Major Hurricane Delta

[JasonOH]

Interesting radar loop from the Cayman Islands. It’s super far from radar but it looks like there *may* be an EWRC in progress/finishing up.
 

http://www.weather.gov.ky/portal/page/portal/nwshome/forecasthome/radar

[WEATHER53]

What is the 1-5 day path of this?

[Doc Jon]

1 minute ago, JasonOH said:

Interesting radar loop from the Cayman Islands. It’s super far from radar but it looks like there *may* be an EWRC in progress/finishing up.
 

http://www.weather.gov.ky/portal/page/portal/nwshome/forecasthome/radar

I was wondering if anyone was going to comment on that.  I noticed that about an hour ago and figured somebody might comment.  Looks like the wind field has expanded too.  I was hoping we'd have a recon to confirm or rule it out by now.

[jpeters3]

6 minutes ago, the ghost of leroy said:

You should know when 12z is dude. It’s something even metfan can tell you. 

It's about #156,000 on the list of most important/relevant knowledge to my career.  But I appreciate the "metfan" advice.

[jojo762]

Current IR presentation is definitely bottom-tier for a 140mph category 4 hurricane... imagine it’ll improve overnight prior to nailing Cancun.

[JasonOH]

Anyone have the recon plan of the day for today? They updated tomorrow’s plan so the plan for today no longer comes up on the NOAA site.

[hlcater]

1 minute ago, JasonOH said:

Anyone have the recon plan of the day for today? They updated tomorrow’s plan so the plan for today no longer comes up on the NOAA site.

Next plane looks to be wheels up at 00z with nearly continuous coverage overnight.

 

[jpeters3]

1 minute ago, jojo762 said:

Current IR presentation is definitely bottom-tier for a 140mph category 4 hurricane... imagine it’ll improve overnight prior to nailing Cancun.

Motion of the cirrus to the east of the system suggests continued easterly shear.  This seems to be reflected in the RAMMB shear analysis, which shows about 15 kt currently.

 

[jpeters3]

Models are suggesting that shear will not abate until after landfall.  Accordingly, they mostly hold at the current intensity.  So I think the show is over in terms of RI prior to landfall.

But sub 900 is still possible, right???

 

 

[brianc33710]

15 minutes ago, WEATHER53 said:

What is the 1-5 day path of this?

Delta is forecast to go over the Yucatan Peninsula & reemerge over the south central Gulf. Then it's forecast to go toward the LA coastline Fri pm/Sat am. The cooler water & increased shear should weaken Delta some before the north Gulf landfall. But the strength at its peak will still determine its strength at its final landfall. 

[hlcater]

As expected, the inner core/eyewall is a mess.

[bobbutts]

If you're going to harass a chaser it should probably be Jeff Piotrowski.

 

(edit: please move to banter thread, didn't mean to have it here)

[Brian5671]

6 minutes ago, jpeters3 said:

Models are suggesting that shear will not abate until after landfall.  Accordingly, they mostly hold at the current intensity.  So I think the show is over in terms of RI prior to landfall.

But sub 900 is still possible, right???

 

 

models locked in with that clip of the very NE tip of the Yucatan....

[Windspeed]

[Radtechwxman]

20 minutes ago, jojo762 said:

Current IR presentation is definitely bottom-tier for a 140mph category 4 hurricane... imagine it’ll improve overnight prior to nailing Cancun.

Yea if someone showed me the current IR satellite loop and ask me to guess intensity I definitely wouldn't be saying cat 4. Curious if the pressure has come up more and if the winds are lower. Cloud tops still very cold but organization is poor. 

[hlcater]

fringe radar image suggests maybe a larger eye trying to take over/absorb the 4nmi wide eye. Regardless, I think intensification is probably done for now. Remains to be seen whether it resumes later.

[Castaway]

Wondering if the pin hole is teetering those cold tops around and causing it to look not as organized and if that second outer ring will ultimately broaden it out in the future cycles. Trend and timing. 

Going to try to look back on past pin hole radar examples to study their evolution and possible outcomes 

[NavarreDon]

145/956 @ 5


.

[Prospero]

Similar in size to Hurricane Charlie:

[Castaway]

Some intense looking cloud tops starting to pop up around the core

[NavarreDon]

Yikes!


064
WTNT41 KNHC 062034
TCDAT1

Hurricane Delta Discussion Number 9
NWS National Hurricane Center Miami FL AL262020
500 PM EDT Tue Oct 06 2020

Shortly after the release of the 1500 UTC advisory package, the
NOAA Hurricane Hunter aircraft measured a peak flight-level wind
of 132 kt, and during its final passage through the northeast
eyewall around 1700 UTC it reported a peak SFMR wind of 121 kt.
The aircraft continued to report an extremely small 4-to-5-nmi-wide
eye. The central pressure did level off somewhat on the final
couple of penetrations, with the latest reported central pressure
at 956 mb. The initial wind speed was raised to 120 kt on the
earlier intermediate advisory, and has been set at 125 kt for this
advisory. The next reconnaissance aircraft mission into the
hurricane is scheduled for this evening.

There has been no evidence of an outer eyewall from the aircraft
reports or earlier radar imagery from Grand Cayman. As a
result, some additional strengthening is likely to occur before
Delta reaches the northeastern coast of the Yucatan peninsula late
tonight or early Wednesday. The NHC intensity forecast is once
again a little above the various intensity aids until landfall in
Mexico. When the small inner core of Delta moves over land,
weakening is expected, but warm waters and low vertical wind shear
over the southern Gulf of Mexico should support re-strengthening,
and a second peak in intensity is likely when Delta is over the
central Gulf of Mexico in 48-60 hours. After that time, increasing
southwesterly shear and the cooler shelf waters over the
northern Gulf are expected to cause some reduction in wind speed.
The global models, however, depict a significant increase in the
size of Delta's wind field while it is over the Gulf of Mexico,
which increases the spatial extent of the storm surge and wind
threats for the northern Gulf coast. So regardless of Delta's
final landfall intensity, the projected large size of the hurricane
is likely to result in a significant storm surge and wind event for
portions of the northern Gulf coast later this week.

Delta has been moving steadily west-northwestward today at 300/15
kt. The track forecast reasoning remains unchanged from the previous
advisory. A mid-level ridge over Florida and the northeastern Gulf
of Mexico is expected to continue steering Delta west-northwestward
during the next 36-48 hours. After that time, a developing trough
over the south-central United States should cause Delta to turn
northward, and by Friday the hurricane is forecast to begin
accelerating northward or north-northeastward ahead of the trough.
This motion will bring Delta onshore along the northern Gulf coast
between 72 and 96 hours. The dynamical models continue to be
tightly clustered through 48-72 hours with some increase in spread
thereafter. The overall trend in the guidance has been slightly
westward, and the new forecast has been adjusted accordingly and
lies near the middle of the envelope. Supplemental upper-air balloon
launches at 0600 and 1800 UTC have begun at upper-air sites across
portions of the southeastern United States. In addition, a NOAA
G-IV synoptic surveillance mission is in progress and should provide
additional data for the 0000 UTC cycle of the dynamical models.

Key Messages:

1. Life-threatening storm surge and potentially catastrophic wind
damage are expected within portions of the northern Yucatan
Peninsula of Mexico beginning tonight. All preparations to protect
life and property should be rushed to completion.

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, flash and possible minor
river flooding will increase across portions of the central Gulf
Coast, Tennessee Valley, and southeastern United States as Delta
moves inland later this week.

3. There is an increasing likelihood of life-threatening storm surge
and dangerous hurricane-force winds, especially along the coasts of
Louisiana and Mississippi, beginning on Friday. Residents in these
areas should ensure they have their hurricane plan in place and
follow advice given by local officials. Storm surge and hurricane
watches will likely be issued for portions of the northern Gulf
Coast on Wednesday.

FORECAST POSITIONS AND MAX WINDS

INIT 06/2100Z 18.9N 84.1W 125 KT 145 MPH
12H 07/0600Z 20.2N 86.1W 135 KT 155 MPH
24H 07/1800Z 21.8N 88.8W 105 KT 120 MPH
36H 08/0600Z 23.0N 91.1W 110 KT 125 MPH
48H 08/1800Z 24.4N 92.6W 115 KT 130 MPH
60H 09/0600Z 25.9N 93.2W 115 KT 130 MPH
72H 09/1800Z 28.0N 92.9W 110 KT 125 MPH
96H 10/1800Z 32.4N 90.9W 55 KT 65 MPH...INLAND
120H 11/1800Z 35.5N 87.3W 20 KT 25 MPH...POST-TROP/REMNT LOW


.

[brianc33710]

8 minutes ago, NavarreDon said:

145/956 @ 5


.

The pressure is still very high for a 145 mph hurricane. 

[Windspeed]

Starting to think the small eye has collapsed but convection is still very intense due to strong banding. Call it an ERC or merely just the tiny eyewall losing integrity and succumbed to stronger outer convective banding but this appears to be morphing into a larger eye. I only say that because it didn't seem to have very dominate outer concentric band earlier on MW. Perhaps just a strong backside band. But it is a tiny 'cane so changes can likely happen over a much shorter period of time since the last scan. Yes, I did read the NHC discussion. Still, it does not look as organized as it was even an hour ago.

 

[Doc Jon]

2 minutes ago, brianc33710 said:

The pressure is still very high for a 145 mph hurricane. 

this was the case with Laura too.

[Castaway]

[hawkeye_wx]

The larger eyewall is mostly there.  It's just broken on the n/ne side.

[jpeters3]

12 minutes ago, hawkeye_wx said:

The larger eyewall is mostly there.  It's just broken on the n/ne side.

attenuation 

[MUWX]

Pretty decent uptick in lightning on the SW side. Eye seems slightly more apparent on visible as the sun sets.... *ducks* 

[Radtechwxman]

This is the ugliest 145mph hurricane I ever laid my eyes on via satellite. Lol. I'm shocked the winds went up. Only in 2020. Despite it being disorganized in the inner core, it still has took advantage of the great environment conditions. 

[Amped]

There's a noticeable fujiwara between Delta and Gamma on the visible the last couple hours.