Unseasonable chill and much-needed rain in store

/ April 1, 2019 at 12:43 AM

No fooling: It’s not going to get out of the 50s on Monday. (Nor will it on Tuesday.) The good news is that we may actually see something resembling substantial rainfall across much of the area for the first time all year. Will it be enough to bust the drought?

Unusual chill to start April

Earlier Sunday afternoon, a cold front swung through the area with a few showers. Rainfall amounts were unsubstantial, perhaps measuring in the hundredths of inches at best based on radar estimates. The airmass it ushered in, though…by late March/early April standards, brrr.

The late-season cold front will continue to push offshore, stalling out somewhere around the FL/GA line on Monday. Behind the front, high pressure will wedge down into the area from the north. This will help lock in a rather chilly airmass (and a breezy northeast wind, particularly at the coast). Despite some peeks of sun, don’t expect temperatures to get out of the mid-50s on Monday.

Late-season nor’easter to develop and move nearby Tuesday

Simple Water Vapor RGB from GOES-East depicting a strong upper-level low moving out of the Four Corners region. Said low will help to spin up a surface low off the coast of Florida, increasing rain chances across the area for Tuesday.

Monday night into Tuesday, we’ll be watching a piece of upper-level energy as it barrels toward the Southeast. As this energy approaches the stalled front, a low pressure system is expected to spin up somewhere near or just offshore of the east coast of Florida. Said low pressure system is then forecast to track northeastward along the Southeast coast, making its closest pass to the Charleston area early Tuesday.

While it appears that the low pressure system will track just offshore, keeping the heaviest rain along and east of its track, there is still good potential for up to an inch of rain with locally heavier amounts across the area Tuesday — and boy, do we need it, having just completed the fourth driest March on record at the airport with a grand total of 0.69″ for the month (including a hundredth of an inch on Sunday).

Rainfall will be at its heaviest for the Tuesday morning commute, it appears, gradually beginning to taper off in the early afternoon. (More on the potential for flooding in a minute.) While the rain won’t totally erase our drought in one sitting, it does appear that it could make at least a bit of a dent, which is better than we can say for many rainfall events so far this year.

By Tuesday night, we should see much fewer clouds with temperatures falling into the low 40s for much of us. Inland locations may deal with some frost, especially if temperatures can fall into the upper 30s. Keep an ear out for possible Frost Advisories from the National Weather Service.

Coastal flooding concerns

While we should not see salt water flooding merely from tidal heights, strong, gusty winds (gusts upwards of 25-30 MPH) could drive tides over 6.5′ in the harbor particularly Tuesday morning. While this height alone is not enough to cause salt water flooding in downtown Charleston, this may coincide with a period of heavy rainfall, and will need to be monitored carefully for potential travel trouble as a result. High tide is expected Tuesday morning at 7:03 AM.

By Tuesday evening, the low pressure system will be moving away from the area, shutting off both the rainfall and turning the winds more northerly and eventually around to the northwest, which will also cut off the onshore flow.

Warming trend for the second half of the week

Looking ahead toward Wednesday and beyond, we will find that temperatures will begin to warm back closer to April normals. Wednesday looks particularly pleasant, if not a touch below average, with highs in the upper 60s to around 70 under mostly sunny skies. Warmer-than-normal temperatures will follow from Thursday into the weekend, despite a cold frontal passage on Friday which could stir up a few showers and thunderstorms.

#SafePlaceSelfie: April 3 at 11:11am

On Wednesday, April 3, join the National Weather Service and Weather-Ready Nation Ambassadors (such as yours truly!) and take a #SafePlaceSelfie from your severe weather safe room. It’s important to know where to go in your home or business when severe weather, such as damaging winds and tornadoes, threatens. The #SafePlaceSelfie campaign is a great way to encourage your friends and family to ensure they, too, have a severe weather safety plan, know what it is, and are prepared to execute it should the need arise.

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