Why Dorian stalled out over the Bahamas

[Yo_Mama_Been_Loggin]

Hurricane Dorian’s projected course has shifted dramatically over the past few days, spreading a menacing uncertainty across the Caribbean, Florida, and the southeastern coast of the US. As the storm continues to lash the Bahamas with deadly force, changing weather patterns have pushed the storm around, leading to mounting frustrations as US residents struggle to prepare for the storm, and meteorologists try to pin down where it will go next.

After a stint as a powerful storm that smashed records across the Caribbean, Dorian’s winds have weakened to a Category 2 storm. But the hurricane has also grown in size. Over the next several days the most intense parts of the storm will stay over the Atlantic rather than making landfall in the US, but the National Hurricane Center warned that it would get “dangerously close” to Florida over the evening before it begins to crawl up the southeast coast.

The Verge spoke with meteorologists to understand what’s going on with Dorian’s path.

-snip-

Why has the predicted track of the storm changed so much?

As Dorian initially approached Florida, an atmospheric ridge — a peak of high pressure — was in place just to the north of Dorian in the Atlantic. In the Northern Hemisphere, air flows counterclockwise around a ridge. So with a ridge to the north of Dorian, the winds would have likely pushed it west, directly into the Florida Coast.

A trough of low pressure is now drawing the hurricane away from the East Coast and out to sea.

Tropical storms like Dorian typically move slower than weather patterns further north in the Atlantic. With the storm already moving so gradually, the ridge had time to weaken and a “trough” of low pressure moved in toward the storm. The collapse of the ridge slowed the storm down even further, since it could no longer drive it west. Then the trough changed the hurricane’s direction.

https://www.msn.com/en-us/weather/topstories/why-dorian-stalled-out-over-the-bahamas/ar-AAGLbuZ?li=BBnb7Kz

[saidsimplesimon]

1. Thanks for the link

This is good news. "Out to sea" is an ideal outcome, imo.

[doc03]

2. That's b.s. it was the barbed wire fence Trump

put around Floridah. I can't imagine what they went through had to terrifying.

[Quemado]

5. I was wondering when Trump would take credit

for keeping the hurricane away from Florida.

[magicarpet]

6. I thought trDump fired 300 Tomahawk nuclear missiles into the eye of the hurricane to show it ....

.... who was really the boss ?

[muriel_volestrangler]

3. Interesting; I suspect they need a correction

As Dorian initially approached Florida, an atmospheric ridge — a peak of high pressure — was in place just to the north of Dorian in the Atlantic. In the Northern Hemisphere, air flows counterclockwise around a ridge. So with a ridge to the north of Dorian, the winds would have likely pushed it west, directly into the Florida Coast.
...
“A trough is just the opposite,” Knox says. “It’s like a valley in pressure and the winds in the Northern Hemisphere blow counterclockwise around the trough. If you’re south of a trough, then you’re nudged in the east or northeast direction.” That trough is now drawing the hurricane away from the East Coast and out to sea.

"The opposite", but both are called 'counterclockwise' flow. It would make more sense if the 1st paragraph said "air flows clockwise around a ridge".

[muriel_volestrangler]

7. The original has now been corrected

"Correction 9/4: A previous version of this article stated that in the Northern Hemisphere, air flows counterclockwise around a ridge. It flows clockwise. We regret the error."

https://www.theverge.com/2019/9/3/20848149/hurricane-dorian-national-weather-service-forecast-florida-bahamas

[0rganism]

4. Florida got lucky this time, i hope their luck holds

just looking at media i've seen so far of what Dorian has done to the Bahamas brings the fear.

the damage from a storm like Dorian squatting on, say, Miami for 48 hours would be immense. i hope Florida stays lucky, and the rest of the east Caribbean gets luckier.