ATL: WANDA - Post-Tropical - Discussion

[zzh]

AL, 94, 2021102600, , BEST, 0, 330N, 746W, 40, 1002, LO, 34, NEQ, 40, 40, 0, 0, 1007, 100, 40, 0, 0, L, 0, , 0, 0, INVEST, M, 0, , 0, 0, 0, 0, genesis-num, 049, SPAWNINVEST, al742021 to al942021,

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

[Sciencerocks]

[Teban54]

Is this the first orange in October?

[Teban54]

1. A deepening, non-tropical low pressure system with gale-force winds
is located about 250 miles east-northeast of Cape Hatteras, North
Carolina. This gale area is forecast to move north-northeastward
today, and could acquire some limited subtropical characteristics
before it merges with a frontal system by this afternoon. The
extratropical low is then expected to meander off the mid-Atlantic
and northeast U.S. coasts tonight and Wednesday, bringing rain and
wind impacts to portions of those areas. After that time, the low
is expected to move eastward away from the U.S. coast, and could
again acquire some subtropical characteristics while it moves
eastward or southeastward over the warmer waters of the central
Atlantic. For more information on this system, including storm
warnings, see products issued by your local National Weather Service
office and High Seas Forecasts issued by the National Weather
Service.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...50 percent.

[jconsor]

 https://twitter.com/yconsor/status/1452901751124807681

[Ubuntwo]

Is this the first orange in October?

There was also 92L offshore the Outer Banks.

[Sciencerocks]

[aspen]

This storm sucks. If something of this magnitude happened in January instead of October, we’d likely be getting nearly a foot of snow. Driving conditions are garbage and are made worse by the covering of now-wet leaves on the road, and my university was having power issues; they didn’t have any during Ida despite its much higher rainfall.

[Sciencerocks]

How does this compare to the perfect storm of 1991?

[Hurricanehink]

How does this compare to the perfect storm of 1991?

Two major differences. The 1991 storm originated from a nor’easter near Atlantic Canada, which moved southwestward. Second, the 1991 storm was fueled by the remnants of Hurricane Grace near Bermuda. The current storm is perhaps more reminiscent of Tropical Storm Melissa in 2019.

Here’s a satellite loop of the 1991 storm
[youtube]https://youtu.be/MQBq25SwWxM[/youtube]

Here’s a satellite loop of 2019’s Melissa
[youtube]https://youtu.be/sdCXdrTMmJk[/youtube]

[xironman]

Impressive northeaster if nothing else, any time you get 30ft wave heights just offshore the storm has it going on.
https://www.ndbc.noaa.gov/station_page. ... tion=44029

5-day plot - Wind Direction Wind Direction (WDIR): NNE ( 30 deg true )
5-day plot - Wind Speed Wind Speed (WSPD): 38.9 kts
5-day plot - Wind Gust Wind Gust (GST): 50.5 kts
5-day plot - Wave Height Wave Height (WVHT): 32.2 ft
5-day plot - Dominant Wave Period Dominant Wave Period (DPD): 11 sec
5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES): 29.31 in
5-day plot - Air Temperature Air Temperature (ATMP): 52.2 °F
5-day plot - Visibility Visibility (VIS) (0 to 1.6 nmi): 1.6 nmi
5-day plot - Wind Chill Wind Chill (CHILL): 43.5 °F
5-day plot - Wind Speed at 10 Meters Wind Speed at 10 meters (WSPD10M): 44.7 kts
5-day plot - Wind Speed at 10 Meters Wind Speed at 20 meters (WSPD20M): 48.6 kts

[aspen]

Quite an impressive non-tropical low, but it needs to develop deep convection to tighten up its core if it ever wants to become a TC. Chances are already going down.

If the Mediterranean can produce a TC in October, surely the Nina-favored Atlantic should be able to.

[Teban54]

1. A deep, non-tropical low pressure system with storm-force winds is
centered more than 200 miles south-southeast of Cape Cod,
Massachusetts. The extratropical low is forecast to bring wind
impacts to portions of the northeastern U.S. coast for several more
hours as it begins to move eastward, away from the United States.
Thereafter, the low could acquire some subtropical characteristics
while it moves eastward or southeastward over the warmer waters of
the central Atlantic through this weekend. For more information on
this system, including storm warnings, see products issued by your
local National Weather Service office and High Seas Forecasts issued
by the National Weather Service.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...30 percent.

[skyline385]

Quite an impressive non-tropical low, but it needs to develop deep convection to tighten up its core if it ever wants to become a TC. Chances are already going down.

If the Mediterranean can produce a TC in October, surely the Nina-favored Atlantic should be able to.

Well right now, the Atlantic doesn't seem to be acting like a Nina-favored one...

[aspen]

Quite an impressive non-tropical low, but it needs to develop deep convection to tighten up its core if it ever wants to become a TC. Chances are already going down.

If the Mediterranean can produce a TC in October, surely the Nina-favored Atlantic should be able to.

Well right now, the Atlantic doesn't seem to be acting like a Nina-favored one...

The question is why, and whether or not it has to do with the state of this La Niña. If the 2021-22 Nina is going to behave differently than a normal Nina, then it’ll have major impacts for CONUS winter forecasts over the next several months.

[hurricanes1234]

Down to 30% on the latest TWO. Another October 2021 bust.

[skyline385]

Quite an impressive non-tropical low, but it needs to develop deep convection to tighten up its core if it ever wants to become a TC. Chances are already going down.

If the Mediterranean can produce a TC in October, surely the Nina-favored Atlantic should be able to.

Well right now, the Atlantic doesn't seem to be acting like a Nina-favored one...

The question is why, and whether or not it has to do with the state of this La Niña. If the 2021-22 Nina is going to behave differently than a normal Nina, then it’ll have major impacts for CONUS winter forecasts over the next several months.

That is the question on a lot of people's minds over here probably. I have been curious myself as well on how the winter plays out...

[Sciencerocks]

[jconsor]

Thread on #94L which is gaining convection and will likely be named soon as a subtropical storm. It could briefly complete transition to tropical in the next day or two, before shear increases.

Wouldn't rule out the possibility it becomes a strong STS or hurricane by mid next week as shear decreases again, but first it has to weather the rapid ramp-up in shear over the weekend.

 https://twitter.com/yconsor/status/1453690696695795722




 https://twitter.com/yconsor/status/1453691896518303751

[tolakram]

Saved loop