Monday, February 24, 2014

Winter Rainy Season Underway, Flooding Risk?

Did you know that the Floods are the #1 natural disaster in the Unites States and nearly 20% of all insurance claims due to flooding come from moderate to low risk areas?

We've seen this happen in our own communities as recently as 2011 when collectively the Ohio, Mississippi, Cumberland, Tennessee, and Clarks Rivers experienced "100 yr" floods. Even areas that had never seen major flooding were inundated by an overly active winter rainy season that did not relent while transitioning into Spring.

We are entering a delicate time of the year where Winter transitions to spring and several factors can play a part in our flooding risk. Snow melt, spring thaw, heavy rains, and even ice jams (rarely) can contribute to the cause. To evaluate exactly what your risks are where you live (here in the Local 6 area or elsewhere) check out this interactive panel below.

In general the Local 6 area is prone to flooding from the Spring thaw and heavy thunderstorms. Snowfall becomes more of a factor usually once every 3-5 years when late season high snow totals are recorded. The winter freeze has been very prolonged this winter so the subsurface soil has remained fairly frozen allowing for very little infiltration of runoff or melting. In a matter of another week, a rapid thaw will take place with 50's & 60's in the forecast. Heavy rain with thunderstorms is also expected during this period and much of that water is likely to runoff with an already saturated ground. Local creeks and tributaries are already at bank-full or swollen and may rise a bit further before some sort of relief is available in the short term. With this being said, low lying areas near creeks and tributaries should be alert to lowland flooding and ponding of water.


The larger rivers are in better shape at the moment but snow melt to the North may play a factor in the coming weeks. Our weather pattern has remained cooler and wetter than normal with little chance in sight when looking at global signals like the North Atlantic Oscillation and a near Neutral El Nino influence.


Our wettest months tend to be in the early spring then again in the late fall. Heavy rain events have also become more frequent so flash flooding should always be prepared for as well.

Precipitation totals for the Winter of 2013/2014 have been above normal thus far. To the right is a graphic that illustrates how we compare to other states in the Midwest. Below shows precip totals from across Western Kentucky and how it compares to the average each month (Dec/Jan).


 Looking to the growing season, farmers are usually optimistic after a wet spring but there is too much of a good thing. If crop fields are too wet, getting crop planted become very difficult and nutrients can be unevenly distributed or even stripped across the soil. How long into the growing season the wet conditions persists can also determine which crops can be planted. To the left is the Crop Moisture Index showing Western Kentucky and NW Tennessee are currently above normal as we get closer to the start of Meteorological Spring starting March 1st. To see a larger version, click on the image.

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