Newby question: Hurricanes and Water Vapor

[HK47]

First, I admit that I'm a complete weather newbie. So I realize my question may be silly.

I notice that there is a greater chance of a storm developing when the water vapor satellite image indicates moisture. Conversely, when the air is dry, storms seem less likely.

However, I notice that even though Caribbean surface water temperatures seem fairly high, the satellite image of moisture level over the gulf shows it as dry.

Does this mean that, for the present, a hurricane is unlikely to form in the gulf?

This isn't a prediction, isn't intended to be a prediction, and I wouldn't know how to make a prediction anyway - I hope that's a strong enough disclaimer.

[Stratusxpeye]

Welcome to storm 2k! First post first thread! You'll enjoy it here and learn a lot of information.

Storms do need moisture and convection to start to form. Usually from a tropical wave or stalled front over open waters or a "blob" . Currently there is pretty high shear in the gulf meaning the upper level winds would blow the clouds, convection, moisture away from the LLC Center and wouldnt be able to wrap around and strengthen. Also it is dry in the area. Here is a link and a quote on general tropical cyclone generation and how they form.

"It can take anywhere from hours to several days for a thunderstorm to develop into a hurricane. Although the whole process of hurricane formation is not entirely understood, three events must happen for hurricanes to form:

A continuing evaporation-condensation cycle of warm, humid ocean air
Patterns of wind characterized by converging winds at the surface and strong, uniform-speed winds at higher altitudes
A difference in air pressure (pressure gradient) between the surface and high altitude
Warm, moist air from the ocean surface begins to rise rapidly. As this warm air rises, its water vapor condenses to form storm clouds and droplets of rain. The condensation releases heat called latent heat of condensation. This latent heat warms the cool air aloft, thereby causing it to rise. This rising air is replaced by more warm, humid air from the ocean below. This cycle continues, drawing more warm, moist air into the developing storm and continuously moving heat from the surface to the atmosphere. This exchange of heat from the surface creates a pattern of wind that circulates around a center. This circulation is similar to that of water going down a drain. "


http://science.howstuffworks.com/hurricane.htm

[SouthFloridawx]

Welcome to storm2k HK47!!!

[wxman57]

First, I admit that I'm a complete weather newbie. So I realize my question may be silly.

I notice that there is a greater chance of a storm developing when the water vapor satellite image indicates moisture. Conversely, when the air is dry, storms seem less likely.

However, I notice that even though Caribbean surface water temperatures seem fairly high, the satellite image of moisture level over the gulf shows it as dry.

Does this mean that, for the present, a hurricane is unlikely to form in the gulf?

This isn't a prediction, isn't intended to be a prediction, and I wouldn't know how to make a prediction anyway - I hope that's a strong enough disclaimer.

Your observations about conditions across the Gulf are right on. A sharp trof axis across the central Gulf and plenty of northerly flow aloft means lots of dry air and wind shear out there. Not very conducive to development.

[wjs3]

Wxman57...

You make a subtle point that's important..."aloft"

The surface can be quite moist even under a dry slot in a WV image, right?

That might be some of the confusion...how there could be a dry slot in WV over the tropics which are generally moist at the surface given warm water temps, etc.

And the answer is that WV imagery tells us avout things going on higher up in the tropshphere, not so much (directly) about the surface.

HK47, your analysis is right on.

WJS3

[HurricaneHunter914]

Welcome to storm 2k! First post first thread! You'll enjoy it here and learn a lot of information.

Storms do need moisture and convection to start to form. Usually from a tropical wave or stalled front over open waters or a "blob" . Currently there is pretty high shear in the gulf meaning the upper level winds would blow the clouds, convection, moisture away from the LLC Center and wouldnt be able to wrap around and strengthen. Also it is dry in the area. Here is a link and a quote on general tropical cyclone generation and how they form.

"It can take anywhere from hours to several days for a thunderstorm to develop into a hurricane. Although the whole process of hurricane formation is not entirely understood, three events must happen for hurricanes to form:

A continuing evaporation-condensation cycle of warm, humid ocean air
Patterns of wind characterized by converging winds at the surface and strong, uniform-speed winds at higher altitudes
A difference in air pressure (pressure gradient) between the surface and high altitude
Warm, moist air from the ocean surface begins to rise rapidly. As this warm air rises, its water vapor condenses to form storm clouds and droplets of rain. The condensation releases heat called latent heat of condensation. This latent heat warms the cool air aloft, thereby causing it to rise. This rising air is replaced by more warm, humid air from the ocean below. This cycle continues, drawing more warm, moist air into the developing storm and continuously moving heat from the surface to the atmosphere. This exchange of heat from the surface creates a pattern of wind that circulates around a center. This circulation is similar to that of water going down a drain. "


http://science.howstuffworks.com/hurricane.htm

Wow lots of good information, thanks Stratusxpeye. And HK47 your answer isn't silly you were just trying to learn and get an answer to your question, which is what Storm2K is for. So whenever you have a weather related question, just post it here and someone will answer it.

[wxmann_91]

Welcome to Storm2k HK7!

Wxman57...

You make a subtle point that's important..."aloft"

The surface can be quite moist even under a dry slot in a WV image, right?

That might be some of the confusion...how there could be a dry slot in WV over the tropics which are generally moist at the surface given warm water temps, etc.

And the answer is that WV imagery tells us avout things going on higher up in the tropshphere, not so much (directly) about the surface.

HK47, your analysis is right on.

WJS3

That's a good explanation. Thunderstorms can and do develop in a dry air aloft environment, however, hurricanes, it is much harder to do so. If there is both dry air and shear, it is virtually impossible for hurricanes to form.

[HK47]

Thanks to all of you for your kind welcome and generous answers.

I can see I need to study the maps!

[coriolis]

We'll take a dozen people who don't know that much, but want to learn, over one person who thinks he knows it all.

That's why they let me stick around here.

[StormScanWx]

WELCOME TO STORM2K!!

I haven't been on this forum for a year, and it is the best tropical weather forum (IMHO) on the internet.

[Aquawind]

Welcome HK47!

Speaking of water vapor you should see this presentation.

http://www.storm2k.org/phpbb2/viewtopic.php?t=85335