HURRICANE DELTA Discussion Thread

Gamma is dieing.


Post-Tropical Cyclone Gamma Advisory Number 15
NWS National Hurricane Center Miami FL AL252020
1000 PM CDT Mon Oct 05 2020


...GAMMA BECOMES POST TROPICAL NEAR THE NORTHERN COAST OF THE
YUCATAN PENINSULA...
...PERIODS OF HEAVY RAINFALL POSSIBLE TONIGHT...



SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...21.6N 88.4W
ABOUT 85 MI...140 KM ENE OF PROGRESO MEXICO
ABOUT 125 MI...200 KM NW OF COZUMEL MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...SW OR 220 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

Winds are up to 80mph.


ESTIMATED MINIMUM CENTRAL PRESSURE 977 MB

MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT.

New 10 PM CDT forecast shows Delta remaining a MH longer over the central GOM but still forecasted to make landfall as a Cat 2.

Hurricane Delta Discussion Number 6
NWS National Hurricane Center Miami FL AL262020
1100 PM EDT Mon Oct 05 2020

A few hours ago, data from the NOAA Hurricane Hunters supported
upgrading Delta to a hurricane. Very recent reports from the Air
Force Hurricane Hunters, who are currently in Delta, support
increasing the intensity a little more to 70 kt. The minimum
pressure has also decreased a few mb from the NOAA mission, and is
now estimated to be 977 mb. Delta has strengthened at a rapid rate
of 40 kt since genesis occurred just 24 hours ago. The hurricane is
quite compact with a developing tight inner core, and even the
tropical-storm-force winds extend only up to 60 n mi or so from the
center.

After moving westward for much of the day, aircraft fixes from NOAA
and the Air Force indicate that the hurricane has resumed a
west-northwest motion, with the latest initial motion estimated to
be 295/6 kt. Delta is expected to move to the northwest at a fairly
quick pace on Tuesday and Wednesday as it moves in the flow between
a subtropical high over the western Atlantic and Post-Tropical
Cyclone Gamma over or near the Yucatan Peninsula. This motion
should take Delta over or very near the northeastern portion of the
Yucatan Peninsula by Tuesday night and over the southern Gulf of
Mexico on Wednesday. After that time, the western part of the ridge
is expected to slowly erode as a trough moves eastward across the
south-central U.S. This change in the steering pattern should cause
Delta to slow down and then turn northward toward the northern Gulf
coast, and it will likely make landfall there in a little more
than 4 days. The models are in fair agreement, and the NHC
track forecast is only a touch to the west of the previous one.

The hurricane has taken advantage of the near ideal conditions of
low vertical wind shear, high amounts of moisture, and very warm
29-30 C SSTs. These favorable environmental conditions for the
hurricane will persist for the next 2 or 3 days or so, and
therefore, it seems reasonable to believe that rapid intensification
will continue in the short term. Delta is expected to become a major
hurricane in about 24 hours when it is near the Yuctan Peninsula.
If Delta makes landfall on that landmass, it would likely temper
the cyclone's strength for a period of time. Beyond a few days,
when Delta is forecast to approach the northern Gulf coast, there
will likely be an increase in southwesterly wind shear. These less
conducive upper-level winds and cooler shelf waters should end the
strengthening trend prior to the U.S. landfall. The NHC intensity
forecast is largely an update of the previous one and lies close to
the HCCA and IVCN consensus models.

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. Dangerous storm surge and hurricane conditions are expected
within portions of the northern Yucatan Peninsula of Mexico
beginning Tuesday night, and a Hurricane Warning is in effect.

2. Heavy rainfall will affect portions of Jamaica, the Cayman
Islands, western Cuba and the northern Yucatan Peninsula during the
next few days. This rainfall could lead to significant flash
flooding and mudslides.

3. Tropical storm conditions are expected in portions of the Cayman
Islands beginning early Tuesday, and a Tropical Storm Warning is in
effect.

4. 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 an increasing 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 06/0300Z 16.8N 80.3W 70 KT 80 MPH
12H 06/1200Z 18.1N 82.0W 85 KT 100 MPH
24H 07/0000Z 19.8N 84.6W 100 KT 115 MPH
36H 07/1200Z 21.5N 87.1W 105 KT 120 MPH...INLAND
48H 08/0000Z 23.0N 89.5W 105 KT 120 MPH
60H 08/1200Z 24.0N 90.8W 105 KT 120 MPH
72H 09/0000Z 25.2N 91.7W 100 KT 115 MPH
96H 10/0000Z 28.6N 91.2W 85 KT 100 MPH
120H 11/0000Z 33.6N 88.4W 35 KT 40 MPH...INLAND

$$
Forecaster Cangialosi

sooo, over water it shifts slight west, the track once it hits near Dulac and Houma shifts slightly east (David just mentioned it on tv) and on my emergency management program I can toggle between current and old tracks to see how it shifted. 

Look at the distance traveled from when it is lastly a major, to right at landfall. The speed picks up significantly! Sure sign of steering pattern.