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Flash Flood Potential Increases Wednesday

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HARDWICK – Abnormally wet conditions remain in place for the weather, as we start the forecast period with the likelihood of showers and thunderstorms with the potential to produce very heavy downpours and flash flooding. As mentioned in previous weeks, we have seen 30-day rain totals on the order of eight to 10 inches, mainly across southern Orleans, Lamoille, and northern Caledonia Counties. These rainfall amounts are about 150 to 200 percent above normal, according to the National Weather Service. Slightly less rainfall is seen further south.

We have seen near-to-above normal temperatures, with humidity rising as we moved into the early part of the week. A warm front is approaching our region from the south today with significant moisture availability due to interactions with Tropical Storm Beryl, which is currently approaching the Ohio Valley. The front begins to stall as it lifts north through our region this afternoon as an area of high pressure over eastern Canada slows its forward motion. Where the front stalls, we are expecting thunderstorms to train, meaning that they develop and move over the same area repeatedly.

Some slight uncertainty remains in the predicted stall location, but many models have it over northern Vermont.

In the heaviest pockets of accumulation, we are likely to see a wide swath of 2 to 4 inches of rainfall, which would fall over a period of six to 12 hours. Locally heavier amounts of five or six inches may occur where sustained rainfall rates exceed two inches an hour. A flash flood risk exists for this reason, mainly with smaller creeks and streams, which will not tolerate rainfall in excess of a couple of inches in less than three hours. This has the potential to wash out roads and displace residents with very little notice. Larger rivers will likely have some time to absorb this inundation better, but will still experience significant rises. Our area is primed for this situation given the antecedent rainfall and recent model trends. The flooding potential certainly warrants further monitoring.

The rain will persist overnight Wednesday into Thursday morning. Some additional heavy rain risk continues Thursday, although it will be more scattered in nature as the associated cold front crosses the region. A shower may exist over the higher terrain Friday as the frontal system slowly marches out, leaving us with a sunny and mild weekend ahead, a good opportunity to dry out. Here are the forecast details:

photo by Vanessa Fournier The weather was rainy last week with warm temperatures, as shown from Orton Road showing the Stannard Mountain Road toward Greensboro Bend. The Lamoille Valley Rail Trail bridge was decorated with flags for Independence Day.

Wednesday: Mostly cloudy. Showers and thunderstorms developing by afternoon. Heavy rainfall expected through the overnight with flash flooding possible. High: 81. Low: 68.

Thursday: Partly cloudy. Scattered showers and thunderstorms. High: 85. Low: 63.

Friday: Partly cloudy. Isolated showers and thunderstorms. High: 83. Low: 61.

Saturday:  Mostly sunny. High: 86. Low: 61.

Sunday: Sunny. High: 88. Low: 64.

Tyler is our weather reporter and a community journalist. He works as a nurse and EMT, volunteers with Hardwick Rescue and helps to train new EMTs.

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