Official Discussion issued by the National Hurricane Center

Delta (AL262020) DATA RELEASED: 10/6/2020 10:00:00 PM UTC

Copy of official data

Hurricane Delta Discussion Number  10
NWS National Hurricane Center Miami FL       AL262020
1000 PM CDT Tue Oct 06 2020

Observations from a NOAA Hurricane Hunter aircraft and conventional 
and microwave satellite imagery indicate that Delta has not 
intensified since earlier today.  The central pressure has risen 
somewhat and the current intensity estimate, 115 kt, is probably 
generous based on flight-level and SFMR-observed surface winds from 
the NOAA plane.  Although the hurricane continues to have very deep 
convection near and over the center, the cloud pattern lacks 
well-defined banding features, and an eye is not evident on either 
geostationary or polar-orbiting satellite images.  Surveillance 
data from the NOAA G-IV aircraft suggest that Delta's circulation 
does not extend as markedly into the upper troposphere as one would 
expect for a major hurricane.  Given the current state of the 
system, not much strengthening seems likely before the center 
reaches northeastern Yucatan tomorrow morning.  Some weakening is 
likely due to the interaction with land during the next 12-18 
hours.  Re-intensification over the southern Gulf of Mexico is 
still expected, but when Delta reaches the northern Gulf, lower 
oceanic heat content is likely to cause at least slight weakening.  
The official intensity forecast is somewhat above most of the model 
guidance, but not much different from the regional hurricane 
models, HWRF and HMON, over the northern Gulf.

Fixes from the aircraft indicate a continued west-northwestward 
motion at just a slightly slower forward speed, 300/14 kt.  The 
track forecast reasoning is basically unchanged from earlier 
today.  Delta should move along and around the southwestern and 
western periphery of a mid-tropospheric anticyclone centered just 
east of Florida for the next couple of days.  Around 72 hours, the 
flow ahead of a shortwave trough over the south-central United 
States should cause the tropical cyclone to turn north-northeastward 
and move across the central Gulf coast late Friday or early 
Saturday.  The official track forecast remains close to the 
dynamical model consensus, TVCA. 

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.


INIT  07/0300Z 19.5N  85.1W  115 KT 130 MPH
12H  07/1200Z 20.9N  87.1W  115 KT 130 MPH...INLAND
24H  08/0000Z 22.3N  89.8W  105 KT 120 MPH...OVER WATER
36H  08/1200Z 23.6N  91.7W  110 KT 125 MPH
48H  09/0000Z 25.0N  92.7W  115 KT 130 MPH
60H  09/1200Z 26.8N  92.8W  115 KT 130 MPH
72H  10/0000Z 29.0N  92.2W  110 KT 125 MPH
96H  11/0000Z 33.0N  89.8W   50 KT  60 MPH...INLAND
120H  12/0000Z 36.0N  86.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

Forecaster Pasch