# One hurricane into two

**URL:** <https://boards.straightdope.com/t/one-hurricane-into-two/461912>\
**Category:** Factual Questions\
**Created:** [September 4, 2008, 12:04am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912 "2008-09-04T00:04:24Z")\
**Posts on this page:** 12\
**Page:** 1

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**Author:** ![ltfire](https://avatars.discourse-cdn.com/v4/letter/l/7ea924/32.png) [@ltfire](https://boards.straightdope.com/u/ltfire)\
**Post date:** [September 4, 2008, 12:04am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/1 "2008-09-04T00:04:24Z")

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Can one hurricane join up with another hurricane?  
There are presently 3 storms on the road to the Florida area. If the lead one stalls in its forward motion, can the one behind it meld into the first one and create a super storm?

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [September 4, 2008, 12:10am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/2 "2008-09-04T00:10:05Z")

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[It happens on Jupiter](http://mienfoks.blogspot.com/2008/07/jupiters-big-red-spot-swallows.html)  
I don’t think there’s any historical examples of such mergers on Earth.

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**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\
**Post date:** [September 4, 2008, 1:13am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/3 "2008-09-04T01:13:39Z")

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When hurricanes get somewhat close on Earth, they affect each other, but they more or less go around each other. I think the space shuttle and some satellites have photographed two hurricanes spinning relatively close together.

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**Author:** ![NinetyWt](https://avatars.discourse-cdn.com/v4/letter/n/cc9497/32.png) [@NinetyWt](https://boards.straightdope.com/u/NinetyWt)\
**Post date:** [September 4, 2008, 1:54am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/4 "2008-09-04T01:54:52Z")

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According to what I’ve read, no.

[QUOTE=wikipedia]  
The Fujiwhara effect or Fujiwhara interaction is a type of interaction between two nearby cyclonic vortices, causing them to appear to “orbit” each other.  
[/QUOTE]

From [here.](http://en.wikipedia.org/wiki/Fujiwhara_effect)

[QUOTE=Jeff Masters’ weather blog]  
When hurricanes collide  
I’m getting this question a lot–can hurricane collide to form a super hurricane? No, hurricanes cannot collide to make a bigger hurricane. When hurricanes get within about 900 miles of each, they begin to interact. There are three possible outcomes:

1. The larger storm will destroy the smaller one. The larger storm’s upper-level outflow will bring hostile wind shear over the smaller storm, and the larger storm may steal the smaller storm’s moisture. This occurred in 2005, when Hurricane Wilma destroyed Tropical Storm Alpha over Hispaniola.

2. Both hurricanes will compete for the same energy, resulting in weakening of both storms.

3. The storms will rotate around a common center of rotation (the Fujiwhara Effect), before going on their separate ways. Hurricane Humberto and Hurricane Iris took part in a brief Fujiwara interaction in 1995. Iris then began interacting with a third storm, Tropical Storm Karen, which orbited and later merged with the more intense Iris.

Sometimes, a recurving hurricane will leave behind an enhanced trough of low pressure that will act to help recurve the storm behind it along the same path. This is possible this week with Ike and Hanna.  
[/QUOTE]

From [here](http://www.wunderground.com/blog/JeffMasters).

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**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\
**Post date:** [September 6, 2008, 3:08am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/5 "2008-09-06T03:08:21Z")

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Surely. Did you ever read the book by Sebastian Junger or see the movie, **The Perfect Storm**?

It/they were based on these phenomena:

[http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/cyclones/pfctstorm91/pfctstorm.html](http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/cyclones/pfctstorm91/pfctstorm.html)

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**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\
**Post date:** [September 6, 2008, 3:18am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/6 "2008-09-06T03:18:09Z")

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Ten or so years ago two hurricanes in the Florida vicinity started breaking up around the same time. The remnants of the two hurricanes then formed a new named storm. (Don’t recall the names, but I seem to recall it was in the G,H,I area.)

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**Author:** ![NinetyWt](https://avatars.discourse-cdn.com/v4/letter/n/cc9497/32.png) [@NinetyWt](https://boards.straightdope.com/u/NinetyWt)\
**Post date:** [September 6, 2008, 4:02am UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/7 "2008-09-06T04:02:29Z")

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Strictly speaking, neither of those two examples consists of “two hurricanes into one”.

In\*\* Ignatz’ \*\*link, it describes a hurricane and an “extratropical low”.

In **Earl** ’s example, the _ **remains** _ of two storms re-form into another storm. (Are you thinking of Iris and Karen in 1995?)

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**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\
**Post date:** [September 6, 2008, 3:24pm UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/8 "2008-09-06T15:24:40Z")

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**Jeff Masters’ weather blog** seems to contradict itself:

> [@Jeff Masters' weather blog](#):
>
> No, hurricanes cannot collide to make a bigger hurricane.

> [@Jeff Masters' weather blog](#):
>
> Iris then began interacting with a third storm, Tropical Storm Karen, which orbited and later merged with the more intense Iris.

Now, _Karen_ was a tropical storm, not a hurricane, but that’s just size difference. If a tropical storm and a hurricane can merge, surely a large and a small hurricanes could merge in the same way.

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**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\
**Post date:** [September 6, 2008, 5:45pm UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/9 "2008-09-06T17:45:51Z")

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I think it’s more likely that if two hurricanes get close enough together, they weaken each other. No cite, but I was watching the Weather Channel the other week and they mentioned that a particular storm would be weakening because another tropical storm was nearby.

It seems to make sense, as a tropical storm draws its energy from the warm ocean, thus cooling it and leaving less energy for the next one on the same path.

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**Author:** ![Marley23](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Marley23](https://boards.straightdope.com/u/Marley23)\
**Post date:** [September 6, 2008, 6:03pm UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/10 "2008-09-06T18:03:16Z")

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> [@NinetyWt](#):
>
> In **Earl** ’s example, the _ **remains** _ of two storms re-form into another storm. (Are you thinking of Iris and Karen in 1995?)

I think Katrina drew a lot of strength by absorbing the remains of another hurricane that had weakened into a tropical depression or less. But that’s still not the same as two hurricanes combining.

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**Author:** ![NinetyWt](https://avatars.discourse-cdn.com/v4/letter/n/cc9497/32.png) [@NinetyWt](https://boards.straightdope.com/u/NinetyWt)\
**Post date:** [September 6, 2008, 6:03pm UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/11 "2008-09-06T18:03:22Z")

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> [@ZenBeam](#):
>
> \*\*Now, _Karen_ was a tropical storm, not a hurricane, but that’s just size difference. If a tropical storm and a hurricane can merge, surely a large and a small hurricanes could merge in the same way.

I think that’s exactly what he’s on about. Seems to me, from what I’ve read, that up to a certain size it’s possible, but once one of the storms reaches hurricane strength it’s not.

I’m not a weather guru however, so I may be understanding it wrong.

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**Author:** ![WF\_Tomba](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@WF\_Tomba](https://boards.straightdope.com/u/WF_Tomba)\
**Post date:** [September 6, 2008, 6:29pm UTC](https://boards.straightdope.com/t/one-hurricane-into-two/461912/12 "2008-09-06T18:29:19Z")

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> [@ZenBeam](#):
>
> **Jeff Masters’ weather blog** seems to contradict itself:
> 
> Now, _Karen_ was a tropical storm, not a hurricane, but that’s just size difference. If a tropical storm and a hurricane can merge, surely a large and a small hurricanes could merge in the same way.

A question, though, is whether the result would be “a super storm” or “a bigger hurricane”.

From **Ignatz** ’s link:

> [@](#):
>
> Extensive extratropical cyclones such as the Halloween Storm usually cover larger areas than even the largest hurricanes or typhoons. Sometimes, as was the case with Hurricane Grace’s interaction with the Halloween Storm, a hurricane will be absorbed by a larger extratropical storm and the hurricane’s energy becomes a part of the larger storm’s circulation. **This sometimes leads to a dramatic energizing of the larger storm** , often with disastrous consequences. Such was the case with Hurricane Hazel in October, 1954 which first struck the Carolinas as a Category 4 hurricane, and then merged with a low pressure center to become a monstrous extratropical storm which devastated Toronto, Canada causing 76 deaths.

(bolding added)

Whether this could happen with two storms of the hurricane variety, I don’t know.
