We have three areas of interest in the Atlantic Basin today; one is close to home, and the other two won't come anywhere near us.
The one close to home is a weak disturbance that we have been tracking for about a week and is centered near Jacksonville, Florida, this morning. It became better defined over the last 24 hours, and a coherent circulation has formed. However, it's already partly over land and will drift further inland later today.
A loop of visible satellite images gives a closeup view of a weak disturbance centered near Jacksonville, Florida, this morning. Source: University of Wisconsin RealEarth
This feature is reminiscent of Tropical Storm Colin from last July, which became a tropical cyclone just before moving into the Lowcountry. If it had more time over water, it would probably become a tropical depression or storm within a day. It will move north through coastal Georgia and then along our Coastal Plain tonight through tomorrow. After that, a cold front approaching from the north will kick this feature out to the east. If it manages to stay separate from the front, it could develop early next week as it moves out over the water.
The effects on us should be limited to a scattering of soaking tropical downpours along our Coastal Plain through tomorrow. Some areas in the Lowcountry could see prolonged downpours that lead to minor flooding. Fortunately, astronomical tides are low right now, which helps keep the flooding risk low. One more thing to watch for is isolated waterspouts over our coastal waters that might move ashore. The tornado threat on land probably isn't zero through tomorrow but should remain low since this feature is weak.
The other features of interest over the Atlantic are in the deep tropics, far from the Palmetto State.
A loop of visible satellite images from this morning showing most of the Atlantic Basin. Source: University of Wisconsin RealEarth
The first is a tropical wave that is moving into Central America. Thunderstorm activity associated with it flared up last night, and this is another situation where it probably would become a tropical cyclone if it had more time over water. Fortunately for the people of Nicaragua and Honduras, it's out of time over water. It will cross Central America with soaking rains through tomorrow. After that, it may develop further over the East Pacific.
The next feature is a weak tropical wave along 63° west, moving through the Lesser Antilles. It's only causing a few thunderstorms, so it's not very interesting. It's unlikely to develop further as it crosses the Caribbean Sea due to strong vertical shear.
A much more impressive tropical wave is over the tropical Atlantic along 43° west. It's causing a large area of disorganized thunderstorms. Conditions are more favorable in this area, with lighter winds aloft and warmer-than-average ocean waters. The waters get even warmer as it tracks westward. We must watch it closely, with most of our computer model guidance indicating that this feature will develop in the next few days. However, it likely will turn north and remain far to our east. It looks like it will be more of a concern for Bermuda than us, but if it becomes a hurricane, it might eventually send ocean swells our way, causing dangerous boating and surf conditions along our coast.
August is nearly here, so the busiest part of the hurricane season is on the horizon. Please take some time to get ready for storms that might affect us later this season. As always, you can find storm preparation tips at hurricane.sc.
Areas not feeling the effects of the tropical disturbance moving through tonight and tomorrow remain in the sultry summertime weather regime. A thunderstorm will pop up here and there this afternoon and evening, then again tomorrow afternoon and evening. Highs in this area, mostly the Upstate, will reach the low 90s. Clouds and rain keep the rest of the state in the 80s to perhaps 90.
By Sunday, this tropical critter should be out of our hair. Simmering heat returns with afternoon thunderstorms few and far between. Highs will mainly be in the middle to upper 90s. Heat index values will exceed 100 over most of the state, so use caution if you must spend extended periods outdoors.
Learn the symptoms of heat exhaustion and heat stroke so you know what to do if you or someone you know becomes affected.
On Monday, another cold front gets farther south than usual for midsummer and moves into South Carolina. That should increase in afternoon thunderstorm activity. It looks hotter than average again on Monday, but the heat will ease starting Tuesday. The front will become stationary and dissipate near our coast, so it likely remains active with widespread afternoon thunderstorms in that area Tuesday and Wednesday as the rest of the state stays mainly dry with a slight reduction in humidity. We could see hotter days at the end of next week, but early signs are that another front might get this far south next weekend.
