ATL: ISAIAS - Post-Tropical - Discussion

[NDG]

Pretty good gusts in SW P.R.

 https://twitter.com/AbimaelTiempoPR/status/1288839689122852864

[Airboy]

Peak (10s) Flt. Lvl. Wind: 59 kts (67.9 mph) in the NE of the LLC

[DestinHurricane]

https://twitter.com/Meteophile1/status/1288839461359493120?s=19

Reminds me of Irma skidding up the coast of Cuba.

[Aric Dunn]

I remember David very well back in "79. This indeed has a chance to mimick that analog just in terms of track.

more closely relates to Debbie.

David was a Cat 5 hurricane before getting badly disrupted after striking Hispaniola. However,he recovered to become a Cat 1 cane and moved North , making landfall in Palm Beach, then.moved parallel up along the Florida East Coast, with the eyewall passing just 35 miles off of Jacksonville Beach. .It made a second landfall up the coast near Savannah. Jax had storm force winds up to 50 mph on the outer edge of the western eyewall as he passed just east of here off the coast.

I was talking about the approach and interaction with Hispaniola.

David plowed through the middle.

Debbie got the SE circulation caught up in the terrain and turned into a tether ball. lol

[chaser1]

Outflow has consistently been impressive to the west and north however here too will this storm be tested in regards to how strong it may or may not be as it approaches Florida and the W. Bahamas. A sharp drop off in convection would dramatically reduce it's ability to stave off increasing southwesterly shear with time. Those massive mountains just wreck a tropical cyclones' circulation but then again, Isaias' overall envelop is pretty sprawling. It'll be interesting to see if enough of a wave axis (or broad circulation around it's COC) still exists to allow strong convection to pop both north and south of The Rock and continue to fuel the upper anticyclone above the storm. Here is where the majority of models had begun to have the storm outrun it's upper level support due to it's land interaction with SSW shear slowly encroaching as the storm eventually progresses further toward the WNW. I expect to see this storm look like it had just gone through a meat grinder over the course of the day. Just how quick any jump to form a new LLC will occur will be interesting to see. What a shocker if contrary to all models this didn't occur off the North coastline. Oh southern 'lobe, you still around?

[GCANE]

In some moderate convection, 10 to 30 mm/hr rain rate.
60 knot flight level winds at 5000'
40 knot SFMR 30-sec avg, in the clear.
Middle of the Mona Passage

[northjaxpro]

more closely relates to Debbie.

David was a Cat 5 hurricane before getting badly disrupted after striking Hispaniola. However,he recovered to become a Cat 1 cane and moved North , making landfall in Palm Beach, then.moved parallel up along the Florida East Coast, with the eyewall passing just 35 miles off of Jacksonville Beach. .It made a second landfall up the coast near Savannah. Jax had storm force winds up to 50 mph on the outer edge of the western eyewall as he passed just east of here off the coast.

I was talking about the approach and interaction with Hispaniola.

David plowed through the middle.

Debbie got the SE circulation caught up in the terrain and turned into a tether ball. lol

Yes she did. I commented eatlier in a post about Hispaniola's effects on cyclones
That needs a short book.to fully explain be honest lol..
.

[TheStormExpert]

Palm Beach post headline:

“Isaias Storm: Tropical Storm now but could be hurricane strength as it nears Florida.”

https://www.palmbeachpost.com/

I'm definitely getting a Hurricane David (1979) vibe from this one. Fortunately nowhere near the strength David was when it hit the island of Hispanola. But in terms of future track? If midday U.S. models (GFS etc) today continue the morning shift west (after the overnight shift east), I'm going to be very concerned for a grazing-of-East-Coast-FL scenario

Was David even that bad for Florida?

[NDG]

Wow, 69 knot flight level winds!!!

40700 1832N 06746W 8431 01552 0097 +174 +174 153062 064 055 040 00
140730 1833N 06745W 8421 01565 0101 +172 +172 157060 064 054 045 00
140800 1835N 06744W 8437 01549 0102 +174 +174 155055 059 051 070 00
140830 1836N 06742W 8430 01558 0105 +173 +173 153061 065 039 046 00
140900 1837N 06741W 8436 01559 0110 +172 +172 152056 064 041 021 00
140930 1839N 06740W 8431 01563 0107 +171 +171 152064 066 048 024 00
141000 1840N 06739W 8439 01552 0108 +169 +169 149064 069 050 026 00
141030 1841N 06738W 8424 01572 0113 +164 +164 143059 061 032 016 00
141100 1842N 06737W 8438 01560 0106 +166 +166 144060 062 036 010 00
141130 1844N 06735W 8433 01566 0110 +168 +168 146059 062 037 011 00
141200 1845N 06734W 8436 01567 0115 +167 +167 147050 057 035 012 00
141230 1846N 06733W 8433 01569 0115 +168 +168 148047 052 039 018 00
141300 1848N 06732W 8458 01545 0115 +173 +173 152052 056 038 013 00
141330 1849N 06731W 8424 01578 0112 +167 +167 155057 058 039 010 00
141400 1850N 06729W 8433 01572 0113 +167 +167 152059 062 040 010 00
141430 1851N 06728W 8436 01568 0116 +169 +169 152056 058 041 009 00
141500 1853N 06727W 8434 01569 0117 +169 +169 149054 055 038 010 00
141530 1854N 06726W 8435 01570 0116 +168 +168 149054 055 039 008 00
141600 1855N 06725W 8433 01576 0115 +170 +170 151054 054 040 008 00
141630 1857N 06723W 8436 01571 0115 +170 +170 148052 053 039 009 00
$$

[St0rmTh0r]

Wow, 69 knot flight level winds!!!

40700 1832N 06746W 8431 01552 0097 +174 +174 153062 064 055 040 00
140730 1833N 06745W 8421 01565 0101 +172 +172 157060 064 054 045 00
140800 1835N 06744W 8437 01549 0102 +174 +174 155055 059 051 070 00
140830 1836N 06742W 8430 01558 0105 +173 +173 153061 065 039 046 00
140900 1837N 06741W 8436 01559 0110 +172 +172 152056 064 041 021 00
140930 1839N 06740W 8431 01563 0107 +171 +171 152064 066 048 024 00
141000 1840N 06739W 8439 01552 0108 +169 +169 149064 069 050 026 00
141030 1841N 06738W 8424 01572 0113 +164 +164 143059 061 032 016 00
141100 1842N 06737W 8438 01560 0106 +166 +166 144060 062 036 010 00
141130 1844N 06735W 8433 01566 0110 +168 +168 146059 062 037 011 00
141200 1845N 06734W 8436 01567 0115 +167 +167 147050 057 035 012 00
141230 1846N 06733W 8433 01569 0115 +168 +168 148047 052 039 018 00
141300 1848N 06732W 8458 01545 0115 +173 +173 152052 056 038 013 00
141330 1849N 06731W 8424 01578 0112 +167 +167 155057 058 039 010 00
141400 1850N 06729W 8433 01572 0113 +167 +167 152059 062 040 010 00
141430 1851N 06728W 8436 01568 0116 +169 +169 152056 058 041 009 00
141500 1853N 06727W 8434 01569 0117 +169 +169 149054 055 038 010 00
141530 1854N 06726W 8435 01570 0116 +168 +168 149054 055 039 008 00
141600 1855N 06725W 8433 01576 0115 +170 +170 151054 054 040 008 00
141630 1857N 06723W 8436 01571 0115 +170 +170 148052 053 039 009 00
$$

this has had some strong winds that's almost a hurricane

[ColdMiser123]

Wow, 69 knot flight level winds!!!

40700 1832N 06746W 8431 01552 0097 +174 +174 153062 064 055 040 00
140730 1833N 06745W 8421 01565 0101 +172 +172 157060 064 054 045 00
140800 1835N 06744W 8437 01549 0102 +174 +174 155055 059 051 070 00
140830 1836N 06742W 8430 01558 0105 +173 +173 153061 065 039 046 00
140900 1837N 06741W 8436 01559 0110 +172 +172 152056 064 041 021 00
140930 1839N 06740W 8431 01563 0107 +171 +171 152064 066 048 024 00
141000 1840N 06739W 8439 01552 0108 +169 +169 149064 069 050 026 00
141030 1841N 06738W 8424 01572 0113 +164 +164 143059 061 032 016 00
141100 1842N 06737W 8438 01560 0106 +166 +166 144060 062 036 010 00
141130 1844N 06735W 8433 01566 0110 +168 +168 146059 062 037 011 00
141200 1845N 06734W 8436 01567 0115 +167 +167 147050 057 035 012 00
141230 1846N 06733W 8433 01569 0115 +168 +168 148047 052 039 018 00
141300 1848N 06732W 8458 01545 0115 +173 +173 152052 056 038 013 00
141330 1849N 06731W 8424 01578 0112 +167 +167 155057 058 039 010 00
141400 1850N 06729W 8433 01572 0113 +167 +167 152059 062 040 010 00
141430 1851N 06728W 8436 01568 0116 +169 +169 152056 058 041 009 00
141500 1853N 06727W 8434 01569 0117 +169 +169 149054 055 038 010 00
141530 1854N 06726W 8435 01570 0116 +168 +168 149054 055 039 008 00
141600 1855N 06725W 8433 01576 0115 +170 +170 151054 054 040 008 00
141630 1857N 06723W 8436 01571 0115 +170 +170 148052 053 039 009 00
$$

55 KT SFMR as well, that should be good enough to bump up winds just a bit at 11 am.

[St0rmTh0r]

Wow, 69 knot flight level winds!!!

40700 1832N 06746W 8431 01552 0097 +174 +174 153062 064 055 040 00
140730 1833N 06745W 8421 01565 0101 +172 +172 157060 064 054 045 00
140800 1835N 06744W 8437 01549 0102 +174 +174 155055 059 051 070 00
140830 1836N 06742W 8430 01558 0105 +173 +173 153061 065 039 046 00
140900 1837N 06741W 8436 01559 0110 +172 +172 152056 064 041 021 00
140930 1839N 06740W 8431 01563 0107 +171 +171 152064 066 048 024 00
141000 1840N 06739W 8439 01552 0108 +169 +169 149064 069 050 026 00
141030 1841N 06738W 8424 01572 0113 +164 +164 143059 061 032 016 00
141100 1842N 06737W 8438 01560 0106 +166 +166 144060 062 036 010 00
141130 1844N 06735W 8433 01566 0110 +168 +168 146059 062 037 011 00
141200 1845N 06734W 8436 01567 0115 +167 +167 147050 057 035 012 00
141230 1846N 06733W 8433 01569 0115 +168 +168 148047 052 039 018 00
141300 1848N 06732W 8458 01545 0115 +173 +173 152052 056 038 013 00
141330 1849N 06731W 8424 01578 0112 +167 +167 155057 058 039 010 00
141400 1850N 06729W 8433 01572 0113 +167 +167 152059 062 040 010 00
141430 1851N 06728W 8436 01568 0116 +169 +169 152056 058 041 009 00
141500 1853N 06727W 8434 01569 0117 +169 +169 149054 055 038 010 00
141530 1854N 06726W 8435 01570 0116 +168 +168 149054 055 039 008 00
141600 1855N 06725W 8433 01576 0115 +170 +170 151054 054 040 008 00
141630 1857N 06723W 8436 01571 0115 +170 +170 148052 053 039 009 00
$$

this has had storm strong winds that's almost a hurricane

[northjaxpro]

Wow, 69 knot flight level winds!!!

$$

Now, this caught my attention when I saw this as well.

[Evil Jeremy]

NHC is in a small pickle. Models overall shifted slightly West since 5am, but the NHC track is still slightly West of the TCVN. My guess is NHC makes very minimal, if any, adjustments to the track. Makes sense to wait until after there's a center reformation.

Maintaining the track would put SE FL about 36 hours away from the possibility of TS winds (going by their Earliest Reasonable graphic). If there was less uncertainty than what currently exists, it would make sense for the NHC to issue TS Watches for portions of E FL at 11am. I'd wager that doesn't happen, and NHC punts that decision to 5pm, when hopefully there's much more clarity regarding the LLC reformation.

[TheStormExpert]

NHC is in a small pickle. Models overall shifted slightly West since 5am, but the NHC track is still slightly West of the TCVN. My guess is NHC makes very minimal, if any, adjustments to the track. Makes sense to wait until after there's a center reformation.

Maintaining the track would put SE FL about 36 hours away from the possibility of TS winds (going by their Earliest Reasonable graphic). If there was less uncertainty than what currently exists, it would make sense for the NHC to issue TS Watches for portions of E FL at 11am. I'd wager that doesn't happen, and NHC punts that decision to 5pm, when hopefully there's much more clarity regarding the LLC reformation.

TS Watches will likely go up later today.

[Aric Dunn]

Also remember that some of these winds are MOna passage effect.

[Jr0d]

Another factor that should help to limit the mountain shredder effect is how fast Isaias is still moving.

I am a little surprised at the west shift in the models today. We will see how that plays out. I expect TS warnings for Florida at the 5pm advisory though. My guess will from Key Largo to Cape Caneveral, maybe further down the keys if the models keep trending west.

[SFLcane]

NHC is in a small pickle. Models overall shifted slightly West since 5am, but the NHC track is still slightly West of the TCVN. My guess is NHC makes very minimal, if any, adjustments to the track. Makes sense to wait until after there's a center reformation.

Maintaining the track would put SE FL about 36 hours away from the possibility of TS winds (going by their Earliest Reasonable graphic). If there was less uncertainty than what currently exists, it would make sense for the NHC to issue TS Watches for portions of E FL at 11am. I'd wager that doesn't happen, and NHC punts that decision to 5pm, when hopefully there's much more clarity regarding the LLC reformation.

Maybe...12z guidance now all mostly offshore SFL all the strong winds with this all NE of llc.

[chaser1]

I'm definitely getting a Hurricane David (1979) vibe from this one. Fortunately nowhere near the strength David was when it hit the island of Hispanola. But in terms of future track? If midday U.S. models (GFS etc) today continue the morning shift west (after the overnight shift east), I'm going to be very concerned for a grazing-of-East-Coast-FL scenario

I remember David very well back in "79. This indeed has a chance to mimick that analog just in terms of track.

more closely relates to Debbie.

I remember David of '79 well. Following The Rock, it essentially came out "half" of a hurricane. It's trajectory up to the Florida coastline prevented us in W. Kendall from receiving sustained tropical storm force winds. Heck, I don't think I even recall getting gusts to T.S. strength. That was a result of the significantly weaker hurricane and the changing upper level conditions which David was unable to significantly combat. We'd like to think that we know whether Isaias will traverse the entirety of Hispaniola or more quickly reorganize more quickly just to the north of the island. Either way though, those massive mountains will still prove a big factor toward cutting off surface inflow to the old or new COC. I'm just gonna get the popcorn out and kick back to see how (and how long) this will play out. God help those potentially impacted on both P.R. and Hispaniola from the flooding and mud slides.

[txwatcher91]

Just remember ... eddys eddys and more eddys.

just track the overall mass of the system..

we wont know much until tomorrow when the energy reaches the NW side of the islands ... how well it is still intact and how long it takes to recover.

No, it seems the system is doing exactly what the GFS, para GFS and HWRF have been showing. The southern circulation is dying out and jumping north to where the MLC is, also evidenced by pressure falls in that area. Everything appears right on track.

MLC is moving over land.. nothing else needs to be said..

No the MLC is skirting along the northern coast and the terrain there is relatively flat. Little to no disruption and this was well modeled by the above referenced models in recent runs.