ATL: INVEST 90L - Discussion

[cycloneye]

AL, 90, 2023112318, , BEST, 0, 264N, 424W, 35, 1005, EX, 34, NEQ, 0, 0, 0, 150, 1011, 220, 120, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 049, SPAWNINVEST, al752023 to al902023,

https://ftp.nhc.noaa.gov/atcf/btk/bal902023.dat

Thread at Talking Tropics forum that was the topic for this area.

https://www.storm2k.org/phpbb2/viewtopi ... 4#p3054874

[cycloneye]

Nothing impressive so far.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
700 PM EST Thu Nov 23 2023

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

1. Central Subtropical Atlantic (AL90):
A non-tropical area of low pressure located in the central
subtropical Atlantic is producing winds up to gale-force while
associated with disorganized shower and thunderstorm activity. This
system could become a subtropical or tropical storm over the next
few days as it gradually loses its frontal characteristics while
it moves northeastward. By early next week, its chances of
subtropical or tropical development should end as the system moves
over cooler waters. For more information on this system, including
gale warnings, please see High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...medium...40 percent.

High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php

Forecaster Papin

[cycloneye]

Hey folks, I dont want to be the only one posting in this thread. Come and participate to discuss about this low pressure.

AL, 90, 2023112400, , BEST, 0, 264N, 416W, 35, 1005, EX

Some convection tries to build near the low.

[tolakram]

I guess I'm in shock it was tagged an invest.

[Hurricane2022]

Hey folks, I dont want to be the only one posting in this thread. Come and participate to discuss about this low pressure.

AL, 90, 2023112400, , BEST, 0, 264N, 416W, 35, 1005, EX

Some convection tries to build near the low.


https://i.imgur.com/PtNQCqc.gif

I'm sorry if I'm rude but I don't think there's much to discuss about this much...So far, it is a large system, somewhat anemic and a little slow to develop. I'm becoming somewhat skeptical about a development into a (Sub)tropical Storm from this system...but it's best to wait a little longer before making definitive statements

[InfernoFlameCat]

Yeah, it’s not looking too good. Low is too broad and it seems too dry to get tropical. Subtropical maybe.

[LarryWx]

Because this thread is so quiet, I’m assuming that a separate models thread isn’t needed for this. Thus, here’s the 0Z UKMET:

TROPICAL STORM 90L ANALYSED POSITION : 26.0N 41.7W

ATCF IDENTIFIER : AL902023

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 24.11.2023 0 26.0N 41.7W 1009 29
1200UTC 24.11.2023 12 27.8N 39.8W 1009 27
0000UTC 25.11.2023 24 29.8N 37.1W 1008 31
1200UTC 25.11.2023 36 32.8N 35.1W 1008 36
0000UTC 26.11.2023 48 36.6N 33.3W 1005 29
1200UTC 26.11.2023 60 39.2N 31.7W 1003 31
0000UTC 27.11.2023 72 40.6N 30.2W 1002 31
1200UTC 27.11.2023 84 42.6N 26.7W 1003 33
0000UTC 28.11.2023 96 44.2N 22.6W 1003 35
1200UTC 28.11.2023 108 45.6N 18.3W 1002 35
0000UTC 29.11.2023 120 46.6N 12.0W 999 32
1200UTC 29.11.2023 132 47.8N 3.4W 990 35
0000UTC 30.11.2023 144 48.8N 3.6E 987 22
1200UTC 30.11.2023 156 CEASED TRACKING

[cycloneye]

I guess I'm in shock it was tagged an invest.

I now agree 100%.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
700 AM EST Fri Nov 24 2023

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

1. Central Subtropical Atlantic (AL90):
A non-tropical area of low pressure located over the central
subtropical Atlantic is producing disorganized shower and
thunderstorm activity. This system could acquire some subtropical
or tropical characteristics during the next day or two while it
moves northeastward at 15 to 20 mph. The chance for subtropical or
tropical development is likely to end by Sunday as the low moves
over much colder waters.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...low...30 percent.

Forecaster Kelly

[cycloneye]

Nothing to see here.

[cycloneye]

Keeps going down.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
100 PM EST Fri Nov 24 2023

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

Central Subtropical Atlantic (AL90):
A non-tropical area of low pressure located over the central
subtropical Atlantic is producing disorganized shower and
thunderstorm activity. This system could acquire some subtropical or
tropical characteristics during the next day or so while it moves
northeastward at 15 to 20 mph. Thereafter, the low will be moving
over much colder waters ending the chance of subtropical or tropical
development.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Kelly

[LarryWx]

12Z UKMET much less impressed and dissipates the low within 36 hours: Bones, where are you?

TROPICAL DEPRESSION 90L ANALYSED POSITION : 27.5N 39.0W

ATCF IDENTIFIER : AL902023

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 24.11.2023 0 27.5N 39.0W 1008 28
0000UTC 25.11.2023 12 29.2N 36.9W 1007 30
1200UTC 25.11.2023 24 33.0N 34.2W 1007 37
0000UTC 26.11.2023 36 CEASED TRACKING

[cycloneye]

He did the tagging.

NWS National Hurricane Center Miami FL
700 PM EST Fri Nov 24 2023

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

Central Subtropical Atlantic (AL90):
Shower and thunderstorm activity has not yet become better organized
with a non-tropical area of low pressure located over the central
subtropical Atlantic. There is still a chance the system could
acquire some subtropical or tropical characteristics during the next
day or so as it continues moves northeastward. Thereafter, the low
will begin moving over much colder waters, likely ending its chances
of subtropical or tropical development by early next week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Papin

[USTropics]

NHC just wanted to end the season where they started (90L):

First invest of the season all the way back in January with the post-season subtropical system

AL, 90, 2023011618, , BEST, 0, 378N, 636W, 50, 986, LO, 50, NEQ, 0, 60, 60, 0, 1012, 500, 50, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 001,

In all seriousness though, if I had to ponder why this was tagged, the main reason was shipping interests and some earlier GFS runs had the potential for another deep system developing in the North Atlantic that could impact Europe (similar to the significant system that underwent bombogenesis a few weeks ago).

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
700 AM EST Sat Nov 25 2023

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

Eastern Subtropical Atlantic (AL90):
Showers and thunderstorms remain disorganized in association with a
non-tropical area of low pressure located over the eastern
subtropical Atlantic. This system is forecast to move
north-northeastward at 20 to 25 mph toward much colder waters and
develop more pronounced frontal features during the next day or so,
ending its chances of subtropical or tropical development.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

$$
Forecaster Kelly

[johngaltfla]

And now, let me the one of "those" guys; we can stick a fork in this season.

Off to watch the ENSO updates for months to come now.

[cycloneye]

And that is it.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
100 PM EST Sat Nov 25 2023

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

Eastern Subtropical Atlantic (AL90):
A non-tropical low pressure system located over the eastern
subtropical Atlantic is producing disorganized showers and
thunderstorms. The low is forecast to move north-northeastward at 20
to 25 mph over much colder waters later today and tonight, and
become embedded in a cold air mass with frontal boundaries.
Therefore, it is unlikely that the low will transition to a
subtropical or tropical cyclone.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...near 0 percent.

$$
Forecaster Kelly