ATL: IRMA - Models

[SFLcane]

will there be a 2pm update and discussion per nhc?

Yep! Winds likely increased to 185 or so

[tolakram]

Since I was doubting Irma intensity estimates earlier it must be said that just about every reliable model has this storm very intense all the way to Florida. Obviously why the NHC predicts cat 5 almost all the way in. Not GFS intense, but honestly it just doesn't matter when we are talking cat 5.

[tolakram]

[meriland29]

will there be a 2pm update and discussion per nhc?

Yep! Winds likely increased to 185 or so

I see the max wind as per last Recon was around 169mph (and other factors of course). Does anyone know what the max wind was in the Recon pass prior to the last one?

[Steve]

CMC is a terrible model for forecasting TC track. If the Euro comes in similar to GFS and UK then I wouldn’t put much stock into it at all. Plus, it did shift east from its prior run.

I've been running it for 20+ years. It was #2 for a while with IRMA behind HWRF. It's a model. It's the model thread. NHC often uses it and defers to it. It often sucks too and completely botches a solution. However, it's not been all that terrible since the upgrade last year. Also, it's the model thread and it is currently running. Its track is closer to the NHC's track than the current GFS. I'm not suggesting anyone rely on the CMC for life and death decisions. I'm reporting what it shows on the run.

I certainly understand, I’ve been running it 20 years myself. Yes it is useful for observing trends and worth mentioning for that reason alone, but it has performed horribly this year and many new people who read this and see that it hits the FL panhandle may not understand that.

I hear you. I don't claim to be the NHC or a guru or anything so I'll put this out there:

For those of you who are new, I'll tell you if/when I have a specific call or disagreement with a model, the NHC, pro-mets or whatever. As for the models, CMC is one of the main models the NHC uses to make and adjust forecasts. For my money, by itself, it can be particularly useful to sniff out patterns of high/low pressure in the CONUS and in Canada. It's got a pretty good handle usually on upper flow. We here always referred to it as the Crazy Uncle Canadian because at times it used to spin up 4, 5, 6 lows in the basin - basically any spin had the potential to be a storm on the CMC. They tweaked it a bit last year, and the forecasts and reliability are better. But it's not nearly as good as the GFS or ECMWF (both suspect themselves) and is more in the NAVGEM realm - models you want to throw out but still need to consider how they are handling the pattern and interactions with airmasses.

[txwatcher91]

Since I was doubting Irma intensity estimates earlier it must be said that just about every reliable model has this storm very intense all the way to Florida. Obviously why the NHC predicts cat 5 almost all the way in. Not GFS intense, but honestly it just doesn't matter when we are talking cat 5.

The strengthening shown in the Bahamas is concerning. The models are probably too extreme on the pressure (GFS and HMON) but the upper level conditions seem about as perfect as one could imagine. If it taps into the huge outflow channel into the trough to the north... it could be really bad. The high heat content, moist environment, and exceptional upper level conditions are probably why all the models bomb this like they do. I’ve never seen the UK forecast a sub 920mb storm before...

[Blown Away]

Only 9 more Euro runs before reaching Florida ATM...

[dukeblue219]

will there be a 2pm update and discussion per nhc?

Yep! Winds likely increased to 185 or so

I see the max wind as per last Recon was around 169mph (and other factors of course). Does anyone know what the max wind was in the Recon pass prior to the last one?

The last recon pass (maybe 20 minutes ago?) had a SFMR reading of about 184mph. The vortex message from 17:05 UTC contains this too:

D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 160kts (~ 184.1mph)

[tolakram]

Since I was doubting Irma intensity estimates earlier it must be said that just about every reliable model has this storm very intense all the way to Florida. Obviously why the NHC predicts cat 5 almost all the way in. Not GFS intense, but honestly it just doesn't matter when we are talking cat 5.

The strengthening shown in the Bahamas is concerning. The models are probably too extreme on the pressure (GFS and HMON) but the upper level conditions seem about as perfect as one could imagine. If it taps into the huge outflow channel into the trough to the north... it could be really bad. The high heat content, moist environment, and exceptional upper level conditions are probably why all the models bomb this like they do. I’ve never seen the UK forecast a sub 920mb storm before...

Yea, having the UKie go that low after land interaction is a little alarming.

[jdjaguar]

Only 9 more Euro runs before reaching Florida ATM...

when is the next run?

[Ken711]

I've been running it for 20+ years. It was #2 for a while with IRMA behind HWRF. It's a model. It's the model thread. NHC often uses it and defers to it. It often sucks too and completely botches a solution. However, it's not been all that terrible since the upgrade last year. Also, it's the model thread and it is currently running. Its track is closer to the NHC's track than the current GFS. I'm not suggesting anyone rely on the CMC for life and death decisions. I'm reporting what it shows on the run.

I certainly understand, I’ve been running it 20 years myself. Yes it is useful for observing trends and worth mentioning for that reason alone, but it has performed horribly this year and many new people who read this and see that it hits the FL panhandle may not understand that.

I hear you. I don't claim to be the NHC or a guru or anything so I'll put this out there:

For those of you who are new, I'll tell you if/when I have a specific call or disagreement with a model, the NHC, pro-mets or whatever. As for the models, CMC is one of the main models the NHC uses to make and adjust forecasts. For my money, by itself, it can be particularly useful to sniff out patterns of high/low pressure in the CONUS and in Canada. It's got a pretty good handle usually on upper flow. We here always referred to it as the Crazy Uncle Canadian because at times it used to spin up 4, 5, 6 lows in the basin - basically any spin had the potential to be a storm on the CMC. They tweaked it a bit last year, and the forecasts and reliability are better. But it's not nearly as good as the GFS or ECMWF (both suspect themselves) and is more in the NAVGEM realm - models you want to throw out but still need to consider how they are handling the pattern and interactions with airmasses.

Both the CMC and UKMET interestingly are the two models that take a track through most of Cuba, unlike the GFS and Euro that skirt to the north of it.

[meriland29]

Yep! Winds likely increased to 185 or so

I see the max wind as per last Recon was around 169mph (and other factors of course). Does anyone know what the max wind was in the Recon pass prior to the last one?

The last recon pass (maybe 20 minutes ago?) had a SFMR reading of about 184mph. The vortex message from 17:05 UTC contains this too:

D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 160kts (~ 184.1mph)

Oh, I stand corrected, I apologize. I apparently can't keep up fast enough. Thank you for informing me.

[tolakram]

Only 9 more Euro runs before reaching Florida ATM...

when is the next run?

1:45 EDT am/pm

[M3gaMatch]

UK Plot



16.7, -57.7
17.2, -60.2
17.9, -63.0
18.9, -65.4
19.8, -68.0
20.6, -70.7
20.9, -73.1
20.9, -75.2
21.0, -77.2
21.2, -78.7
22.2, -79.7
23.5, -79.6
25.5, -79.5

Map tool: https://www.darrinward.com/lat-long/?id=59aed24b454f67.43185594

Thanks tola, still right into Cuba

[gatorcane]

12Z NAVGEM shifts EAST, now east of SE Florida:

[jdjaguar]

Only 9 more Euro runs before reaching Florida ATM...

when is the next run?

1:45 EDT am/pm

thank you.

are they every 6 hours?

or 12?

[tolakram]

[Steve]

at 66 hours, HWRF is passing between Mayaguana to the North and Inagua to the South and appears to be headed for the Bahamas at that point as Strong Cat 5. Been my #1 worry for the last week that some of the Bahamas would get wrecked. HWRF seems to agree with the scenario.
https://www.tropicaltidbits.com/analysi ... 0512&fh=66

[ronjon]

12z HWRF a little SW of 06z run at 60 hrs.

[tolakram]

when is the next run?

1:45 EDT am/pm

thank you.

are they every 6 hours?

or 12?

12, just twice a day.

GFS is 4 times daily. 11:25 am/pm and 5:25 am/pm