Tropical depression sixteen approaches the Yucatan Peninsula - Now Tropical Storm NATE

#1

TROPICAL DEPRESSION SIXTEEN (NHC)

000
WTNT41 KNHC 042051
TCDAT1

Tropical Depression Sixteen Discussion Number 2
NWS National Hurricane Center Miami FL AL162017
500 PM EDT Wed Oct 04 2017

Visible satellite images show that the depression has lots of
curved bands, although it is somewhat lacking any inner core
features. An Air Force Reserve Hurricane Hunter flew into the
depression this afternoon and found a well-defined circulation, with
maximum flight-level winds of 37 kt and SFMR values around 30 kt.
These data support keeping the intensity at 30 kt for this advisory.

Environmental conditions look quite favorable for strengthening over
the next few days, with low shear and very warm and deep water in
the path of the cyclone. The various rapid intensification indices
are all higher than the last cycle, suggesting an increasing chance
of rapid intensification occurring. The fly in the ointment,
however, is all of the potential land interaction, first over
Central America and then possibly over the Yucatan Peninsula. As
a compromise, the intensity forecast is raised considerably from the
previous one during the first 3 days, but is still below some
guidance, such as the HWRF.

The depression continues to move slowly northwestward, steered by a
distant ridge over the southwestern Atlantic. However the steering
pattern is forecast to change quickly tomorrow as a mid-tropospheric
trough over the Florida Straits moves across the northwestern
Caribbean into the southwestern Gulf of Mexico. Southerly flow on
the eastern side of that trough should cause the cyclone to move
much faster to the north-northwest by Friday and northward into the
Gulf of Mexico on Saturday. While there is some agreement on the
synoptic pattern, the model track agreement is rather poor, even in
the short term, with the GFS and ECMWF being 90 miles apart on the
forecast track as soon as 24 hours out. This has profound
differences down the road, with the GFS-based guidance moving
considerably faster and to the left of the ECMWF and UKMET across
the Gulf of Mexico. Overall, the guidance has generally shifted a
bit westward since the last cycle, so the latest points in the long
range have been adjusted in that direction. At this point, I
wouldn’t focus too much attention on the details of the long-range
forecast until the guidance comes into better agreement. A G-IV
mission and Florida special soundings have been set up for tomorrow
to better determine the synoptic steering flow around the cyclone.

KEY MESSAGES:

  1. The depression is forecast to strengthen and bring tropical storm
    conditions to portions of Nicaragua and Honduras tonight through
    Friday. Heavy rainfall could produce life-threatening flash
    flooding and mud slides in portions of Nicaragua, Honduras, Costa
    Rica, and Panama through Friday night.

  2. The system is expected to be near hurricane intensity when it
    approaches the Yucatan Peninsula late Friday or Saturday, bringing
    direct impacts from wind, storm surge, and heavy rainfall. A
    hurricane watch could be issued for this area later this evening.

  3. The system is forecast to continue strengthening over the Gulf of
    Mexico and could affect portions of the northern Gulf Coast as a
    hurricane this weekend, with direct impacts from wind, storm surge,
    and heavy rainfall. However, it is too early to specify the timing,
    location, or magnitude of these impacts. Residents along the Gulf
    Coast from Louisiana to Florida should monitor the progress of this
    system for the next several days and heed any advice given by local
    officials.

FORECAST POSITIONS AND MAX WINDS

INIT 04/2100Z 12.5N 82.5W 30 KT 35 MPH
12H 05/0600Z 13.2N 83.1W 40 KT 45 MPH
24H 05/1800Z 14.6N 83.8W 40 KT 45 MPH…INLAND
36H 06/0600Z 16.7N 84.6W 50 KT 60 MPH
48H 06/1800Z 19.5N 85.8W 60 KT 70 MPH
72H 07/1800Z 25.0N 88.0W 75 KT 85 MPH
96H 08/1800Z 30.5N 86.0W 65 KT 75 MPH…INLAND
120H 09/1800Z 35.5N 82.0W 30 KT 35 MPH…POST-TROP/INLAND

Forecaster Blake
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#2

Hey @fredwx any updates on this one? I just looked at your website and blog? Your WX updates are appreciated. Hope all is well.

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#3

000
WTNT41 KNHC 060843
TCDAT1

Tropical Storm Nate Discussion Number 8
NWS National Hurricane Center Miami FL AL162017
400 AM CDT Fri Oct 06 2017

An Air Force plane fixed the center of Nate as it was moving back
over the waters of the Gulf of Honduras a few hours ago. The minimum
central pressure was estimated at 999 mb, and a combination of
flight-level and the SFMR winds yield an intensity of 40 kt. The
surface circulation is broad, and the strongest winds are within a
cyclonically curved band in the eastern semicircle. Radar from
Honduras also helped to track the center when the cyclone was over
Honduras. Nate is moving toward the very warm waters of the
northwestern Caribbean Sea and within an environment of light shear.
On this basis, the NHC forecast calls for some strengthening through
the next 48 hours, and Nate is expected to be a Category one
hurricane by the time it is close to the U.S. coast. The interaction
with the Yucatan peninsula, however, could halt the strengthening
temporarily in the 12 to 24 hour period. Once Nate moves inland
over the U.S., weakening is anticipated and the cyclone most likely
will dissipate by the end of the forecast period.

Nate is moving toward the north-northwest or 340 degrees at 12 kt.
The cyclone is sandwiched between a large cyclonic gyre over
Central America and a developing subtropical ridge over the
western Atlantic. This flow pattern should steer Nate on the same
general north-northwest track with a marked increase in forward
speed for the next 2 days. After that time, Nate should be on the
northern edge of the subtropical high and become steered toward the
northeast by the mid-latitude westerly flow. The confidence in the
track forecast is high since most of the reliable guidance have come
to a very good agreement, and models are tightly clustered at least
for the next 2 to 3 days. The NHC forecast is in the middle of the
envelope.

KEY MESSAGES:

  1. Heavy rainfall is the main threat from Nate in portions of
    Central America, with life-threatening flash flooding and mud slides
    possible in portions of Nicaragua, Honduras, Costa Rica, Panama, and
    Belize through tonight.

  2. There is a possibility that Nate could be near hurricane
    intensity when it approaches the Yucatan Peninsula later today
    bringing direct impacts from wind, storm surge, and heavy rainfall.
    A tropical storm warning and a hurricane watch are in effect for a
    portion of this area, and life-threatening flash flooding is also
    possible.

  3. Nate is forecast to reach the northern Gulf Coast late Saturday
    or Sunday morning as a hurricane, and the threat of direct impacts
    from wind, storm surge, and heavy rainfall is increasing from
    Louisiana through the western Florida Panhandle. Hurricane and
    tropical storm watches, as well as a storm surge watch, are in
    effect for a portion of the northern Gulf Coast, and residents in
    these areas should monitor the progress of Nate, heeding any advice
    given by local officials.

FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 16.9N 85.1W 40 KT 45 MPH
12H 06/1800Z 19.2N 85.9W 50 KT 60 MPH
24H 07/0600Z 22.7N 87.8W 50 KT 60 MPH
36H 07/1800Z 26.4N 89.5W 60 KT 70 MPH
48H 08/0600Z 29.3N 89.6W 70 KT 80 MPH
72H 09/0600Z 36.0N 84.0W 30 KT 35 MPH…INLAND
96H 10/0600Z 40.5N 74.5W 20 KT 25 MPH…POST-TROP/REMNT LOW
120H 11/0600Z…DISSIPATED

Forecaster Avila
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#4

Offshore Waters Forecast for the Gulf of Mexico
NWS National Hurricane Center Miami, FL
555 PM EDT Fri Oct 6 2017

Offshore Waters Forecast for the Gulf of Mexico

Seas given as significant wave height, which is the average
height of the highest 1/3 of the waves. Individual waves may be
more than twice the significant wave height.

GMZ013-071000-
N Central Gulf including Flower Garden Banks Marine Sanctuary-
555 PM EDT Fri Oct 6 2017

…HURRICANE WARNING…

.TONIGHT…TROPICAL STORM CONDITIONS POSSIBLE. E to SE winds
20 to 25 kt. Seas 8 ft. Scattered showers and thunderstorms.
.SAT…TROPICAL STORM CONDITIONS EXPECTED. W of 90W, SE to S
winds 15 to 20 kt, becoming SE 25 to 30 kt in the afternoon. Seas
7 to 10 ft. Elsewhere, SE winds 30 to 35 kt, becoming E to SE
45 to 55 kt in the afternoon. Seas 7 to 9 ft, except E of 91W
building to 13 to 24 ft in the afternoon. Numerous squalls and
thunderstorms E of 91W.
.SAT NIGHT…TROPICAL STORM CONDITIONS EXPECTED. W of 90W, N
winds 25 to 30 kt. Seas 14 to 15 ft. Elsewhere, S winds 55 to
65 kt, becoming S to SW 35 to 40 kt late. Seas 16 to 24 ft
N of 27N E of 91W, and 9 to 16 ft elsewhere except 6 to 9 ft
W of 93W. Numerous squalls and thunderstorms.
.SUN…TROPICAL STORM CONDITIONS POSSIBLE. W of 90W, W winds
25 to 30 kt, becoming SW to W 15 to 20 kt in the afternoon.
Elsewhere, SW winds 25 to 30 kt. Seas 7 to 10 ft W of 90W, and
10 to 13 ft elsewhere. Scattered showers and thunderstorms.
.SUN NIGHT…S to SW winds 15 to 20 kt, diminishing to 5 to
10 kt late. W of 90W, seas 4 to 5 ft. Elsewhere, seas 6 to 8 ft,
subsiding to 4 to 5 ft late.
.MON…S to SW winds 5 to 10 kt. Seas 3 to 4 ft.
.MON NIGHT…SE to S winds 5 to 10 kt. Seas 3 to 4 ft.
.TUE…E winds 5 to 10 kt. Seas 3 to 4 ft.
.TUE NIGHT…NE winds 10 to 15 kt. Seas 3 to 4 ft.
.WED…NE winds 10 to 15 kt. Seas 3 to 4 ft.
.WED NIGHT…NE to E winds 10 to 15 kt. Seas 3 to 4 ft.

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#5

24HR Wind/Wave Forecast VT00Z 0N-31N 35W-100W

image

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#6

GMZ013-080315-
N Central Gulf including Flower Garden Banks Marine Sanctuary-
1104 AM EDT Sat Oct 7 2017

…HURRICANE WARNING…
Offshore Waters Forecast for the Gulf of Mexico
NWS National Hurricane Center Miami, FL
1104 AM EDT Sat Oct 7 2017

Offshore Waters Forecast for the Gulf of Mexico

Seas given as significant wave height, which is the average
height of the highest 1/3 of the waves. Individual waves may be
more than twice the significant wave height.

GMZ001-080315-
Synopsis for the Gulf of Mexico
1104 AM EDT Sat Oct 7 2017

.SYNOPSIS…Hurricane Nate is located near 26.6N 88.4W at
07/1500 UTC moving NNW at 23 kt. Maximum sustained winds have
increased to 80 kt with gusts 95 kt. Estimated minimum central
pressure is 984 mb. The center of Nate will move across the
central and northern Gulf of Mexico the rest of today, reaching
near 29.1N 89.0 this evening, and will make landfall along the
central U.S. Gulf coast tonight. Marine conditions will
gradually improve by late Sun. A ridge will build across the
area in the wake of Nate early next week.

.**THIS AFTERNOON…HURRICANE CONDITIONS. W of 90W, NE to E winds **
**20 to 25 kt. Seas 9 to 10 ft. Elsewhere, E to SE winds 60 to 70 **
**kt. Seas 26 to 27 ft. Scattered showers and isolated **
thunderstorms.
.TONIGHT…TROPICAL STORM CONDITIONS EXPECTED. W of 90W, NW to
N winds 20 to 25 kt. Seas 12 to 14 ft. Elsewhere, S to SW winds
60 to 70 kt, diminishing to 30 to 35 kt late. Seas
25 ft, subsiding to 16 ft late. Scattered showers and
isolated thunderstorms.

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