ATL: IAN - Post-Tropical - Discussion

[Iceresistance]

Hurricane Warning in effect for Orlando

[Gatos del Sol]

Surface winds usually drop really quickly due to frictional effects even just a few miles inland.

Though note that swampy areas like you get with the Everglades or coastal Louisiana have less friction than dry land. IIRC, Wilma might have slightly increased wind speed as she crossed the Florida peninsula at the Everglades.

[cheezyWXguy]

Inner eyewall degrading at a good clip on radar, only the northern half still seems to be convectively active

[StormingB81]

Hurricane Warning in effect for Orlando

I’m a little surprised they didn’t move those to the east coast

[GCANE]

That 4000 CAPE Ridge SE of the Keys is getting bigger. Feeding directly into the core.

[Gatos del Sol]

Another Governor’s press conference. I think he said they’re getting 30K utility workers staged for recovery efforts. Sadly, I think they’re all going to be much needed.

[floridasun]

https://i.postimg.cc/qBsNV8GD/C38-BAA1-A-DFFF-49-BC-9-E4-B-CB0-C0-BB9291-A.jpg

what that mean?

[GCANE]

Significant Tornado Parameter also increasing and coverage area widening.
Looks like will come onshore tonight.
Not good having nocturnal tornadoes

[orion]

Just a general question about the various types of graphics available under "Lower Dynamics" on sites like Tropical Tidbits.

I see 10m wind height and 850mb wind height. A quick google search says that 850mb wind height is roughly the wind at 5000 feet. As a human that happens to live closer to 33ft (10m) as opposed to 5000 feet, when I look at those two maps and it shows wind speeds, it seems that the wind speeds for 10m height drop off really quickly after landfall. Is that actually right? I suppose the wind speeds at 5000 feet might be 80+ mph, but at ground level, is it really that much lower?

No, I'm not asking this in order to make a decision to evacuate or not (I'm not in FL). I suppose it is more idle curiosity. I've had some hurricanes skirt my area before. I'm about 25 miles inland in SC and curious what sort of wind someone would actually see at ground level from a (for example) Cat 1 coming onshore. Given what these maps are showing in Florida for Ian, it makes me wonder what sort of wind speeds someone in the middle of the state along the path would actual see at ground level.

The standard height for wind speed is 10m above the ground. When you hear the NWS or NHC talking about surface winds, this is the level they are referring to (Similarly the standard height above the ground for temperature is 2m). When we get above the surface, we look at the winds not at certain heights above the ground, but at certain pressure levels. In the example you gave, the winds would be measured at the height where the pressure is 850mb. Going higher up, the 500mb level is about the level where half atmosphere is above and half below it. These pressure levels are 3D surfaces that have highs and lows, but have average heights around 1500m (5000 ft) for 850mb and 5500m (18,000 ft) for 500 mb.

In the absence of friction, the winds are geostrophic - parallel to the height contours - at levels around 500mb and higher... as you get lower you start feeling the effects of friction which disrupts the balance of the pressure gradient force and coriolis. Friction slows the wind speeds considerably and the imbalance in the forces causes the direction of the wind to turn toward the low pressure area, which, although I've simplified it a bit, leads to the cyclonic circulation around the low pressure center of the hurricane.

[NDG]

You know that you are in a true tropical hurricane in Key West when is raining with 84 degrees and a dewpoint of 79 degrees.
It feels that way here also in Orlando this afternoon.

Sep 27, 5:35 pm 84 79 84 96 ESE 41G54 6.00 Lt rain

[jlauderdal]

TS warnings now for the SE FL metros.

They held us out to the very end, winds have been increasing this afternoon.

[Sciencerocks]

[NDG]

Hurricane Warning in effect for Orlando

Yeah I saw it coming, if Ian keeps moving faster than though and we end up in the NW quadrant which models are persistent will become the strongest side of Ian after making landfall we will indeed see hurricane force winds.

[Patrick99]

You know that you are in a true tropical hurricane in Key West when is raining with 84 degrees and a dewpoint of 79 degrees.
It feels that way here also in Orlando this afternoon.

Sep 27, 5:35 pm 84 79 84 96 ESE 41G54 6.00 Lt rain

Yeah there's a certain feeling for sure.

[GCANE]

New eye seems to be already contracting on radar

[eastcoastFL]

I'm under a tropical storm warning in Martin but 17 miles from my house in Okeechobee there's a hurricane warning. I hope Ian knows that.

[ElectricStorm]

Definitely looks a lot more like an ERC now. Interested to see what the planes find. Good luck and stay safe to everyone in the path of this thing

[Iceresistance]

Did Ian literally cancel or delay the EWRC?


https://s4.gifyu.com/images/KBYX_loop.gif

[NDG]

https://imagizer.imageshack.com/img924/4457/Tuw3Jm.gif

Ian is now running fairly much parallel to the SW shear, a sure bet that it will make landfall as a MH, hopefully not Cat 4.

[TheHurricaneGod]

TS warnings now for the SE FL metros.

They held us out to the very end, winds have been increasing this afternoon.

We should probably end up about 110 miles east of the center, and if we get a complete ERC, we could be seeing very windy conditions tomorrow.