2018 Hurricane Season

[TomK]

Reni - a digging trough north of the islands is causing Norman to move northwards. A trough is an elongated area of low pressure in the mid to upper atmosphere. Digging means it's getting bigger. Because winds tend to flow from high to low-pressure regions, the steering winds from the high-pressure system in the NE Pacific are starting to push Norman north. Always best to remain prepared though.

[reni]

you're just awesome Tom! Mahalo for your explanation !!!!

[Frank]

quote:

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Originally posted by TomK

Reni - a digging trough north of the islands is causing Norman to move northwards. A trough is an elongated area of low pressure in the mid to upper atmosphere. Digging means it's getting bigger. Because winds tend to flow from high to low-pressure regions, the steering winds from the high-pressure system in the NE Pacific are starting to push Norman north. Always best to remain prepared though.

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Have ya got a link to a page showing that dig trough ? thanks

[TomK]

Bear in mind this is a dynamic link, so will be updated as time goes on:

https://www.opc.ncep.noaa.gov/P_sfc_full..._color.png

NOAA also mention it:

http://www.prh.noaa.gov/cphc/tcpages/arc...1809060308

"The forecast track philosophy has not changed, with a digging trough in the middle and upper levels north of the main Hawaiian Islands imparting a more northwestward motion with time."

[Frank]

Thanks Tom so... per the link - appears the Low center is approx 1000 nmiles NNE of the storm which is approx 500 nmiles due East of Hilo...seems that low will have to dig deep quickly for the storm to pass North leaving the Big Island out of harms way...Hope that is the case

[TomK]

That's how I understand things, Frank, although Norman is already moving NW, so the effect seems to be happening already. Norman started its move northwards Weds afternoon.

PS. You can also use the MKWC site to see the various satellite images:

http://mkwc.ifa.hawaii.edu/satellite/

Click on the image you like and then you can select Javascript, flash or gif animations. Norman has a well-defined eye as I write this and you can already see it's turning quite sharply to the north.

[ElysianWort]

So as predicted it is taking that north turn.

It will be interesting to see if we get that nice weather for a couple days on Hawaii island (that I anticipate because of previous trends), followed by more nice, (but hot) days with Kona winds for Puna.

[glinda]

quote:

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Originally posted by TomK

That's how I understand things...

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There is an eye.. there isn't. It's well formed, it has fallen apart. The trough is this the trough is that. Unfortunately there's a bit of a discrepancy between our "scientist's" interpretation and NOAA's.

I strongly recommend folks read NOAA's posts. I think their interpretation might be a tad better.

[PaulW]

"I don't understand the confidence that it will suddenly take a northward path"

Because we have Magic Mountains protecting us! Amirite, glindakine?

[Durian Fiend]

quote:

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Originally posted by PaulW

"I don't understand the confidence that it will suddenly take a northward path"

Because we have Magic Mountains protecting us! Amirite, glindakine?

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None of the models have Norman getting close enough to affect Hawaii, thanks to atmospheric conditions. Those conditions will be changing next week though, so rather than conveniently scooting off to the north Olivia may be a threat.