ATL: IAN - Models

[SouthernBreeze]

TVCN is more than consensus of 3, it gets it's data from:

1) The average of the last two runs of the members within the TCON plus the ECMWF model is known as the TVCN consensus.

2) The TCON consensus is the GUNA consensus plus the Hurricane WRF model.

3)The GUNA model is a consensus of the interpolated versions of the HMON, UKMET with quality control applied to the cyclone tracker, United States Navy NAVGEM, and GFS models.

So the TVCN involves the ECMWF, HWRF, HMON, UKMET, NAVGEM, and GFS.

[NDG]

GFS is coming up with an almost Donna like solution. We're going to need one more run to sell me on that one. It's the UKMET and Euro's turn to confirm a new trend.

What new trend?

[Bocadude85]

6z TVCN is south of Tampa, down around Sarasota/Bradenton.

TVCN is a consensus model, NHC mentioned it in the 5 AM update.
Last night I saw the HMON flip from south of Tallahassee to the Atlantic headed for south Carolina.

If you have 3 members of a consensus model and they vary widely it isn't a forecast tool.

Lets say there is a 33% chance Ian powers up and his outflow overcomes the trough so he tracks for the big bend area.

Now there may also be a 33% chance that the trough digs fast and strong undercutting Ians CDO so that he limps east over Sarasota across the state of Florida to the Atlantic.

And that leaves a 33% chance that the trough remnants will potentially steer the perfect storm towards Tampa bay area between the two outliers.

Now since the consensus follows the middle track towards Tampa there is actually only a 33% chance of verifying.

NHC really can't do much better forecasting trough interactions out beyond 24 hours and they repeated this in the 5 AM update.

"There continues to be larger-than-normal
spread in the track guidance by 36-48 hours, however the trend in
the global models has been more southward and eastward over the
last cycle or two."

Yes I’m well aware that the TVCN is a consensus model that the NHC almost always follows when releasing their updated forecasts.

[johngaltfla]

Crazy amounts of rain the latest 06z GFS forecasts because it shows Ian stalling for 36 hrs, 40"+ in parts of Manatee County.
Both the GFS and Euro have been persistent that the NW quadrant of Ian will have the heaviest amount of rain because of shear and dry air wrapping around the south side of the circulation.
Good news storm surge wise for Tampa Bay but bad news for possibly getting the heaviest amount of rain for Ian.

https://i.imgur.com/50m2pZm.png

If this area gets 20" of rain it's bad. 40"? Not only historic, but a disaster of epic proportions.

[johngaltfla]

GFS is coming up with an almost Donna like solution. We're going to need one more run to sell me on that one. It's the UKMET and Euro's turn to confirm a new trend.

What new trend?

South (the further the better, sorry Lee County bros)!!!!

Wow that GFS precip model is terrifying.

[Fancy1001]

So it looks like tampa's 100 year streak will hold after all.

[gatorcane]

The GFS ensembles are not shifting east but they do weaken some near Tampa:

[BobHarlem]

I want to caution anyone who forgets landfall isn't the only thing, it still could meander around, this track is not going to be quick and will probably move around more than this.

[NDG]

GFS is coming up with an almost Donna like solution. We're going to need one more run to sell me on that one. It's the UKMET and Euro's turn to confirm a new trend.

What new trend?

South (the further the better, sorry Lee County bros)!!!!

Wow that GFS precip model is terrifying.

The GFS joins the UKMET and ICON which are south of Sarasota, now is the 06z Euro to see if it also goes south of Sarasota, but as I mentioned, if it goes south of you, you will be in the heaviest amounts of rain, in the NW quadrant.

[BobHarlem]

6z CMC landfall near Cedar Key

[gatorcane]

In fact many GFS ensembles are just west of Tampa area heading north and/or stalling just offshore definitely no east shift if anything is a west shift:

[jlauderdal]

So it looks like tampa's 100 year streak will hold after all.

yes but at the expense fo the heaviest rain the system can offer, hopefully, the heaviest rain stays offshore but that is unlikely

[NDG]

In fact many GFS ensembles are just west of Tampa area heading north and/or stalling just offshore definitely no east shift if anything is a west shift:

https://i.postimg.cc/BtWQtknG/gfs-ememb-lowlocs-watl-fh0-78.gif

They are all alone with its operational and the rest of the models taking it inland near or south of Tampa Bay including the Euro ensembles.

[Jelmergraaff]

So it looks like tampa's 100 year streak will hold after all.

yes but at the expense fo the heaviest rain the system can offer, hopefully, the heaviest rain stays offshore but that is unlikely

What is the elevation of Tampa's city center compared to sea level? I can imagine catastropic flooding if it lies below sea level.

[gatorcane]

In fact many GFS ensembles are just west of Tampa area heading north and/or stalling just offshore definitely no east shift if anything is a west shift:

https://i.postimg.cc/BtWQtknG/gfs-ememb-lowlocs-watl-fh0-78.gif

They are all alone with its operational and the rest of the models taking it inland near or south of Tampa Bay including the Euro ensembles.

https://i.imgur.com/kSvqMv8.png

Still though you can’t throw them out and they look to have shifted slightly west. So the east shifts could be done. Best to look at the ensembles given the uncertainty still even in this close-range.

[Wakeknight]

So it looks like tampa's 100 year streak will hold after all.

yes but at the expense fo the heaviest rain the system can offer, hopefully, the heaviest rain stays offshore but that is unlikely

What is the elevation of Tampa's city center compared to sea level? I can imagine catastropic flooding if it lies below sea level.

This isn’t New Orleans, most of the Bay Area is 20-40’ above sea level. Nothing here is below sea level, the soils don’t support that type of construction.

[toad strangler]

In fact many GFS ensembles are just west of Tampa area heading north and/or stalling just offshore definitely no east shift if anything is a west shift:

https://i.postimg.cc/BtWQtknG/gfs-ememb-lowlocs-watl-fh0-78.gif

They are all alone with its operational and the rest of the models taking it inland near or south of Tampa Bay including the Euro ensembles.

https://i.imgur.com/kSvqMv8.png

Still though you can’t throw them out and they look to have shifted slightly west. So the east shifts could be done. Best to look at the ensembles given the uncertainty still even in this close-range.

Once Ivanhater posts will will know the west shifts have commenced
wasn't wxman57's initial call DAYS ago south of Tampa?

A whole bunch of rain for nearly the entire peninsula.

[Jr0d]

It's the NAM so take it with a grain of salt, but still jaw dropping and terrifying.
901mb

[NDG]

In fact many GFS ensembles are just west of Tampa area heading north and/or stalling just offshore definitely no east shift if anything is a west shift:

https://i.postimg.cc/BtWQtknG/gfs-ememb-lowlocs-watl-fh0-78.gif

They are all alone with its operational and the rest of the models taking it inland near or south of Tampa Bay including the Euro ensembles.

https://i.imgur.com/kSvqMv8.png

Still though you can’t throw them out and they look to have shifted slightly west. So the east shifts could be done. Best to look at the ensembles given the uncertainty still even in this close-range.

GFS ensembles look lost to me. They have been west biased all along.

[NDG]

They are all alone with its operational and the rest of the models taking it inland near or south of Tampa Bay including the Euro ensembles.

https://i.imgur.com/kSvqMv8.png

Still though you can’t throw them out and they look to have shifted slightly west. So the east shifts could be done. Best to look at the ensembles given the uncertainty still even in this close-range.

Once Ivanhater posts will will know the west shifts have commenced
wasn't wxman57's initial call DAYS ago south of Tampa?

A whole bunch of rain for nearly the entire peninsula.

Everybody at one time had Tampa before the GFS and its hurricane models started shifting west towards the Panhandle/Bing Bend and they jumped on their wagon, including wxman57.