ATL: ISAIAS - Post-Tropical - Discussion

[Shell Mound]

Something I was thinking about is a similarity to the 2017 season.

The real big kickoff that year was Harvey hitting Texas. This year we currently have Hanna intensifying and getting ready to make landfall in Texas.

After Harvey, we had the I storm, Irma, become a powerful long track CV hurricane. After Hanna, this could become Isaias, a powerful long track CV hurricane (potentially). And it's July 24th.

The fact that this is designated 92L and is likely posing a threat to the same areas that Irma (and Maria) impacted is also somewhat ominous.

Maybe this will end up as a blend of 1926, 1928, Andrew, Irma, and Maria. The 00Z EPS has trended stronger and slightly northward compared to 00Z.

This would imply a greater threat to the Leeward Islands, Puerto Rico, the southern Bahamas, and possibly FL/GA farther down the line, so to speak.

[Chris90]

The fact that this is designated 92L and is likely posing a threat to the same areas that Irma (and Maria) impacted is also somewhat ominous.

Maybe this will end up as a blend of 1926, 1928, Andrew, Irma, and Maria. The 00Z EPS has trended stronger and slightly northward compared to 00Z.

This would imply a greater threat to the Leeward Islands, Puerto Rico, the southern Bahamas, and possibly FL/GA farther down the line, so to speak.

Are there some really notable storms that came from 92Ls? I went back to the archives and Irma was a 93L and Maria a 96.

I am feeling fairly bullish on this one right now. It looks good with some really good convection and I think there's a decent chance it becomes the season's first major.

I also saw your post in the thread for Cat 5 landfalls, I thought it was really interesting that the 1825 hurricane had a measured pressure of 918mb in July, that certainly suggests a Cat 5 storm, especially in that area of the basin. Hopefully this potential storm doesn't make an impact like that.

[Shell Mound]

The fact that this is designated 92L and is likely posing a threat to the same areas that Irma (and Maria) impacted is also somewhat ominous.

Maybe this will end up as a blend of 1926, 1928, Andrew, Irma, and Maria. The 00Z EPS has trended stronger and slightly northward compared to 00Z.

This would imply a greater threat to the Leeward Islands, Puerto Rico, the southern Bahamas, and possibly FL/GA farther down the line, so to speak.

Are there some really notable storms that came from 92Ls? I went back to the archives and Irma was a 93L and Maria a 96.

I am feeling fairly bullish on this one right now. It looks good with some really good convection and I think there's a decent chance it becomes the season's first major.

I also saw your post in the thread for Cat 5 landfalls, I thought it was really interesting that the 1825 hurricane had a measured pressure of 918mb in July, that certainly suggests a Cat 5 storm, especially in that area of the basin. Hopefully this potential storm doesn't make an impact like that.

Another interesting coincidence: both Irma and our current 92L were detected by global and even weekly models (such as the CFSv2) up to several weeks out.

[Shell Mound]

I see two possible scenarios for 92L:

1) Stronger solution: most probable outcome, in my view, given high PWATs (thanks, Gonzalo!) and low VWS; two possible variants
*a) over or just east of Puerto Rico → easternmost Bahamas → bend back toward Georgia coastline? Analogs: 1881, 1893, 1898 GA hurricanes
*b) Mona Passage → southernmost Bahamas → Southeast Florida (Miami area)? Analogs: 1903, 1926 hurricanes + Georges ‘98, Irma ‘17

2) Weaker solution: less likely; over or just south of the mountainous Greater Antilles

[gatorcane]

https://twitter.com/derekortt/status/1286914114380595201

https://twitter.com/derekortt/status/1286917676716130304

That has been my thinking on this invest but model support is increasing so that can’t be ignored. Latest visible still shows the SAL depleting the northern half of the wave from any significant convection as it gets stretched.

[gatorcane]

Up to 60%:

A tropical wave is producing an area of disorganized showers and
thunderstorms a few hundred miles southwest of Cabo Verde Islands.
The wave is expected to move westward at about 15 mph during the
next several days, and a tropical depression could form by early
next week when the system reaches the western tropical Atlantic.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...60 percent.

[Blown Away]

Classic setup with location and time of year for 92L as he makes his way towards Caribbean & possibly CONUS.

[cycloneye]

[hurricaneCW]

https://twitter.com/derekortt/status/1286914114380595201

https://twitter.com/derekortt/status/1286917676716130304

That has been my thinking on this invest but model support is increasing so that can’t be ignored. Latest visible still shows the SAL depleting the northern half of the wave from any significant convection as it gets stretched.

It's still a little early for CV storms and SAL is a factor until mid August so I wouldn't be shocked if this struggles for a while.

[cycloneye]

12z Best track:

AL, 92, 2020072512, , BEST, 0, 111N, 286W, 25, 1010, WV, 34, NEQ, 0, 0, 0, 0, 1012, 120, 50, 0, 0, L, 0, , 0, 0, INVEST, M, 0, , 0, 0, 0, 0, genesis-num, 021,

[cycloneye]

Got a feeling this thread is going to be a really long one. Let the games begin.


Sent from my iPhone using Tapatalk

It has started slow for two reasons.

1-Is still very far from any land but as soon is code red,things will pick up.

2-Attention is focused on Hurrricane Hanna but once it's gone, all the focus will be on this thread.

[chaser1]

Got a feeling this thread is going to be a really long one. Let the games begin.


Sent from my iPhone using Tapatalk

It has started slow for two reasons.

1-Is still very far from any land but as soon is code red,things will pick up.

2-Attention is focused on Hurrricane Hanna but once it's gone, all the focus will be on this thread.

For those outside of Texas, this is the entree being served up next. Not sure i'm liking the models hinting toward a slight northward track shift. That could be bad for P.R. and potentially S. Fla too. Plenty of time to see though since we're at least 48 hours from knowing where a COC might finally form. Broad LLC seems easy enough to spot but vigorous convection to it's west might well play a role where a true center eventually co-locates. Side note..... does everyone realize how close we got to seeing 3 simultaneous storms occurring at the same time in July?? Has that ever even occurred? Heck, how many times have we even seen two named storms at the same time in July?

[Nimbus]

No TUTT activity discernible to my eye on the water vapor imagery yet and I haven't looked at the polar vortex lobes. Generally if we get an early spin up with a hurricane forming before -50W there is more poleward motion and the upper air pattern becomes more active raising chances for a TUTT or shortwave induced recurve.
Gonzalo was fighting dry air all the way west.

[HurricaneFrances04]

Cherry

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sat Jul 25 2020

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

The National Hurricane Center is issuing advisories on Tropical
Depression Gonzalo, located just of northwest of Trinidad.

The National Hurricane Center is also issuing advisories on
Hurricane Hanna, located over the western Gulf of Mexico just
offshore the southern coast of Texas.

1. A tropical wave is producing a broad area of cloudiness and
disorganized showers and thunderstorms several hundred miles
southwest of Cabo Verde Islands. The wave is expected to move
westward at about 15 mph during the next several days, and a
tropical depression is likely form early next week when the system
reaches the central tropical Atlantic.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...high...70 percent.

Forecaster Stewart

[SFLcane]

Code red folks!

[cycloneye]

The stakes are raised bigtime.

[abajan]

Code red folks!

Every time I see Code Red mentioned on these forums, the first thing that comes to mind is this sound. Perhaps I used to watch Star Trek a tad too much.

[aspen]

I had a feeling they would pull the Cherry Trigger for 2 pm. Model support is at an all-time high with this, and many have development in as little as 48-72 hours.

[Shell Mound]

Hopefully, this will somehow find a way to miss the Leeward Islands/Puerto Rico to the north and then curve just east of the Bahamas and the mainland U.S.

[gatorcane]

Models have trended stronger and more towards a recurve in the 12Z suite (well I guess the Euro is the exception) after going through the NE Lesser Antilles. So it is possible but too early to know yet