Charleston Weather Blog

Forecast explanations, atmospheric science, and other cool weather-related stuff for Charleston, SC

Low pressure to bring more rain to the Lowcountry this week

/ July 5, 2020 at 10:58 PM

We’ve got a soggy, stormy start to the week in store as a low pressure system moves through the Gulf Coast states and strafes our coastline. We’re already starting to see some shower activity from this storm system this evening, and more is expected through at least Wednesday night, if not beyond.

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Unsettled, occasionally rough, weather possible this week

/ June 28, 2020 at 10:39 PM

We’ve got a fairly active week of weather ahead as we move toward Independence Day this weekend. First off, the warmth: Temperatures will push the mid-90s on Monday and Tuesday, and the humidity will push heat indices well into the 100s. Could scrape 105° at times, so be sure that you are hydrating well and taking plenty of breaks if you’re outdoors.

Thunderstorms will feature prominently in the forecast this week as we remain in northwest flow aloft Monday and Tuesday. This will allow thunderstorm complexes to move into the area from the northwest, potentially packing strong winds and heavy rain. Thereafter, a trough of low pressure aloft and at the surface will keep us in a fairly unsettled pattern, with showers and thunderstorms possible each afternoon with peak heating. This pattern may last into the weekend, so be thinking about indoor alternatives to your July 4 plans now, just in case. Will keep an eye on it to see how things evolve throughout the week. Stay tuned.

A drier, warmer weekend lies ahead

/ June 25, 2020 at 10:20 PM

High pressure ridging overhead is going to keep thunderstorm chances low and temperatures up for Friday and the weekend. Couple that with a side of Saharan dust advecting in from the southwest and we’ll have a few hot, hazy, and humid days ahead. In fact, during the afternoons, heat indices may approach the upper 90s to around 100 at times, so be sure you’re getting hydration if you are outdoors. A stray thunderstorm or two will be possible Friday and Saturday afternoon, with a tighter lid on potential storms for Sunday (as things stand right now, anyway).

Sunsets could be particularly colorful Saturday and Sunday night, as NASA dust modeling suggests peak Saharan dust activity around these times. It remains to be seen what, if any, air quality impacts there will be, but we’ll want to keep an eye on that for sensitive groups, especially with our recent acceleration in coronavirus cases aggravating respiratory matters.

Summer in full effect this week

/ June 21, 2020 at 8:58 PM

The solstice must have kicked something into alignment, because this week fits perfectly into the normal summertime routine with temperatures running in the upper 80s to low 90s each day and a chance of thunderstorms each afternoon. Could see some additional coverage of showers and storms Wednesday and Thursday, but other than that, it’ll be a typical Charleston summer setup. If you’ve got outdoor plans, just keep an eye on the weather each afternoon. When thunder roars, go indoors!

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A stretch of cool for the history books, but summer will return

/ June 17, 2020 at 9:45 PM
National surface analysis with satellite overlay at 2PM June 17, 2020.

We have been in quite the cool spell this week as an upper-level low pressure system in concert with a stalled front have kept clouds and showers in the forecast. The cool temperatures have been rather remarkable for June, with legitimate hoodie weather the past couple days as several record low maximum temperatures were achieved both at Charleston International Airport and downtown Charleston. Summer’s coming back, though…

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Lingering coastal storm keeps us cool, rainy for a couple more days

/ June 14, 2020 at 9:03 PM

It sure has been cool and occasionally rainy over the last few days! Today’s high only made it to 77° at the airport, which barring an unforecasted heating episode will be a new record low maximum temperature for the date. The previous record low max for June 14 was 78° set in 1939. This cool pattern is thanks to an upper low aloft and a wedge of high pressure at the surface. Moisture riding atop the wedge is keeping cloud cover and the occasional showers around, and this will continue for a couple more days before the pattern turns more summer-like by the end of the week.

Periods of heavy rain will continue for much of Monday before winding down in the evening. Once again, temperatures will run well below normal (upper 70s) thanks to cloud cover and rain-cooled air. While we’ll have less rain on Tuesday, we will have one more day of cool temperatures with continued cloud cover and northerly winds on the back side of a coastal low. Before it’s all said and done, another 1-3″ of rain may have fallen across the area in what has been a wet year — we have a 6.2″ surplus of rain at the airport.

As we get into mid-week, we’ll begin to see the upper low finally take leave of the area, allowing the surface low to go with it. Showers will continue to be in the forecast, but temperatures will moderate into the lower 80s. By the end of the week and into the weekend, expect temperatures to head back into the upper 80s and lower 90s with the typical afternoon thunderstorm regime we all know and love during summers in Charleston.

The week ahead: Warm, humid, unsettled

/ June 7, 2020 at 10:23 PM

June in Charleston is typically characterized by afternoon thunderstorms and highs in the upper 80s, and this week will not disappoint in either department. We’re caught between Atlantic high pressure and the broad circulation of Tropical Storm Cristobal, putting us within a corridor of deep moisture which will help drive scattered showers and thunderstorms each afternoon to start the week. All the while, a stalled frontal boundary will be hanging around to our north, meandering for the next several days and acting as another focal point for showers and storms. As we get into the weekend, another front approaches. As we so often see in the warm season, though, the front looks to have a hard time getting through the area, keeping us in the soup with scattered afternoon thunderstorms through Sunday.

It’s hurricane season again

/ June 1, 2020 at 8:12 AM

It’s June 1, and that means that the Atlantic hurricane season has once again officially started. (Don’t tell Arthur and Bertha that they were early to the party.)

Through November 30, we’ll be keeping a weary eye on the Gulf of Mexico, Caribbean Sea, and Atlantic Ocean for possible tropical mischief. It could be a busy year for tracking storms, too. Let’s dig in.

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The week ahead: A taste of spring followed by summer weather

/ May 31, 2020 at 5:51 PM

Monday and Tuesday sure won’t feel like June in the wake of a cold front that came through earlier today. Cool high pressure will wedge into the area, and the resulting onshore flow will keep temperatures rather pleasant and cloud cover reasonably low to start the new work week. We’ll begin a warming trend on Wednesday with a return to the 90s by Thursday. Next rain chances arrive by this weekend.

Looking back on Bertha

/ May 30, 2020 at 9:45 AM
Tropical Storm Bertha at landfall northeast of Charleston on Wednesday morning.

In case you missed it — and you’ll be forgiven if you did — we had our first landfalling tropical cyclone of the 2020 hurricane season on Wednesday. Tropical Storm Bertha, which was classified as such when it was 30 miles southeast of Charleston, came ashore around 9:30am with maximum sustained winds (primarily offshore) of 50 MPH. Bertha was not a major wind-maker on land, but dropped enough rain at low tide to cause flooding in downtown Charleston. Its heavy rain spread inland, adding to rain totals on what has been a soggy second half of the month already. Charleston Airport set a new rainfall record on Wednesday, as well; 2.08″ broke the record of 2″ set in 1977.

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