ATL: IAN - Post-Tropical - Discussion

[3090]

Looks as if Ian just started shooting NW

Oh yeah at 12mph!

[Deshaunrob17]

Lol what’s with these Caribbean systems this year… Anyways the next 24hours would be telling⚡️

[eastcoastFL]

Convection starting to fire up

[Sanibel]

I would guess we will see a slow development over the day as Ian starts to make his own environment as it gets stronger...


Euro gives us a strong hurricane so that means full preparations today which is going to be a lot of back-breaking heavy lifting...


Even though this stall/turn is the least predictable steering environment for track, can't take any chances...

[aspen]

Extrapolated pressure at the CoC down to 1001.9 mb per AF301 Recon.

I guess the ramp up has begun...

It has definitely not begun yet. Ian won’t be ramping up until it has consistent, expansive, deep convection over its LLC. It’s nowhere near that yet.

[Iceresistance]

Extrapolated pressure at the CoC down to 1001.9 mb per AF301 Recon.

I guess the ramp up has begun...

It has definitely not begun yet. Ian won’t be ramping up until it has consistent, expansive, deep convection over its LLC. It’s nowhere near that yet.

Agree, the first warning sign of RI is when there is powerful convection that is developing near the CoC and starts to rotate with it and spin faster.

[Blown Away]

No shear, no dry air, hot SST’s- once this gets stacked it’s all systems go

http://tropic.ssec.wisc.edu/real-time/temp/tcmovieFinal.gif

Hey EC, cool graphic, can you provide link?

[Iceresistance]

No shear, no dry air, hot SST’s- once this gets stacked it’s all systems go

http://tropic.ssec.wisc.edu/real-time/temp/tcmovieFinal.gif

Hey EC, cool graphic, can you provide link?

I'm not eastcoastFL, but I have the link here

http://tropic.ssec.wisc.edu/real-time/storm.php?&basin=atlantic&sname=09L&invest=NO&zoom=4&img=1&vars=11111000000000000000000&loop=0&llval=OFF

[wxman57]

Ian looks like a real TS today. I always though it would struggle until Sunday. I see the ICON shifted a bit east, right into Tampa. NHC shifted their track a little east of TVCN now. Better chance Ian tracks inland farther down the Peninsula. Tampa maybe? That would be bad.

[kevin]

Also with all the talk about potential RI, here are the fastest 24 hour pressure drops & wind increases of all hurricanes that passed through the WCar (see polygon) this century. Only hurricanes that intensified with 35 kt or more in 24 hours are shown. According to the latest NHC discussion Ian has roughly 42 hours left until it passes by/landfalls on Cuba and almost 120 hours until landfall in the US (even though it starts weakening after 72 hours).

Storm / Year / Wind increase / Pressure drop

Wilma / 2005 / 95 kt / 97 mb
Felix / 2007 / 85 kt / 57 mb
Eta / 2020 / 70 kt / 60 mb
Ike / 2008 / 70 kt / 57 mb
Iota / 2020 / 65 kt / 65 mb
Dean / 2007 / 65 kt / 46 mb
Keith / 2000 / 65 kt / 46 mb
Gustav / 2008 / 65 kt / 41 mb
Delta / 2020 / 65 kt / 32 mb
Ida / 2021 / 60 kt / 57 mb
Ivan / 2004 / 55 kt / 43 mb
Paloma / 2008 / 50 kt / 35 mb
Dennis / 2005 / 50 kt / 31 mb
Grace / 2021 / 50 kt / 27 mb
Michelle / 2001 / 45 kt / 42 mb
Iris / 2001 / 45 kt / 39 mb
Zeta / 2020 / 45 kt / 20 mb
Ida / 2009 / 45 kt / 20 mb
Michael / 2018 / 40 kt / 42 mb
Emily / 2005 / 40 kt / 39 mb
Charley / 2004 / 40 kt / 39 mb
Sandy / 2012 / 40 kt / 33 mb
Isidore / 2002 / 40 kt / 23 mb
Otto / 2016 / 40 kt / 17 mb
Gamma / 2020 / 35 kt / 27 mb
Rina / 2011 / 35 kt / 20 mb

[Poonwalker]

https://cdn.star.nesdis.noaa.gov/FLOATER/data/AL092022/GEOCOLOR/20222680750-20222681340-GOES16-ABI-AL092022-GEOCOLOR-1000x1000.gif

You can see the shear line end at about 76-77 longitude line 15N. I bet this was the limitation and causing the NW tilt. Ian looks free of that now.

[underthwx]

Assuming Ian undergoes RI...can a more intense cyclone cause track changes?....I remember Neil Frank talking about that awhile back, when he was a Met with KHOU Houston

[vbhoutex]

AM discussion from Jeff Lindner:

Hurricane Warning in effect for the Cayman Islands

Hurricane Watch in effect for western Cuba.

Discussion:

USAF mission overnight found a slowly developing tropical cyclone in the western Caribbean Sea. The low and mid level centers are still not aligned with the low level center to the south and southeast of the mid level circulation. In fact the circulation is sort of elongated in a WNW to ESE fashion. Outflow has continued to improve and Ian is in a very favorable environment for development. The plane found winds around 45kts and the intensity has not been changed. Ian continues to move W to WNW at 12mph.

Track:

All US upper air sounding sites east of the Rockies began 2 additional upper air sounding launches yesterday along with a NOAA high altitude GIV upper air sampling mission yesterday evening. This additional data has been ingested into the global model guidance overnight, and yet there remains significant spread at days 4-5. Additional US soundings will continue daily through this week in support of NHC operations and another GIV mission will be flow today.

Ian is at the western limit of the narrow ridge to the northeast and will begin to turn to the NW shortly. Track guidance has changed little through the next 48 hours with Ian moving across the western Caribbean Sea just west of the Cayman Islands and then toward the western tip of Cuba by Tuesday. This part of the forecast track is of high confidence. Ian will then continue NNW/N into the eastern Gulf of Mexico during the mid to late week period as the hurricane interacts with a trough along the US east coast. The difficulties at the longer range continue to be with how Ian interacts with the trough and the depth of the hurricane over the eastern Gulf. There have been big shifts in the guidance over the last 24 hours…especially the GFS which has moved well west with a landfall toward the FL panhandle while the ECWMF and UKMET are along the eastern edge of the guidance suite near the Tampa area. The spread at days 4-5 remains unusually large.

The official NHC forecast brings Ian northward over the eastern Gulf of Mexico and then toward the FL Big Bend area and is very near the multi-model consensus and down the middle of the guidance split between the ECWMF and GFS models. There has been little change in the NHC track over the last 3 forecast packages. [/quote]

Intensity:

Ian is in a near excellent environment for intensification, but there is no alignment yet of an inner core and convection is somewhat scattered this morning. Once an inner core forms, there will be nothing to prevent extensive and rapid deepening of Ian and the system will quickly become a hurricane and then likely a major hurricane. Nearly all guidance shows explosive deepening of the system with Ian likely becoming a major hurricane before reaching western Cuba and then a category 4 hurricane in the eastern Gulf of Mexico.

As Ian nears the FL coast later this week, strong southwesterly wind shear and dry air to the west may begin a quick weakening process, but even should Ian weakened from a high end hurricane over the eastern Gulf, models show an expanding wind field and a slowing forward motion which will drive significant storm surge and rainfall impacts.

[eastcoastFL]

No shear, no dry air, hot SST’s- once this gets stacked it’s all systems go

http://tropic.ssec.wisc.edu/real-time/temp/tcmovieFinal.gif

Hey EC, cool graphic, can you provide link?

If you click on Ian on this page it will open it up with a ton of options for overlays. It’s pretty cool and a good source for seeing if it’s on course. You can even overlay the models and ensembles too

http://tropic.ssec.wisc.edu/tropic.php#

[Poonwalker]

I guess the ramp up has begun...

It has definitely not begun yet. Ian won’t be ramping up until it has consistent, expansive, deep convection over its LLC. It’s nowhere near that yet.

Agree, the first warning sign of RI is when there is powerful convection that is developing near the CoC and starts to rotate with it and spin faster.

Ian will develop a CDO prior to RI and keep us agonizing over recon visits.

[eastcoastFL]

Also with all the talk about potential RI, here are the fastest 24 hour pressure drops & wind increases of all hurricanes that passed through the WCar (see polygon) this century. Only hurricanes that intensified with 35 kt or more in 24 hours are shown. According to the latest NHC discussion Ian has roughly 42 hours left until it passes by/landfalls on Cuba and almost 120 hours until landfall in the US (even though it starts weakening after 72 hours).

Storm / Year / Wind increase / Pressure drop

Wilma / 2005 / 95 kt / 97 mb
Felix / 2007 / 85 kt / 57 mb
Eta / 2020 / 70 kt / 60 mb
Ike / 2008 / 70 kt / 57 mb
Iota / 2020 / 65 kt / 65 mb
Dean / 2007 / 65 kt / 46 mb
Keith / 2000 / 65 kt / 46 mb
Gustav / 2008 / 65 kt / 41 mb
Delta / 2020 / 65 kt / 32 mb
Ida / 2021 / 60 kt / 57 mb
Ivan / 2004 / 55 kt / 43 mb
Paloma / 2008 / 50 kt / 35 mb
Dennis / 2005 / 50 kt / 31 mb
Grace / 2021 / 50 kt / 27 mb
Michelle / 2001 / 45 kt / 42 mb
Iris / 2001 / 45 kt / 39 mb
Zeta / 2020 / 45 kt / 20 mb
Ida / 2009 / 45 kt / 20 mb
Michael / 2018 / 40 kt / 42 mb
Emily / 2005 / 40 kt / 39 mb
Charley / 2004 / 40 kt / 39 mb
Sandy / 2012 / 40 kt / 33 mb
Isidore / 2002 / 40 kt / 23 mb
Otto / 2016 / 40 kt / 17 mb
Gamma / 2020 / 35 kt / 27 mb
Rina / 2011 / 35 kt / 20 mb

https://i.imgur.com/e6HsGTm.png

That map is identical to what the GEPS ensembles looked like yesterday lol

[eastcoastFL]

https://cdn.star.nesdis.noaa.gov/FLOATER/data/AL092022/GEOCOLOR/20222680750-20222681340-GOES16-ABI-AL092022-GEOCOLOR-1000x1000.gif

You can see the shear line end at about 76-77 longitude line 15N. I bet this was the limitation and causing to NW tilt. Ian looks free of that now.

Yup, kinda hard to get decent outflow going with that. Now that it’s getting clear of that environment there’s not a whole lot in its way but land eventually.

[Patrick99]

This strange large line of storms from just south of Cuba stretching all the way back to SA....I can't recall seeing something like this. Possibly this is restricting the storm somehow?

[CronkPSU]

GFS moves east...one time model error or start of a trend...now we wait for the Euro to see what it does

[MGC]

This strange large line of storms from just south of Cuba stretching all the way back to SA....I can't recall seeing something like this. Possibly this is restricting the storm somehow?

Yes, perhaps robbing moisture inflow to the northern part of the circulation......MGC