ATL: INVEST 90L - Discussion

[Nancy Smar]

AL, 90, 2020112800, , BEST, 0, 455N, 181W, 30, 1000, EX

[Dean_175]

Seasons often produce "interesting" systems like these, which don't develop, as a last sign of life before finally pettering out for the off season.

[aspen]

The HWRF has this become a hurricane by Day 4. Hurricane Kappa in early December...only in 2020 lol.

[Sciencerocks]

A non-tropical low pressure system over the far eastern Atlantic is
expected to move southward about midway between Portugal and the
Azores over the weekend. Environmental conditions are forecast to be
marginally conducive for the low to acquire subtropical
characteristics early next week while it meanders just to the north
of the Canary Islands. Additional information on this system can be
found in high seas forecasts issued by Meteo France.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...30 percent.

[cycloneye]

2 PM.

A strong, non-tropical low pressure system over the far eastern
Atlantic is expected to move southward about midway between Portugal
and the Azores through the weekend. Environmental conditions could
allow the low to acquire subtropical characteristics early next week
while it meanders just to the north of the Canary Islands. By the
middle of next week, environmental conditions are forecast to become
unfavorable for further development. Additional information on this
system can be found in high seas forecasts issued by Meteo France.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

[CrazyC83]

It would be a much more fitting end to the season than the last storm becoming a category 5 monster though. At least this is in a more traditional position for a late-season last hurrah.

[ElectricStorm]

I have a feeling this will be the last real chance of development this season. Although the way this year has gone, I wouldn't be surprised if we get another one in December.

[CrazyC83]

I have a feeling this will be the last real chance of development this season. Although the way this year has gone, I wouldn't be surprised if we get another one in December.

Some models show a SW Caribbean system next week.

[supercane4867]

Models seem to be very optimistic on the development of a subtropical storm. I think the chance we get Kappa out of this is high.

[AJC3]

A strong and large non-tropical low pressure system over the far
eastern Atlantic is expected to continue moving southward during the
next day or so. This low could acquire subtropical characteristics
in a couple of days while it meanders just to the north of the
Canary Islands. By the middle of the week, environmental conditions
are forecast to become unfavorable for further development.
Additional information on this system can be found in High Seas
Forecasts issued by Meteo France.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
700 AM EST Sun Nov 29 2020

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

A strong and large non-tropical low pressure system over the far
eastern Atlantic is expected to continue moving southward during the
next day or so. The associated shower and thunderstorm activity has
become a little better organized this morning, and the low could
acquire subtropical characteristics in a couple of days while it
meanders just to the north of the Canary Islands. By the middle of
the week, environmental conditions are forecast to become
unfavorable for further development. Regardless of development,
this system could cause strong winds and locally heavy rains in the
Madeira Islands later today through Monday. Additional information
on this system can be found in High Seas Forecasts issued by Meteo
France.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...medium...40 percent.

&&
High Seas Forecasts issued by Meteo France can be found under WMO
header FQNT50 LFPW.

$$
Forecaster Beven

[AJC3]

Latest GOES-16 visible satellite image...

[Sciencerocks]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
100 PM EST Sun Nov 29 2020

Shower and thunderstorm activity associated with a strong and large
non-tropical low pressure system over the far eastern Atlantic has
become a little better organized since yesterday. This low could
acquire subtropical characteristics during the next couple of days
while it meanders just to the north of the Canary Islands. By the
middle of the week, environmental conditions are forecast to become
unfavorable for further development. Regardless of development, this
system should cause strong winds and locally heavy rains in the
Madeira Islands through Monday or Tuesday. Additional information
on this system can be found in High Seas Forecasts issued by Meteo
France.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

[Sciencerocks]

[aspen]

This is starting to look less likely to develop. No model, not even the HWRF, shows this concentrating into a tropical or subtropical system, and now there’s a time limit before it gets ripped to shreds. 90L might end up as yet another failed AOI.

[HurricaneEnzo]

Doesn't look like it has any tropical characteristics but it sure is a big impressive area of low pressure!

https://www.tropicaltidbits.com/sat/sat ... product=ir

[CrazyC83]

The low is well defined and clear. Just need central convection closer to the low center.

[CrazyC83]

The OPC analysis shows a clearly non-frontal low. It seems the lack of convection is the limiting factor - how much more is needed for an STC?

[Hurricanehink]

http://moe.met.fsu.edu/cyclonephase/ - it's still slightly cold core, or neutral, according to its phase diagram. The models have it transitioning overnight though.

[CrazyC83]

Convection has increased somewhat this evening. It isn't there yet though but might have a shot.