Major Hurricane Delta

[tiger_deF]

Looks like an eye might be popping out

[Doc Jon]

6 minutes ago, Griizzcoat said:

The cart before the horse so to say, but can a greek letter , "Delta" - in this case be retired?  And if so- replaced with what?  Never had this stuff in MET school. Just saying.../.

it's never happened before.  If the models are correct it should prove to be a topic of conversation at the post-season conference.  The current models have delta hitting the delta with the only question being the delta-v.

[Amped]

HMON and HWRF in perfect agreement with a 929mb low over Cancun. HMON is a few hours faster.

[hlcater]

8 minutes ago, tiger_deF said:

Looks like an eye might be popping out

You would've saved calories by not posting this.

[tiger_deF]

[hlcater]

Just now, tiger_deF said:

no

[the ghost of leroy]

Needs to shed the tumor 

[Calderon]

It's always a race to see who can say they "see an eye developing" first in hopes of being right, I swear. 

[hawkeye_wx]

82 kt SFMR this pass

968 or 969 mb from the latest dropsonde

Despite the continued deepening, Grand Cayman radar still does not show a great eye presentation, and satellite shows a lack of outflow to the east and south.

[sojitodd]

Up to 100mph now.

[OhioWX]

Radar presentation has improved. NHC is now forecasting Delta to reach category 4 before landfall near Cancun.

[CoastalWx]

Not the most classic looking on IR. Sort of oblong shaped with it being squeezed from the east. Not sure if that ridge pushing in will have an effect or not. 

[olafminesaw]

5 minutes ago, CoastalWx said:

Not the most classic looking on IR. Sort of oblong shaped with it being squeezed from the east. Not sure if that ridge pushing in will have an effect or not. 

Maybe somewhat improved from earlier though? It lost the big convective blob to the south

[yoda]

Interesting statement i bolded in the 5am disco from Blake

Hurricane Delta Discussion Number   7
NWS National Hurricane Center Miami FL       AL262020
500 AM EDT Tue Oct 06 2020

Delta has maintained a very deep central dense overcast during the
past several hours, with overshooting cloud-top temperatures to
-90C, and perhaps hints of an eye trying to emerge.  On the last 
pass through the center, the Air Force plane reported a 4-mb 
pressure fall in one hour to 968 mb, with believable SFMR values of 
80-85 kt.  Thus, the initial wind speed is set to 85 kt.

The hurricane is in the midst of a very impressive rapid
intensification episode, having strengthened over 50 kt during the 
past 24 hours.  I honestly don't see much that will stop it until it
reaches Yucatan, due to low vertical wind shear, high deep-layer
moisture, and the very warm and deep waters of the northwestern
Caribbean.  This is also supported by SHIPS rapid intensification 
probabilities that are well above 50 percent for most categories.  
Thus, the intensity forecast is raised to 115 kt near Yucatan 
landfall, closest to the HWRF forecast model, which has been a 
good performer this year, especially after ingesting NOAA radar 
data.  Some weakening is expected due to land interaction, but 
conditions look ripe for re-intensification over the Gulf of Mexico. 
Almost all the guidance is higher, now showing Delta reaching 
category 4 status in the 2-to-3 day time frame, and the new NHC 
intensity forecast reflects this likelihood.  However, an increase 
in southwesterly shear and cooler shelf waters near the northern 
Gulf coast should promote weakening, and little change has been made 
to the intensity forecast near landfall.  

Delta is moving much faster this morning to the west-northwest, with 
the latest estimates at about 13 kt.  A strengthening mid-level 
ridge across Florida should steer the hurricane to the 
west-northwest or northwest during the next couple of days.  Likely 
because of the deterioration of Gamma, model guidance is showing 
less poleward motion before Yucatan, and the official track is 
shifted to the west for the first day or so.  Over the Gulf of 
Mexico, Delta should slow down and turn northward ahead of a trough 
moving eastward across Texas in a few days.  Model guidance has 
again shifted westward, like the last cycle, and the official 
forecast is trended in that direction. However, it remains slightly 
east of the model consensus, due to a notable westward bias in some 
of the guidance during this hurricane season.

Users are reminded to not focus on the details of the track or
intensity forecasts, as the average 4-day track error is around 150
miles and the average 4-day intensity error is close to 15 mph.

Key Messages:

1. Extremely dangerous storm surge and hurricane conditions are
expected within portions of the northern Yucatan Peninsula of
Mexico beginning tonight, and a Hurricane Warning is in effect.

2. Heavy rainfall will affect portions of the Cayman Islands, 
western Cuba and the northern Yucatan Peninsula through midweek. 
This rainfall could lead to significant flash flooding and 
mudslides. The potential for heavy rain and flash flooding will 
increase across portions of the central Gulf Coast, Tennessee 
Valley, and southeastern United States as Delta moves inland later 
this week.

3. Delta is forecast to approach the northern Gulf Coast late this
week as a hurricane. While there is large uncertainty in the track
and intensity forecasts, there is a significant risk of dangerous
storm surge, wind, and rainfall hazards along the coast from
Louisiana to the western Florida Panhandle beginning Thursday night
or Friday. Residents in these areas should ensure they have their
hurricane plan in place and monitor updates to the forecast of
Delta.


FORECAST POSITIONS AND MAX WINDS

INIT  06/0900Z 17.5N  81.3W   85 KT 100 MPH
 12H  06/1800Z 18.7N  83.1W  100 KT 115 MPH
 24H  07/0600Z 20.4N  85.8W  115 KT 130 MPH
 36H  07/1800Z 21.8N  88.5W  105 KT 120 MPH
 48H  08/0600Z 23.0N  90.4W  110 KT 125 MPH
 60H  08/1800Z 24.2N  91.5W  115 KT 130 MPH
 72H  09/0600Z 25.8N  92.0W  110 KT 125 MPH
 96H  10/0600Z 29.8N  91.1W   85 KT 100 MPH...INLAND
120H  11/0600Z 34.0N  88.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Blake

[CoastalWx]

7 minutes ago, yoda said:

Interesting statement i bolded in the 5am disco from Blake

Hurricane Delta Discussion Number   7
NWS National Hurricane Center Miami FL       AL262020
500 AM EDT Tue Oct 06 2020

Delta has maintained a very deep central dense overcast during the
past several hours, with overshooting cloud-top temperatures to
-90C, and perhaps hints of an eye trying to emerge.  On the last 
pass through the center, the Air Force plane reported a 4-mb 
pressure fall in one hour to 968 mb, with believable SFMR values of 
80-85 kt.  Thus, the initial wind speed is set to 85 kt.

The hurricane is in the midst of a very impressive rapid
intensification episode, having strengthened over 50 kt during the 
past 24 hours.  I honestly don't see much that will stop it until it
reaches Yucatan, due to low vertical wind shear, high deep-layer
moisture, and the very warm and deep waters of the northwestern
Caribbean.  This is also supported by SHIPS rapid intensification 
probabilities that are well above 50 percent for most categories.  
Thus, the intensity forecast is raised to 115 kt near Yucatan 
landfall, closest to the HWRF forecast model, which has been a 
good performer this year, especially after ingesting NOAA radar 
data.  Some weakening is expected due to land interaction, but 
conditions look ripe for re-intensification over the Gulf of Mexico. 
Almost all the guidance is higher, now showing Delta reaching 
category 4 status in the 2-to-3 day time frame, and the new NHC 
intensity forecast reflects this likelihood.  However, an increase 
in southwesterly shear and cooler shelf waters near the northern 
Gulf coast should promote weakening, and little change has been made 
to the intensity forecast near landfall.  

Delta is moving much faster this morning to the west-northwest, with 
the latest estimates at about 13 kt.  A strengthening mid-level 
ridge across Florida should steer the hurricane to the 
west-northwest or northwest during the next couple of days.  Likely 
because of the deterioration of Gamma, model guidance is showing 
less poleward motion before Yucatan, and the official track is 
shifted to the west for the first day or so.  Over the Gulf of 
Mexico, Delta should slow down and turn northward ahead of a trough 
moving eastward across Texas in a few days.  Model guidance has 
again shifted westward, like the last cycle, and the official 
forecast is trended in that direction. However, it remains slightly 
east of the model consensus, due to a notable westward bias in some 
of the guidance during this hurricane season.

Users are reminded to not focus on the details of the track or
intensity forecasts, as the average 4-day track error is around 150
miles and the average 4-day intensity error is close to 15 mph.

Key Messages:

1. Extremely dangerous storm surge and hurricane conditions are
expected within portions of the northern Yucatan Peninsula of
Mexico beginning tonight, and a Hurricane Warning is in effect.

2. Heavy rainfall will affect portions of the Cayman Islands, 
western Cuba and the northern Yucatan Peninsula through midweek. 
This rainfall could lead to significant flash flooding and 
mudslides. The potential for heavy rain and flash flooding will 
increase across portions of the central Gulf Coast, Tennessee 
Valley, and southeastern United States as Delta moves inland later 
this week.

3. Delta is forecast to approach the northern Gulf Coast late this
week as a hurricane. While there is large uncertainty in the track
and intensity forecasts, there is a significant risk of dangerous
storm surge, wind, and rainfall hazards along the coast from
Louisiana to the western Florida Panhandle beginning Thursday night
or Friday. Residents in these areas should ensure they have their
hurricane plan in place and monitor updates to the forecast of
Delta.


FORECAST POSITIONS AND MAX WINDS

INIT  06/0900Z 17.5N  81.3W   85 KT 100 MPH
 12H  06/1800Z 18.7N  83.1W  100 KT 115 MPH
 24H  07/0600Z 20.4N  85.8W  115 KT 130 MPH
 36H  07/1800Z 21.8N  88.5W  105 KT 120 MPH
 48H  08/0600Z 23.0N  90.4W  110 KT 125 MPH
 60H  08/1800Z 24.2N  91.5W  115 KT 130 MPH
 72H  09/0600Z 25.8N  92.0W  110 KT 125 MPH
 96H  10/0600Z 29.8N  91.1W   85 KT 100 MPH...INLAND
120H  11/0600Z 34.0N  88.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Blake

Euro has had an awful west bias this season with all tropicals across the globe. Not good at all this season. 

[Superstorm93]

Heck of a burst in the southern eyewall 

[olafminesaw]

4 minutes ago, Superstorm93 said:

Heck of a burst in the southern eyewall 

 

Recon will be heading in soon. May very well find the most dramatic strengthening yet

[friedmators]

959.4 extrap 107 mph surface

[tiger_deF]

[weatherCCB]

I also think the sky the limit with this.  Again let’s hope the models weakening this at landfall are correct. Either way, looks like big surge threat. 

[dan11295]

Regardless of effects on the Gulf Coast, this is looking like it could be a bad hit to the NE Yucatan. Would be worst hit for that area since Wilma in 2005.

[Superstorm93]

And now we're up 60 knots since 8am yesterday...

[A-L-E-K]

RIP Señor Frog's 

[CoastalWx]

Yeah it's starting to look like the eye is getting more defined and trying to clear out. 

[olafminesaw]

The core is only about 40 miles across. With a little under 24 hrs until landfall, I expect it to make a run at cat 5

[Brian5671]

29 minutes ago, dan11295 said:

Regardless of effects on the Gulf Coast, this is looking like it could be a bad hit to the NE Yucatan. Would be worst hit for that area since Wilma in 2005.

what's the population like in that area?   Thinking sparsely populated outside of cancun and cozumel....

[Windspeed]

You can plainly see the small 6-8nm eye is merely obscured by high cirrus. That should clear out as the day progresses. This is a very small eyewall though. It's a little tough to forecast internal structural changes with such a tiny eye. An intense convective burst could even widen the eyeband and the eye could get larger without a traditional ERC. We've seen eyes get larger without an ERC. But 24 hrs is a long time when you have a rapidly intensifying core. MW doesn't reveal strong enough concentric banding for a new much larger eyewall to yet form. So really, Delta could very well make a run at Cat 5 prior to a NE Yucatán impact. It should still be a compact hurricane and core regardless of eyeband fluctuations.

[weatherwiz]

Pretty scary that we're continuing to see model intensity guidance bump in the stronger direction. I agree with @WxWatcher007 too...not very sold on the rapid weakening prior to LF. 

[Baltimorewx]

14 minutes ago, Brian5671 said:

what's the population like in that area?   Thinking sparsely populated outside of cancun and cozumel....

Cancún is pretty heavily populated and with the track it looks like it could go right over the barrier island where all the resorts are and then downtown Cancún. It won’t be good 

[Windspeed]

The eye is only 5 miles wide.  One would think an eyewall replacement cycle would occur at some point.

Just as an FYI, a statute mile is 1.15 nm. So 5 miles to nm is 5.75 and just rounding to 6nm. That being said, small eyewalls will fluctuate based on micro perturbations of strong meso bursts. That can morph and fluctuate the eyeband a nm or two even when small over short periods of time. Larger eyes do the same but it's obviously less noticeable due to larger diameter and area. Next recon could hypothetically find an even smaller eyewall on next mission, however, it has been reported open in portions of the band. It wouldn't surprise me if it expands a little as deep convection keeps bursting. Again, these small eyewalls are chaotic and futile to predict.