ATL: INVEST 90L - Discussion

[abajan]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Jul 25 2021

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A low pressure area located about 150 miles east of Daytona Beach,
Florida, is producing disorganized shower and thunderstorm activity
mainly over the southern part of its circulation. Preliminary
reports from an Air Force Reserve reconnaissance aircraft indicate
that this system has changed little in strength since yesterday.
Environmental conditions are marginally conducive for development,
and a tropical depression could still form later today or early
Monday while the low drifts westward or west-northwestward toward
the northeast coast of Florida. Interests in Florida should
continue to monitor the progress of this system.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

$$
Forecaster Pasch

Wow, still at 50%!
Interesting.

[psyclone]

Good thing i don't make bets! I would have put my chips on a reduced probability and lost...again!

[AlphaToOmega]

The NHC is likely still keeping the 50% chance because of model support. 15 global and hurricane models show Invest 90L developing.

[Category5Kaiju]

The NHC is likely still keeping the 50% chance because of model support. 15 global and hurricane models show Invest 90L developing.
https://i.postimg.cc/bYHHcG6F/90-L-intensity-latest.png

Into a TD? Perhaps, although not many show TS. We’ll have to wait though and see what happens soon, it still has some time over water

[NDG]

This can still develop if it somehow recurves out to sea. It is too early to make a definitive judgement about the development of this system.

You should at least get an E for effort & persistency for looking for anything that "could" make it develop

The NHC still has it at a 50% chance for a reason. Plus, the HWRF still shows development. I still need to see what the 12Z ECMWF says in terms of chances. We are also approaching diurnal minimum. The GEFS ensembles and hurricane models are split about whether or not this system will recurve out to sea or go into the Gulf.

This looks like a mesoscale convective vortex. We got Hurricane Barry out of one. I still think it has a chance.

Are you looking at the same HWRF that I am looking?
This is not an MCV any more, it clearly is a weak surface low pressure now. It might have been a couple of days ago but since then the convection has died off after tracking to the south.
BTW, the 12z Euro still shows no development.

[InfernoFlameCat]

Convergence is helping convection. If this becomes a tc I predict this short convective burst will dwindle and then refire into deep convection. if not it will dwindle into nothingness.

[xironman]

Nice little llc found by recon, hard to believe there is a 29kt surface wind.

[Nimbus]

There is a tiny surface circulation which we didn't expect to do much with the dry air, didn't even develop a squall line across south Florida that I was expecting.

[AlphaToOmega]

The latest ECMWF 12Z run has increased the chance of the development Invest 90L from 10-20% to 30-40%. There is also a subtropical feature that the NHC is not monitoring for some reason.

https://www.ecmwf.int/en/forecasts/charts/catalogue/medium-tc-genesis?facets=Parameters,Tropical%20cyclones&time=2021072512,72,2021072812&projection=classical_global&layer_name=genesis_td

[wwizard]

This is your reminder that storms can form on land

OMG! Stop trying to wish this thing into existance.

[Sciencerocks]

[Hypercane_Kyle]

Ironically, the weather here in Tampa the past two days has been the best since May.

[toad strangler]

There literally looks like nothing is left of 90L.

[NDG]

The latest ECMWF 12Z run has increased the chance of the development Invest 90L from 10-20% to 30-40%. There is also a subtropical feature that the NHC is not monitoring for some reason.

https://www.ecmwf.int/en/forecasts/charts/catalogue/medium-tc-genesis?facets=Parameters,Tropical%20cyclones&time=2021072512,72,2021072812&projection=classical_global&layer_name=genesis_td

This is a horrible chart to go by for tropical development, IMO, if you go to the 12z ensembles not one ensemble shows this developing further than the current weak state. The same chart shows high chances for development in the southern Caribbean which we know is not happening. This chart must be showing chances for any little weak surface low to develop like 90L but not that it will become a TD or TS.

[Jr0d]

Still looks horrible.

I was expecting more afternoon thunderstorm across Florida today...but they seemed repressed a bit. Maybe tomorrow when this little swirl is on the coast.

Kind of surprised it's still at 50%....seems to me the chance of development is getting lower by the hour.

[AlphaToOmega]

Still looks horrible.

I was expecting more afternoon thunderstorm across Florida today...but they seemed repressed a bit. Maybe tomorrow when this little swirl is on the coast.

Kind of surprised it's still at 50%....seems to me the chance of development is getting lower by the hour.

I believe the NHC is still keeping it at 50% based on model guidance.

[Category5Kaiju]

Oof, now a 40/40 chance of forming..

[HurricaneBelle]

Ironically, the weather here in Tampa the past two days has been the best since May.

If you like oppressive heat unbroken by any cloud cover or cooling showers, that is.

[AlphaToOmega]

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Jul 25 2021

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. Satellite and radar data indicate that showers associated with a low
pressure area located about 150 miles east-southeast of
Jacksonville, Florida, remain disorganized and limited in coverage.
However, environmental conditions are marginally conducive for
development, and a tropical depression could still form overnight or
on Monday while the low moves slowly west-northwestward or
northwestward, reaching the coast of northeastern Florida or Georgia
Monday evening or Monday night. Interests in these areas should
continue to monitor the progress of this system.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

Forecaster Berg

[TallyTracker]

This reminds me of STS Andrea in 2007 except weaker. Same area and sparse convection.