Sunday will be a much more traditional warm and somewhat muggy June day across the Lowcountry than we’ve felt for much of the month, really. We start the day in the low 70s before temperatures warm into the low 90s under mostly sunny skies. Kick in some humidity and it’ll feel closer to 95° in the afternoon at peak heating. It looks quite unlikely that a shower or storm will develop, though it can never be totally ruled out in the summertime. Suspect it’ll be another day full of Instagram stories from the beach. Use that sunscreen as the UV index will be a solid 10.
Wednesday could be a busy weather day here in the Lowcountry as a very dynamic storm system moves into the eastern half of the continental US, dragging a cold front through the Southeast throughout the day with showers and thunderstorms ahead of it.
We have a potentially very busy 18-24 hours of weather ahead as Tropical Storm Nicole makes the turn to the north and the northeast overnight into Friday, keeping us on the “dirty” side of the storm. The main concern is overwhelmingly the threat for tornadoes overnight. A Tornado Watch is in effect until 1am, and it wouldn’t be surprising to see it extend even beyond that. Secondary to this will be the continued risk for heavy and potentially flooding rain at times, with gusty winds also a concern.
Nicole’s roughest weather arrives tomorrow and will last through Friday afternoon before improvement sets in just in time for the weekend. Heavy rain, gusty winds, tidal flooding, and a few tornadoes are all on the table with this event. Here’s what to expect.
We have a busy few days of weather ahead of us as Tropical Storm Nicole makes landfall on Florida, perhaps as a hurricane, and then turns north and northeast to strafe the Carolinas with heavy rain, wind, and maybe even some severe weather.
We are breezy but rain-free this evening as dry high pressure remains in control of our weather. It will hang on for a bit for the first part of Thursday, but a gradual deterioration in weather will begin in the afternoon. It’s a good time to finish gathering supplies for a rough period of weather beginning later Thursday through Saturday morning.
A vigorous complex of showers and thunderstorms will traverse the Southeast tomorrow, arriving here in the Lowcountry around early evening with a risk of damaging wind gusts and a tornado or two.
Tuesday’s severe weather potential has a little different feel in that there’s a good chance more instability will be available ahead of the line, as it should be coming through right in that sweet spot time of 5-10 PM or so. (Stay tuned for inevitable tweaks to exact timings as the storm system gets underway.) Wind shear is plentiful, on the order of 50-60 knots, and if thunderstorm updrafts can take advantage of instability rooted in the surface, there will be plenty of available energy for strong to severe thunderstorms. (More on this in a sec, though.) Despite expected cloud cover, the heat pump is on, and warm and moist air will flow into the area readily during the day, allowing for highs near 80°. Winds outside of thunderstorms will once again be gusty as well, with gusts 30+ MPH not out of the question particularly on elevated surfaces.
Damaging straight-line wind gusts are certainly the main concern, with probabilities high enough to drive an Enhanced (level 3 out of 5) risk in tomorrow’s severe weather outlook. However, tornadoes will be possible with any discrete storms as well as embedded within a squall line (if that ends up being the storm mode).
There are possible failure modes here, though. Forecast soundings from this evening’s models do show some capping trying to hold across the Charleston metro with an inversion a few thousand feet up and dry air entrainment trying to put a damper on an even more unstable environment. This could act as a governor on a more substantially widespread severe threat. We can’t bank on this, though, especially as wind shear remains strong enough to keep thunderstorm updrafts healthy.
Bottom line: Be ready for possible watches and warnings tomorrow. Keep weather radios in the alerting position and phones charged. Know what you’ll do if a warning is issued for your area. If you live in a mobile home, be thinking carefully about where you’ll go if severe weather threatens. Damaging winds, tornadoes, and mobile homes can be a tragic mix. A site-built structure will give you more protection in situations like these.
With any luck, we’ll see another round of storms fizzle out as it reaches Charleston. But if that doesn’t happen, you’ll be glad you were prepared.
We’ve gotten off to a fairly benign start here in the Lowcountry, but that may change later today as a cold front approaches. Temperatures as of this writing are in the low 70s already with dewpoints in the low to mid-60s, pretty ripe for this time of year. Cloud cover has ticked up somewhat in part due to anvil blow-off from some thunderstorms already firing in southeast Georgia. Winds have also ticked up some, with a gust to 23 MPH recorded at the airport as of the 10am observation.
High temperatures across the Charleston metro should top out in the mid-to-upper 70s this afternoon before the cold front gets closer to the area. It’s this surface feature, currently moving across Georgia and into upstate South Carolina, which should provide the needed lift to allow for scattered thunderstorm development this afternoon. Wind shear and instability will not be lacking, and with some capping in place limiting more widespread development to start, storms could initially start off as supercells, increasing the severe weather threat. The strongest storms will be capable of damaging straight-line wind gusts and large hail. A tornado can’t be ruled out, particularly where storms interact with the seabreeze, which is forecast to be near the coast for much of the day. Given strong SW winds keeping the seabreeze pinned to the coast, it is unlikely that cooler waters will have a significant impact on storm strength.
Given the initially isolated nature of these thunderstorms and the timing of the cap breaking, it’s going to be very tough to pinpoint who exactly will see storms and when. General thinking, according to NWS, is that the greatest risk of thunderstorms will generally run between 3-9 PM. Trying to pin down too much more detail may be foolhardy without clairvoyance beyond what the science can provide.
Today’s advice is familiar: Stay close to reliable, redundant weather warning sources, one of which should not be your smartphone. NOAA Weather Radio and broadcast stations are two great ways to fulfill this recommendation. Not everyone will see severe weather today — perhaps, deity of your choice willing, none of us will! — but if it does threaten your location, you’ll want to be prepared to receive that warning and take action on it by having a safe space indoors, away from windows.
Saturday could be a bit of a wild day of weather across the Lowcountry. We’ll start with a strong cold front bringing a risk for strong to severe thunderstorms in the morning, and we’ll finish with Arctic air rushing into the area, leading to a hard freeze for many of us Sunday morning.
Temperatures will once again reach the mid-90s this afternoon across the area (fun fact: yesterday was the first 95° day all year at the airport). Combined with moisture-laden air characterized by dewpoints near 80°, this will once again drive the risk for excessive heat indices upwards of 115° near the coast, where an Excessive Heat Warning is in effect for today. For the inland counties, a Heat Advisory will be in effect with heat indices approaching 110°. Regardless of whether you are in the advisory or warning area today, you’ll want to take precautions against heat illness if you must be outside during the afternoon.
Showers and thunderstorms look to initiate a little later in the day than we saw yesterday, with the best risk of storms coming in the late afternoon and early evening hours. Models suggest a line of thunderstorms could develop and move across the area today. Timing is always a question mark, but I would be on guard for storms starting about 3-4 PM, with the earlier timeframe the further north and west you are. Available energy will be abundant with such strong surface heating and moist dewpoints. Thus, a few storms could be on the strong to severe side with damaging wind gusts, but frequent cloud-to-surface lightning and pockets of heavy rain remain the overwhelming concern from any storms that form this afternoon.
A cold front looks to get close to the area tonight. This will help shut off the oppressive heat of the last few days, but at the cost of another few days of on and off heavy, flooding rainfall. Will have more on the upcoming week later this evening.
