Tropical flooding concern for CNY? Details here
Tue, 28 Sep 2010 14:15:11 GMT —
Tropical trouble in the Caribbean will head towards Florida and the Carolinas over the next 36 to 48 hours. This system has the potential to move northbound towards our area. Central New York has a history of receiving flooding from hurricanes and tropical storms after they make landfall to our south. This web story will give you the reason for our concern regarding Thursday into Thursday night here locally and some history as a perspective.
With respect to our local forecast, an area of disturbed tropical moisture located nearly 2000 miles away south of Cuba and near the Cayman Islands may develop into tropical storm Nicole. Click here for a water vapor satellite loop of the disturbed weather. Normally, you would not think that weather this far away would not be any concern for our area. However, the jet stream is positioned in such a way that anything occurring directly to our south will move straight northward into our area. This includes Pennsylvania, Virginia, North Carolina, Florida and all the way south into the western Caribbean! The upper level winds that are orchestrating the weather pattern will not change very much between now and Thursday night. Unfortunately, this means the connection to this tropical moisture is open for business. The question becomes: How much rain will the east coast of the United States and, more importantly, central New York receive? The answer to this question will be directly connected to how strong this tropical system gets and how this tropical system interacts with the upper level wind flow. An early prediction from one of our computer models indicates the potential for over 4 inches of rain within an 18 hour period. That type of rainfall in said period of time would likely cause localized flooding for some rivers, streams, and low-lying flood prone spots. Within a rainfall like this, there are usually some areas that receive more and some that receive less. It is way too early to pinpoint the exact amount of rainfall we will receive. However, I have concerns about this system. This is why I am highlighting them in this web story.
In the past, hurricanes and tropical storms have made landfall to our south and have subsequently caused flooding across portions of central New York and Pennsylvania. The following is a short recap of just 4 of the major tropical systems that have affected the area.
In 2004, the remnants of Hurricane Frances produced 1 to 3 of rain on September 9th and 10th. That was quickly followed by the leftovers of Hurricane Ivan on September 17th and 18th. While the immediate central New York area was spared the worst of the rainfall, the southern tier of New York and much of Pennsylvania received 3 to 5 inches of rain. This caused major flooding of main rivers including the Susquehanna and Delaware Rivers.
In 1972,Hurricane Agnes brought crippling rainfall to Pennsylvania and tough rainy conditions into central and western New York. Between June 19th and 24th, a combination of an upper level disturbance and Agnes caused 10 to 19 inches of rain in central Pennsylvania. A swath of 10 inches of rain occurred across the southwestern sections of the Finger Lakes to near Bath and Olean, NY. Most of our immediate area received 3 to 6 of rain during this time period. For more on Agnes, click here and here.
In 1954, Hurricane Hazel brought strong winds and flooding rains to western NY and much of Ontario province Canada. While central New York did not receive much rainfall, wind was a major fact. I am including Hazel in this discussion because of the tremendous flooding that occurred in Toronto and other areas of southern Ontario. Some of this was likely due to a Lake Ontario storm surge of water. There are some interesting details regarding Hazel and how it affected southern Ontario, Canada here and here. This includes pictures and video from 1954.
Tropical inland flooding is such a concern that the National Weather Service, in coordination with Flood Safety Awareness week, discusses this topic. You can find more in this story here. We will continue to watch the progression of the entire weather pattern for you here at CNYcentral. We will keep you posted if flooding fears become more of a reality.
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