Reservoir and the Schoharie Creek by roughly an inch, but DiRienzo said snow water equivalents between 2 and 4 inches currently surrounding Capital Region waterways isn’t very much.
In “bad years,” he said, the snow water equivalent has been measured at 10 to 14 inches in some places by late March and early April. DiRienzo said 2011 was one of those bad years, when heavy rain, melting snow and an ice jam led to flooding along the Mohawk River from March 11-13 in Albany, Saratoga and Schenectady counties.
Ice that had been jammed up between Erie Canal locks 9 and 10 in Glenville broke free, moved downstream and jammed up again between the Twin Bridges and Lock 7 that weekend. Between 1 and 3 inches of rain added to mild temperatures and the ice jam restricting the river’s flow to flood homes along Rosendale Road, Vischer Ferry Road, Forts Ferry Road, Ferry Drive and Riverview Road.
The current Flood Potential Outlook shows soil moisture, which impacts runoff potential, is considered between normal and above normal. The ground was frozen to a depth of 23 inches in Albany on Wednesday. Flows in local rivers are near normal, and the ice is measured at roughly 6 inches.
“Can there be some jamming? Yes. But if the ice was a foot thick, I’d be more worried,” DiRienzo said.
The forecast suggests continued below-normal temperatures make for “plenty of ice jam potential for the next major warm-up.”
Reservoirs are considered near to above normal, and the New York City reservoirs, including the Schoharie Reservoir held back by the Gilboa Dam, are 3 percent above normal capacity.
DiRienzo said it’s too early to tell if the region is bound for flooding this spring.
“There could certainly be problems if it stays cold. We could be looking at a problem come March,” DiRienzo said.
The next Flood Potential Outlook is scheduled to be released around Feb. 20. The report can be found on the website of the National Weather Service’s Albany forecast office at http://forecast.weather.gov.