ATL: DELTA - Post-Tropical - Discussion

[CrazyC83]

There's another Recon pass probably coming. Out of respect of the satellite, I'd probably go 85 kt if no other data comes out.

[CrazyC83]

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 08 OCT 2020 Time : 015018 UTC
Lat : 22:40:03 N Lon : 90:28:13 W


CI# /Pressure/ Vmax
5.0 / 963.3mb/ 90.0kt


Final T# Adj T# Raw T#
5.0 5.0 7.3

Estimated radius of max. wind based on IR :<10 km

Center Temp : -29.0C Cloud Region Temp : -78.0C

Scene Type : PINHOLE EYE

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : MW ON
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 87nmi
- Environmental MSLP : 1008mb

Satellite Name : GOES16
Satellite Viewing Angle : 31.6 degrees

[ElectricStorm]

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 08 OCT 2020 Time : 015018 UTC
Lat : 22:40:03 N Lon : 90:28:13 W


CI# /Pressure/ Vmax
5.0 / 963.3mb/ 90.0kt


Final T# Adj T# Raw T#
5.0 5.0 7.3

Estimated radius of max. wind based on IR :<10 km

Center Temp : -29.0C Cloud Region Temp : -78.0C

Scene Type : PINHOLE EYE

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : MW ON
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 87nmi
- Environmental MSLP : 1008mb

Satellite Name : GOES16
Satellite Viewing Angle : 31.6 degrees

Dang raw 7.3

[TallyTracker]

How is it raw 7.3? It looks good, but not that good! lol

[supercane4867]

Eye is starting to clear

[CrazyC83]

How is it raw 7.3? It looks good, but not that good! lol

It diagnosed a pinhole eye amidst deep cloud tops. That was Raw 7.3 despite penalties for eye adjustments.

[ElectricStorm]

How is it raw 7.3? It looks good, but not that good! lol

It diagnosed a pinhole eye amidst deep cloud tops. That was Raw 7.3 despite penalties for eye adjustments.

Extreme convection yes... But recon had the eye at 30 miles...

[aspen]

At the rate Delta is organizing, I’ll be surprised if it’s anything less than a 960-965 mbar, 95-100 kt Cat 2/3 tomorrow morning.

[LarryWx]

Based on analogs, how healthy the storm appears, and the near ideal conditions projected for the next 36 hours, I'm growing more and more concerned that there will be a cat 4 offshore and a subsequent 950-955ish mb cat 3 landfall on LA despite the cooler shelf waters. I've now completed my search for analogs and can show the entire list of 6 analogs.

Here are the analogs that are mainly from the same time of year (early Oct thus meaning very likely similarly cooler shelf waters) and mainly peaked in the N Gulf as a cat 4 in some cases after rapid intensification. In 4 of the 6 cases, landfall was in LA. In all but one case, ENSO is similar to today's. In 4 of the 6 cases, it had crossed or was just offshore the Yucatan:

1. Opal of 1995: in early Oct and came off Yucatan. It went from a TS to a 916 mb cat 4 in the N Gulf within only 48 hours! It then weakened but still landfalled as a cat 3 in the FL Panhandle.

2. Carmen of 1974: Only one not in Oct. Like Delta, it was very powerful before major weakening on the Yucatan as it weakened to only a TS. But soon after, he went from a TS to cat 4 H within only 48 hours just S of LA with SLP down into the 930s! He then turned left/weakened slightly and landfalled in LA as a cat 3 I think.

3. Hilda of 1964: in early October in the C GOM south of LA went from a TS to a cat 4 941 mb H (150 mph winds) within only a 36 hour period. She made landfall in LA as a cat 3 with 950 mb SLP.

4. 1893 storm #10: Even though it was early Oct., it rapidly strengthened into a 948 mb cat 4 in the shelf waters just off SE LA and it made landfall in SE LA as a cat 4.

5. 1886 storm #10: after crossing the corner of the Yucatan, it at about the same time in Oct became a cat 3 only within 100 miles offshore LA and made landfall in W LA with ~120 mph winds. Lowest pressure was 955 mb, which I assume was onshore.

6. 1877 storm # 4: only one with different ENSO (El Nino). After the center barely missed the Yucatan, it strengthened into a 960 mb cat 3 just offshore Apalachicola on October 2 and then came ashore as a cat 3.

[dukeblue219]

Hmm, extrapolated 972.2 on the latest pass is actually up a bit from last.

[wx98]

Recon hasn't found anything that would support a lower pressure or winds higher than 90 mph, so I doubt that will change on this advisory.

[Steve]

Absolutely. Chances of surviving COVID are a lot higher than surviving a major surge in a low lying area. Can wear a mask in shelter, can't do much about a 15 foot surge.

Exactly. I just don't get it. Open the dang shelters

Democratic Governor playing politics with COVID-19. I can't wear a mask due to Manic Anxiety, so I wouldn't be able to go to one anyway.

Governor Edwards won for a reason and also enjoys majority support for a reason. Don’t talk politics. And wear a fn mask (when you can)

PS blin, hope things go well as they can for you and the family this week.

[JabNOLA]

I know we are living in an age when politics can not be involved in any discussion but perhaps there are no shelters open because it is Wednesday and no one is under a hurricane warning and there is still nearly 72 hours before landfall. Just saying.

[LarryWx]

Hmm, extrapolated 972.2 on the latest pass is actually up a bit from last.

Levi said that it usually takes ~12-24 hours for a storm to start significantly restrengthening, if it is going to do so, after a major disruption like Delta had today. So, since it moved offshore the Yucatan around noon today, that would mean at least around midnight before major restrengthening would possibly start.

[MONTEGUT_LA]

I know we are living in an age when politics can not be involved in any discussion but perhaps there are no shelters open because it is Wednesday and no one is under a hurricane warning and there is still nearly 72 hours before landfall. Just saying.

Terrebonne is opening a shelter tomorrow...parish government, not state...

[ElectricStorm]

I know we are living in an age when politics can not be involved in any discussion but perhaps there are no shelters open because it is Wednesday and no one is under a hurricane warning and there is still nearly 72 hours before landfall. Just saying.

For this storm yes. But they didn't open shelters for Laura so I would think they wouldn't for this storm either. Hopefully I'm wrong though and they open them

[ScottNAtlanta]

I see the last recon pass had the eye closed...it should be able to ramp up pretty quickly now

[edu2703]

10:00 PM CDT Wed Oct 7
Location: 22.5°N 90.9°W
Moving: WNW at 17 mph
Min pressure: 972 mb
Max sustained: 90 mph

[wx98]

...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR A PORTION OF THE NORTHERN GULF COAST...
10:00 PM CDT Wed Oct 7
Location: 22.5°N 90.9°W
Moving: WNW at 17 mph
Min pressure: 972 mb
Max sustained: 90 mph

[eastcoastFL]

I know we are living in an age when politics can not be involved in any discussion but perhaps there are no shelters open because it is Wednesday and no one is under a hurricane warning and there is still nearly 72 hours before landfall. Just saying.

Im pretty sure that’s the reason. They’ll open them later tomorrow probably