Nate

[NavarreDon]

N Gulf coast landfall, Coastal impacts LA, MS, AL, FL, & inland SE US.

 

 

 

[sandi]

Watching closely here in Destin. 

[MJO812]

Euro has it hitting the panhndle

[hlcater]

I'm still not a fan of firing off threads for storms that may or may not even develop.

[NavarreDon]

It's still really early and there's lot's of variables to hash out but with tomorrow being the 22nd anniversary of Opal. The whole N Gulf area should be on guard.


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[Windspeed]

I'll just carry some of this over from the Atlantic Discussion thread.

1 hour ago, Windspeed said:

I. ATLANTIC REQUIREMENTS........(CHANGED)
1. SUSPECT AREA (OFF NICARAGUAN COAST)
FLIGHT ONE -- TEAL 71
A. 04/1800Z
B. AFXXX 01DDA INVEST
C. 04/1400Z
D. 11.5N 82.5W
E. 04/1730Z TO 04/2100Z
F. SFC TO 10,000 FT

 

 

2 hours ago, Windspeed said:

The ECMWF is now also agressive with development. That's a dangerous track and obviously has downstream implications for the northern Gulf Coast.
 

Overall, my opinion of this system is a high impact event for the northern Gulf Coast as a hurricane. Keep in mind that we didn't have an invest and satellite fix for the 12z models. Now that we do, we should have a little better model guidance for the 18z and 00z operational runs. The 12z Euro is a little troubling as it keeps a developed core over water for a much longer duration. We'll have to watch if the 18z GFS shifts east or decreases initial land interaction and stronger system. Of course, the 00z ECMWF could shift west also.

The upper environment looks favorable for marginal intensification in the first 24-36 hrs. However, a more eastern track thereafter could result in significant intensification if it traverses the central-to-eastern Gulf. 300-200mb upper high is modeled to develop over the eastern GOM. Of course, even a further west track through the  western GOM is not that much less favorable with regards to southerly shear. A strengthening system is still quite likely.

[andyhb]

Beware of the Carla Cradle...

[AfewUniversesBelowNormal]

Nice surprise. If named, may easily coast into Hurricane, possibly strong, given the location in this year of La Nina that is underestimated by models. MJO and shear forecast is also favorable. Developing circulation the biggest variable. 

[NavarreDon]

I'm still not a fan of firing off threads for storms that may or may not even develop.

I understand and generally feel the same way, with that being said....with the way things kinda came together quickly today, a seemingly bullish outlook by some ( Dr Knabb incl ), and the aspect that this isn't going to be a long track event with impacts possible this weekend. I felt it was warranted to pull the trigger on a thread. I might look like an idiot sooner than later for doing so but isn't this kinda the purpose of these forums?


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[SnoSki14]

This has the potential to pull a Harvey and surprise everyone with how strong it gets but it's way too early to make that kind of assumption.

[Windspeed]

 

I understand and generally feel the same way, with that being said....with the way things kinda came together quickly today, a seemingly bullish outlook by some ( Dr Knabb incl ), and the aspect that this isn't going to be a long track event with impacts possible this weekend. I felt it was warranted to pull the trigger on a thread. I might look like an idiot sooner than later for doing so but isn't this kinda the purpose of these forums?

 

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I think in general it is a good idea to wait until the NHC classifies a system or issues a PTC advisory. But in this particular case, it may be warranted simply due to the close proximity to land and timing constraints.

 

As far as busts, I'm already calling for a hurricane. This system has good potential of becoming a hurricane even if it tracks further west spending less time over water. But nobody will look more silly than me if it in fact doesn't develop. Perhaps it doesn't reach hurricane intensity, but I think the odds of it not being a named system are very low now.

 

[the ghost of leroy]

14 minutes ago, SnoSki14 said:

This has the potential to pull a Harvey and surprise everyone with how strong it gets but it's way too early to make that kind of assumption.

so why even post that?

[Windspeed]

Well it's early and this will change but the first HWRF run is not playing nice.

[Seminole]

18 minutes ago, Windspeed said:

Well it's early and this will change but the first HWRF run is not playing nice.

This is sure to get some people excited. 

[Amped]

 

It is over the warmest waters of the basin between about 48 and 72hrs.   A number of GEFS members keep it off honduras and move it through the Yucatan channel where there will be less land interaction, hence a stronger storm.  

 

[SnoSki14]

2 hours ago, cmasty1978 said:

so why even post that?

Because it could happen, a few hurricane models are starting to show it.

[Windspeed]

17 minutes ago, Amped said:

 

It is over the warmest waters of the basin between about 48 and 72hrs.   A number of GEFS members keep it off honduras and move it through the Yucatan channel where there will be less land interaction, hence a stronger storm.  

 
 

Additionally, by the time Nate would be traversing the shallower and lower heat content at depth of the northern Gulf, it will be moving fast enough that shallower surface layer heat content will be plenty to sustain intensity.

A more eastern track would perhaps allow for a system that is weakening at landfall versus intensifying, where as a more western track would sustain intensification through landfall. But the system should be moving at a decent enough clip that its own upwelling from depth won't be much of an issue.

[Amped]

16 minutes ago, Windspeed said:

Additionally, by the time Nate would be traversing the shallower and lower heat content at depth of the northern Gulf, it will be moving fast enough that shallower surface layer heat content will be plenty to sustain intensity.

A more eastern track would perhaps allow for a system that is weakening at landfall versus intensifying, where as a more western track would sustain intensification through landfall. But the system should be moving at a decent enough clip that its own upwelling from depth won't be much of an issue.

OPAL was a 944mb CAT3 when it made landfall.   I don't imagine Nate will be a much stronger than that at landfall unless it hits extreme SE LA where it's more exposed.   If it bombs to CAT 5 in the central gulf it will weaken back, just like Opal, Katrina, Dennis, Ivan, Lili  and a bunch of others.

[Windspeed]

OPAL was a 944mb CAT3 when it made landfall.   I don't imagine Nate will be a much stronger than that at landfall unless it hits extreme SE LA where it's more exposed.   If it bombs to CAT 5 in the central gulf it will weaken back, just like Opal, Katrina, Dennis, Ivan, Lili  and a bunch of others.

 

 

Opal also had a small core that was going through an ERC and being encroached upon by shear. Certainly, I think a more western track or more central Gulf landfall increases potential threat of an intensifying cyclone at landfall versus weakening, but we should be careful as the synoptic setup isn't the same. At this point, the main focus is answering the question, can a hurricane strike any part of the northern Gulf coast? Absolutely, Yes. The potential for even a major hurricane at any point of landfall is real. Obviously, we're still very early into this event. We don't even have a named system yet. But at the sake of modeling and hypotheticals, the potential is concerning.

 

 

[NavarreDon]

Opal also had a small core that was going through an ERC and being encroached upon by shear. Certainly, I think a more western track or more central Gulf landfall increases potential threat of an intensifying cyclone at landfall versus weakening, but we should be careful as the synoptic setup isn't the same. At this point, the main focus is answering the question, can a hurricane strike any part of the northern Gulf coast? Absolutely, Yes. The potential for even a major hurricane at any point of landfall is real. Obviously, we're still very early into this event. We don't even have a named system yet. But at the sake of modeling and hypotheticals, the potential is concerning. 

 

Opal also hit the loop current and dropped 42mb in a 12hr period! (MOB has a nice write up on their homepage) It's forward speed was around 20+ mph when it came in. While the N Gulf has some of the deepest water in spots for the most part it still has a 20+ mile run of less then 300ft of water so the speed of any storm will have a role in upwelling. Quite a few strange things this year but I would be somewhat surprised if any system isn't weakening upon landfall.




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[Windspeed]

ASCAT is showing an organizing surface low. Still broad and not quite there yet as far as a vortex. Convection needs to get going before anything can consolidate. Recon will be there in 15 hrs.

[Windspeed]

Well that didn't take long. Intense convection is beginning to organize and consolidate near the satellite estimated center of the surface low. If that persists, a tighter vortex may very well form by the time recon reaches the invest tomorrow.

[NavarreDon]

Curious what the 8:00am NHC update will be. I'm not a great model reader but it seems 6Z GFS backed off to 1000mb system into SE LA. Looks like the Euro shifted E to a big bend landfall. Convection looking good on the IR near or over what would be the possible COC this am. 

[stormtracker]

17 minutes ago, NavarreDon said:

Curious what the 8:00am NHC update will be. I'm not a great model reader but it seems 6Z GFS backed off to 1000mb system into SE LA. Looks like the Euro shifted E to a big bend landfall. Convection looking good on the IR near or over what would be the possible COC this am. 

Looks that way to me, but I'm not great at all with tropical weather so I'll leave it to @Windspeed et al to decipher.  6z especially looks weaker down toward the Yucatan (where I'm looking closely).  Hope the trend continues.  

[NavarreDon]

3 minutes ago, stormtracker said:

Looks that way to me, but I'm not great at all with tropical weather so I'll leave it to @Windspeed et al to decipher.  6z especially looks weaker down toward the Yucatan (where I'm looking closely).  Hope the trend continues.  

 Showers and thunderstorms associated with an area of low pressure
located over the southwestern Caribbean Sea have become better
organized since yesterday.  This system is expected to become a
tropical depression later today while it moves northwestward toward
the coast of Nicaragua.  The low should move slowly northwestward
across or near the eastern portions of Nicaragua and Honduras on
Thursday, move into the northwestern Caribbean Sea by Friday, and
emerge over the southern Gulf of Mexico by Saturday.  Interests in
Nicaragua, Honduras, the Yucatan peninsula and western Cuba should
monitor the progress of this system as watches or warnings could be
issued later today.  An Air Force Reserve reconnaissance aircraft is
scheduled to investigate the disturbance this afternoon.  Regardless
of development, this system will produce heavy rains over portions
of Central America during the next few days, likely causing flash
floods and mudslides.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

Hope the trip works out for you!

[NavarreDon]

Levi Cowan‏ @TropicalTidbits

Pressures nearby Invest 90L have dropped to 1006mb since yesterday. Along with convective organization, this is a sign of development.

Levi Cowan‏ @TropicalTidbits 13

Replying to @TropicalTidbits

Model intensity guidance is not yet useful. Development within favorable environment but also a monsoon gyre means high ceiling & low floor.

[Windspeed]

Levi Cowan‏ @TropicalTidbits

Pressures nearby Invest 90L have dropped to 1006mb since yesterday. Along with convective organization, this is a sign of development.

Levi Cowan‏ @TropicalTidbits 13

Replying to @TropicalTidbits

Model intensity guidance is not yet useful. Development within favorable environment but also a monsoon gyre means high ceiling & low floor.

I agree with Levi's assessment. Convection pulsed early AM then waned a bit where the estimated center is located. There may be several small circulations rotating within a broader low. At any rate, recon may find enough supportive data for the NHC to classify a depression, but at the time of this post, the system doesn't yet have a core. Recon will confirm what is going on soon enough.

Another possibility is land interaction could actually assist in development tonight. The 00z ECMWF seems to form/tighten a vortex near the Nicaraguan coast by Thursday morning. It pivots around the surface trough over Central America, and intensifies this into the main cyclonic feature as it lifts NNW into the W. Caribbean. OTOH, GFS is maintaining the overall broader circulation and doesn't allow any single vortex to take over, basically taking multiple competing weaker vortices within the surface gyre over the Yucatan and throughout the Gulf.

Two pretty different developments between the GFS and Euro with drastically different outcomes. Gyre versus hurricane. Gyre further west; hurricane further east.

[40/70 Benchmark]

11 minutes ago, Windspeed said:

 

 

I agree with Levi's assessment. Convection pulsed early AM then waned a bit where the estimated center is located. There may be several small circulations rotating within a broader low. At any rate, recon may find enough supportive data for the NHC to classify a depression, but at the time of this post, the system doesn't yet have a core. Recon will confirm what is going on soon enough.

Another possibility is land interaction could actually assist in development tonight. The 00z ECMWF seems to form/tighten a vortex near the Nicaraguan coast by Thursday morning. It pivots around the surface trough over Central America, and intensifies this into the main cyclonic feature as it lifts NNW into the W. Caribbean. OTOH, GFS is maintaining the overall broader circulation and doesn't allow any single vortex to take over, basically taking multiple competing weaker vortices within the surface gyre over the Yucatan and throughout the Gulf.

Two pretty different developments between the GFS and Euro with drastically different outcomes. Gyre versus hurricane. Gyre further west; hurricane further east.

 

 

I'd be suprised if we never see one prominent vortex prevail. 

I'll go Euro. 

[hlcater]

1 minute ago, 40/70 Benchmark said:

I'd be suprised if we never see one prominent vortex prevail. 

I'll go Euro. 

Especially noting that the GFS has had a tendency(per a Levi tweet awhile ago) to spin up too many areas of vorticity within a larger low pressure envelope. Keeping this bias in mind, I'd also be surprised if we never get a dominant vortex.

[40/70 Benchmark]

3 minutes ago, NWLinnCountyIA said:

Especially noting that the GFS has had a tendency(per a Levi tweet awhile ago) to spin up too many areas of vorticity within a larger low pressure envelope. Keeping this bias in mind, I'd also be surprised if we never get a dominant vortex.

Can't wait for that first run of the GFS that catches on, and drives a 902mb into New Orleans lol.