ATL: ZETA - Post-Tropical - Discussion

[jlauderdal]

Heavy rains and wind going in lake toxaway,nc..300,000 without power in Atlanta and we are downstream from that

Power is out lake toxaway, nc

[chaser1]

Hope I'm doing this correctly. My first post, been reading for years. I would like to thank ya'll for the information you share. We are still cleaning up from Sally and now this. My son just hooked my generator up, purchased a month ago due to Sally. Just know ya'll help many people out here. Thank you.

Welcome aboard. Glad everyone was safe. This was certainly one for the record books in terms of area affected and strengthening tendency as Zeta made landfall so late into the season. Am enjoying all the report and posts from everyone. It's just nice to be in Florida while sitting back and not having to jump into clean-up mode. Good luck to you all and hope everyone affected get's their power back on a.s.a.p!

[Do_For_Love]

Getting some decently heavy rain from Zeta here in DE now. Seems like from everyone's posts that this storm has had an impact on a whole lot of people!

[sjbarrow]

Heavy rains and wind going in lake toxaway,nc..300,000 without power in Atlanta and we are downstream from that

Power is out lake toxaway, nc

Be extra cautious if you go out. There are reports of trees and power lines down all across Transylvania county.

[TheStormExpert]

TWC just said the top wind gust in New Orleans was 77mph. The NHC wind history shows the worst of the wind went to the east of there near the Louisiana/Mississippi border.

[bella_may]

Hi everyone! Just a quick update:

Got really bad gusts around 8:30 last night and that’s when the power went. Never in my life had I experienced thunder and lightning During a hurricane until then. Looks like a war zone this morning. Lines down everywhere, carports collapsed, sheds on the road. Our garbage cans are no where to be seen. A little damage to the side of our house but better than some people. Thankful for the cooler weather cause the power will likely be off for a few days. George County took a big hit

[ColdMiser123]

Wind damage seems severe from this in the worst hit areas, definitely some of the worst wind damage I've seen from any Category 2.

https://www.youtube.com/watch?v=y_eRALfrd0w

[us89]

ATL metro got hit hard. Looks like most areas had peak wind gusts somewhere in the 50-60 mph range. Rain was less than expected, but the wind really did a number on the trees. I somehow never lost power, but more than 1 million Georgia Power customers were not so lucky.

And now we have blue skies and the wind has died down. Unreal.

[Nuno]

ATL metro got hit hard. Looks like most areas had peak wind gusts somewhere in the 50-60 mph range. Rain was less than expected, but the wind really did a number on the trees. I somehow never lost power, but more than 1 million Georgia Power customers were not so lucky.

And now we have blue skies and the wind has died down. Unreal.

Very much like our experience with Wilma in SFL. 100+ MPH early in the day and by afternoon is cool, dry and blue outside.

[Frank P]

I have a question for the experts in the forum. The top of the sea wall in front of my house is 10 feet asl. I know because I was with the guy who took the survey after Katrina. The surge reported at BSL was 9 ft and Pascagoula was 7 ft. I had a water debris trash line in my driveway near the highway. That is at least 13 feet asl. The East bound lane on HWY 90 was a good 2-3 feet under water. I was down there to see it. How is it possible to get 2-3 feet of water in a HWY at least 9 feet asl. Is the wave action that adds to the total? The waves were 2-3 feet high. You don’t count the height of the waves in determining storm surge?
Damage on the front beach in Biloxi was minimal. Trees down, broken window from tree limbs, a few shingles gone, hardy board siding blown off, chimney off roof. I personally had numerous large oak limbs down.

[NDG]

I have a question for the experts in the forum. The top of the sea wall in front of my house is 10 feet asl. I know because I was with the guy who took the survey after Katrina. The surge reported at BSL was 9 ft and Pascagoula was 7 ft. I had a water debris trash line in my driveway near the highway. That is at least 13 feet asl. The East bound lane on HWY 90 was a good 2-3 feet under water. I was down there to see it. How is it possible to get 2-3 feet of water in a HWY at least 9 feet asl. Is the wave action that adds to the total? The waves were 2-3 feet high. You don’t count the height of the waves in determining storm surge?
Damage on the front beach in Biloxi was minimal. Trees down, broken window from tree limbs, a few shingles gone, hardy board siding blown off, chimney off roof. I personally had numerous large oak limbs down.

I believe the height of the waves on top of surge are not counted on the surge forecast.

[ColdMiser123]

I'll do a full best track tomorrow, but here are my thoughts on the peak intensity of Zeta.

* Surface observations were quite significant. There were unofficial reports of sustained winds over 100 mph in southern Lafourche Parish and a gust to 136 mph. The strongest winds would have been over Grand Isle and into Plaquemines Parish where there were no observations. Even in southern Mississippi, sustained winds were well into hurricane territory. (New Orleans, where the eye went through, had relatively modest winds in comparison - likely a low-end category 1 or a strong tropical storm impact. That was because of the fast motion moving the strongest winds east.) All that data suggests winds of at least 90 kt.

* The highest flight-level winds were 119 kt, which would ordinarily support winds of 107 kt at the surface using a 90% reduction factor. Using an 80% reduction factor to account for the nearby trough interaction, however, would result in winds of 95 kt at the surface.

* The highest SFMR reading was 106 kt, but it was flagged and in very shallow water with shoaling issues. I would disregard all SFMR readings near landfall, or at least weigh them a lot less.

* The highest radar velocities were around 126 kt at 10,000 feet around the time of landfall. Using the same caveats as the flight-level winds would translate to winds of 101 kt at the surface.

* The minimum pressure at landfall I estimate was 967 mb, based on a combination of dropsondes (often misplaced, one would translate to 964 mb while the lowest eye drop was 970 mb), inland pressure observations (971 mb in New Orleans) and extrapolated pressures (about 967 mb). Based on that, using the KZC that would translate to about 95 kt when considering the fast motion I believe.

* The satellite signature was fast improving at landfall. From what I could see it was a T5.5 which would equate to 102 kt.

* Conclusion: I believe the landfall intensity was 95 kt, which was the operational intensity. It was difficult to decide between 95 kt and 100 kt. However, I'm not fully convinced that 100 kt would be accurate since the radar may have been transient. The 106 kt SFMR reading could be a deciding point except it was literally at the edge of the marsh. A case could be made for a category 3 landfall, but it is not convincing enough for me.

Thanks for summarizing all of this information, Crazy!

Just a question, what literature supports the 80% reduction figure that you have listed here for systems that interact with upper level troughs? I'm familiar with Franklin, Black, & Valde (2003) which document the 90% reduction in 700 mb FL wind for standard warm core systems. I'd have to imagine that there is a significantly smaller sample size for these kinds of systems, and thus there is probably more uncertainty in that reduction factor as a result.

[NDG]

Many Mets out there don't seem to learn from what had happened all season long in the northern GOM with every storm except with Marco to use it in consideration on Zeta's forecast strength. They are scratching their heads for no reason, they should had remembered that Hanna, Laura, Sally & Delta all strengthened more than forecasted despite the forecasted windshear, cooler waters or very warm shallow waters, etc. When the over all atmospheric environment in an area is in the storm's favor for strengthening it should had not been no surprise that Zeta strengthened to almost a Cat 3 just before landfall on "cooler" SSTs.
It was a mistake from their part to downplay the chances of it becoming a Cat 2 as the GFS, SHIPS and WHRF were showing 2 days before landfall, it never should had been questioned.
One huge fact that Nola and all of SE LA & MS should had been thankful for, that Laura spent 9 hours over land in the Yucatan, enough to stop its strengthening face for 24 hours that it was on prior to making landfall in the Yucatan, otherwise it probably would had gotten up to a Cat 4 prior to landfall with the perfect UL conditions it had over the GOM and probably would had made landfall at least as a strong Cat 3.

[Hypercane_Kyle]

I don't think we've seen this level of inland damage since Michael.

[NDG]

One of many impressive satellite images Zeta had was last night when it was well inland over southern MS, more than 120 miles away from where it made landfall, the feed that it got from the GOM must have been enough to strengthen it in the higher levels, the hurricane was being pushed in a deep layer of SW winds from the surface to the upper levels why it did not get sheared away at that time.

[AnnularCane]

Zeta is almost right on top of me right now, maybe slightly due south. It's been raining all morning but oddly there doesn't seem to be much in the way of wind. Yet. It's supposed to be quite breezy at least through the afternoon so I suppose things can change at any time.

I heard from my aunt in Ponchatoula this morning. Oddly she never lost power, although my dad (in Abita Springs) did. He's still out last I heard. He hasn't seen much damage there, except for a few branches being down. He said it got scary for about 30 minutes though.

[Pearl River]

Checking in from the Pearl: Last night lost power for about 5 hours, even cell service was lost. Went thru the eyewall and eye. The back end of the eyewall was really not there, had some gusty winds, but that was about it, nothing compared to the front side. My lowest pressure measured here at home was 28.86 and recorded 4.53" of rain.


Mike

[AutoPenalti]

Maybe slightly off-topic but it just so happens that Alabama Power and Light misprinted their phone number, they were one number off (ours ends in -2776, theirs is -2726) and now we have been flooded with a lot of 251, 334 area codes calling us even though we are a design firm located in South Florida. Of course we lead them to call the right number but compared to the last 2 hurricanes that went by, Zeta is by far the most we've ever received calls from power being out.

[EquusStorm]

Managed to keep power with only some 30-40mph gusts and heavy rain being on the northwest side of such a fast moving system. Intriguingly, had a several minute span with lots of thunder and lightning as the outer section of what was once the core slid just to the south.

[kiblet]

Greetings from the Atlanta suburbs. Power went out at 5am this morning and the wind was pretty insane. Went for a drive once everything cleared out and there were lots of trees down. Our power came back on around noon but neighborhoods around us are still without power, and friends farther north outside the suburbs have been told it will be two days before power comes back for them. I have a friend whose house was hit by a tree, and saw another car being towed out of our neighborhood and it looked like it had been hit by a tree as well. I don't think anyone expected it to be such a wind event. Happy to be safe!