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Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

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31–40 of 156 posts

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#32

This site makes an appearance on HN somewhat regularly, but in case it's new to anyone, it tends to be a pretty useful forecast visual for wind: https://www.windy.com/?25.820,-67.720,5

it's only showing about 60 knots (70MPH). is the model off? does the model show higher altitudes? are the news exaggerating?

I'm wondering if it's a limitation of Windy. Their scale only goes up yo 70mph no matter where you are on the map, so I'm guessing that's as high as they can show.

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#33

This site makes an appearance on HN somewhat regularly, but in case it's new to anyone, it tends to be a pretty useful forecast visual for wind: https://www.windy.com/?25.820,-67.720,5

it's only showing about 60 knots (70MPH). is the model off? does the model show higher altitudes? are the news exaggerating?

I noticed that too when looking at hurricane Harvey. I use windy.com for sailing, and for low windspeeds, I can say that in my experience it has been pretty accurate.

For any given area you click, I think if you click on the details link you'll see a forecast that shows the gusts. I figure, new broadcasts will use the highest record windspeed for their headline (commercial news outlets being what they are). And you can see gusts that are far higher than nominal when you click on the detailed forecast. I see one area that is nominally 62 knots and gusting to 109 knots (125 mph).

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#34

This site makes an appearance on HN somewhat regularly, but in case it's new to anyone, it tends to be a pretty useful forecast visual for wind: https://www.windy.com/?25.820,-67.720,5

ventusky.com also has all the rest of the metrics as well.

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#35

This site makes an appearance on HN somewhat regularly, but in case it's new to anyone, it tends to be a pretty useful forecast visual for wind: https://www.windy.com/?25.820,-67.720,5

It's also interesting to look at the bigger picture. The southern hemisphere has its own level of insanity going on: https://www.windy.com/?-22.513,39.375,3

I think that's somewhat normal below 40 degrees south. Lots of open ocean without any significant land masses to slow things down. See more here:

https://en.wikipedia.org/wiki/Roaring_Forties

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#36

I know that this is slightly off-topic so feel free to downvote if you feel so inclined: There's a lot of money that goes into disaster relief and recovery. I think that's great and very worthwhile, thoughts on charity accountability notwithstanding. What I wonder, though, is if there are any organizations that provide pre-relief (prelief?) for disasters. For instance, the comment in this discussion about the airline…

It isn't feasible, but the reasons are weather prediction, not economics. Those who live in hurricane reasons are warned far enough in advance to evacuate 10 times every year. Many years not even one hurricane turns out big enough that an evacuation was required, and even when one does turn out that big, that vast majority of the land that was warned is never affected.

When we can accurately predict 1 week in advance how big and where a hurricane will land it is easy to evacuate those people over that week. However we don't yet have enough information to do that.

People living in those areas soon learn that most hurricanes are non-events: either they hit elsewhere, or they are small enough that their house can safely ride it out. Either way they can go years without evacuating. When a big one finally comes for them they don't realize until it is too late. Then the evacuation becomes a massive traffic jam of people trying to get out in not enough time.

Note that even if weather prediction is good enough people will take years to undo their habit of ignoring the predictions until it is too late as they have learned that the warnings are not worth paying attention to. (For all I know prediction might already be good enough)

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#37

Earlier quoted context omitted.

it's only showing about 60 knots (70MPH). is the model off? does the model show higher altitudes? are the news exaggerating?

I noticed that too when looking at hurricane Harvey. I use windy.com for sailing, and for low windspeeds, I can say that in my experience it has been pretty accurate. For any given area you click, I think if you click on the details link you'll see a forecast that shows the gusts. I figure, new broadcasts will use the highest record windspeed for their headline (commercial news outlets being what they are). And you c…

The news generally reports the maximum sustained winds as such, in addition to the maximum gusts. Naturally, the maximum sustained wind speed is not the same throughout the storm - it's mostly in the eyewall. The category rating is based on the max sustained wind speed.

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#38
post #13

I remember reading a few days ago that European models were predicting a turn to the north, and US models were predicting a high pressure ridge holding the hurricane to the west. Anyone know more about this? Because if true, it's the second time European models were more correct than American ones. Last time they decided we needed more supercomputing power, and they got it. Did it help?

> Last time they decided we needed more supercomputing power, and they got it. Did it help? Per a few sources I've seen, no, it didn't. One big cause of the GFS (USA) model's inaccuracy is lack the of computing power, which we've addressed a few times with new supercomputing clusters. The bigger problem is that the GFS model uses bad underlying physics. Decades ago we made several choices to optimize around the curre…

Thank you very much for pointing this out, TIL. To save others the time to look up which model the US National Weather Service (NWS) chose, they selected the [1] Geophysical Fluid Dynamics Lab (GFDL) FV-3, which the author of the linked blog article above was opposed to. The US has a "weather modeling gap", which is surprising to me, because of the economic (many futures contracts move on forecasts, though many of the forecasting used by financial firms is increasingly from private sources), public policy, and military applications.

[1] http://cliffmass.blogspot.com/2016/07/the-national-weather-s...

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#39

This site makes an appearance on HN somewhat regularly, but in case it's new to anyone, it tends to be a pretty useful forecast visual for wind: https://www.windy.com/?25.820,-67.720,5

It's also interesting to look at the bigger picture. The southern hemisphere has its own level of insanity going on: https://www.windy.com/?-22.513,39.375,3

Is that normal?

Re: Category 5 Hurricane Irma Brings 180-MPH Winds to Bear on Caribbean Islands

#40
post #6

As a Puerto Rican preparing for Irma, yes, we're pretty freaked.

chances are you will just be saved : https://earth.nullschool.net/#2017/09/07/0000Z/wind/isobaric...

This is shockingly bad "advice".

A Category 5 hurricane is not a point source, and storm prediction is far from an exact science.

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