re: Hurricane Nate - Moving Inland - Hurricane Season Over?

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Looking over the models they definitely shifted west on the last runs. Even Euro looks like it's slightly to the west too. I would think they're going to change the tracks on NHC.

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The NHC shifts, if any, are usually pretty subtle, but we'll see.

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

just let me know when there's a probable potential for Nate to be stronger than a 2 somewhere.

They have it as a hurricane faster on this NHC advisory now too. So far nothing but bad news with this system. It also shifted west as expected though very subtle.

Intermediate adv at 7 CT, Complete adv at 10 CT

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just let me know when there's a probable potential for Nate to be stronger than a 2 somewhere.

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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.

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The potential is there, unfortunately, but land interaction will be a deciding factor.

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Not sure if you're joking but a couple of these guys really really know their shite.

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By definition, if there are more than three of us here, then most of them don't, though.

It's all about knowing which ones to listen to.

PROTIP: Not Peej.

I didn't realize how fast the GFS had this thing flying into the Gulf. At 96 hours it's on land. That's crazy. That is where the Euro and GFS do not agree as that advisory above said. Euro has it much slower allowing that NE turn to steer it more towards Florida. Euro has it hitting land basically an entire day later. Interesting to see such a big difference between the models there.

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During Harvey and Irma I learned more and was better informed from the weather gurus on this forum than anywhere else. Keep up the good work baws.

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We learned that w/ Katrina and Bob's crappy Viper.

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So a question I have is if your models are not in agreement and over half push between a westward and the other half eastward...why is the cone not larger?

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Definition of the NHC Track Forecast Cone


Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2017 for the Atlantic and eastern North Pacific basins are given in the table below.

One can also examine historical tracks to determine how often the entire 5-day path of a cyclone remains completely within the area of the cone. This is a different perspective that ignores most timing errors. For example, a storm moving very slowly but in the expected direction would still be within the area of the cone, even though the track forecast error could be very large. Based on forecasts over the previous 5 years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60-70% of the time.

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LINK

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Why are they reluctant to move it?

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They're looking at their data and trying to make adjustments for outliers. They're not going to make major shifts just because an operational run on a certain model has moved 400 miles, for example.

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I said this during Irma but I don't like how NHC does their cones every few hours.

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Once you understand what they're doing and what the cone represents, it makes more sense as to why they make those minor adjustments with each update.

They're moving the center line, and the cone follows. Keep in mind they've gotten much more accurate in the last 5 years, but the entire track of a storm has stayed within the cone roughly 60-70% of the time, based on the article quoted/linked above.