Major Hurricane Ida

[David Reimer]

It would appear the 0Z Euro deterministic is on the eastern edge of its ensembles. Plenty take it into LA, but not as much of a shift east as I expected. Still going to have to keep an eye on the Upper Texas Coast. 

 

[yoda]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
505 AM EDT Thu Aug 26 2021

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

Special tropical weather outlook issued to update the discussion of 
the system south of Jamaica. 

1. Updated: Shower and thunderstorm activity continues to become better 
organized in association with a trough of low pressure located less 
than 200 miles south of Jamaica. Environmental conditions remain 
conducive for development, and a tropical depression or storm is 
expected to form later today or tomorrow. This system is forecast to 
move northwestward over the northwestern Caribbean Sea near the 
Cayman Islands tonight, near Cuba and the Yucatan Peninsula of 
Mexico on Friday, and into the Gulf of Mexico this weekend. Given 
the recent developmental trends, Tropical Storm Warnings for the 
Cayman Islands and Tropical Storm Watches for western Cuba could be 
required later today. 

Regardless of development, locally heavy rainfall and flooding will 
be possible over portions of Jamaica and the Cayman Islands today 
and tonight, and will likely spread across Cuba and the Yucatan 
Peninsula on Friday. In addition, this system could bring dangerous 
impacts from storm surge, wind, and heavy rainfall to portions of 
the coasts of Louisiana, Texas, and the Mexican state of Tamaulipas 
late this weekend and early next week. However, uncertainty remains 
large since the system has yet to form. Interests in these areas 
should closely monitor the progress of this system and ensure they 
have their hurricane plan in place. An Air Force Reserve 
reconnaissance aircraft is scheduled to investigate the system later 
today, if necessary. Additional information on this system, 
including gale warnings, can be found in High Seas Forecasts issued 
by the National Weather Service.    
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[NorthHillsWx]

06z GFS takes this much further East into Cuba as a hurricane 

[CheeselandSkies]

HWRF with this has given us Laura Pt. 2, Ike Pt. 2, and now Rita Pt. 2. Nothing good, either way.

[Seminole]

This will get some attention.

 

[BlueDXer75]

13 minutes ago, NorthHillsWx said:

06z GFS takes this much further East into Cuba as a hurricane 

And right over NOLA

[Seminole]

Borderline CAT 5 around Port Arthur

[AChilders]

15 minutes ago, Seminole said:

This will get some attention.

 

That will test the $50B flood wall

[BlueDXer75]

5 minutes ago, AChilders said:

That will test the $50B flood wall

Kingston (MKJP) is gusting to 34KTs right now 

[Kevin Reilly]

6 minutes ago, BlueDXer75 said:

Kingston (MKJP) is gusting to 34KTs right now 

Sounds like we may have to skip depression and go to Tropical Storm Ida.

[AChilders]

1 minute ago, Kevin Reilly said:

Sounds like we may have to skip depression and go to Tropical Storm Ida.

Wherever the LLC closes off is the key. Looks to be sooner than later and on the north side of the axis. 

[SnowenOutThere]

44 minutes ago, AChilders said:

Wherever the LLC closes off is the key. Looks to be sooner than later and on the north side of the axis. 

Well here we go. 

[blueberryfaygo]

1 hour ago, AChilders said:

That will test the $50B flood wall

And we will see if people actually take advice and evacuate this time.

[Dunkman]

1 hour ago, blueberryfaygo said:

And we will see if people actually take advice and evacuate this time.

This is not a good take. I grew up on the coast and we dealt with many hurricanes. Whether or not to evacuate is a difficult, complicated decision in many cases.

[Windspeed]

This is not a good take. I grew up on the coast and we dealt with many hurricanes. Whether or not to evacuate is a difficult, complicated decision in many cases.

Agreed, even more complicated now by the societal state in the wake of a pandemic, when many have yet been reluctant to travel. There is a mental barrier for some to overcome. It's a tough decision regardless if you live in a rural or urban area.

[smokeybandit]

23 minutes ago, Windspeed said:

42 minutes ago, Dunkman said:

This is not a good take. I grew up on the coast and we dealt with many hurricanes. Whether or not to evacuate is a difficult, complicated decision in many cases.

Agreed, even more complicated now by the societal state in the wake of a pandemic, when many have yet been reluctant to travel. There is a mental barrier for some to overcome. It's a tough decision regardless if you live in a rural or urban area.

 

That and 3 days away by a storm that isn't even formed yet is fools gold to start evacuating

[MattPetrulli]

 

[Windspeed]

Suspicious low-level circulation evident on visible. NHC must have sniffed out something just SW of Jamaica for TD vs PTC advisories. We'll know more soon enough.

[eyewall]

[SnowenOutThere]

After staring at this because we are not doing anything in school I have to say that there is definitely a closed low level circulation and pretty far north. Wonder if we are already looking at a tropical storm. Looks to be a bad scenario shaping up. 

[SnowenOutThere]

2 minutes ago, eyewall said:

Called it, also yikes that cone path. 

[WxWatcher007]

Onshore by Monday morning too. Not a lot of time to prepare. 

[OKwx_2001]

I've seen them go with a 95kt peak on the first advisory before, but it's rare. I've never seen them go higher than that in the Atlantic. The ceiling is very high with this one.

[Windspeed]

Onshore by Monday morning too. Not a lot of time to prepare. 

Unfortunately another landfall under darkness.....

[Intensewind002]

9 minutes ago, OKwx_2001 said:

I've seen them go with a 95kt peak on the first advisory before, but it's rare. I've never seen them go higher than that in the Atlantic. The ceiling is very high with this one.

Yeah first call is always conservative, especially when storms threaten the US coast, probably to not cause any immediate panic and just in case models are overestimating the strengthening. That’s definitely one of the highest initial forecasts by the NHC I’ve seen for an Atlantic storm though. I wouldn’t be surprised if we see Cat 3 or even 4 predicted by tomorrow.

[MUWX]

Will going over western Cuba disrupt this at all? Really interested to see what recon finds this afternoon 

[Windspeed]

Here is the 11AM EDT Discussion for posterity...

044 
WTNT44 KNHC 261456
TCDAT4

Tropical Depression Nine Discussion Number   1
NWS National Hurricane Center Miami FL       AL092021
1100 AM EDT Thu Aug 26 2021

Early morning visible satellite imagery shows that the circulation 
associated with the area of low pressure over west-central 
Caribbean Sea has become better defined. There has also been an 
increase in the organization of the associated convective activity, 
and based on consensus Dvorak T-numbers of 2.0 from TAFB and SAB, 
advisories are being initiated on a tropical depression. The initial 
intensity is set at 30 kt, in agreement with the subjective 
satellite estimates.  The official reporting station in Kingston, 
Jamaica, has reported sustained winds of 25 kt with gusts to 35 kt 
during the past couple of hours. An Air Force Reserve 
reconnaissance aircraft is scheduled to be in the system later this 
afternoon to provide more information on the system's structure 
and intensity. 

The depression is moving northwestward or 325/11 kt, however the 
initial motion is a bit more uncertain than normal since the low-
level center has only recently formed.  The cyclone is forecast 
to move steadily northwestward around the southwestern portion of a 
deep-layer ridge centered over the western Atlantic.  This track 
should bring the center near or over western Cuba late Friday,  
over the southeastern and central Gulf of Mexico Friday night and 
Saturday, and have the center approach the northern Gulf coast on 
Sunday.  The track guidance is in relatively good agreement, however 
the average NHC track forecast error at day 4 is around 175 miles, 
so users should not focus on the details of the long range track 
forecast. Some shifts in the track are likely until the system 
consolidates and becomes better defined. The NHC track is near the 
various consensus model aids and is in best agreement with the GFS 
ensemble mean.  

The depression will be moving over the high ocean heat content 
waters of the northwestern Caribbean Sea during the next 24-36 
hours.  This, in combination with low vertical wind shear and a 
moist environment, should allow for steady strengthening.  The 
depression is forecast to become a tropical storm later today or 
tonight, and could approach hurricane strength as it passes near 
or over western Cuba.  Once the system moves into the Gulf of 
Mexico, conditions are expected to be conducive for additional 
strengthening, and rapid intensification is explicitly shown in 
the NHC forecast between 48 and 72 hours. The NHC intensity forecast 
brings the system near major hurricane strength when it approaches 
the northern Gulf coast on Sunday. This forecast is supported by the 
HWRF and CTCI models, and the GFS, ECMWF, and UKMET global model 
guidance, which all significantly deepen the cyclone over the Gulf 
of Mexico.  As a result, there is higher-than-normal confidence 
that a strengthening tropical cyclone will be moving over the Gulf 
this weekend. 

Key Messages:

1. Tropical storm conditions are likely in portions of the Cayman 
Islands tonight and western Cuba Friday and Friday night, with 
dangerous storm surge possible in portions of western Cuba, 
including the Isle of Youth, in areas of onshore flow. 

2. The system is expected to produce life-threatening heavy rains, 
flash flooding and mudslides across Jamaica, the Cayman Islands, 
western Cuba, including the Isle of Youth and northeastern portions 
of the Yucatan Peninsula.  

3. This system is forecast to approach the northern Gulf Coast at or 
near major hurricane intensity on Sunday, although the forecast 
uncertainty is larger than usual since the system is just forming. 
There is a risk of life-threatening storm surge, damaging 
hurricane-force winds, and heavy rainfall Sunday and Monday along 
the northern Gulf Coast from the Florida Panhandle to the upper 
Texas coast, with the greatest risk along the coast of Louisiana.  
Interests in these areas should closely monitor the progress of this 
system and ensure they have their hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 16.9N  79.2W   30 KT  35 MPH
 12H  27/0000Z 18.2N  80.4W   35 KT  40 MPH
 24H  27/1200Z 20.3N  82.0W   45 KT  50 MPH
 36H  28/0000Z 22.5N  83.9W   55 KT  65 MPH...INLAND
 48H  28/1200Z 24.4N  86.0W   65 KT  75 MPH...OVER WATER
 60H  29/0000Z 26.1N  88.1W   80 KT  90 MPH
 72H  29/1200Z 27.7N  90.0W   95 KT 110 MPH
 96H  30/1200Z 30.5N  92.0W   70 KT  80 MPH...INLAND
120H  31/1200Z 33.7N  91.2W   30 KT  35 MPH...INLAND

$$
Forecaster Brown

 

[CheeselandSkies]

11 minutes ago, MUWX said:

Will going over western Cuba disrupt this at all? Really interested to see what recon finds this afternoon 

Effect will be negligible if only goes over that narrow western end. It didn't do much to Charley as I recall (maybe knocked it back 5kt, but that didn't stop the RI prior to Florida landfall).

[Windspeed]

I reckon this is the most intensification in an initial advisory I can recall aside from Iota last year. This forecast essentially ties that one.  35 kts to 95 kts in 72 hours. I suppose it's warranted based on all the available data, empirical and simulated. Now just to wait and see what recon finds.

[CheeselandSkies]

Just now, Windspeed said:

I reckon this is the most intensification in an initial advisory I can recall aside from Iota last year. This forecast essentially ties that one.  35 kts to 95 kts in 72 hours. I suppose it's warranted based on all the available data, empirical and simulated.

...and that leaves room for further intensification with 24 hrs between forecast points.