stormwatch

Weather Underground

Weather Underground's track map:

Interview: NWS Charleston

Remember the rain we had a week ago? According the National Weather Service in Charleston, Tropical Storm Ernesto could wind up producing less local flooding than that less dramatic, unnamed storm that dumped about 3 inches of rain in an hour, right on top of a high tide.

Today's ground-zero for the 10-mile wide eye of Ernesto: Georgetown, mostly likely coming ashore around 8 p.m.

That's leaving Charleston on Ernesto's weak western side. The Lowcountry's near-miss "seems pretty certain based on the radar trends," said NWS meteorologist Frank Alsheimer. 

"We certainly are on the weaker side in terms of winds and rain along the west side of the storm, but there is still a lot of rain on the west side of the storm as it's passing over Georgia right now."

That means Charleston can expect about 2 to 3 inches of rain on Thursday, with the most likely time for intense showers coming in the midafternoon, when the eye of the storm will be directly to our east.

"(The eye will pass) near the time of high tide (1:44 in Charleston harbor), which is why we're still in a flood watch for Charleston, Berkeley and Dorchester counties," Alsheimer said.

But it's not just the amount of rain that affects flooding: it's also the rate at which it falls. And with Ernesto trucking north at 15 mph, even the most intense rainfall isn't going to hang around one place and pound it, like last Thursday's storm did to the peninsula.

The Lowcountry isn't expected to get by unscathed, as we're likely to receive tropical storm force winds this afternoon. Ernesto's TS winds already extend 85 miles from the center, and with its central pressure dropping again, forecasters expect the storm to intensify today as it cruises up the gulf stream.

"It's still going to come close enough to give some of the area tropical storm effects," Alsheimer said.

Tracking ground zero

Predicting tropical storm tracks is an extremely difficult task, and sometimes the best that can be said is that the predictions get more accurate as the storm gets closer. If that's true, then one of the remarkable things about Ernesto is that the track for its projected Carolinas landfall has changed very little in the past 36 hours.

Look back at yesterday's 11 a.m. projection and you'll notice that there really isn't much difference between that map and today's 2 p.m. update. Charleston County has been in the crosshairs since before we activated this blog.

One relatively late trend that bears watching: After moving to the east on Tuesday, the landfall coordinates have been drifting west again since the 5 a.m. update. When most people got up this morning the likely landfall was near Bull's Bay. It moved east at 8 and at 11, then again at the 2 p.m. At this hour, the projected landfall coordinates are 32.8 N, 79.8 W -- still in the East Cooper area, but the trend is pointing back toward the harbor.

Expect this forecast line to keep moving up until the storm either hits us or passes us by. But where it ends up going isn't just a subject for casual curiosity: It will likely determine who has electrical power on Thursday night and who doesn't.

The 5 p.m. update should give us a more detailed picture of just what this storm is up to.

2 p.m. Ernesto Map

Tropical Depression Ernesto is moving over Lake Okeechobee. A tropical storm warning is in effect from Sebastian Inlet Florida northward and Northeastward along the coast to Cape Fear, North Carolina.

The depression is moving toward the north near 10 mph. This general motion is expected to  continue today with a gradual turn to the north-northeast along the Florida peninsula. On this track the center should move over the Atlantic waters late tonight.

Maximum sustained winds are near 35 mph with higher gusts. No change in strength is forecast while Ernesto is over land but some intensification could occur on Thursday as the sytem moves over the Atlantic.

5 a.m. reaction: NWS Charleston

Here's the local take on the latest NHC updates from Steven Taylor, senior forecaster for the National Weather Service in Charleston.

Basically, the overnight change has moved the projected landfall "very slightly" from Charleston harbor north to Bull's Bay/Awendaw, which isn't enough of a shift to move the Lowcountry out of the affected area.

Taylor is expecting winds of 40 to 50 mph, gusting to 60 mph, over much of Charleston County on Thursday afternoon. Look for this combination: a storm surge of 2 to 3 feet on top of high tide (Charleston harbor = 1344 EDT, or about a quarter till 2), with heavy rains of 3-5 inches. The NWS actually toned down the projected winds a bit in this forecast.

Bear in mind, though, that this could still show up on our coast as a strong tropical storm  and pull a Gaston -- jumping to official Category 1 hurricane status right before it makes landfall.  "The difference between a 70 mph tropical storm and a 75 mph hurricane is pretty much what you call it,"  Taylor said.

"All of our intensity models remain at just under hurricane force," he said. "We're not out of the woods by any means yet."

Reason: That combination of organization and gulf-stream recharging mentioned in the 5 a.m. update discussion. Ernesto is loosely organized now, with large, broad circulation, "and sometimes land can give a storm just enough friction to sorta congeal it," Taylor said. The barometric pressures recorded for Ernesto have actually dropped since it came ashore in Florida, he said.

Does that mean we're going to move up from a hurricane watch to a hurricane warning? Don't expect it before the 11 a.m. update, which will be the next time forecasters get a look at the full mathematical models.

Next intermediate update: 8 a.m.

The view from the blogs, etc.

If you're keeping track of Ernesto at home -- and many of you are -- you'll want to bookmark these local sites:

Jared W. Smith: The Blog. Jared is a local computer expert and blogger who tends to keep excellent tabs on developing weather situations. From his latest post:

Charleston is still right in the path of the center of the storm, and now the timing is starting to come into focus a little more clearly, and it does seem that landfall will unfortunately coincide with high tide at 2PM Thursday. I still anticipate seeing a watch sometime today, possibly as soon as 2PM.

Butterfat's Weather Page: Butterfat is a combination of several of the Lowcountry's smartest Web minds. In addition to some of their other endeavors, they've put up this free page that automatically collects and presents the latest tropical weather information. A great resource.

The Charleston.net Storm Center page is another excellent new resource. It archives the paper's storm coverage -- so if you're looking for something you missed, you can find it -- while providing raw RSS feeds from local, state and federal agencies. This one was created by David MacDougall, the P&C's open-source software guru.

Brian Goode's blog: Brian is a TV meteorologist for ABC News 4.

To see what local bloggers have to say about the storm, try the automated site Lowcountry Blogroll. Meanwhile, the P&C blog Lowcountry Blogs keeps track of sites the automated sites don't, and provides daily roundups of local blog buzz.