# Hurricane's "engine" **URL:** \ **Category:** Factual Questions\ **Created:** [September 4, 2019, 12:40pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676 "2019-09-04T12:40:45Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [September 4, 2019, 12:40pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/1 "2019-09-04T12:40:45Z")
I always thought the eye was the “engine” of a hurricane. Going with that I assumed that disruption of the eye via physical obstructions (hills/buildings/etc) or loss of fuel (warm sea water) would be the only way to slow down a hurricane. Going with that I assumed that once the eye left Grand Bahama Island and was totally over the warm ocean/ gulf stream, that it would pick up speed. This did not happen. I tried asking the Weather Channel/Weather nation folk via Twitter but got no reply. So, any weather mavens out there have the scoop? Were my assumptions way too simplistic? ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [September 4, 2019, 12:47pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/2 "2019-09-04T12:47:06Z")
No. The eye is an emergent phenomena derived from the strength of the cyclonic winds. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 4, 2019, 1:50pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/3 "2019-09-04T13:50:30Z")
Dorian slowed almost to a stop over the Bahamas. It is indeed [gaining speed](https://www.thedailybeast.com/hurricane-dorian-tropical-storm-conditions-hit-florida)as it’s moving over the water. > [@](#): > > However, it’s gaining speed as it moves toward the U.S. coast and is still causing maximum sustained winds as high as 105 mph. [Another](https://wfin.com/abc-national-news/hurricane-dorian-lashes-florida-as-storm-makes-its-way-up-us-coast/): > [@](#): > > Dorian finally began to pick up some speed Tuesday morning and slowly moved away from the Bahamas toward Florida’s east coast, along which it’s moving on a parallel. It is slow-moving, true, but from listening to reports I believe it was moving at 1 mph over the Bahamas and and at 6 mph afterward. The eye is not the engine. It’s a \*product \*of the spin, from the Coriolis effect. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [September 4, 2019, 1:51pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/4 "2019-09-04T13:51:08Z")
Heat and moisture drive hurricanes, which is why they gain strength as they travel over warm tropical waters. As soon as they make land fall, they lose strength dramatically. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [September 4, 2019, 3:10pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/5 "2019-09-04T15:10:51Z")
Any part of the cyclone parked over land reduces the am’t of the storm over warm water and should have a negative affect, but the eye is a consequence and not a driver. Stationary cyclones may weaken because they are stationary from running into a front or are being subjected to steering and sheering winds. These weaken the storm. Being stationary doesn’t weaken the storm insomuch as indicate something is acting on it, and this is a clue that it is likely to weaken. Anecdotal: The straight-pathed storms are sliding into a route that has favorable forces on them and tend to be powerful and continually gain in intensity. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [September 4, 2019, 4:48pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/6 "2019-09-04T16:48:53Z")
Another factor that weakens a tropical storm when stationary is that the heat in the top layer of the ocean is “used up” and the churning mixes it with cooler, lower water. Also, in this case, the Bahamas are shallow water so there’s not a lot of deep heat to absorb. They are like sharks, they need to keep moving. It would take Dorian a while to recover from the standstill but it’s nearing the mainland so that keeps it from doing a major burst in power. ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [September 4, 2019, 5:04pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/7 "2019-09-04T17:04:22Z")
> [@BwanaBob](#): > > Going with that I assumed that once the eye left Grand Bahama Island and was totally over the warm ocean/ gulf stream, that it would pick up speed. This did not happen. I tried asking the Weather Channel/Weather nation folk via Twitter but got no reply. > > So, any weather mavens out there have the scoop? Were my assumptions way too simplistic? Others have covered how the eye is not the engine of a hurricane, but I thought it might also be helpful to add that the overall speed of the storm system (not to be confused with windspeeds within the storm) is determined by the greater flow of air in the atmosphere. Hurricane Dorian moves slowly because the atmosphere around it is moving slowly - there’s a high pressure ridge in the Atlantic northeast of Dorian (it can be seen on the pressure map [here](http://www.stormsurfing.com/cgi/display_alt.cgi?a=natla_slp)) [which is stalling/moving slowly](https://www.nbcnews.com/news/weather/why-hurricane-dorian-moving-so-slowly-n1049156). As huge as these hurricanes are (Dorian had tropical storm force winds about 140 miles from its eye on Sept. 2nd) the currents within the atmosphere that push hurricanes around are orders of magnitude larger, and it’s weird to think about the wind pushing a hurricane around, but that is exactly what happens. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [September 4, 2019, 6:06pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/8 "2019-09-04T18:06:08Z")
I think it would be instructive for the OP to keep an eye on the NOAA hurricane page for the next few months- tropical depressions and even storms crop up fairly regularly, and the main distinction between them and hurricanes is the wind speed and degree of organization, both of which are (AFAIK) dependent on each other. In other words, storms originating due to the heated water crop up regularly, and only some end up organized enough with fast enough winds to qualify as hurricanes. Having an eye is just a manifestation of that organization. And yeah, **ftg** , that explains why some hurricanes lose steam over Cuba and the Caribbean, but gain strength once they move into the Gulf of Mexico proper before hitting Texas or Louisiana. The water deepens, and thus can contain more heat. ---
**Author:** ![DaveRaver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/daveraver/32/1078_2.png) [@DaveRaver](https://boards.straightdope.com/u/DaveRaver)\ **Post date:** [September 4, 2019, 6:36pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/9 "2019-09-04T18:36:10Z")
The surrounding high and low pressure areas are what moves the hurricane around. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [September 5, 2019, 2:41pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/10 "2019-09-05T14:41:36Z")
Recommended reading: > **[Hurricanes: Science and Society: Hurricane Decay: Demise of a Hurricane](http://www.hurricanescience.org/science/science/hurricanedecay/)** > > \[NULL\] ---
**Author:** ![KMS94](https://avatars.discourse-cdn.com/v4/letter/k/ad7895/32.png) [@KMS94](https://boards.straightdope.com/u/KMS94)\ **Post date:** [September 5, 2019, 8:53pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/11 "2019-09-05T20:53:51Z")
Since the OP has been answered, I’ll be the first one to admit I clicked this thread thinking it was about the WWII fighter plane. :o :smack: ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [September 5, 2019, 11:59pm UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/12 "2019-09-05T23:59:13Z")
> [@Jasmine](#): > > As soon as they make land fall, they lose strength dramatically. No, that is fake news. Alabama is still in grave danger. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 6, 2019, 6:41am UTC](https://boards.straightdope.com/t/hurricanes-engine/839676/13 "2019-09-06T06:41:11Z")
> [@Hampshire](#): > > No, that is fake news. Alabama is still in grave danger. Well, yeah, the Tide could be caught looking past NM State to their big showdown with South Carolina next week. After all, the Aggies did lose to Washington State by 50 points last week. So I suppose there’s a chance of a major upset there.