ATL: IDA - Models

[StormPyrate]

HWRF down to 933 right before landfall

[supercane4867]

933mb would make Ida a CAT5 in this case. Strong pressure gradient backed by August ridging pattern would be enough to do this.

[tolakram]

Strengthens all the way in



precip / simulated radar looks very symmetrical.

[IcyTundra]

HWRF and HMON have New Orleans avoiding the worst of Ida.

[Nimbus]

HWRF, for documentation purposes (which is why I post models, even near landfall)

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

Forecaster Dan Brown who did the 5 PM update tonight talks about "denial" in his Bio. He said it was one of the biggest problems in recognizing dangerous storms . Ida has all the ingredients to be the storm of the century.

[PandaCitrus]

Baton Rouge might get a lot more wind than New Orleans in this scenario.

[PandaCitrus]

Yup, looks to be like nothing but tropical storm winds and hopefully far enough away from peak surge so the Cat 3 levees hold...

I'm more concerned about historic inland wind event for Baton Rouge. They could get Cat 2/3 winds if this comes in as a strengthening 5.

HWRF and HMON have New Orleans avoiding the worst of Ida.

[TallahasseeMan]

Peak strength shown on HWRF over the last 4 runs.

0z 950mb
6z 940mb
12z 938mb
18z 933mb

[supercane4867]

Simulated IR looks more impressive than Laura. Looks more like Katrina

[aspen]

I hate to say it, but it’s possible the HWRF is slightly underestimating Ida’s RI phase. It has a rather modest deepening rate of just 1.28 mb/hr between 15hr (979mb) and 51hr (933mb). Other notorious Gulf majors have deepened faster between first going sub-990mb and peak intensity: Katrina (1.42 mb/hr in 60 hrs), Rita (2.44 mb/hr in 36 hrs), and Laura (1.47 mb/hr in 36 hrs). Harvey and Michael had very similar deepening rates of 1.26 mb/hr and 1.09 mb/hr, respectively. It’s important to note that Michael and Katrina had more time over the Gulf or over water without land interaction than Ida will. Right now, it seems that Laura is the best analog in terms of Gulf entrance state and time over water, so Ida could end up deepening at 1.45-1.50 mb/hr and peak in the 920s.

Predicting deepening rates is quite difficult and might not be all that useful, but I’m thinking a peak in the range of 925-940mb seems possible.

[TallahasseeMan]

I hate to say it, but it’s possible the HWRF is slightly underestimating Ida’s RI phase. It has a rather modest deepening rate of just 1.28 mb/hr between 15hr (979mb) and 51hr (933mb). Other notorious Gulf majors have deepened faster between first going sub-990mb and peak intensity: Katrina (1.42 mb/hr in 60 hrs), Rita (2.44 mb/hr in 36 hrs), and Laura (1.47 mb/hr in 36 hrs). Harvey and Michael had very similar deepening rates of 1.26 mb/hr and 1.09 mb/hr, respectively. It’s important to note that Michael and Katrina had more time over the Gulf or over water without land interaction than Ida will. Right now, it seems that Laura is the best analog in terms of Gulf entrance state and time over water, so Ida could end up deepening at 1.45-1.50 mb/hr and peak in the 920s.

Predicting deepening rates is quite difficult and might not be all that useful, but I’m thinking a peak in the range of 925-940mb seems possible.

Seems like it's been playing catch up today, will be interesting to see what kind of solutions it spits out when Ida makes it into the gulf.

[NDG]

Pretty good shift to the east by the 18z Euro. This is 3 runs in a row shifting east.

[chaser1]

Peak strength shown on HWRF over the last 4 runs.

0z 950mb
6z 940mb
12z 938mb
18z 933mb

A very scary trend indeed

[LARanger]

What in the world is going on? The models are spreading out again and the max wind projections, which at one point were edging up toward 5, are borderline 3/4 . . . can anyone explain what's new?

[tolakram]

What in the world is going on? The models are spreading out again and the max wind projections, which at one point were edging up toward 5, are borderline 3/4 . . . can anyone explain what's new?

?? Spreading out?

[PTPatrick]

That’s def a good shift east on the Euro. Oddly east of HwRF and close to GFS. I trust models as much as anybody here and with excellent model agreement so far, feel reasonably good about this missing New Orleans far enough west to spare the worst effects to the metro. My big concern is last minute changes. They happen (see sally last year). Also this thing seems to have hugged the right side of the cone or even right outside cone for a while. So we watch and wait

[Dean4Storms]

This scenario reminds me of Michael, rounding a ridge with a trough expected to turn it more north then NNE after landfall near Destin, suddenly a day or so before the models moved eastward with a landfall even east of Panama City.

Best not write off New Orleans with a direct hit yet.

[BobHarlem]

0z earlies, tvcn no real change.

[LARanger]

?? Spreading out?

See the "Global + Hurricane Models" Tidbits graphic now versus the last . . . the last one had a tighter group. Similarly, the model intensity guidance graphic no longer shows some straining toward 5, but instead clustering closer to the 3/4 border again.

[gatorcane]

18Z GFS IR simulation: