ATL: DORIAN - Models

[Aric Dunn]

wsw turn for the ICON again.

[SFLcane]

icon is a good deal farther north and faster.

Hey Aric, seems to be moving wsw as it near the lake. Any insights or thoughts on tonight’s models?

[JPmia]

So what in the atmosphere or data has changed with the Euro to flip to the north like this? Was it new data being used for the model? This is quite the change.

[Mouton]

This is some info from the NHC who get paid to make the calls:

"The ridge over the western Atlantic appears to be already building
to the north of Dorian and is beginning to force the hurricane on a
more west-northwest track or 300 degrees at 9 kt. The ridge is
forecast to build even more and steer Dorian on a westward track for
the next 3 to 4 days. However, the steering currents will then
weaken, and this should result in a decrease in the hurricane's
forward speed. Given the collapse of the steering currents, the
track forecast by the end of the forecast period is highly
uncertain, and any small deviation in the track could bring the
core of the powerful hurricane well inland over the Florida, keep
it near the coast, or offshore. The models have not been very
consistent from run to run in terms of the timing of the northward
turn, but there are more models now indicating that the turn could
occur near the east coast of Florida instead of well inland. Given
this latest change, the NHC forecast has been shifted just a little
to the right at this time, but users should be prepared for
additional adjustements to the left or right depending on future
model trends."

The first team is in there now BTW.

[supercane4867]

ICON still insists on taking the WSW dive

[Aric Dunn]

Thing to note about the ICON and HWRF and others that keep the westward motion .. the low over the florida straights becomes more substantial and slightly more organized.

[BobHarlem]

18z Icon, landfall Boca. Faster, Monday night. vs Tuesday afternoon near Miami on 12z. Again I think the low to the west is the key on speed. Forward speed of Dorian is what would likely alter the models the most out this far.

[jlauderdal]

it slows down near the coast just like the gfs and euro but heads wsw instead nnw, easy to see why as the ridge is much stronger in its depiction..the solution makes perfect sense but is it reality

[SFLcane]

18z ICON brings Dorian into SFL intense hurricane

[Orlando]

Could someone with professional knowledge explain to us exactly how the models know how and what to predict? Someone mentioned earlier something about atmospheric machines regarding model predictions. What exactly are those and how do they work?

This isn’t a question that can really be answered in a post. If you are good with math, thermodynamics, fluid dynamics and general physics, NCEP & the Climate Prediction Center have explanation pages. Some are statistical, some are dynamic. They get fed data from a variety of sources and are programmed to output. They are very complex.

For most people, being able to identify what they show and understanding basic stuff like high and low pressure and wind currents, we can put 2 and 2 together.

Thank you for the websites:

https://www.ncep.noaa.gov/
https://www.cpc.ncep.noaa.gov/

Those are great sites for studying up. I appreciate it!

[Blown Away]

Wow, how much fun are the next 24 hours of model runs going to be... Got my alarm set for 1:45 am Euro...

[Aric Dunn]

Wow, how much fun are the next 24 hours of model runs... Got my alarm set for 1:45 am Euro...

LAME sleeping is not allowed....

[jlauderdal]

18z ICON brings Dorian into SFL intense hurricane

even though it slows like the big 2, it really sees the pattern differently and the result is textbook based on the heights

[AutoPenalti]

ICON still has that 1020mb high stacked right on her.

That isn’t going anywhere.

[Orlando]

Could someone with professional knowledge explain to us exactly how the models know how and what to predict? Someone mentioned earlier something about atmospheric machines regarding model predictions. What exactly are those and how do they work?

Would any of the following be of help?

http://www.storm2k.org/phpbb2/viewtopic.php?f=61&t=102873
https://www.emc.ncep.noaa.gov/gmb/ens/info/ens_detbak.html

They are in the Tropical Reference Library here at Storm2k.http://www.storm2k.org/phpbb2/viewforum.php?f=61

Yes, great stuff, thank you! I will study up.

[beachman80]

I don’t see that High holding in place like the ICOn says. We will see what the GFS says here in the next 20 min.

[Weatherboy1]

Again, there is no powerful front/trough swooping down to grab Dorian and steer him up and out to sea. That's what you typically see later in the season. This is more of a subtle handoff from ridge to potential weakness. That's why the models are slowing Dorian's movement down so much … and also swinging around a bit from run to run. It is a VERY close call for the FL east coast and I definitely would not recommend letting your/our guard down unless we see persistence/trending in model runs over a longer period of time.

[jlauderdal]

the ICON has a low sitting to the NE, dont remember seeing that feature before

[AutoPenalti]

What a nightmare scenario for the tri-county cities. ICON has it nearly hovering over Palm beach, Broward and Dade.

[jlauderdal]

I don’t see that High holding in place like the ICOn says. We will see what the GFS says here in the next 20 min.

the last runs of gfs dont have that much ridging anymore, euro had it yesterday....all eyes on the next gfs and euro runs