Tropical Storm Eta

[USCAPEWEATHERAF]

5 minutes ago, the ghost of leroy said:

we are such a third world country these days

How is this a third world country issue?  Please explain?

[the ghost of leroy]

3 minutes ago, USCAPEWEATHERAF said:

How is this a third world country issue?  Please explain?

we cant even fund basic science

[jjwxman]

3 minutes ago, JasonOH said:

I wonder if the abort was due to the mesovorts.  They may have decided it was too dangerous.

You might be right. Based on this plot map, it looks like they were apart of the circulation for a while traversing the pinhole eye.  I’m sure that was a wild ride. 

[USCAPEWEATHERAF]

1 minute ago, the ghost of leroy said:

we cant even fund basic science

That is not a question you can answer!

[Moderately Unstable]

11 minutes ago, JasonOH said:

I wonder if the abort was due to the mesovorts.  They may have decided it was too dangerous.

That is quite possible actually, perhaps likely.

[JasonOH]

Just now, Moderately Unstable said:

That is quite possible actually, perhaps likely. 

The biggest thing that makes me think that is the timing of the aborts being almost identical.  With that tiny of the eye it will be very hard to avoid the mesovorts.  I'm thinking the turns around the eye were to time the exit to avoid mesovorts.

[USCAPEWEATHERAF]

Just now, JasonOH said:

The biggest thing that makes me think that is the timing of the aborts being almost identical.  With that tiny of the eye it will be very hard to avoid the mesovorts.  I'm thinking the turns around the eye were to time the exit to avoid mesovorts.

Perhaps why they found 155-knot surface winds and the upper level winds were much weaker

[Maestrobjwa]

So we haven't yet officially reached a Category 5?

[downeastnc]

3 minutes ago, JasonOH said:

The biggest thing that makes me think that is the timing of the aborts being almost identical.  With that tiny of the eye it will be very hard to avoid the mesovorts.  I'm thinking the turns around the eye were to time the exit to avoid mesovorts.

I am not sure what speed the plane is moving at when it makes these passes but at 250 mph it would takes them what 80-90  seconds to cross a 6 miles wide eye....

[hawkeye_wx]

It appears to have turned west toward the coast.  One would think pulling air off the land would keep it in check as it closes in.

[SnowLover22]

7 minutes ago, JasonOH said:

The biggest thing that makes me think that is the timing of the aborts being almost identical.  With that tiny of the eye it will be very hard to avoid the mesovorts.  I'm thinking the turns around the eye were to time the exit to avoid mesovorts.

what makes flying through mesovorts even more dangerous than the eyewall itself?

[Moderately Unstable]

11 minutes ago, jjwxman said:

You might be right. Based on this plot map, it looks like they were apart of the circulation for a while traversing the pinhole eye.  I’m sure that was a wild ride. 

 

3 minutes ago, downeastnc said:

I am not sure what speed the plane is moving at when it makes these passes but at 250 mph it would takes them what 80-90  seconds to cross a 6 miles wide eye....

So you can see from the plot that they flew a circle. Each of those wind barbs is a data point. They weren't embedded in the circulation, they flew a circle inside the eye. They basically found an opening and took it. 

[Radtechwxman]

Just now, SnowLover22 said:

what makes flying through mesovorts even more dangerous than the eyewall itself?

More turbulence. Changing wind directions 

[JasonOH]

2 minutes ago, SnowLover22 said:

what makes flying through mesovorts even more dangerous than the eyewall itself?

Wind shear. Rapid onset of wind shear can result in high G loads (and turbulence). The eyewall is pretty homogenous and there isn’t actually that much shear since it gradually ramps up. The mesovorts have wind directional and speed changes that happen exceptionally fast. 

[Moderately Unstable]

7 minutes ago, SnowLover22 said:

what makes flying through mesovorts even more dangerous than the eyewall itself?

In short, windspeeds are much higher, and the wind curvature is higher. It's like a mesovort in a multi vortex tornado. Same cyclostrophic balance equation, same enhancement of momentum. Definitely can be risky to fly through particularly at low speeds. Aircraft have a lower turbulence speed than clear air speed. That's (part of) why they slow down as they approach the storms. However, slow speed increases the risk of stalling. Wind shear is a rapid change in wind speed and direction. At low speeds, that places the plane at risk of stalling. You don't want to stall in an eyewall. There are other issues, basically, a meso in an eyewall is like flying through a tornado both in terms of size and what it does to the plane. It can down the plane, even without a stall. 

[SnowLover22]

6 minutes ago, Moderately Unstable said:

 

So you can see from the plot that they flew a circle. Each of those wind barbs is a data point. They weren't embedded in the circulation, they flew a circle inside the eye. They basically found an opening and took it. 

I assume that means you can identify a mesovort with the radar. I would assume they used their plane radar to know when/where to exit.

[Radtechwxman]

Overall CDO seems to have warmed some but man that lightning in the southern to southwest eyewall has been relentless. Not sure this will hit cat 5 before landfall though. 

[Moderately Unstable]

1 minute ago, SnowLover22 said:

I assume that means you can identify a mesovort with the radar. I would assume they used their plane radar to know when/where to exit.

Bingo.

[Windspeed]

Eta may very well not get upgraded though it's borderline right now. Eventually time is going to run out. Either way, definitely the best looking Atlantic hurricane for 2020. Now beyond the semantics before I fall over. Unfortunately an awful scenario for Nicaragua. Eta is now making a beeline for the most populated city in that region, Puerto Cabezus. Then it moves on into higher terrain and dumps insane amounts of rainfall over the next 72 hours.

 

 

[WeatherQ]

16 minutes ago, Moderately Unstable said:

In short, windspeeds are much higher, and the wind curvature is higher. It's like a mesovort in a multi vortex tornado. Same cyclostrophic balance equation, same enhancement of momentum. Definitely can be risky to fly through particularly at low speeds. Aircraft have a lower turbulence speed than clear air speed. That's (part of) why they slow down as they approach the storms. However, slow speed increases the risk of stalling. Wind shear is a rapid change in wind speed and direction. At low speeds, that places the plane at risk of stalling. You don't want to stall in an eyewall. There are other issues, basically, a meso in an eyewall is like flying through a tornado both in terms of size and what it does to the plane. It can down the plane, even without a stall. 

*this* .... when training to fly your rough wx penetration speed is generally 15-20 kts north of V1 or takeoff speed .... there is a set configuration and airframe characteristic for rough air penetration. Shear in a mesovortex can rip the wings off the plane as the airframe is stressed beyond its engineering limits or shredded by winds from opposing directions that can unduly stress the airframe or defeat lift thus creating a stall 

[yoda]

wow

 

[raindancewx]

The only November category five in the Atlantic according to Phil Klotzbach (CSU) is the Cuba hurricane of 1932. So I think you'll see some hesitation by NHC to call Eta a five before landfall unless they are absolutely certain. It is interesting looking back, a lot of the strongest La Ninas have had fives - 2007 (Dean), 1988 (Gilbert), 1998 (Mitch), and so on. It did snow in October 1932 in the valleys of the SW, so the pattern that year is likely similar in an MJO sense. The record cold at times this Fall in the West is also similar to some of the great cold waves of the 1932-33 winter (-66 in Wyoming...seems unreal, but Montana set a record low for the continental US in October).

 

[hlcater]

Satellite presentation degrading and EWRC becoming increasingly dominant. That's probably all she wrote for this one. Doesn't look like it ever got 5 despite the incredible satellite presentation.

[Intensewind002]

The main thing I learned today is how lucky we are to have recon, any other basin and Eta would've probably been deemed a cat 5 ( and earlier this season, Delta would've probably never even made it to major status without recon). Is Eta the best ever looking storm not to get to Category 5 status?

[Tallis Rockwell]

I stop looking at this storm for 2 days and it becomes cat 5?! That's life I guess.

[yoda]

BULLETIN
Hurricane Eta Advisory Number  11
NWS National Hurricane Center Miami FL       AL292020
400 AM EST Tue Nov 03 2020

...EXTREMELY DANGEROUS HURRICANE ETA VERY NEAR THE COAST OF
NORTHEASTERN NICARAGUA...
...LIFE-THREATENING STORM SURGE, CATASTROPHIC WINDS, FLASH FLOODING,
AND LANDSLIDES EXPECTED ACROSS PORTIONS OF CENTRAL AMERICA...


SUMMARY OF 400 AM EST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.8N 83.1W
ABOUT 25 MI...40 KM SE OF PUERTO CABEZAS NICARAGUA
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H
PRESENT MOVEMENT...WSW OR 250 DEGREES AT 5 MPH...7 KM
MINIMUM CENTRAL PRESSURE...923 MB...27.26 INCHES

[yoda]

Hurricane Eta Discussion Number  11
NWS National Hurricane Center Miami FL       AL292020
400 AM EST Tue Nov 03 2020

Eta remains an extremely well-organized hurricane with a distinct 
eye embedded within cloud tops colder than -80C.  Based on 
continuity from the earlier Hurricane Hunter observations and 
Dvorak classifications from TAFB and SAB, the current intensity 
estimate remains 130 kt.  Images from the San Andres radar show 
at least one concentric eyewall, and this structure has likely 
stopped the rapid deepening process.  Nonetheless, Eta is an 
extremely severe hurricane, capable of causing very high storm 
surges and catastrophic damage.  After the center moves inland 
later today, rapid weakening is likely while the circulation 
interacts with land.  The official forecast is similar to the 
Decay-SHIPS guidance, and shows the cyclone weakening to a 
depression by tomorrow.  It is not certain that the surface 
circulation will survive after moving over Central America for the 
next 3 days or so.  The official forecast shows the system, perhaps 
at first the upper-level remnant of Eta, emerging over the 
northwestern Caribbean Sea in the latter part of the forecast 
period.  It should be noted that both the intensity and track at 4-5 
days are highly uncertain at this time.

The hurricane has slowed down and is now moving a little south of 
west or about 250/4 kt.  This motion will take the center across 
the coast in the Hurricane Warning area very soon.  A weak ridge to 
the north of Eta should cause the cyclone to move west to 
west-northwest, over Central America, during the next few days.  By 
96-120 hours, a trough developing over the Gulf of Mexico should 
cause the system to turn northward and northeastward but, as noted 
earlier, this future track is quite uncertain.

Since Eta is likely to be a very slow-moving system after it makes
landfall in Central America, torrential rains and inland flooding 
will be an extremely serious threat over the next few days.

Key Messages:

1. Catastrophic wind damage is expected where Eta's eyewall moves
onshore along the northeastern coast of Nicaragua this morning.  
Tropical-storm-force or greater winds are already occuring within 
the Hurricane Warning area in Nicaragua.  A Tropical Storm Warning 
is also in effect for the northeastern coast of Honduras.  

2. A catastrophic and life-threatening storm surge, along with
destructive waves, are expected along portions of the northeastern
coast of Nicaragua near and to the north of where the center makes
landfall.  Water levels could reach as high as 14 to 21 feet above
normal tide levels in some parts of the hurricane warning area.
Preparations to protect life and property should now be complete.

3. Through Friday evening, heavy rainfall from Eta will lead to 
catastrophic, life-threatening flash flooding and river flooding 
across portions of Central America, along with landslides in areas 
of higher terrain.  Flash and river flooding is also possible across 
Jamaica, southeast Mexico, El Salvador, southern Haiti, and the 
Cayman Islands.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0900Z 13.8N  83.1W  130 KT 150 MPH
 12H  03/1800Z 13.8N  83.6W  110 KT 125 MPH...INLAND
 24H  04/0600Z 13.8N  84.5W   50 KT  60 MPH...INLAND
 36H  04/1800Z 14.0N  85.9W   30 KT  35 MPH...INLAND
 48H  05/0600Z 14.5N  87.5W   25 KT  30 MPH...INLAND
 60H  05/1800Z 15.0N  88.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  06/0600Z 15.7N  89.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  07/0600Z 17.0N  88.0W   25 KT  30 MPH...OVER WATER
120H  08/0600Z 19.0N  83.5W   35 KT  40 MPH

$$
Forecaster Pasch

[Crocodile23]

5 hours ago, JasonOH said:

I wonder if the abort was due to the mesovorts.  They may have decided it was too dangerous.

This is from a post on twitter.
 

[sojitodd]

25 minutes ago, Crocodile23 said:

This is from a post on twitter.
 

Well I am glad they are ok and turned around-it just isn't worth it when they run into conditions like that. We know it is bad-we don't need anymore info if it leads to a situation like this.

[Windspeed]

Classic and mature ERC this morning prior to landfall.