May showers bring June...I dunno

After a wet start to spring, things suddenly turned dry a few weeks ago, but that is in the process of changing as an unsettled pattern takes hold over the eastern United States.

Almost daily rain chances should persist over the next couple of weeks, at least, with numerous thunderstorms possible during this time frame. Not everyone will see rain every day, and it’s impossible to say who the winners and losers will be in the rainfall category, but there could be some occasional flash flooding threats where the heaviest rains set up.

A low pressure system is currently spinning slowly to our southwest, funneling Gulf of Mexico moisture into our region. As thunderstorms develop this afternoon, a weak steering flow in the mid levels of the atmosphere should mean that they’re slow-moving, meaning heavy rain is a threat.

This low pressure system will continue to pump copious amounts of moisture into the region tomorrow. The primary drivers of thunderstorms (besides moisture, of course) will be absent with low instability and little forcing, so storm coverage should be less widespread tomorrow than today. However, heavy rain will still be a possibility.

That low pressure system finally exits the region to our north for the weekend, and with our air flow shifting from the south to the west in its wake, drier air should begin working its way into the atmosphere. So storm coverage should decrease even more on Saturday, and decrease again on Sunday as ridging develops over the region. Summer-like afternoon thunderstorms will remain a possibility, however. In fact, the National Weather Service has a 50% chance of thunderstorms in the forecast for Saturday, a 40% chance for Sunday and a 50% chance for Monday.

The GFS forecast model shows six inches of rainfall over the northern Cumberland Plateau region over the next 15 days. That’s likely way overdone, as the convective nature of these storms will make it impossible to forecast who sees rain and who doesn’t each day.

Already, we’re seeing a big difference between where rain is falling and where it isn’t. Between three and four inches of rain have fallen over parts of Fentress County over the last couple of days, for example, while parts of Scott County haven’t received a drop.


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