Category 4 Hurricane Helene continuing to grow with little forecast change this morning (UPDATED 6:50 PM ET Thurs)

(6:50 PM ET Update): Helene is now a category 4 hurricane with maximum sustained winds of at least 130 mph. Helene is pretty clearing undergoing a rapid intensification cycle at present, and the only question at this point is if it will level off before it makes landfall. The track continues to wobble a bit, perhaps on the right side of the specific track, but in general, the forecast remains steady.

For Tallahassee, it remains really a question of whether it’s really bad or terribly bad. So, neither outcome is great. Looking at satellite imagery this evening, the west side of this thing is no picnic either. Yes, the “dirty” side is living up to its name, but the thunderstorms in the northwest quadrant are going to cause significant wind and rain, and even if this tracks east of Tallahassee, it’s going to be a really bad night.

Landfall is expected later this evening, probably close to midnight.

Rainfall will continue to lead to severe flooding well north of where Helene comes ashore. Flood warnings extend in broken fashion from just west of Tallahassee through Atlanta to Charlotte, into far southwest Virginia. Catastrophic flooding remains a strong possibility in the mountains.

Water levels continue to rise on the Florida coast, and the expected catastrophic storm surge north of Tampa through Apalachee Bay will proceed apace in the coming hours. Avoid the coast, do not go see it, it will be deadly. More to come later this evening.

(2:45 PM ET Update): Hurricane Helene is now a 120 mph major hurricane.

(11:25 AM ET Update): The 11 AM ET advisory is out with Helene up to 105 mph. Its structure and organization have improved since earlier. The track forecast has not shifted much in the new advisory, but it’s noteworthy that there have been a few wobbles to the east side of the track forecast.

Wobbles are normal with hurricanes of this size and intensity. The question is whether or not they fundamentally alter the track, particularly at this angle of approach. For most folks in the path of Helene, this has minimal impact on the end result. But for a place like Tallahassee, ending up on the west side of the storm would be immeasurably less impactful than the east side. Still bad to be sure, but not quite as bad as it could be otherwise. This would also impact the western fringe of the surge forecast a bit too. So it’s something to monitor through the day today if you have interests in Tallahassee or along Apalachee Bay.

Whatever the case, nothing has appreciably changed, and a major hurricane is still expected at landfall tonight around Midnight, give or take.

Tropical Storm and Hurricane warnings still extend almost absurdly far inland, but they will almost certainly verify.

A couple other notes: We already have additional numerous flash flood warnings near Tallahassee, between Macon and Augusta, just north of Greenville, SC, south of Asheville, near Johnson City, TN, and up into Virginia. The inland flooding component will continue to worsen as the day continues.

Tornado warnings have been numerous, and we currently have 3 warnings as I write this in Georgia and South Carolina. This system has the potential to be a prolific tornado producer from Florida into southeast Georgia, South Carolina, and parts of North Carolina. Please ensure you have a way to receive warnings, even if you’re 250 miles from the center of the storm.

Previous post follows…

What’s changed since last night

• No meaningful change to the forecast intensity, track, or impacts into Florida.
• A slight nudge east in the track in North Georgia.
• Helene is now a category 2 storm

Larger storms tend to be a little more unruly in terms of how they organize. Helene meets that bill today. Reports of “concentric eyewalls” in the storm, almost as if the system is trying to figure out how large it wants to be.

We’ve seen bursts of thunderstorms wax and wane near the center, but we’re currently in an uptick. Recent reports from NOAA flights into Helene suggest surface winds have increased to close to 100 mph. We’ll see what the new advisory shows just after I publish this. (Editor’s note: It has. Now a cat 2 with 100 mph winds). Basically, Helene continues to intensify, and there’s no reason to think the dire forecasts we and everyone else discussed yesterday have changed.

The surge forecast is basically unchanged from last night, with a 15 to 20 foot, unsurvivable peak surge in Apalachee Bay and the Big Bend.

Tampa Bay continues to see a 5 to 8 foot surge, which will be some of the worst surge experienced in modern times there.

The track of Helene is virtually unchanged as well. The most likely landfall point is between Apalachicola and Steinhatchee right now. There remains at least some risk that wobbling of the track could force it closer to Cedar Key in an extreme scenario. I would not rule that out, but I would be absolutely preparing for the worst between Apalachicola and Homosassa and for very bad outcomes south of there to Tampa Bay. Landfall should occur late this evening.

A Tornado Watch is in effect for most of the Florida Peninsula today.

That watch goes til 8 PM ET, and additional watches could be required to the north later today. Isolated tornadoes seem to already be a bit of a threat and this should escalate some through the day and into tonight.

The heavy rainfall threat continues to look very, very bad for both areas near landfall and interior locations in the Appalachians in North Carolina, Upstate South Carolina, and North Georgia.

After heavy rain yesterday, we continue to see the risk for 10 to 16 inches of additional rainfall with the storm today, tonight, and early Friday before things slowly ease up a little tomorrow. Catastrophic interior flooding, especially in that high risk area northeast of Atlanta remains a high likelihood.

Real quick tangent here. One of the reasons Helene is going to be such a monster storm as it comes inland is because it’s essentially “phasing” with a massive upper cutoff low over the mid-South. A cutoff low is a storm system in the upper atmosphere that has essentially cut itself off from the jet stream. When this happens, the system tends to just meander around until something changes to kick it out. In this situation, you can see the animation below with the big upper low north of Memphis, and then Helene surging in on the right side of the image.

This complex merger is something we don’t usually think of with a hurricane. Hurricane Sandy was a good example of this happening with tropical systems and showed why its winds and size caused so much damage despite “not technically being a hurricane” when it hit New Jersey in 2012. The whole process extends the life cycle of the winds of the hurricane and it’s why tropical storm warnings extend so far inland. The rain element is related as well. With Helene being pulled northeast, then suddenly hooking back northwest “into” the upper low, it will continue to produce rain on the windward side of the Appalachians, leading to additional rain tomorrow and further flooding.

Anyway, that explains some of what’s going on behind the scenes with Helene after it moves inland. We’ll update this post with any notable changes throughout the day.