Tropical Storm Isaias

[Nomz]

NHC issuing advisories for TS Isaias. Max intensity forecast 95 kt @ 6z on the 9th. 

[dbullsfan]

Wait all year for a Cane.... I asked ChatGPT about my flight home Friday...because why not lol

 

The timing is almost comically bad

This is what caught my attention once you gave me the exact flight.

Your flight:

5:45 PM CDT departure = 6:45 PM EDT

Scheduled duration:

2h25m

About 90 minutes into the flight:

~8:15 PM EDT

Nominal position:

~28.8N, 88.4W

Current NHC hurricane forecast:

8:00 PM EDT — 28.8N, 88.3W — 100 mph

That's about as direct a conflict between a tropical-cyclone forecast and a normal airline route as you could construct.

[NorthHillsWx]

Think we’re gonna make it all year without a hurricane then literally the last disturbance with a chance not only becomes a hurricane but now looks increasingly likely to become a major hurricane and threaten the gulf coast. Overnight pretty much all guidance ticked east and faster which aligns better with shear vector snd the right entrance region of the jet so now it’s finding the best runway available in the gulf to strengthen. The impressive organization overnight is no doubt the reason why, it is very clearly stronger than a lot of guidance had it at this point from yesterday. Not surprisingly, intensity has gone way up and I now think this becomes a major and I’m not convinced it doesn’t peak pretty close to the coast. This is becoming an increasingly dangerous situation for the coast. Mobile bay to Panama City seem to have the highest likelihood of landfall given overnight trends.

[Floydbuster]

Wow I am surprised how far east the 5am track shifted. Landfall 12 hrs ago was forecast near Pascagoula, Mississippi, now all the way to Gulf Shores, Alabama and from the sounds of the NHC discussion, they are likely thinking even further east.

[NorthHillsWx]

Per Levi’s video yesterday this storm has trended to the exact thread the needle scenario he described to maximize intensity in this environment 

[CoastalWx]

1 hour ago, Floydbuster said:

Wow I am surprised how far east the 5am track shifted. Landfall 12 hrs ago was forecast near Pascagoula, Mississippi, now all the way to Gulf Shores, Alabama and from the sounds of the NHC discussion, they are likely thinking even further east.

Deep mind baby. 

[Windspeed]

Looks like we're going to have quite a battle of timing and walking thin ice with that shear axis. Might be a back and forth between 6 hr runs on the TC model suites today until they get a better feel for track motion, and if/when the mid-level shear begins encroaching. For example, the 18z HAFS suites kept intensity in check, preventing a major. The 00z suites kept the core on the edge and bombed Isaias into a strong major. The recent 06z runs are back to allowing encroachment in the mid-levels again, though it may still be reaching Category 3 / 960s prior to weakening. We'll have to see if the 12z suite swing back to flirting with the 940s and a more significant major.

[40/70 Benchmark]

2 hours ago, Floydbuster said:

Wow I am surprised how far east the 5am track shifted. Landfall 12 hrs ago was forecast near Pascagoula, Mississippi, now all the way to Gulf Shores, Alabama and from the sounds of the NHC discussion, they are likely thinking even further east.

I was thinking last night that the correction vector is usually east with a poleward moving tropical cyclones and an approaching front.

[NorthHillsWx]

Regardless what happens on approach this thing is going to go boom today. That’s a heck of a satellite presentation this morning 

[40/70 Benchmark]

What is the best link for the deep mind ensemble suite?

Ugh...I didn't want to, as I'm about to jump into winter outlook mode, but the tropics call.

Man, I'm sick-

[NorthHillsWx]

Small cyclone, nuclear grade water temps, BOC, divergent flow. This is going to explode today. Think even the aggressive models are undershooting intensity. Do not think this landfalls near peak intensity but next 24 hours I expect this to become a high end cane I’ve seen this look before in the gulf…

[40/70 Benchmark]

1 minute ago, NorthHillsWx said:

Small cyclone, nuclear grade water temps, BOC, divergent flow. This is going to explode today. Think even the aggressive models are undershooting intensity. Do not think this landfalls near peak intensity but next 24 hours I expect this to become a high end cane I’ve seen this look before in the gulf…

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

[NorthHillsWx]

1 minute ago, 40/70 Benchmark said:

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

Agreed 100%. I don’t see how this doesn’t weaken and possibly significantly before landfall but it might be too late. That extremely fast motion into the coast is going to make this dangerous and likely have some jet streak interactions which could help it hold onto intensity longer than usual. I’m convinced tho that this exceeds most guidance (not unusual at all for this location especially with a small storm) in the short term 

[Newman]

10 hours ago, 40/70 Benchmark said:

Yea, I found that, but not the super ensemble plot...his data seems to be in flux as he is in the process of moving to that site.

The super ensemble, deep mind ensemble, and every other model ensemble is there on the site. You have to click the storm itself and then it brings up the storm specific information, in which you can toggle to model ensemble data

https://polarwx.com/tropical/#al092026/ensembles

[olafminesaw]

4 minutes ago, 40/70 Benchmark said:

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

It's easy to forget because of our unprecedented streak of strengthening hurricanes at landfalls in the GOM, but I remember how in the early 2000s it felt inevitable that significant weakening would occur at landfall along the GOM coast 

[40/70 Benchmark]

Just now, NorthHillsWx said:

Agreed 100%. I don’t see how this doesn’t weaken and possibly significantly before landfall but it might be too late. That extremely fast motion into the coast is going to make this dangerous and likely have some jet streak interactions which could help it hold onto intensity longer than usual. I’m convinced tho that this exceeds most guidance (not unusual at all for this location especially with a small storm) in the short term 

Not to undermine hydro concerns, which will be plentiful near the shore, but hopefully progressive enough to limit freshwater flooding.

[40/70 Benchmark]

Just now, olafminesaw said:

It's easy to forget because of our unprecedented streak of strengthening hurricanes at landfalls in the GOM, but I remember how in the early 2000s it felt inevitable that significant weakening would occur at landfall along the GOM coast 

It's easy to grow complacent and fall victim to recency bias, and I know we have had some feast right up to the shore in the gulf of late, but I don't think this is Michael.

[Windspeed]

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

I am starting to lean into a major being a real possibility, but I still anticipate it getting hammered in the mid-levels prior to landfall. Wouldn't even be surprised if it got decapitated. 30+ kts of shear is still going to win the battle, regardless of the vector of motion and all other favorable factors. Keep in mind that some of the 500 hPa barbs of flow may be in excess of 50 kts by landfall. I would still be cautious of early onset RI being a sure thing as well. It may thread the needle, but you can clearly see assymmetry already in the cloud pattern, and the coldest tops are NE of the surface circulation. It may be slower to moderate intensification instead if it gets hampered by westerly flow. You can easily see this flow on satellite moving in quickly from Mexico. Again, RI is a possibility, but absolutely not certain.

[40/70 Benchmark]

8 minutes ago, 40/70 Benchmark said:

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

Lilly is about the most profound example that I can recall...went from about 145mph to 100mph upon LF near the TX/LA border in 2002.

[jconsor]

2 hours ago, NorthHillsWx said:

Think we’re gonna make it all year without a hurricane then literally the last disturbance with a chance not only becomes a hurricane but now looks increasingly likely to become a major hurricane and threaten the gulf coast. Overnight pretty much all guidance ticked east and faster which aligns better with shear vector snd the right entrance region of the jet so now it’s finding the best runway available in the gulf to strengthen. The impressive organization overnight is no doubt the reason why, it is very clearly stronger than a lot of guidance had it at this point from yesterday. Not surprisingly, intensity has gone way up and I now think this becomes a major and I’m not convinced it doesn’t peak pretty close to the coast. This is becoming an increasingly dangerous situation for the coast. Mobile bay to Panama City seem to have the highest likelihood of landfall given overnight trends.

Side comment - I think we will see 1-3 named storms after this one with about a 50% chance of of another hurricane (likely in the subtropics).  But yeah, it's pretty comical that this one seems to be defying many of our expectations.

[NorthHillsWx]

2 minutes ago, 40/70 Benchmark said:

It's easy to grow complacent and fall victim to recency bias, and I know we have had some feast right up to the shore in the gulf of late, but I don't think this is Michael.

From a public messaging perspective idk if we want to fall victim to ensuring everyone this falls apart before landfall especially if this, say it peaks as a cat 4 18 hours from landfall, and is roaring to the coast at 20 mph. That’s a big gamble 

[Seminole]

11 minutes ago, 40/70 Benchmark said:

Strikes me as one of those N GOM collapse-deals, like Opal or Ivan....

Either possible solution faces the inevitable 30 to 40 knot shear prior to landfall. 

[NorthHillsWx]

Recon will tell us a lot here shortly. If this is going to make a run at a major, the bones need to be there now. A tight developing core would mean this likely goes major. Anything strung out and it probably doesn’t have time before shear inhibits it 

[40/70 Benchmark]

12 minutes ago, NorthHillsWx said:

From a public messaging perspective idk if we want to fall victim to ensuring everyone this falls apart before landfall especially if this, say it peaks as a cat 4 18 hours from landfall, and is roaring to the coast at 20 mph. That’s a big gamble 

I think that is implicit in the tone of the NHC public products, but yea...I mean, it won't even matter in terms of surge.