There’s not too much to write home about weather-wise for Tuesday other than it will be a really nice mid-September day across the Lowcountry. Below-normal temperatures continue, with lows in the low 60s warming to the low 80s in the afternoon under mostly sunny skies. Dewpoints mix down to the mid-50s in the afternoon, making the warmth comfortable. Plus, water levels will fall short of flood stage Tuesday as we get further away from the full moon and the recent perigee, so there are no coastal flooding concerns for the rest of the week, either.
The week ahead will remain generally quiet, but we’ll start to turn warmer later this week as high pressure ridges in aloft. Slight shower and storm chances return to the area for the weekend, particularly on Sunday.
A front which helped stir up another round of heavy rain and flooding in downtown Charleston on Sunday will clear the area overnight into early Monday, yielding a week of comfortable temperatures with occasional slight shower and storm chances.
After a few welcome rain-free days, shower and storm chances return to the forecast for Sunday as a cold front moves into the area. We’ll start the day in the low 70s, working our way into the upper 80s in the afternoon before showers and storms kick off. Some rain could be heavy at times, and lightning may be an issue particularly inland where some stronger storms may be possible. It won’t be an all-day rainout, thankfully, but you’ll want to have your indoor plans ready to go if thunderstorms approach.
Isolated salt water flooding may also be a concern around the 7:47 PM high tide. The current total water level forecast brings the tide right to around 7′, which may be enough to cause a little flooding on the most vulnerable roads in downtown Charleston. The risk for coastal flooding around times of high tide increase throughout the first part of the week with the combination of the full moon, lunar perigee, and northeasterly winds in the wake of Sunday’s front, so stay tuned for Coastal Flood Advisories from the National Weather Service.
Warmer and a little more humid air will return to the area Friday as winds go more southerly. With high pressure remaining in control for a few more days, though, we’ll stay largely quiet weather-wise this weekend before a front starts to affect the area later Sunday.
We’ll start to turn a little warmer on Thursday as high pressure to the northeast breaks down a bit, but we should still get one more good day of low humidity in before we start to see dewpoints begin to climb back toward 70° starting Friday. Temperatures on Thursday start quite comfortably once again, with mid-60s the general rule across much of the area. We’ll warm to the upper 80s on Thursday afternoon with plenty of sunshine. The only fly in the ointment may be some very minor coastal flooding around the 6:19 PM high tide, with water levels currently forecast just below 7′. If water levels trend a little higher, a Coastal Flood Advisory may be issued. Otherwise, though, it’ll be another really nice early September day in the Lowcountry.
The rest of the work week will remain generally quiet (weather-wise, anyway), as high pressure remains in control at the surface. Temperatures will be on a warming trend as we get over the hump and into the second half of the work week as the mid-level trough that’s kept us on the cool side flattens out and retreats a bit north. We’ll also start to see high pressure build back in from the Atlantic for a few days, which turns the flow at the surface more southerly and starts to bring that more warm and humid air back to the area. We’re in the mid-80s Wednesday, upper 80s Thursday, and likely back to around 90° on Friday, with lows steadily climbing with the dewpoints back to around 70° by Friday morning. However, we look to stay rain-free through about Saturday before another front approaches for late weekend/early next week.
Friday and the weekend will be on the unsettled side as a front stalls out nearby. Waves of low pressure developing along the front will help to tap into resurgent tropical moisture, and given how soggy it’s been this month, it won’t take terribly much for flooding to develop. Thus, a Flood Watch will go into effect at 8am Friday, lasting into late Saturday night/early Sunday morning. We’ll want to pay close attention around the evening high tides on Friday and Saturday, as water levels in Charleston Harbor will remain elevated in the wake of Hurricane Erin. Salt water flooding looks like a good bet, and any heavy rain on top of that would cause widespread issues in downtown Charleston. Keep an ear out for flood alerts from the National Weather Service, especially for Flash Flood Warnings, as they may become necessary over the next few days.
The upside to this is that temperatures will run below normal. Highs on Friday should only top out in the mid-80s, while Saturday’s high may only climb to the low 80s. We’ll warm up a little on Sunday as the periods of heavy rain should taper off, but highs in the mid-80s still run a few clicks below the normal high of 89° this time of year.
Thursday will be another warm day across the Lowcountry, with lows in the mid-70s warming to the low-to-mid-90s in the afternoon. Heat indices will run in the upper 90s to perhaps 100° in spots under generally partly cloudy skies. We should start to see cloud cover begin to thicken a bit as we get into the afternoon and evening hours, though, with rain chances increasing as Hurricane Erin accelerates to the northeast and a cold front drives south into the area, stalling out as it gets to our south.
After an uncharacteristically quiet Monday (weather-wise, anyway), Tuesday should feature a few more storms as a little energy aloft moves through and interacts with the afternoon seabreeze. Temperatures start in the mid-70s, warming to the upper 80s to around 90° before thunderstorms disrupt the temperature curve for some of us. Models do indicate some isolated heavy downpours, though with less in the way of deep moisture, the flooding threat shouldn’t be terribly high.
