ATL: IAN - Post-Tropical - Discussion

[ScottNAtlanta]

Ok...bedtime...either I will wake up to a surprise Hurricane or tilt-a-whirl storm that ain't stacked

Tilt-a-Whirl it is apparently

[Dean4Storms]

I don’t get all the trust on this storm with the ECM when a couple days ago it had this storm up near Jamaica crossing just west of central Cuba and heading for the very tip of South Florida. The GFS on the other hand had it right about where it’s at now. I know that could change but the GFS has performed well with this storm so far as far as track is concerned. It’s also different with the westerlies getting involved in a couple days, but until the ECM proves itself I am leaning toward the GFS camp with track.

[Hypercane_Kyle]

I'm surprised even with the synoptic data that NOAA got last night the EURO hasn't budged. They had a lot of new data that made it into the latest runs.

Euro probably has the right thinking with gradual intensification. I am not sure if/how this correlates to a more eastern track.

[chris_fit]

I don’t get all the trust on this storm with the ECM when a couple days ago it had this storm up near Jamaica crossing just west of central Cuba and heading for the very tip of South Florida. The GFS on the other hand had it right about where it’s at now. I know that could change but the GFS has performed well with this storm so far as far as track is concerned. It’s also different with the westerlies getting involved in a couple days, but until the ECM proves itself I am leaning toward the GFS camp with track.

Interesting and valid point.

[cane5]

Can anyone say what percentage of chances Ian moves even move more west by the time it arrives in the Gulf thanks in advance

[LARanger]

If I lived in a truly flood prone area out there, I wouldn’t need the government to tell me when to go. I’d be out of there already.

You have to understand the mindset over here because the Gulf coast here rarely gets a major hit. A lot of the people think that storm surge only impacts beachfront property. What they do not understand is that a Cat 3-4 slowing into the Bay area is the nightmare scenario for flooding when adding 15" plus of rain on top of it. This area is already saturated so more rain is only going to make things a lot worse in those neighborhoods which tend to flood.

Even that last "tend to flood" is a dangerous presumption. The 2016 Louisiana flooding, caused by what was basically a stationary inland hurricane, dropped around 7 trillion gallons on around a third of the state. That was up to 30"+ of rain in places over an area large enough to cover (and defeat) river systems, leaving folks that had barely ever seen so much as an overtopped ditch with water lapping at the ceiling. A year later, Harvey doubled the Louisiana 2016 event in size and intensity, doubling or tripling the total rainfall volume (though you can find some wilder estimates from the time suggesting as high as 33 trillion gallons), and resulting in literally five feet of rain in places. That's sufficient to not just defeat river systems, but basically to defeat drainage *as a concept*.

[tropicwatch]

Kind of boring this morning. Pressure has not started to drop and winds are pretty constant. Other than that, the satellite presentation looks good albeit with limited convection.

[johngaltfla]

If I lived in a truly flood prone area out there, I wouldn’t need the government to tell me when to go. I’d be out of there already.

You have to understand the mindset over here because the Gulf coast here rarely gets a major hit. A lot of the people think that storm surge only impacts beachfront property. What they do not understand is that a Cat 3-4 slowing into the Bay area is the nightmare scenario for flooding when adding 15" plus of rain on top of it. This area is already saturated so more rain is only going to make things a lot worse in those neighborhoods which tend to flood.

Even that last "tend to flood" is a dangerous presumption. The 2016 Louisiana flooding, caused by what was basically a stationary inland hurricane, dropped around 7 trillion gallons on around a third of the state. That was up to 30"+ of rain in places over an area large enough to cover (and defeat) river systems, leaving folks that had barely ever seen so much as an overtopped ditch with water lapping at the ceiling. A year later, Harvey doubled the Louisiana 2016 event in size and intensity, doubling or tripling the total rainfall volume (though you can find some wilder estimates from the time suggesting as high as 33 trillion gallons), and resulting in literally five feet of rain in places. That's sufficient to not just defeat river systems, but basically to defeat drainage *as a concept*.

Drainage in Florida is the interstate system for alligators.

[wxman57]

Yes or No - If you were Tampa Area (Bradenton) - Would you be shuttering up?

My plan is to wait until this afternoon models, if E shift in most guidance, shutter up - otherwise no. Wise plan?

My decision to shutter or not would depend on the time involved and whether you would be evacuating. How long does it take to install the shutters? The earliest Ian could be there would be Wednesday evening. I would be waiting and watching at this point, if shuttering takes only a few hours. Maybe Tuesday morning for the decision.

[cane5]

Going to rely on points and how far Ian is away from those points now until until north of Key West to get an idea of how much of an impact we will likely experience.

First point was 15n 80w,(missed just right). Next point for me is 17N 81W, if it hits or misses right we can expect more of an impact, NHC official forecast is left of that point).

Ian appears to be moving NW now and not forecast to move due north until it clears Cuba, obviously if it turns NNW then N before Cuba, this is bad for me and the peninsula. As we know, the further south at land fall the stronger the storm will be.

Not a forecast by any means, but I am NOT expecting a panhandle landfall. My best guess is Fort Myers to Cedar Key. The angle of the storm.vs coastline make it impossible to narrow it down.

While obviously a much different set up, Charley hooking
right earlier than expected and strengthening comes to mind as a bad outlier

My strong belief based on what I’m seeing out there is that IF Ian tracks in a direction out of line with the official forecast, it’ll be to the south and East not north and west. In other words, I think the chance is higher Ian landfalls south of, say, Tampa than well north

That’s a bold prediction based on what ?

[CronkPSU]

I'm surprised even with the synoptic data that NOAA got last night the EURO hasn't budged. They had a lot of new data that made it into the latest runs.

Could say the same thing about the GFS refusing to budge with the new data, one would think ONE of them would have budged but nope

[Weatherboy1]

Going to rely on points and how far Ian is away from those points now until until north of Key West to get an idea of how much of an impact we will likely experience.

First point was 15n 80w,(missed just right). Next point for me is 17N 81W, if it hits or misses right we can expect more of an impact, NHC official forecast is left of that point).

Ian appears to be moving NW now and not forecast to move due north until it clears Cuba, obviously if it turns NNW then N before Cuba, this is bad for me and the peninsula. As we know, the further south at land fall the stronger the storm will be.

Not a forecast by any means, but I am NOT expecting a panhandle landfall. My best guess is Fort Myers to Cedar Key. The angle of the storm.vs coastline make it impossible to narrow it down.

While obviously a much different set up, Charley hooking
right earlier than expected and strengthening comes to mind as a bad outlier

My strong belief based on what I’m seeing out there is that IF Ian tracks in a direction out of line with the official forecast, it’ll be to the south and East not north and west. In other words, I think the chance is higher Ian landfalls south of, say, Tampa than well north

That’s a bold prediction based on what ?

Same as all of us. My best-guess analysis of models, overall atmospheric set up, decades of watching systems closely, etc, etc.

[wxman57]

To help with the decision whether to shutter and/or evacuate. The SLOSH graphic below represents a "what if?" for a landfall near Tampa of an average-sized hurricane that is borderline Cat 2/Cat 3. If you're in one of those very low-lying communities on the coast, then your home/business will be inundated by lots of water. Tampa hasn't seen this kind of surge since the 1940s or 1950s. It's only a POSSIBLE surge for now. Ian would have to track inland just west of Tampa. Blue flags indicate water depth (not subtracting land, though all flags touch the water, not land).

http://wxman57.com/images/SLOSHTPA.JPG

[chaser1]

I'm surprised even with the synoptic data that NOAA got last night the EURO hasn't budged. They had a lot of new data that made it into the latest runs.

Could say the same thing about the GFS refusing to budge with the new data, one would think ONE of them would have budged but nope

Great point. Though this conversation is drifting into the "Models thread", I'd be more curious if (and how) the new data impacted the ensembles

[aspen]

I'm surprised even with the synoptic data that NOAA got last night the EURO hasn't budged. They had a lot of new data that made it into the latest runs.

Euro probably has the right thinking with gradual intensification. I am not if/how this correlates to a more eastern track.

The Euro and GFS/HWRF/HMON tracks all looked pretty similar up until Cuba’s latitude despite the former showing a weaker system than the latter. It’s after that when they diverge, with the Euro having a sharper turn towards Florida. Possibly some progressive GFS bias at play, trying to move that trough out too quickly.

RI is still a possibility that needs to be watched out for. Ian still has another 48 hours before reaching Cuba’s latitude and a possible Cuba landfall, and if it consolidates a core by tonight, it’ll probably be a major by Tuesday morning. But that’s a pretty big if. Almost zero structural improvements have taken place since shear dropped to favorable levels, so another full day of limited organization is possible.

[Steve]

My strong belief based on what I’m seeing out there is that IF Ian tracks in a direction out of line with the official forecast, it’ll be to the south and East not north and west. In other words, I think the chance is higher Ian landfalls south of, say, Tampa than well north

For sure!

I am currently limited by my cognitive "location" bias that is preventing me from seeing this clearly. I will subconsciously make assumptions or see things that bring Ian closer To Key West. Having those hit it miss points help me a little.

If I were to place bets for a landfall, it would be Tarpon Springs, with Ian hitting south being much more likely than missing north.

Good luck this week jr0d. Hope you guys make out okay. More people need to admit location bias, and you know I appreciate acknowledgment.

[wxman57]

If the storm makes landfall north of Tampa as an average sized Cat 2, then this is the potential surge. Note that the values are only for near where the center makes landfall and down the coast a ways. Surge would be lower west of landfall.

http://wxman57.com/images/SLOSHCat2.JPG

[Poonwalker]

Shuttering up is always a good bet but what I would look at first is any old trees and branches and remove them. That takes time and effort. What I usually see causing the most wind damage comes from trees. The other source is loose projectiles like chairs. Trampolines, rotted fences etc. They should be dismantled or taken down.

[Jr0d]

[


At a minimum, you should get a surge to deal with in KW. The problem with a storm like this is a few hours of wobble to the east and you have a power outage. We had a situation in sofla mid 2000's where we were hit with one big gust from a feeder band that knocked out power to 250,000 customers. Otherwise, it was sunny and we had less than an inch of rain from a gulf system.

One sailboat getting loose and hitting powerlines can knock.out power for all of the lower Keys.

While I think its safe we will not get a direct hit, we will be on the dirty side of it. If it follows the NHC, even the right side of the cone and stats compact we will.not see much, however a few wobbles right could be a world of difference.

I expected storm watches this afternoon. While the city emergency management generally does a good job, I am a little dissapointed they have not ordered tourist to evacuate.

[blp]

Intensity on this pathetic.