Tuesday will be another steamy July day in the Lowcountry. We’ll start the day in the mid-to-upper 70s in much of the metro area, while the beaches and downtown may very well not get below 80°. Highs will climb into the low 90s; mix in the humidity and it’ll feel closer to the low 100s. Unlike the past few days, showers and thunderstorms should hold off until the afternoon. As always, a strong storm or two can’t totally be ruled out, with wet microbursts a possibility. More broadly, though, heavy rain will be possible as precipitable water values remain around 2”, and ample amounts of energy will be conducive to lightning-laden storms.
We’ll stay in the 90s for much of the rest of the week, with heat indices approaching 105° at times. Scattered afternoon showers and storms will be the rule, with perhaps a little uptick in activity heading toward Friday as a front approaches the area.
Another front will be approaching the area on Thursday, and this will bring a renewed round of heavy showers and thunderstorms in the afternoon and evening hours, one or two of which could be on the strong to severe side with damaging wind gusts. The main concern, though, will be the potential for very heavy rain. We’ve gotten pretty waterlogged in the past few weeks, and continued heavy rain on top of it will lend itself to the risk of some flooding.
It will be another sauna day, with highs topping out around 90° and heat indices rising into the low 100s thanks to the continued stifling humidity that’s blanketed our neck of the woods for the better part of July. The heat and humidity should help fuel-wise for showers and thunderstorms in the afternoon.
After an absolutely delightful break from the heat today — as of this writing, today’s high was 80°, putting us on track to break the record low maximum temperature of 81° set in 1972 — we return to a little more reality for Tuesday as the wedge of high pressure in place today breaks down and the stationary front washes out. Air temperatures will approach 90° in the afternoon, and with the humidity in place, it’ll feel closer to 100°.
Showers and thunderstorms will be a possibility throughout the day, with the best chance in the afternoon. It wouldn’t be shocking to see a few storms earlier in the morning, though, based on some of the high-resolution guidance. In particular, the HRRR depicts a cluster of storms moving northeastward through the Tri-County in the morning, and the NAM 3km gives some support to this idea as well. We’ll want to keep an eye on that for commute-time downpours. Otherwise, the seabreeze should do its thing in the afternoon, with scattered thunderstorms a possibility along and ahead of it. Not everyone will see a storm, but where it does storm, there will be a risk for heavy rain considering the abnormally high moisture content in our little slice of the atmosphere. Lightning and maybe an isolated wet microburst will pose a concern as well, but widespread severe weather is not anticipated.
Moderate coastal flooding will be a concern in the evening around the 7:47 PM high tide. Water levels could approach 7.6-7.8′ in the harbor, leading to another round of road closures due to salt water flooding. With any luck, the thunderstorm threat should be inland by this point, but we’ll keep an eye on it.
A similar pattern continues into Wednesday before another front approaches Thursday, driving rain chances up quite highly once again to close out the week. We’ll want to watch Thursday and Friday for the potential for another round of flooding rainfall, too. As always, stay tuned…
Another round of soaking, heavy rain is expected on Sunday as a front sinks into the area and stalls out. There will be a chance of rain for much of the day, but the best risk of rain will arrive in the afternoon and evening hours as thunderstorms look to erupt near the frontal zone as well as on other boundaries. Thunderstorms will be capable of very heavy rain and a good bit of lightning. Minor flooding will be a concern given 2.3-2.4” precipitable water values — atmospheric moisture that’s very much on the top end of what we’d see this time of year. We’ll also want to watch closely around the time of the evening high tide (5:48 PM) for the potential for heavy rain and said tide to coincide, perhaps increasing the flood threat for downtown Charleston in particular. An isolated wet downburst could pose an issue as well, but the overall severe threat will be limited.
We should see temperatures run up to the mid-80s before storms fire; this, combined with mid-to-upper 70s dewpoints will yield heat indices around 100° in the afternoon.
Stay alert for rapidly changing conditions tomorrow, and be ready to find alternate routes in case you encounter flooded roadways!
We’ve got another hot day on tap Thursday as heat indices soar well into the 100s, perhaps approaching 110° in the afternoon. (Never mind the fact that the lows will barely get below 80° inland and likely will stay in the 80-82° range at the coast.) Once again, isolated to scattered afternoon showers and thunderstorms will be possible along and ahead of the seabreeze, and we’ll be watching once more for the potential for a more organized thunderstorm complex to approach the area later in the evening, possibly bringing some gusty winds along with it. Overall, there will be plenty of fuel for any storms to work with, but shear remains light. Thus, if storms produce severe weather, it’ll likely be in the form of downburst winds. Frequent lightning and locally heavy rain could factor into any storm that gets going, too, so be aware of that if you’re out and about Thursday afternoon.
Wednesday will be another quite hot July day ahead of the usual round of scattered afternoon thunderstorms. After a very muggy start — lows in the upper 70s inland, probably not getting below 80° downtown and at the beaches — expect air temperatures to top out in the low-to-mid-90s across the area. Mix in dewpoints running in the mid-to-upper-70s and that’ll yield heat indices approaching 107° in the peak of the afternoon. You’ll definitely want to be taking frequent breaks and getting plenty of water if you’ll be outside for an extended period tomorrow. (Note that Heat Advisory criteria for July onward is heat indices at or above 110° for more than two hours, so while these heat indices would have garnered an advisory last month, they will not in this case.)
Showers and thunderstorms should once again develop along and ahead of the seabreeze in the afternoon. The atmosphere will be primed for a strong storm or two, with plenty of available energy for storms to tap into once the capping inversion erodes. Damaging wind gusts and maybe even some hail will be possible in the strongest storms, while all storms will be capable of locally heavy rain and frequent lightning. Not everyone will see severe weather, much less a storm at all — coverage looks scattered at best. But if you do, it could be a good one.
As is customary for the Lowcountry, heat and humidity will feature prominently in the Independence Day forecast, with some scattered afternoon and evening thunderstorms to cool some of us off. Before thunderstorms fire, we should see temperatures reach into the upper 80s to low 90s away from the somewhat cooler (but still quite humid) coastline. This warmth when combined with mid-70s dewpoints will yield heat indices in the low 100s for tomorrow. Be sure to get plenty of water and shady breaks if you’re outside for an extended period. (Don’t forget the sunscreen, either.)
By 1-2 PM, we should begin to see some showers and thunderstorms start to initiate along and inland of the seabreeze circulation. We’ll want to watch the 1-4PM period closely for the greatest risk for lightning to the beaches as there will be more than ample instability for strong updrafts to develop. (Remember: When thunder roars, go indoors!) Places that get caught under a thunderstorm will not see it move too terribly much during its lifecycle; with precipitable water values at or exceeding 2″, we could see some pockets of rather heavy rain in a short time in some spots. Wind shear is nearly nonexistent, so severe weather looks quite unlikely outside of the potential for a wet microburst somewhere. Severe potential aside, lightning makes all thunderstorms dangerous, so please do move indoors if you see lightning or hear thunder.
The good news, though, is that the Fourth of July will not be a complete washout. We should see storms begin to clear the Tri-County by early evening as the seabreeze progresses inland, and fireworks shows should be very much go for liftoff. Have a safe and fun holiday!
After record rainfall today — 1.87″ of rain at the airport breaks the record of 1.54″ set in 2000, while stations in West Ashley picked up 2.5-3″ — more storms are on the horizon for the next few days as we remain within a very humid airmass with plenty of upper-air and surface features to help spur on shower and thunderstorm development.
Thursday looks to go similarly to the past couple days, though there may not be quite as much coverage as we’ve seen thus far this week. We could see showers and storms forming early in the day near the coast, with storms becoming scattered to numerous while translating inland with the seabreeze throughout the afternoon. With precipitable water values near 2″, we once again could see pockets of very heavy rainfall. The past couple days have seen a couple 4″ bullseyes, and I can imagine that will be the case somewhere again tomorrow. The severe weather risk remains very low given the very saturated atmosphere, but lightning and isolated bouts of excessive rainfall will make any thunderstorm dangerous. High temperatures will remain suppressed in the mid-80s, though the humidity will still be rather swampy.
Showers and thunderstorms return to the forecast on Tuesday as a front sinks into the area and stalls out. A good bit of you should see at least some rain tomorrow and over the next few days as the stalled front continues to hang around with plenty of available moisture. Given the time of year, of course, not everyone will see the same amount of rain — some of you could see very little, while others may be crying “Uncle!” by the time the week is over. It all ultimately depends on small mesoscale accidents that are impossible to predict with more than an hour or two of lead time. On average, a half-inch to an inch of rain in spots through the end of the week looks pretty reasonable.
Showers and storms will keep us out of the 90s for the foreseeable future, too. Tuesday will run in the upper 80s, but we should see temperatures suppressed solidly in the mid-80s for the rest of the week with the ongoing unsettled pattern. It looks like we’ll keep elevated storm chances into the holiday weekend, too, so be thinking about a backup plan for your outdoor activities to celebrate the Fourth.
Thursday will be the hottest day this week as air temperatures return to the mid-to-upper 90s across the Lowcountry in the afternoon. Unfortunately, dewpoints will also have recovered back into the 70s, and that could put us close to heat advisory territory for Thursday afternoon as heat indices could approach 105°. There will, however, be a shot at some isolated thunderstorms later in the afternoon into the evening hours as the seabreeze makes its move inland. Lightning and gusty winds will be the primary concern from any thunderstorm that forms, but so far widespread severe weather doesn’t look likely.
