ATL: IAN - Models

[gatorcane]

12Z GFS ensemble mean looks to have shifted a bit east.

[Mob1]

If it turns more NE before landfall, it might negate some of the shear as it moves parallel to the sheer vectors. Obviously given how strong the shear is it'll still weaken, but on a NE heading it might not decouple as quickly.

[eastcoastFL]

Looking at these model overlays it looks like they’re all to the right of the current NHC track right now

[Blown Away]

CMC into the armpit of the Big Bend

What’s also kinda scary is they all seem to go from a NE heading to a N or NNE. So depending on how far it comes into the state it could potentially run right up the center of the state when it turns back to the north.

Yeah that N then NE turn near the coast is weird. Models keep pushing the stall, N, and NE turn farther SE. I think the result will be Ian moving a little faster and a smoother NE recurve over the peninsula into the Atlantic.

[LarryWx]

12Z UKMET initialized one degree further north (15.3 N vs 14.3 N at same time on 0Z run). It ends up ~20 miles north of the Port Charlotte 0Z landfall point, which is Venice. Another difference vs 0Z is that it never goes offshore N FL/S GA as it stays a little inland:


MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 1200UTC 25.09.2022

TROPICAL STORM IAN ANALYSED POSITION : 15.3N 79.2W

ATCF IDENTIFIER : AL092022

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 25.09.2022 0 15.3N 79.2W 1003 29
0000UTC 26.09.2022 12 16.7N 80.8W 1001 31
1200UTC 26.09.2022 24 18.7N 82.8W 998 35
0000UTC 27.09.2022 36 20.8N 83.9W 995 38
1200UTC 27.09.2022 48 22.9N 84.4W 994 40
0000UTC 28.09.2022 60 24.7N 84.1W 992 45
1200UTC 28.09.2022 72 26.2N 83.7W 989 55
0000UTC 29.09.2022 84 26.9N 82.9W 990 53
1200UTC 29.09.2022 96 26.9N 82.7W 991 49
0000UTC 30.09.2022 108 27.5N 82.1W 993 42
1200UTC 30.09.2022 120 29.1N 82.5W 991 42
0000UTC 01.10.2022 132 30.1N 81.8W 993 36
1200UTC 01.10.2022 144 32.8N 81.3W 996 35

[Blown Away]

12Z UKMET initialized one degree further north (15.3 N vs 14.3 N at same time on 0Z run). It ends up ~20 miles north of the Port Charlotte 0Z landfall point, which is Venice. Another difference vs 0Z is that it never goes offshore N FL/S GA as it stays a little inland:


MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 1200UTC 25.09.2022

TROPICAL STORM IAN ANALYSED POSITION : 15.3N 79.2W

ATCF IDENTIFIER : AL092022

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 25.09.2022 0 15.3N 79.2W 1003 29
0000UTC 26.09.2022 12 16.7N 80.8W 1001 31
1200UTC 26.09.2022 24 18.7N 82.8W 998 35
0000UTC 27.09.2022 36 20.8N 83.9W 995 38
1200UTC 27.09.2022 48 22.9N 84.4W 994 40
0000UTC 28.09.2022 60 24.7N 84.1W 992 45
1200UTC 28.09.2022 72 26.2N 83.7W 989 55
0000UTC 29.09.2022 84 26.9N 82.9W 990 53
1200UTC 29.09.2022 96 26.9N 82.7W 991 49
0000UTC 30.09.2022 108 27.5N 82.1W 993 42
1200UTC 30.09.2022 120 29.1N 82.5W 991 42
0000UTC 01.10.2022 132 30.1N 81.8W 993 36
1200UTC 01.10.2022 144 32.8N 81.3W 996 35

15.3N is the current location, so that’s a good start.

[eastcoastFL]

CMC into the armpit of the Big Bend

What’s also kinda scary is they all seem to go from a NE heading to a N or NNE. So depending on how far it comes into the state it could potentially run right up the center of the state when it turns back to the north.

Yeah that N then NE turn near the coast is weird. Models keep pushing the stall, N, and NE turn farther SE. I think the result will be Ian moving a little faster and a smoother NE recurve over the peninsula into the Atlantic.

Yah that seems more like a set up with an east coast approach. Typically from what I can remember storms hitting the peninsula from the west usually keep chugging into the Atlantic. But this doesn’t seem to be a typical set up. I guess we normally get storms from this angle either early or late season so the set ups are different. Now we’re in that weird transition time from summer to fall but not squarely in either yet.

[toad strangler]

 http://twitter.com/ryanmaue/status/1574067357881962497

[toad strangler]

 http://twitter.com/andyhazelton/status/1574063669557633025

[Blown Away]

12z GFS Trend… Continues SE trend and recurve is more of a smoother NE path over stall, loop, etc.

[PTPatrick]

This is starting to have slow moving rainmaking sheared mess written all over it. Given the euro spaghettis and the general slow movement on the other models wouldn’t be surprised to see it collapse and spin anywhere in the big bend of offshore or Tampa. Obviously still time and I wouldn’t be amazed to see it bomb tomorrow, just seems things are trending toward the right sided weaker slow moving solutions.

[Steve H.]

That would be an Elena redo. If the trough catches him he’ll keep moving. If not

[ScottNAtlanta]

Was looking at Windy.com to see what the trough looks like and I believe it is just a bit stronger than what the GFS was showing. We have had some drizzle/light rain in the Atlanta area that was not supposed to happen. If it dries out later today that will be a sign of drier air punching down.

[Coolcruiseman]

I know that the flooding can be really bad, but I think we should all be grateful of the amount of shear that's forecasted to be in the northern gulf.... I can't even imagine how horrible this situation would have been if the conditions were great for intensification, rather than weakening. Cat 1 to maybe Cat 2 seems the most likely strength at landfall... .. I'm not really concerned about the wind as much though, except on the coast... I'm concerned about the rain/surge, especially if the EURO wins out and there's more of a stall over Florida......

Cat 1/2 at landfall would be if it was a Panhandle landfall. Farther south (say Tampa area) landfall is more in line with a Cat 3 or stronger is it not?

[StPeteMike]

I know that the flooding can be really bad, but I think we should all be grateful of the amount of shear that's forecasted to be in the northern gulf.... I can't even imagine how horrible this situation would have been if the conditions were great for intensification, rather than weakening. Cat 1 to maybe Cat 2 seems the most likely strength at landfall... .. I'm not really concerned about the wind as much though, except on the coast... I'm concerned about the rain/surge, especially if the EURO wins out and there's more of a stall over Florida......

Cat 1/2 at landfall would be if it was a Panhandle landfall. Farther south (say Tampa area) landfall is more in line with a Cat 3 or stronger is it not?

Further south means less impact by shear, but will still likely weaken some. But still, it will have the power of surge comparable to a Cat 3 even if it drops down below Major strength.

Still want to see if the models stay on the the whole slowing down scenario on the next rollout, that’s my biggest concern.

[toad strangler]

 http://twitter.com/AndyHazelton/status/1574085007722831888

[tolakram]

Looking at these model overlays it looks like they’re all to the right of the current NHC track right now

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

Stop direct linking to that image, it's temporary and only shows what you see for a few minutes. If you want to post the image take a screen shot or save it and upload to imgur or another image hosting site.

[aspen]

12z HWRF initializes Ian very well.




By tomorrow morning, Ian's multiple bands have wrapped into an eyewall and it has become a hurricane. Despite this delayed start to its RI, the HWRF still makes Ian a 930s Cat 4 in the Gulf.

[capepoint]

Not until I see the Euro start trending to the left towards the official track will I say that the NHC track is good in the 3-5 day range.

I admire the loyalty of the NHC to the GFS, but at some.point you have to pay serious attention to the rock solid Euro. Euro has seemingly been locked on for several days now, while GFS has been on a grand tour of the gulf coast. It looks today like the GFS is starting to fold to the Euro solution, which we have seen happen before as we get into the 3 to 5 day range. I think the NHC will have to shift the track east now, even if they expand the cone to take the gfs swings into consideration. Bottom line is, over 2/3 of the gulf coast of Florida, as well as Alabama and Mississippi better be watching closely and ready to act fast.

[tolakram]

Not until I see the Euro start trending to the left towards the official track will I say that the NHC track is good in the 3-5 day range.

I admire the loyalty of the NHC to the GFS, but at some.point you have to pay serious attention to the rock solid Euro. Euro has seemingly been locked on for several days now, while GFS has been on a grand tour of the gulf coast. It looks today like the GFS is starting to fold to the Euro solution, which we have seen happen before as we get into the 3 to 5 day range. I think the NHC will have to shift the track east now, even if they expand the cone to take the gfs swings into consideration. Bottom line is, over 2/3 of the gulf coast of Florida, as well as Alabama and Mississippi better be watching closely and ready to act fast.

The cone never changes in size during the year, it's a simple calculated error circle around a forecast point. You make a couple of false statements here so please don't assume you understand how their forecasting works. The technique they use has been responsible for steadily increasing accuracy. Sometimes it doesn't work out, but right now the storm isn't even a hurricane yet so I think it might be a little soon to jump the gun.