ATL: IDALIA - Post-Tropical - Discussion

[ronjon]

Pinellas County right on the coast has not issued any evacuation orders yet! Cannot believe this, the surge could be more than anyone has seen. Are they just throwing up their hands at this point?

Probably going to wait for 5pm

I understand the local officials hesitancy to pull the trigger on evacuations. They will get flack no matter what decision they make. If they order an evacuation that is not needed, people will be more complacent next time and they will get chewed out or even fired for their decisions. With that said, personally I find it better to err on the side of caution every time. Evacuations are a life and death matter in a surge zone. I’d rather see people mad and alive at the end of the storm.

I personally plan to evacuate here in Tallahassee since I live in a heavily treed area with a high risk of a tree falling on my rental. The NWS is saying the risk of Cat 1 or Cat 2 winds is increasing here. Would not be surprised to be under a hurricane warning here come 5 pm. I’d rather be out a few hundred dollars for hotels and gas than risk my family’s safety. Some risks are just not worth it.

Pinellas just ordered zone A evacuation.

[fllawyer]

Hillsborough (Tampa) also just issued Zone A evac order.

[LandoWill]

Euro major shift west. Could we see even further tracking change at 5pm?

[snowpocalypse]

What factors would move the track farther west nearer Port St Joe? A number of outliers have in that area on the latest ensemble.

[chris_fit]

Euro major shift west. Could we see even further tracking change at 5pm?

Very very minor shift. Track likely nudged to the left at 5pm, maybe 10-15 miles? Storm will be lopsided it looks like, most of the weather will be on the east side. most of the Western Peninsula will feel her one way or another.

[eastcoastFL]

[tolakram]

Euro major shift west. Could we see even further tracking change at 5pm?

It's not a major shift, it's west but still close to Cedar Key

[Hypercane_Kyle]

Euro major shift west. Could we see even further tracking change at 5pm?

I feel like describing a 10-15 mile shift west as "major" is a bit much.

[Steve]

What factors would move the track farther west nearer Port St Joe? A number of outliers have in that area on the latest ensemble.

Levi shows them on his video today. If you run a water vapor loop of the Gulf you can see it yourself as well. There is ridge in the SW Gulf, a trough farther north (that's the one pushing down on it from the north). Another trough is coming down which is the one that will pick it up, also high pressure off the SE US Coast building in. Those are the adjacent airmass patterns. And we only have a couple of days so nothing is going to be vastly different than what everything shows right now. It will just come down to the fine tuning and Idalia doing what she wants to do.

[Nimbus]

when is the NW motion many models predicted supposed to occur?

It may not be a motion per se but just organizing as it pulses. It’s across 85 at 85.14. I don’t think it gets much farther west though. Public advisory only shows it ever getting to 85.2 in the next several hours. It will probably move 360/N for a while then begin its fade NNE.

The the convection quickly covered the center as the shear let up just a little.
Trough to the north squeezed east so pretty sure that one missed.
The next trough doesn't have much 250 MB easterly wind component that would steer Idalia NNE as depicted by the models at 48 hours yet.

As Franklin moves northeast you would think the teering flow would shift NE north of Florida?

[eastcoastFL]

She’s still pretty tiny compared to uncle Franklin

[Steve]

when is the NW motion many models predicted supposed to occur?

It may not be a motion per se but just organizing as it pulses. It’s across 85 at 85.14. I don’t think it gets much farther west though. Public advisory only shows it ever getting to 85.2 in the next several hours. It will probably move 360/N for a while then begin its fade NNE.

The the convection quickly covered the center as the shear let up just a little.
Trough to the north squeezed east so pretty sure that one missed.
The next trough doesn't have much 250 MB easterly wind component that would steer Idalia NNE as depicted by the models yet.

As Franklin moves northeast you would think the teering flow would shift NE north of Florida?

Yeah I'd agree with that. But there is supposed to be building high pressure off the SE Coast, so as the pattern changes, the flow does as well (from the SSW south of Idalia and to the north based on western periphery of the SW Atlantic High). The first trough is missing it since it's too far south. What the NHC mentioned was a squeeze play which was a building ridge in the SW Atlantic and the second trough. So that's probably what nudges it up toward the descending trough which would be enough influence to get it off the coast. Just not sure what happens after that.

[CryHavoc]

Euro major shift west. Could we see even further tracking change at 5pm?

I feel like describing a 10-15 mile shift west as "major" is a bit much.

Wobble-watching in general chews up this forum whenever a hurricane is forecast to make landfall.

I completely understand that yes, even a dozen or so miles can make a big difference in impact to a lot of people -- but at the same time, this kind of path shift always happens.

[cheezyWXguy]

Idalia looks to be strengthening now. The CDO actually looks like a real CDO now, with even some outflow starting to expand to the west. I'm also seeing overshooting tops starting to make it west of 85W, which would imply they're making better attempts at rotating upshear and maintaining. Would be nice to have a radar that updates more than once every 30 min to confirm, but hey, what can you do...

[Nimbus]

It may not be a motion per se but just organizing as it pulses. It’s across 85 at 85.14. I don’t think it gets much farther west though. Public advisory only shows it ever getting to 85.2 in the next several hours. It will probably move 360/N for a while then begin its fade NNE.

The the convection quickly covered the center as the shear let up just a little.
Trough to the north squeezed east so pretty sure that one missed.
The next trough doesn't have much 250 MB easterly wind component that would steer Idalia NNE as depicted by the models yet.

As Franklin moves northeast you would think the teering flow would shift NE north of Florida?

Yeah I'd agree with that. But there is supposed to be building high pressure off the SE Coast, so as the pattern changes, the flow does as well (from the SSW south of Idalia and to the north based on western periphery of the SW Atlantic High). The first trough is missing it since it's too far south. What the NHC mentioned was a squeeze play which was a building ridge in the SW Atlantic and the second trough. So that's probably what nudges it up toward the descending trough which would be enough influence to get it off the coast. Just not sure what happens after that.

Not much of a squeeze play till after landfall but Jacksonville has already canceled school.

[psyclone]

I'm feeling pretty optimistic here in the bay area with the core expected to remain offshore and some wiggle room. as always tempering that with past tendencies of storms to shift right of track as they head north. that's bailed us out before but would work against us this time. a little dicey. im not seeing any evidence of panic shopping here as has happened well in advance of past (ultimately false alarms) like Dorian.

[ronjon]

Euro major shift west. Could we see even further tracking change at 5pm?

Very very minor shift. Track likely nudged to the left at 5pm, maybe 10-15 miles? Storm will be lopsided it looks like, most of the weather will be on the east side. most of the Western Peninsula will feel her one way or another.

https://i.imgur.com/uc9CtiD.gif

Chris that's a comparison of 06z with 00z.

[Weatherboy1]

From the models thread, chris_fit wrote:
HWRF Trend... Slower and weaker.
https://i.imgur.com/y59NmXB.gif

So my question is:
Wouldn't slower movement likely result in a more easterly path, giving the dip in the jet more time to dig and have greater influence on Idalia's path/landfall?

That is my assumption, yes. Also the issue of wobbles/any jogs eastward which can have big downstream landfall implications just given angle of approach to Fl west coast

[TreasureIslandFLGal]

I'm certainly not letting my guard down at all in the Tampa Bay area yet. We sooo often have seen that the 6th hr and 18th hr model runs tend to be one way, and then the 0 hr and 12th hr model runs swing right back to their general thinking again. A windshield wiper effect as a solution is homed in on. Additionally, the influx of updated info, especially teh atmospheric soundings downstream, can add an additional layer of adjustment.
With a Major storm, especially one that could get even stronger, prepare for the worst and hope for the best!

[chris_fit]

Euro major shift west. Could we see even further tracking change at 5pm?

Very very minor shift. Track likely nudged to the left at 5pm, maybe 10-15 miles? Storm will be lopsided it looks like, most of the weather will be on the east side. most of the Western Peninsula will feel her one way or another.

https://i.imgur.com/uc9CtiD.gif

Chris that's a comparison of 06z with 00z.

Oops- good catch - but same principle applies...