Low pressure developing over the western Caribbean Sea (Is Invest 97L)

[eastcoastFL]

https://i.imgur.com/0LzllYt.png

Yet another reason to always look at ensemble means when looking further than 4 days out. Tends to outperform most all of the time

What exactly am I looking at here?

[Frank P]

The 12z ECMWF-AIFS model similar to the GFS18z but a tad weaker and faster landfall next Friday

[jfk08c]

https://i.imgur.com/0LzllYt.png

Yet another reason to always look at ensemble means when looking further than 4 days out. Tends to outperform most all of the time

What exactly am I looking at here?

Basically a graph from the ECMWF user guide that shows anomaly correlation coefficient between different products of the Euro.

Red is Operational runs, purple is control run, green is ensemble mean, and light blue is individual members. You can see the decline in accuracy as the days go out, yet the ensemble mean remains the most accurate product from the model runs 4+ days out

[Michele B]

GFS a believer of the “Florida Shield.”

There is no such thing as a Florida Shield when Debby hit this year, Idalia last year and Nicole & Ian in 2022.

Until a center forms, it’s best for all to watch.

From his perspective in the Tampa area, it might feel like there is a shield since it has been over 100 years since that area as seen Major hurricane impacts (1921) not to mention Charley (2004) and Ian (2022) looked like shoe-in Tampa Bay hits yet somehow they hit SW Florida.

It’s not a “shield” for Tampa area as much as it is the very warm waters of the Peace River that “lures” the storms in to SW FL coast.

[Ubuntwo]

There is no such thing as a Florida Shield when Debby hit this year, Idalia last year and Nicole & Ian in 2022.

Until a center forms, it’s best for all to watch.

From his perspective in the Tampa area, it might feel like there is a shield since it has been over 100 years since that area as seen Major hurricane impacts (1921) not to mention Charley (2004) and Ian (2022) looked like shoe-in Tampa Bay hits yet somehow they hit SW Florida.

It’s not a “shield” for Tampa area as much as it is the very warm waters of the Peace River that “lures” the storms in to SW FL coast.

Water temps do not guide storms, this is another common misconception (although it kinda feels like they should!). It is the angle of the coastline which takes a very delicate troughing setup to directly strike.

[Spacecoast]

https://i.imgur.com/0LzllYt.png

Red is Operational runs, purple is control run, green is ensemble mean, and light blue is individual members. You can see the decline in accuracy as the days go out, yet the ensemble mean remains the most accurate product from the model runs 4+ days out

Absolutely.
Unfortunately , TT, and Weathernerds do not output ensemble means, just the individual members. Most S2K posts do not show control member, or the mean tracks.
This requires the user to 'visualize', or imagine where the mean track really is, and whether more members are east, or west of a given location
Once the storm gets invested, TT starts displaying on it's current storm page, and weathernerds displays mean track on it's TC Guidance page.

One situation where the Ensemble mean may be less accurate is 'fork in the road' bifurcation. i.e 50% go west, 50% go east, and 0% go north. The mean track would be inaccurate in this case.

My order of accuracy is
1. NHC track (once available)
2. Consensus of operational (or an 'ensemble' of operationals) like TVCN,etc
3. Consensus of Ensemble means, or super-ensemble mean. (Tomer Burg used to generate these). I Think FSSU also.
4. Ensemble means (EEMN, AEMN, CEMN).

Most of these are difficult to find until invest time.

[Blown Away]

18z GEFS… Lots of uncertainty…

[AtlanticWind]

[url]https://i.postimg.cc/W3pgTT9L/IMG-0243.jpg [/url]

18z GEFS… Lots of uncertainty…

You don’t get much more uncertain than that

[Blown Away]

GEFS trending back E today…

[LAF92]

[url]https://i.postimg.cc/BvttgpnD/gfs-ememb-lowlocs-watl-fh192-trend.gif [/url]

GEFS trending back E today…

To me it just shows more uncertainty than ever before

[floridasun]

have notice that upper low over florida causing some shear over northern part of Caribbean

[Blown Away]

NHC’s development area is leaning left and most of the GEFS are right…

[sphelps8681]

I guess we can say they can trend all day long one way or another. And then do the flip flopping all around. But we still don't have a center yet. No models to me should be correct until a center forms. Correct me if I am wrong. This is what I always hear. Hyping one area or another does not help anyone at this point. It could literally be a Nothing-Burger. We all need to be patient. To many on here that depend on the things that are said to be prepared are looking for accurate information. Not something that could or would have. From Texas to Florida is all in play at this point.

[SconnieCane]

Have we set a record for the longest pre-invest thread, yet? How about the longest for one where the 48-hour development chances are still "near 0 percent"?

[Spacecoast]

Formation chance through 48 hours...low...near 0 percent.
I would say 2 percent.

[Ubuntwo]

[url]https://i.postimg.cc/KzLhN3Sx/IMG-0245.jpg [/url]

NHC’s development area is leaning left and most of the GEFS are right…

It’s the possible development area, not track. If it is as far east as peninsular Florida, it will have developed in the western Caribbean vs the Gulf.

[Ubuntwo]

Have we set a record for the longest pre-invest thread, yet? How about the longest for one where the 48-hour development chances are still "near 0 percent"?

To be expected now that the NHC outlooks go out to 7 days instead of 5.

[cycloneye]

Have we set a record for the longest pre-invest thread, yet? How about the longest for one where the 48-hour development chances are still "near 0 percent"?

Closing in on the record 1075 posts from the pre Francine thread.

[Ubuntwo]

All but 2 members of the 12z Euro ensemble develop. That's 96% developing. The spread is colossal and about as wide as I've seen for a storm this (relatively) close to development. From a broad, whole gyre type TS to compact major hurricanes, and tracks buried in the Bay of Campeche to quickly curving through South Florida.

[Steve]

ICON looking like a higher end Cat 2 maybe headed to Alabama or NWFL at 180 hours. Upper 960’s and room to deepen though I haven’t looked at 500 yet.

https://www.pivotalweather.com/model.ph ... &dpdt=&mc=