After a very rare weekend of relatively low humidity (for late July, anyway) we’ll see dewpoints return to the low to mid-70s as tropical moisture builds back into the area. Monday will feature isolated showers and thunderstorms primarily driven by the seabreeze, but as we get into Tuesday and Wednesday, a low pressure system — labeled by the National Hurricane Center as Invest 90L with a 50% chance of tropical development — will be approaching the coastline as we get into mid-week. Regardless of what it ends up doing from a tropical standpoint, it will enhance our shower and thunderstorm chances Tuesday and Wednesday, particularly in the afternoons. Temperatures will top out in the low 90s each day.
As we get closer to the end of the week, the strong high pressure over the central US noses its way into the eastern US. This, in turn, will drive down rain chances and drive up temperatures. Temperatures should top out in the mid-90s Thursday and Friday.
Owing to just how “mild” this summer has actually been, the hottest it’s been this year is 94°, which we’ve reached three times (twice in May and last on June 15). If Friday’s forecast of 96° verifies, that will be the warmest we’ve been all year.
By the weekend, we could see an uptick again in showers and thunderstorms as the ridge backs off a little bit and we get underneath some northwest flow aloft. NWS noted in its afternoon discussion that this could open up the pathway for summer thunderstorm complexes — the technical term for which is “mesoscale convective system” — to roar through the area starting this weekend. Something to watch, but nothing we need to be overly concerned about right now.
We’ll be getting this work week off to a wet start. Showers and thunderstorms will be commonplace as upper level energy combines with a stalling surface front and copious amounts of atmospheric moisture especially Monday afternoon into Tuesday. Heavy rain is certainly a concern, and we will want to monitor the risk for sporadic freshwater flooding episodes closely. Clouds and rain look to keep highs down into the mid-to-upper 80s, a few degrees below normal for this point in July.
As we get into Wednesday, we begin to see this soggier pattern break down and a more standard summertime regime returning to the area. We are back in the 90s by Thursday with more scattered coverage of showers and thunderstorms primarily in the afternoons heading into the weekend.
For the first time in three weeks, we do not have any concerns about a tropical cyclone influencing our forecast. Hooray! We’ll have a much more typical July week of weather ahead featuring temperatures around 90° each afternoon and a chance for isolated to scattered storms pretty much each day, mostly in the afternoons (though Monday could get started and end a little earlier). The only severe weather that might occur this week would be where thunderstorm outflow boundaries interact and enhance lift, perhaps bringing a brief damaging wind threat via downburst winds. Atlantic high pressure building across the area will otherwise put a lid on more widespread shower and thunderstorm activity.
Southerly winds around the high will give us a little bit of an onshore component to the wind, which will help regulate temperatures to near normal levels. We won’t be able to escape the 70s dewpoints, though, so be ready for heat indices in the upper 90s to near 100°, especially around the time the seabreeze circulation passes your location.
We get one more rain-free day on Monday to close out the observance of Independence Day before moisture and unsettled weather return to the picture. Much of this will be influenced by the eventual track and strength of Elsa, which as of the 5PM advisory, is currently forecast to be a depression as it traverses the area sometime Wednesday into Thursday (more on that in a sec). Overall, get ready for periods of showers and thunderstorms with heavy rain and temperatures right at or a little below normal each afternoon, particularly in the middle of the week as Elsa gets involved with the forecast.
As of about 9PM, Claudette’s center was moving eastward across northern parts of South Carolina. The exact center fix is a little murky, but radar suggests that as of this writing it is roughly riding the SC/NC border around Chesterfield County, SC. The leading edge of Claudette’s primary rain band has cleared downtown Charleston and is headed offshore, with light to moderate rain behind it. This rain band appears to have cleared downtown with relatively little fanfare, but winds have been gusting quite a bit, with a recent gust to 62 MPH recorded at the Isle of Palms WeatherFlow station.
Light to moderate rains look to continue for the next few hours as the primary rain band swings through the area. It appears that there could be additional showers and thunderstorms behind it; these are moving southeastward out of Augusta and could swing around into the Tri-County before it’s all said and done. A Flash Flood Watch continues across the Charleston Metro Area effective until 8am Monday, though this may yet be canceled early once this band lifts out.
The risk for severe weather (particularly the tornado threat) has ended across our area at this point. With the center directly to the north, surface winds coming out of the west lowering shear, and instability having been sapped by the rain band, the environment is not really conducive to tornado formation anymore. We caught a break with this today, especially considering the ample sunshine we saw for a good bit of the day to aid destabilization. Still, straight-line gusts of 40-50 MPH across saturated grounds could still be sufficient for downed trees and power lines, so keep flashlights nearby in case of power outages.
After a very soggy weekend, we will get the opportunity to dry out a bit as the deep moisture plume which has been in place for the last few days finally gets shunted away from the area. This week is going to be pretty standard June fare: highs in the upper 80s to low 90s with a chance of isolated afternoon thunderstorms will be common. Thursday and Friday will be a touch cooler and drier in the wake of another front moving south of the area, and this could put the kibosh on even slight chances of afternoon showers and storms (though you can never totally rule it out at this point in the year). Expect slight shower and storm chances to return for the weekend as a little more moisture gets fed our direction from the Gulf.
We’re getting into “copy-paste season,” when the summertime weather pattern is such that you’ll be pretty much on point with upper 80s to low 90s and a 20% chance of storms each afternoon. Of course, much more science goes into the forecast than that, but it goes to show just how static the pattern looks to be for the next few days. As is customary in summer, showers and thunderstorms will be isolated to scattered in nature. It will not rain everywhere, and it will not rain all day. It will be impossible to say with much certainty where storms will form, and if we are lucky to get clues as to where thunderstorms may initiate, we won’t have a lot of lead time.
Temperatures will start around normal before creeping up into the 90s by the weekend. Combined with humidity, that may yield our first 100°+ heat indices of the season, so that’s something you’ll want to plan for if you have outdoor activities scheduled.
Welcome to summer, folks. (Meteorological summer started on June 1; the summer solstice will take place on June 20.)
The upcoming work week will feature temperatures right in line with what we would expect from the third week in May with low-to-mid-80s quite common away from the coast. Humidity will be creeping up a little bit beyond Monday, which will be felt primarily through slightly warmer low temperatures in the low 60s. Keep the sprinklers on standby throughout the week as you’re going to need them with dry weather expected for the next seven days thanks to high pressure at the surface and aloft keeping a lid on afternoon convection. This will expand on this spring’s rainfall deficit, which stands at 2.19″ at publish time. (We are hanging on to a 0.66″ surplus for the year, but this should be erased by the end of this week.)
As we reach the weekend, we’ll start to see the heat kick up a notch as the ridge aloft strengthens. The first 90° temperature at the airport in 2021 should be achieved by Sunday; if this ends up being the case, it’d be the latest first 90° day since 2005. Dewpoints in the low 60s will keep heat indices in check for now, but it’s only a matter of time before the humidity begins to kick in.
After an excellent weekend of weather, we’re back into a bit of an unsettled pattern for the work week. Monday should be mostly dry to start, but showers and thunderstorms will be possible in the afternoon as mid-level energy works its way through the area. Highs will top out in the mid-80s with humidity making it feel a little warmer.
We’ll begin to see a frontal boundary sink into the area on Tuesday, bringing another chance for scattered showers and thunderstorms throughout the day. As the front sinks southward, a wedge of high pressure will begin to build in from the north and northeast, spelling a chilly (by mid-May standards) couple days for Wednesday and Thursday with highs only topping out in the mid-to-upper 60s. Rain looks likely as moisture overruns the wedge, and we sure could still use it as abnormally dry conditions persist across the Lowcountry.
By Friday, we begin to see drier high pressure reassert itself. Rain chances will remain with us especially in the morning before clearing the way for another gorgeous weekend of weather. (I like it when the pattern works out like this!)
Get ready for a very summer-like start to your week. High pressure slipping into the Atlantic with a little ridging aloft will keep us warm — dare I say it, hot — and humid for the first part of the week. Showers and thunderstorms will be possible each day through Thursday before a cold front swings through with drier air and more pleasant temperatures for the weekend.