ATL: 90L - Models

[cycloneye]

Models only.

[xironman]

The NNIC is trying to make a name for itself

The inputs to NNIC include intensity forecasts from 4 deterministic intensity models (HWFI, AVNI, DSHP, LGEM) and 4 other predictors.

The model input includes 5 predictors as follows:

(1) the mean intensity from the 4 models,
(2)-(5) The deviation of each model from the mean.

The four other inputs include the following:

(6) The previous 12 hr intensity change (t=0 minus t=-12h max wind)
(7) The latitude along the OFCI track
(8) The SST along the OFCI track,
(9) The 850-200 hPa shear along the OFCI track

Predictors (6)-(9) are obtained as part of the SHIPS model diagnostics.

The NNIB model is just the simple mean of the same four models used as input to NNIC. It is used as a baseline to see if the neural network can improve on the simple mean.

The NNIC forecast is from a fully connected neural network with 1 input layer (9 nodes), 1 hidden layer (9 nodes) and 1 output layer (1 output per forecast time). The network was trained on data from 2013-2020, with a separate network for each time from 12 to 168 hr. The Atlantic and combined eastern and central Pacific were trained separately. At least 2 of the 4 input models must be available for NNIC to make a forecast. Because HWFI only provides a forecast to 120 hr, the longer range forecasts are less reliable.

NNIC is experimental and is undergoing its first end to end test in 2021 where the output is being put in the public A-decks. Caution should be exercised downloading this model."

[cycloneye]

 https://twitter.com/AndyHazelton/status/1418600796548108293

[ronjon]

Interesting run by 12z Euro. Takes the low into Cape Canaveral and then west across central Florida to just offshore the nature coast Monday morning in the GOM. Then takes a pretty W-NW straight line course to NO. Of course its weak the whole time but definitely a robust vorticity. Something to watch...

https://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=seus&pkg=uv850_vort&runtime=2021072312&fh=72

[Hypercane_Kyle]

Not even the usually enthusiastic HWRF is excited about this one.

[captainbarbossa19]

Interesting run by 12z Euro. Takes the low into Cape Canaveral and then west across central Florida to just offshore the nature coast Monday morning in the GOM. Then takes a pretty W-NW straight line course to NO. Of course its weak the whole time but definitely a robust vorticity. Something to watch...

https://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=seus&pkg=uv850_vort&runtime=2021072312&fh=72

Given how poorly models have been handling intensity, I would not be surprised if this ends up being slightly stronger than currently shown.

[aspen]

CMC is fully on board with development, and the Euro has a trackable corticosteroids signature for 90L. The ICON also gets a weak TC out of this. All show 90L moving away from Georgia before reversing direction and making landfall in 72-78 hours.

[captainbarbossa19]

CMC is fully on board with development, and the Euro has a trackable corticosteroids signature for 90L. The ICON also gets a weak TC out of this. All show 90L moving away from Georgia before reversing direction and making landfall in 72-78 hours.

Meanwhile, the 18z GFS shows nothing at all. I hope the GFS is right, but somehow I think it will not be.

[aspen]

CMC is fully on board with development, and the Euro has a trackable corticosteroids signature for 90L. The ICON also gets a weak TC out of this. All show 90L moving away from Georgia before reversing direction and making landfall in 72-78 hours.

Meanwhile, the 18z GFS shows nothing at all. I hope the GFS is right, but somehow I think it will not be.

Strange to see the GFS showing by far the least development out of the global models. Even the operational Euro has at least some vorticity signature that can be tracked.

[cycloneye]

Most models dont go NE and instead go SW and then to EGOM.

[AlphaToOmega]

The ECMWF has a 50-60% chance of a tropical depression where Invest 90L is, which exactly matches the NHC chances:

[Category5Kaiju]

The ECMWF has a 50-60% chance of a tropical depression where Invest 90L is, which exactly matches the NHC chances:
https://i.postimg.cc/25MNKZQV/render-gorax-green-005-6fe5cac1a363ec1525f54343b6cc9fd8-Ggfdk-Y.png

I wonder if that feature in the Mid-Atlantic is the same front that gave rise to 90L

[AlphaToOmega]

[AlphaToOmega]

50%-60% chance of Invest 90L developing

[aspen]

50%-60% chance of Invest 90L developing

https://i.postimg.cc/bvd9pjy5/render-gorax-green-007-6fe5cac1a363ec1525f54343b6cc9fd8-q-VXo-M5.png

Forget 90L, look at the area highlighted in the eastern MDR. The Euro is picking up on the potential for MDR development eventually. How far does this go out?

[AlphaToOmega]

50%-60% chance of Invest 90L developing

https://i.postimg.cc/bvd9pjy5/render-gorax-green-007-6fe5cac1a363ec1525f54343b6cc9fd8-q-VXo-M5.png

Forget 90L, look at the area highlighted in the eastern MDR. The Euro is picking up on the potential for MDR development eventually. How far does this go out?

The forecast is valid for 2021-07-29T00:00+0000

[AlphaToOmega]

Models are still latching onto Invest 90L