ATL: FLORENCE - Post-Tropical - Discussion

[MississippiWx]

Florence is heading into an area that has been favorable for tropical cyclones all season. While the systems that have developed there have been non-tropical in nature, they eventually became true warm core lows. This area has sea surface temps well above normal, and if the upper level winds allow, this will be a formidable storm on approach to the US/Bermuda. Crazy that it’s a Category 4 now. It’s very difficult for a hurricane of this magnitude to make it all the way across the Atlantic to the US, especially at this latitude. I have my doubts because of that, but the ridging that has been in place across the East makes you wonder if it’s possible as long as Florence misses the first trough. Interesting times.

[JaxGator]

I can't post the Gif that this Met from Bermuda posted, but it does show the current ridge digging southward as Aric was showing on a steering graphic earlier.

Eric Drewitz
‏
@DrewitzWx@DrewitzWx
GOES16 VIS also shows well the ridging over the NE'rn US and Canadian Maritime sinking S'ward which will potentially help keep #Florence on the W'rn side of the model spread. The track is going to depend on this Bermuda-Azores High. #Tropics #Atlantic

[Kazmit]

It has gained quite a lot of latitude today.

[SconnieCane]

[quote="Ntxw"]Raw T's have dropped a bit from earlier today with the warming cloud tops. Still a solid major.



Great to see the ssd.noaa.gov floaters are back up for the Atlantic, at least for the moment. Would have liked to have one for Gordon, although it became kind of a moot point since he didn't take off like I was thinking he might.

[AutoPenalti]

I can't post the Gif that this Met from Bermuda posted, but it does show the current ridge digging southward as Aric was showing on a steering graphic earlier.

Eric Drewitz
‏
@DrewitzWx@DrewitzWx
GOES16 VIS also shows well the ridging over the NE'rn US and Canadian Maritime sinking S'ward which will potentially help keep #Florence on the W'rn side of the model spread. The track is going to depend on this Bermuda-Azores High. #Tropics #Atlantic

He was referring to this graphic on tropical tidbits.

[cycloneye]

00z Best Track stays at 115 kts.

AL, 06, 2018090600, , BEST, 0, 231N, 469W, 115, 953, HU

[Nimbus]

The current ridge is well outlined in the water vapor imagery and there is a weakness on the western periphery that might offer an escape path if the high rolls east far enough..
Major hurricanes tend to stir up the upper level steering environment so a lot can change in a few days.

The high with the clockwise circulation is centered off Cape Cod and there is a trough currently pulling through the great lakes.

[AutoPenalti]

The current ridge is well outlined in the water vapor imagery and there is a weakness on the western periphery that might offer an escape path if the high rolls east far enough..
Major hurricanes tend to stir up the upper level steering environment so a lot can change in a few days.

Can you outline the ridge for me because I can't recognize it..

[sunnyday]

Florence is far away, and I’ve heard Bermuda and the East coast mentioned, but I haven’t heard anything about Florida. Do they seem likely to be all clear down there? Just some opinions would be appreciated bc I know how storms can change Thank you.

[floridasun78]

Florence is far away, and I’ve heard Bermuda and the East coast mentioned, but I haven’t heard anything about Florida. Do they seem likely to be all clear down there? Just some opinions would be appreciated bc I know how storms can change Thank you.

i got feeling weakness will be their if stay strong high will pull it up i seen it gaining latitude today

[storm_in_a_teacup]

The first tweet of that bunch is probably the most important. We have a typhoon near Japan that is going to make significant impacts to the mid-latitude steering flow for a hurricane in the middle of the Atlantic. The models are all over the place because this is an extremely complex situation. Probably a lot more complex than normal.

Okay...super late reply (again, sorry) but what exactly do typhoons do to the mid-latitude steering? I've only heard about this maybe once before. Do other tropical cyclones affect it, or just typhoons in the Pacific?

[StormyWaters93]

The first tweet of that bunch is probably the most important. We have a typhoon near Japan that is going to make significant impacts to the mid-latitude steering flow for a hurricane in the middle of the Atlantic. The models are all over the place because this is an extremely complex situation. Probably a lot more complex than normal.

Okay...super late reply (again, sorry) but what exactly do typhoons do to the mid-latitude steering? I've only heard about this maybe once before. Do other tropical cyclones affect it, or just typhoons in the Pacific?

I'm really curious about this as well. Been looking into getting a meteorology degree since I'm passionate about weather and I teach myself about things related to it. Also, been stalking storm2k for about 2 years, but just now starting to get involved in the forums.


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[LarryWx]

Latest estimate of coordinates (as of 0Z):

AL, 06, 2018090600, , BEST, 0, 231N, 469W, 115, 953, HU

So it is still moving just as NW as it has been. 3 hours earlier it was at 22.7/46.6. So, it has moved 0.4N/0.3W since 5 PM. Still no shift back to the model consensus’ WNW. Just sayin’. Food for thought.

[AutoPenalti]

It's a very choppy set up.

[RL3AO]

The first tweet of that bunch is probably the most important. We have a typhoon near Japan that is going to make significant impacts to the mid-latitude steering flow for a hurricane in the middle of the Atlantic. The models are all over the place because this is an extremely complex situation. Probably a lot more complex than normal.

Okay...super late reply (again, sorry) but what exactly do typhoons do to the mid-latitude steering? I've only heard about this maybe once before. Do other tropical cyclones affect it, or just typhoons in the Pacific?

A common occurrence when a strong typhoon re-curves into the mid-latitudes of the west Pacific is the amplification (strengthening) of the ridges and troughs across the entire Pacific. These are commonly called Rossby Wave Trains. In this case, the typhoon merged into a mid-latitude cyclone coming off of Asia (the track of the typhoon shown by the black arrow near Japan. With the energy injected into the jet stream, you had an intensification of two ridges and two troughs downstream almost reaching the west coast of North America.



In this case, the "train" stopped before reaching North America and it's not really fair to say the typhoon with have a direct impact on Florence, but there will be an indirect one. The typhoon has led to a very chaotic pattern in the jet stream across the entire Pacific. Active and chaotic patterns are not good for models when it comes to making a 7 to 10 day forecast. And since what happens in the Pacific impacts the weather of the US and eventually the Atlantic, it makes it harder than usual to get an idea of the upper air pattern in the mid-latitudes beyond five days right now. And that upper air pattern in 7 to 10 days is absolutely key to Florence potentially impacting North America or going safely out to sea.

[Blown Away]

Last few frames Flo seems to be smoothing out to WNW instead on NW... Look at that eye, almost looks annular...

[Hurricane Andrew]

Last few frames Flo seems to be smoothing out to WNW instead on NW... Look at that eye, almost looks annular...

What a beauty...eye has clearly expanded over the last hour or two.

[Kazmit]

Last few frames Flo seems to be smoothing out to WNW instead on NW... Look at that eye, almost looks annular...

What a beauty...eye has clearly expanded over the last hour or two.

So much for the "weakening".

[Hammy]

Looks like it's cleared out too.

[drewschmaltz]

48H 05/1800Z 21.5N 48.4W 50 KT 60 MPH

This seems quite a bit off for an advisory issued only 48 hours ago. Not even half of the current intensity.