Jared Smith founded @chswx on Twitter in 2008 as an experiment in disseminating weather data through social media. In the ensuing decade-and-a-half, @chswx has provided live coverage of tropical cyclones, tornadoes, severe weather, and even a couple bouts of winter weather to the good people of Charleston, SC.
After a raucous night with Tropical Storm Elsa, we find ourselves in a lull this morning as the storm lifts quickly away to the northeast. Winds are slackening and we are drying out after a very soggy night — 4” is on the low end of rain totals around parts of the Charleston metro area. I’ll discuss more of Elsa’s aftermath later today as damage is assessed and additional rain totals come in.
For now, though, we get a bit of a break, but showers and thunderstorms are expected to fire back up this afternoon as a little energy aloft ripples through and induces some additional development with a little daytime heating. The good news is that additional severe weather is not expected. Rainfall amounts should generally be around a quarter-inch.
Highs top out in the mid-80s; the humidity will make it feel in the 90s.
We continue to monitor Tropical Storm Elsa as it moves through southeast Georgia overnight tonight. A Tornado Watch is in effect until 5am across the Lowcountry. The primary concern for tornadoes will be a strong feeder band that is moving north of Savannah into far southern SC as of this writing. It looks like this band will move into the Charleston metro area in the 1-3am timeframe. This band will produce the heaviest rainfall — observers have measured 3”/hr rain rates from this band in Georgia — and provide the best opportunity for an isolated tornado over the next few hours. Discrete cells ahead of this band could also briefly produce tornadoes.
The weather spotlight turns sharply onto Hurricane Elsa as it becomes the primary weather-maker for our neck of the woods through Thursday evening. Based on the current National Hurricane Center track, it looks as if the bulk of the bad weather associated with Elsa will arrive later Wednesday, with periods of very heavy rain being the overwhelming concern through Thursday morning.
After a remarkably dry Independence Day weekend, we will get back to work and a somewhat more familiar July weather pattern on Tuesday as tropical moisture ahead of Elsa begins to spread northward into the area, enhancing shower and thunderstorm chances in the afternoon. Temperatures will top out in the upper 80s to near 90°, and humidity will push heat indices into the mid-90s. We in #chswx do not expect any direct impacts from Elsa on Tuesday, but it is possible that there will be at least a Tropical Storm Watch put in place by then, so don’t be shocked if one is issued.
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.
This is going to be one of the better Independence Days for weather in the Lowcountry thanks to an exceedingly rare cold front that came through this morning. Tomorrow will be warm, for sure — highs topping out around 90° away from the beaches — but the humidity (or lack thereof) will be the real story. NWS forecast dewpoints are in the low to mid-60s, which is almost unheard of around here in July. Drier air throughout the atmosphere will keep cloud cover to a minimum, making for a fantastic outdoors day across the Lowcountry. Don’t forget the sunscreen and be safe going to the beach!
Rainfall this evening has thankfully been a little tamer than forecast, with the bulk of the heaviest rain developing just offshore this afternoon. We will still see a few showers later this evening and overnight, particularly as the cold front currently draped across the Midlands sinks into the area.
Said front will move well south of the area by tomorrow morning, and skies will clear in its wake, yielding what looks to be an excellent Fourth of July weekend. Temperatures will run in the upper 80s to around 90° each day through Monday, with mostly sunny skies for Saturday and Sunday. We may see a couple storms pop on the seabreeze on Monday, but most of us will stay dry. Then after that, we turn to Elsa.
After a couple days in a classic summertime Bermuda High setup, we’ll see that high continue to retrograde eastward, giving way to a cold front sinking south from the Ohio Valley. Said front will run into an incredibly juicy airmass courtesy of a robust moisture tap from the Gulf, and help to ignite numerous showers and thunderstorms in the afternoon. This will have the effect of holding temperatures down into the mid-80s.
We’ve got a warm Thursday in store ahead of a cold front that will make for an unsettled Friday. Temperatures will run in the upper 80s away from the locally cooler coastline, and the humidity will make it feel well into the mid-90s. There will be a slight chance of showers and storms around midday as the seabreeze pushes inland, but that’s about it.
Friday will be a much different story as showers and thunderstorms become pervasive across the area ahead of a stalling cold front. This activity looks to continue into Saturday, but storm chances diminish significantly as we get into the Fourth. There’s still uncertainty here around the positioning of the front and the ultimate sensible weather outcome for the Charleston Metro Area, so I continue to encourage y’all to keep an eye on forecast updates as we head into the long holiday weekend.
The rest of the work week will feature generally isolated to scattered shower and thunderstorm coverage ahead of a cold front that will stall in the area for Friday into Saturday, bringing greater coverage of unsettled weather (and possibly a low risk of severe weather on Friday). Thereafter, said front introduces a good bit of uncertainty into the forecast.
A Bermuda high will stay in force for Wednesday into Thursday. This will generally keep onshore flow in place, allowing occasional showers and storms to stream into the area from the Atlantic particularly in the morning hours before the seabreeze focuses additional showers and storms inland during the afternoon. Reasonably good atmospheric moisture is in place, allowing a few showers or storms to perhaps generate some locally heavy rainfall, especially where outflow boundaries collide. Temperatures will generally run in the upper 80s away from the coast.
As we get into Friday, a cold front will approach from the northwest in association with a trough of low pressure aloft. This will focus more numerous showers and thunderstorms particularly as we get into the evening. Model soundings suggest some wind shear sufficient for organizing a strong to severe storm or two, so we’ll want to keep an eye on these details as they evolve. Additionally, the Gulf will be open for business with the trough helping to draw more moisture into the area (precipitable water values exceeding 2″ for the geeks out there), so areas of heavy rainfall will certainly be possible. Ahead of the front, temperatures will still flirt with 90° before showers and storms increase in coverage.
Forecast becomes more uncertain heading into the Fourth
The aforementioned cold front will stall out somewhere nearby on Saturday, and this is where a fair bit of forecast uncertainty begins to come into play. Depending on where the front sets up, we could have a warm and fairly dry Fourth, or we might keep some more humidity, showers, and thunderstorms in the forecast. Today’s global model runs were trending a little drier, but one should never put much faith in a stalling cold front in our neck of the woods in July. My advice right now: Stay tuned to forecast updates as the details flesh out a little more.
