First measurable rain of April to arrive Saturday; may come with strong storms and tidal flooding

/ April 23, 2021 at 7:56 PM

Today marks 23 days without measurable rainfall at the airport. This is the driest start to April since 1976, when it took until the last day of the month to record some measurable rainfall. We will not match that streak this time, though, as a potent storm system will bring us gusty winds, a fair bit of rain, and possibly some severe weather on Saturday.

Rainfall forecast

The National Weather Service rainfall forecast for Saturday is quite wet, with anywhere between 1-3″ of rain possible across the Lowcountry. It remains to be seen exactly when all this will ultimately fall, but guidance continues to hit on the bulk of this rain falling Saturday afternoon into the overnight hours. We’ll need to keep a close eye on tides as well, as the 6:43 PM high tide will get very close to 7′ in the harbor. Add heavy rain on top of this, and we have problems in downtown Charleston. Runoff may also be a factor as well in other locations given such dry conditions, so we’ll need to keep an eye on the flood risk overall.

Severe weather outlook

Storms arriving in the evening will arrive alongside favorable wind profiles for severe weather, but what remains to be seen is how unstable the air can become. Prolonged rain during the day Saturday will keep the severe threat much more isolated, but if there are breaks in the rain and the atmosphere has some time to recover, we could see more substantial severe storms later in the day into Saturday evening. Damaging winds and large hail will be the primary threats, but wind profiles are such that a tornado or two cannot be totally ruled out. The greater severe weather risk looks to remain just to our south, but regardless, you’ll want to review your severe weather safety plan and make sure you have multiple ways to get a warning on Saturday.

Our reward for a crappy Saturday? A gorgeous Sunday, with temperatures in the upper 70s and mostly sunny skies.

I’ll have updates throughout the day on Saturday as conditions and forecast updates require. Stay tuned!

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