We’ll start this new work week rainy and warm ahead of a cold front. NWS is forecasting 1-2″ of rain for most of us through early Wednesday before the front swings through. And once that front swings through, what a difference — humidity will get knocked back down a peg and we’ll get into a really nice fall-like pattern to start October with highs in the 70s and lows generally in the 50s away from the coast.
Keep an eye on Tuesday’s forecast. As the cold front swings through with low pressure riding just to the north, there will be a chance for a couple strong storms. Right now, widespread severe weather is not expected. We’ll keep an eye on it.
Otherwise, make sure your hoodies and other light jackets are present and accounted for as we turn nice and crisp heading into next weekend!
We’ll start the week off continuing our taste of fall, with highs running in the mid-70s and lows in the mid-50s — the coolest since mid-May — expected through Wednesday. We’ll also continue to take a break from the rain for a few days as high pressure continues to build overhead. Coastal flooding will remain a concern with Monday and Tuesday’s high tides, with major flooding possible with the high tide cycles on Monday before gradually diminishing on Tuesday. By Wednesday, the coastal flooding risk will have ended.
As we get later into the week, we’ll see some moisture stream into the area courtesy of the remnants of Tropical Storm Beta. This could instigate a few showers at times as we head into the weekend. We’ll also see an uptick in temperatures and humidity as well, but we’ll stay right around normal for late September, so don’t expect anything too heinous.
If you step outside this morning, you’ll notice a welcome lack of humidity as high pressure wedges in from the north, drying out the air at the surface (though cloud cover will remain in place today thanks to some moisture trapped between 4-6,000 feet as well as some upper-level energy that will stir up high cloud cover later today). Dewpoints this morning were running well into the low 60s, with even a reading of 59° at Charleston International Airport at 8am.
Unfortunately, this surge of Fall weather will also come with several rounds of major coastal flooding this weekend into early next week.
So the first thing you will undoubtedly notice in the seven-day is that it is largely bereft of 90s (save for Monday). You may also notice a high of 79° for Sunday. Yes, that’s out there a ways and could still be tweaked upward, but it is just refreshing to see 70s for highs somewhere in the forecast. We’ll need to deal with some rain and coastal flooding to get here, though.
It’s been a minute since we’ve needed to take a critical look at the Atlantic here on this site, but that does not mean things have not been busy. Undoubtedly, if you’ve been following the Atlantic season via the National Hurricane Center or other outlets, you are aware of just how active this hurricane season has continued to be. Let’s recap:
Hurricane Laura making landfall just shy of Category 5 status on Lake Charles, Louisiana, causing significant damage;
Hurricane Marco, which was fortunately not the initial punch ahead of Laura that forecasters had feared;
Tropical Storm Omar, which spent several days battling wind shear as it meandered harmly out to sea before dissipating
Now, we have Tropical Storm Paulette and Tropical Storm Rene far out in the Atlantic, in addition to two areas being monitored for potential development over the next five days. One of these areas is well off of Africa, but the other is somewhat close to home. We’ll talk about that in a sec.
While meteorological fall begins on September 1, summer will blaze on in the Lowcountry over the next several days as we remain within a warm and humid airmass. Showers and thunderstorms will be possible each afternoon along the seabreeze and other outflow boundaries generated by thunderstorm activity. As we head toward the weekend, a nearby frontal boundary could aid in additional showers and thunderstorms. We could see temperatures come down a little bit for Sunday as winds turn more onshore, but showers and storms remain in the forecast.
After what was an uncharacteristically wet and cloudy weekend across the Lowcountry, we will gradually move back into a more typical late-summer regime of afternoon thunderstorms and temperatures reaching the low 90s for the upcoming work week. But first, we’ll need to deal with a higher-than-normal risk for additional showers and thunderstorms on Monday, with potentially heavy rain having impacts starting early in the morning.
We continue to watch Hurricane Marco and Tropical Storm Laura as they continue on an unfortunate course to delivering a 1-2 tropical punch to parts of the Gulf Coast next week. Aside from some enhanced moisture funneling into the area from the storms around the western side of the Atlantic ridge through Monday, it does not appear that Marco or Laura will have any impacts in our area. We are now in the peak of the season, though, and we’ll want to keep a close eye on any waves that meander into the Atlantic from Africa for development over the next few weeks. Stay tuned…
After a brief respite from suffocating humidity today — the overnight temperature dropped to 69°, according to NWS, the coolest since June 20’s low of 67° — we will see rain chances return to the forecast as the upper trough which has kept things quite unsettled remains in place for the next few days. Brief bouts of heavy rain will be possible once again, but it won’t rain all the time or even every day at one particular spot. As we get into the weekend, Atlantic high pressure looks to build back into the area, which will help tamp down the overall coverage of storms (and begin sending temperatures back upwards a bit).
High pressure in the Atlantic and low pressure inland will keep the squeeze on for showers and thunderstorms each afternoon this week. Temperatures will top out in the upper 80s to around 90° each day before the onset of thunderstorms cools some of us down.
Thunderstorms will move slowly and thus have the potential to put down some pretty good rainfall, especially as we start the week, so be ready for localized flooding where storms set up. Lightning will certainly be a hazard as well, but the threat for severe weather otherwise remains low (though a wet microburst can never be ruled out).
After Isaias, we find ourselves back in a wetter-than-normal summertime regime, with scattered thunderstorms possible each day as we remain under a trough of low pressure aloft. Plenty of atmospheric moisture will remain in place, allowing for heavy rain in any thunderstorms that develop. Be on the lookout for plentiful lightning, too, with the occasional storm turning severe with strong downburst winds.
Temperatures will remain generally around where they should be in early August: Upper 80s to low 90s. Mix in the humidity and heat indices in the 100s will be routine, with dangerous heat indices around 105° possible for Thursday and Friday.
@chswx is community-supported, hype-averse weather information, preparedness tips, and alerts for the Charleston, SC Tri-County area (Berkeley, Charleston, Dorchester counties) by Jared Smith.