ATL: LAURA - Models

[ConvergenceZone]

Note that all the sub-990-mb members are on the eastern side of the guidance late on 24 August 2020:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2020082000/gfs-ememb_lowlocs_watl_20.png
These same members show 98L curving just east of or along the east coast of FL, à la Matthew/Dorian:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2020082000/gfs-ememb_lowlocs_watl_22.png

This is definitely an important trend. Given that 98L will likely be even stronger than these members indicate, it would curve even farther east.

If that were the case, all it would mean is that the Carolina's and east could would be in the bulls eye...

If you look at the steering in the links I posted, you’ll notice that there is no ridging over the Northeastern U.S. Aside from the narrow ridge just east of the Southeastern U.S., there is a strong Hudson Bay vortex with northwesterly flow over the top of the ridge. Once 98L bypasses the ridge axis, the northwesterly flow would cause it to curve sharply NE and eventually ENE, which would certainly not favour a direct impact to the Carolinas or Mid-Atlantic, that is, a landfall, but could certainly portend very high surf. Again, I am reiterating that I am merely outlining a modelled scenario and interpreting the modelled meteorology ad verbatim. One would need strong blocking over the Northeast/eastern Canada to steer 98L into the East Coast. No model has shown this scenario even once for 98L. The ridge is narrow and farther south than is needed for a strong major hurricane to hit the East Coast.

Probably only about a 10 to 15% chance going out to sea like you think it is, at this point. So it's definitely not even close to being a "good possibility" . The ridge above will be too strong...... It may be a narrow ridge, but it's an incredibly strong narrow ridge, as the models are depicting...

[Fancy1001]

HWRF misses FL through the straights that will probably pull the TCVN away from the peninsula. If trends continue we won’t be in the cone for to long. Big problem for the GOM

You should say it misses South Florida, it could still hit the panhandle or curve into east Florida.

[AtlanticWind]

HWRF misses FL through the straights that will probably pull the TCVN away from the peninsula. If trends continue we won’t be in the cone for to long. Big problem for the GOM

Maybe , but now the euro seems to be coming in way north

[boca]

Every time lately when Florida is in the cone initially we end up out of the cone usually a day or two after I’m used to this because it happens all the time.

[ConvergenceZone]

HWRF misses FL through the straights that will probably pull the TCVN away from the peninsula. If trends continue we won’t be in the cone for to long. Big problem for the GOM

Maybe , but now the euro seems to be coming in way north

I'm throwing the EURO out at this point. It didn't even realize a storm was going to form. lol...

[SFLcane]

HWRF misses FL through the straights that will probably pull the TCVN away from the peninsula. If trends continue we won’t be in the cone for to long. Big problem for the GOM

You should say it misses South Florida, it could still hit the panhandle or curve into east Florida.

Correction misses metro South Eastern Fl peninsula. South trends tonight atleast from the 2 mesoscale hurricane models.

[AtlanticWind]

HWRF misses FL through the straights that will probably pull the TCVN away from the peninsula. If trends continue we won’t be in the cone for to long. Big problem for the GOM

You should say it misses South Florida, it could still hit the panhandle or curve into east Florida.

Also Key west is part of south florida, passes just a few miles south of them
Would be Huge impact

[SFLcane]

Every time lately when Florida is in the cone initially we end up out of the cone usually a day or two after I’m used to this because it happens all the time.

Yep, that never fails and it’s a good thing. Not Interested in more disruption we have enough with covid.

[SouthFLTropics]

The Euro thinks it's there for a moment and then by hour 72 it says, nah forget about it...

[AtlanticWind]

Every time lately when Florida is in the cone initially we end up out of the cone usually a day or two after I’m used to this because it happens all the time.

I hope we do get out of the cone , but the model runs tonight will keep the cone exactly the same as it is now

[Bocadude85]

I wouldn’t be to invested on any given model run at the moment, still 2,000 miles to go before any potential USA impacts, LOTS more model runs and trends to watch for the next few days.

[SFLcane]

Come to look the 00z TCVN shifted even further north across dade and Broward counties. Expect a potential shift north to nhc track at 5am.

[hurricaneCW]

Note that all the sub-990-mb members are on the eastern side of the guidance late on 24 August 2020:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2020082000/gfs-ememb_lowlocs_watl_20.png
These same members show 98L curving just east of or along the east coast of FL, à la Matthew/Dorian:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2020082000/gfs-ememb_lowlocs_watl_22.png

This is definitely an important trend. Given that 98L will likely be even stronger than these members indicate, it would curve even farther east.

If that were the case, all it would mean is that the Carolina's and east could would be in the bulls eye...

If you look at the steering in the links I posted, you’ll notice that there is no ridging over the Northeastern U.S. Aside from the narrow ridge just east of the Southeastern U.S., there is a strong Hudson Bay vortex with northwesterly flow over the top of the ridge. Once 98L bypasses the ridge axis, the northwesterly flow would cause it to curve sharply NE and eventually ENE, which would certainly not favour a direct impact to the Carolinas or Mid-Atlantic, that is, a landfall, but could certainly portend very high surf. Again, I am reiterating that I am merely outlining a modelled scenario and interpreting the modelled meteorology ad verbatim. One would need strong blocking over the Northeast/eastern Canada to steer 98L into the East Coast. No model has shown this scenario even once for 98L. The ridge is narrow and farther south than is needed for a strong major hurricane to hit the East Coast.

There is almost a 0% chance this curves away from the US. It has a far better shot at getting shredded by land masses than going OTS. The mid-level ridge will be very powerful and will only expand over time.

[SouthFLTropics]

Euro out through 120 hours doesn't show any significant strength but it does show whatever is to become of TD13 moving well north of the islands, through the Bahamas, and across the Florida peninsula. That could end up being significant down the road.

[AxaltaRacing24]

Come to look the 00z TCVN shifted even further north across dade and Broward counties. Expect a potential shift north to nhc track at 5am.

https://cdn1.bbcode0.com/uploads/2020/8/20/63e02369905ce4474992c9da443d89fc-full.gif

that's quite a tight cluster at the moment.

[USTropics]

Just ignore the 5-day forecast for now and look at the spread at even 48 hours in the GFS ensembles. That's a significant spread, and a ton of possibilities still exist. It's not just how strong the system is that will dictate potential impacts in GA and CONUS. Strength of ridging, angle/location of ascent (often forgotten), and storm strength all play a factor:

[Shell Mound]

If that were the case, all it would mean is that the Carolina's and east could would be in the bulls eye...

If you look at the steering in the links I posted, you’ll notice that there is no ridging over the Northeastern U.S. Aside from the narrow ridge just east of the Southeastern U.S., there is a strong Hudson Bay vortex with northwesterly flow over the top of the ridge. Once 98L bypasses the ridge axis, the northwesterly flow would cause it to curve sharply NE and eventually ENE, which would certainly not favour a direct impact to the Carolinas or Mid-Atlantic, that is, a landfall, but could certainly portend very high surf. Again, I am reiterating that I am merely outlining a modelled scenario and interpreting the modelled meteorology ad verbatim. One would need strong blocking over the Northeast/eastern Canada to steer 98L into the East Coast. No model has shown this scenario even once for 98L. The ridge is narrow and farther south than is needed for a strong major hurricane to hit the East Coast.

There is almost a 0% chance this curves away from the US. It has a far better shot at getting shredded by land masses than going OTS. The mid-level ridge will be very powerful and will only expand over time.

As USTropics implied, the stronger 98L becomes in the short term, the more likely it is to curve earlier, all other factors being equal/remaining the same (ceteris paribus). The strongest GEFS members in the short term are the ones that end up taking 98L over or just east of the east coast of FL. Those members show 98L curving NW and even NNW as it nears FL, à la Matthew/Dorian. Global models have been significantly underestimating the short-term organisation of 98L. But I won’t belabour the point. We shall wait and see what happens.

[AxaltaRacing24]

If you look at the steering in the links I posted, you’ll notice that there is no ridging over the Northeastern U.S. Aside from the narrow ridge just east of the Southeastern U.S., there is a strong Hudson Bay vortex with northwesterly flow over the top of the ridge. Once 98L bypasses the ridge axis, the northwesterly flow would cause it to curve sharply NE and eventually ENE, which would certainly not favour a direct impact to the Carolinas or Mid-Atlantic, that is, a landfall, but could certainly portend very high surf. Again, I am reiterating that I am merely outlining a modelled scenario and interpreting the modelled meteorology ad verbatim. One would need strong blocking over the Northeast/eastern Canada to steer 98L into the East Coast. No model has shown this scenario even once for 98L. The ridge is narrow and farther south than is needed for a strong major hurricane to hit the East Coast.

There is almost a 0% chance this curves away from the US. It has a far better shot at getting shredded by land masses than going OTS. The mid-level ridge will be very powerful and will only expand over time.

As USTropics implied, the stronger 98L becomes in the short term, the more likely it is to curve earlier, all other factors being equal/remaining the same (ceteris paribus). The strongest GEFS members in the short term are the ones that end up taking 98L over or just east of the east coast of FL. Those members show 98L curving NW and even NNW as it nears FL, à la Matthew/Dorian. Global models have been significantly underestimating the short-term organisation of 98L. But I won’t belabour the point. We shall wait and see what happens.

i'm hoping for changes in the setup in the next 4 days that could cause an ots shift, but the latest euro doesn't show anything even close to that. the ridge 168 hours out is still favorable for a landfall on this run.

if that ridge verified, this storm was likely hitting florida no matter what strength it became.

[Blown Away]

Just ignore the 5-day forecast for now and look at the spread at even 48 hours in the GFS ensembles. That's a significant spread, and a ton of possibilities still exist. It's not just how strong the system is that will dictate potential impacts in GA and CONUS. Strength of ridging, angle/location of ascent (often forgotten), and storm strength all play a factor:
https://i.imgur.com/klnjgOH.png

2:00 AM AST Thu Aug 20
Location: 15.1°N 49.0°W
Moving: WNW at 20 mph
Min pressure: 1008 mb
Max sustained: 35 mph

Based on the 2am position, we would be on the R side of the ensemble group. Already above 15N before 50W.

[Shell Mound]

There is almost a 0% chance this curves away from the US. It has a far better shot at getting shredded by land masses than going OTS. The mid-level ridge will be very powerful and will only expand over time.

As USTropics implied, the stronger 98L becomes in the short term, the more likely it is to curve earlier, all other factors being equal/remaining the same (ceteris paribus). The strongest GEFS members in the short term are the ones that end up taking 98L over or just east of the east coast of FL. Those members show 98L curving NW and even NNW as it nears FL, à la Matthew/Dorian. Global models have been significantly underestimating the short-term organisation of 98L. But I won’t belabour the point. We shall wait and see what happens.

i'm hoping for changes in the setup that could cause an ots shift, but the latest euro doesn't show anything even close to that. the ridge 168 hours out is still favorable for a landfall on this run.

Compared to yesterday’s 00Z, the latest 00Z ECMWF seems to show weaker, more “squished” ridging whose axis, western periphery, or “flank” does not extend as far west as it did in the same timeframe on yesterday’s 00Z. Trends are important to monitor. A weaker ridge that does not extend as far to the west, combined with a much stronger TD Thirteen in the short term, would quite possible miss FL to the east, as the strongest GEFS members indicate, and even those members are likely underestimating TD Thirteen’s intensity by then. If sufficiently strong, it might even miss most of the Bahamas, hopefully. Neither of these scenarios is guaranteed, but as of now it looks more feasible than it did yesterday.