Charleston Weather Blog

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

Rest of the work week: Turning much cooler and unsettled with a significant coastal flooding risk

/ November 2, 2021 at 8:28 PM

After a couple days of 70s and sunshine, cold air damming will begin to ooze into the area on Wednesday, kicking up cloud cover and keeping temperatures down into the mid-60s. It’s the first really good sweater weather day of the year, and the last fully rain-free day until Sunday. Thereafter, a storm system will affect our area from Thursday into the weekend. The wedge will remain intact through the rest of the work week, keeping gusty northeasterly winds — which could get as strong as gale force over the waters on Friday — in the area and cloud cover in place. Overrunning moisture will help contribute to a few showers on Thursday with more coverage Friday depending on where low pressure develops offshore. This, in turn, will help keep temperatures suppressed at or below 60° for Thursday and Friday. The last time we had a high below 60° was April 2nd, when the high topped out at a balmy 53°.

More on a significant coastal flooding threat thursday and Friday »

One more day in the 70s on Tuesday before we cool off

/ November 1, 2021 at 7:58 PM

We’ve got one more really nice day on Tuesday before temperatures begin to fall back off into sweater weather territory. (Not that there’s anything wrong with that.) Expect highs to top out in the mid-70s after starting around 50° in the morning with mostly sunny skies throughout. We’ll begin to cool off after Tuesday as high pressure wedges southward into the area; highs don’t get out of the 60s on Wednesday and Thursday, and might not even crack 60° on Friday.

After the jump: Latest on the coastal flooding threat »

The week ahead: Sweaters and salt water flooding

/ October 31, 2021 at 9:35 PM

If the random few shots of cool weather in the past few weeks haven’t gotten you to extract your fall attire just yet, you’re going to want to get on that by the end of this week as prolonged below-normal temperatures are in the cards. Indeed, the air is going to take on quite a November feel (though one more characteristic of late November than the beginning) by the weekend. While you’re grabbing the sweaters, though, you might want to reach for the waders, as well, with moderate to major salt water flooding possible around times of high tide by the end of the week.

Read more »

Seasonally-appropriate weather will close out October

/ October 29, 2021 at 7:47 PM

The potent upper low which helped drive through a front with heavy rain and gusty winds yesterday remains over the Southeast through this weekend, keeping temperatures on the cool side and cloud cover a little elevated, particularly on Saturday. We’re very likely not to get out of the upper 60s on Saturday given the mix of clouds and sun that’s expected. (You might want a sweater, at least for a bit!)

Sunday will run a touch warmer and a little sunnier, too, making for a rather pleasant Halloween free of weather-related frights. Nice weather on a warming trend looks to continue for the first few days of November, too. Enjoy your weekend!

Friday & the weekend: Drying out, cooling off

/ October 28, 2021 at 9:30 PM

After some lingering showers clear the area Friday morning, we will head into the weekend with quite seasonable weather to close out October. Friday looks to be another breezy day across the area as low pressure in the Tennessee Valley lumbers northeastward. A shower or two can’t be totally ruled out in spots on Friday afternoon, but the chances are relatively small. Same for Saturday, as a mix of sun and clouds keeps highs in the mid-to-upper 60s across the area with a stray shower or two possible (but unlikely). Expect more sun for Halloween as high pressure begins to reassert itself a little bit and drier air takes hold over the area. Trick-or-treating will be in fine shape (weather-wise, at least). Be safe and enjoy!

Strong storms possible Thursday afternoon and evening, but uncertainty remains

/ October 27, 2021 at 5:58 PM

We’ll start Thursday much as we started today — a mix of sun and cloud cover with a bit of a chill in the air as lows bottom out in the low 50s. We look to end it with widespread rain with embedded thunderstorms, a few of which could be strong to severe, as a potent upper low and associated cold front approach the Lowcountry.

The severe weather threat on Thursday is certainly not a slam-dunk, but there are some concerning signals. First, there’s going to be plenty of wind energy available. A low-level jet of 55-65 MPH winds around 3,500 up looks to traverse the area in the afternoon and evening hours. This will help promote gusty winds throughout the day, even ahead of thunderstorms. Second, winds are veering with height, with southeasterly surface winds turning southerly and then southwesterly as you go up. This wind shear helps sustain thunderstorm updrafts and also can induce spin within stronger storms. Third, there is the potential for instability to spread into the area as a warm front passes by in the evening. However, instability is the biggest question mark given cloud cover and rain ahead of the storms, which often helps to tamp down on this “storm fuel” and, as a result, decreases the severe weather risk.

Ultimately, we will need to keep an eye on how things evolve tomorrow. If that instability does materialize as some of the guidance suggests it will, a few thunderstorms will be able to pull down some strong, potentially damaging winds. Given the spin in the atmosphere, a tornado or two is not out of the cards, either. Our best risk for severe weather appears timed between 4 and 10 PM, according to NWS, with the latter end of the timeline looking the most likely for SC. Stay weather-aware tomorrow and make sure you have multiple, redundant weather warning sources.

Rest of the work week: Crisp Wednesday yields to a stormy Thursday

/ October 26, 2021 at 8:39 PM

Wednesday will be another pleasant weather day. We’re going to get off to a chilly start with lows in the 40s across the area away from the locally warmer coastline. Temperatures will top out in the low 70s, and it’ll feel good in the sun.

As we head into Thursday afternoon and evening, we will want to watch the risk for heavy rain with the potential for a few strong to severe thunderstorms. Damaging wind gusts will be the primary concern, but the forecast wind profiles are such that a tornado cannot be totally ruled out. We’ll need to see how much instability can develop — the less instability, the better. Stay tuned to forecast updates.

The upper-level low that will help to drive Thursday’s severe threat will linger into Friday, keeping clouds and perhaps a few showers in the forecast. Temperatures won’t top out much higher than 70° on Friday afternoon.

Good news, though: The weekend looks good with sweater weather on Saturday, and Halloween is very much game on with picture-perfect weather to close out October.

Tuesday: Turning cooler and more sunny

/ October 25, 2021 at 8:56 PM

A cold front will come through early Tuesday, and with it will be a shot of cooler and drier air that will make for a pleasant day across the Lowcountry. We’ll start the day in the low 60s with highs rising to the mid-70s under mostly sunny skies. Overall, a really good day to get lunch outside if you can.

We’ll see a similar weather day on Wednesday with a cooler start (40s look possible in many spots). Thursday continues to look unsettled as a potent storm system approaches the area. Rain, heavy at times, will be the main concern, though a couple stronger storms are possible as well. We keep showers around on Friday as a lumbering upper low swings through the area before gradual clearing into the weekend.