San Antonio Weather Thread (Anthony: floods, working, hospital)

[ryneone]

Originally Posted by AnthonySA

not unless you really want me to... I was gonna put a 5% or so w/o a graphic.

Pass on it. Hopefully those storms will send us an out flow tomorrow so we get something!

[AnthonySA]

That storm looks like its producing outflow... meaning starting to collapse on itself. On occasion, storms do fire up along the outflow, but the further south this complex travels, the less the conditions are favorable for development.

[AnthonySA]

[hello13685]

What is responsible for the consistent high pressure over us?

[AnthonySA]

Originally Posted by hello13685

What is responsible for the consistent high pressure over us?

It has a lot to do with the natural wind patterns of the earth. If you divide the flow of the winds you'll get 3 different cells on either side of the equator... Hadley (tropics to ferrel), Ferrel(hadley to polar), and Polar.

Image from Wikipedia


Places where the winds converge at the surface (tropical rain forests, coniference forests) tend to get the most precipitation. This is because when the opposing winds collide/converge, the air has nowhere to go but up, or lift. Strong air is what promotes the vertical growth in clouds necessary to produce rain. The places of strongest convergence are usually located along jet streams where most of the disturbances/storms follow. A jet stream is a division of air masses, and usually is the dividing place between the different atmospheric circulation cells shown in the image above.

However, in the polar and subtropic regions, we have deserts and tundras, both of which are known for their lack of precipitation. If you look at the image, you'll see that at the surface the winds are diverging, or facing away from eachother. Further up in the atmosphere, you see the air molecules traveling down towards the surface... or sinking. This limits any vertical growth of clouds and as a result, conditions remain dry.

The more the air sinks, the higher the atmospheric pressure. Conversely... the more the air lifts, the lower the atmopsheric pressure.

Now, this map is not static and there are very wet or dry areas located at most latitudes. Other factors are also involved in shaping climates such as elevation, land-water distribution, prevailing winds, geographical features (nearby mountains, etc.).

[KY Filly]

Wow Anthony, that's really interesting. So how come it seems so difficult to break out of a certain weather pattern? For instance, although I didn't live hear then, last year the area was in a pattern of heavy rain about this time wasn't it? Seems like I remember watching the news and seeing that this area had 40-something days of rain in a row. (I bet it felt like Noah and the ark! LOL)

[ryneone]

Looks like we are in a slight risk for severe tomorrow!

[AnthonySA]

Originally Posted by KY Filly

Wow Anthony, that's really interesting. So how come it seems so difficult to break out of a certain weather pattern? For instance, although I didn't live hear then, last year the area was in a pattern of heavy rain about this time wasn't it? Seems like I remember watching the news and seeing that this area had 40-something days of rain in a row. (I bet it felt like Noah and the ark! LOL)

LOL ... our weather patterns are usually fairly stagnant here. The reason is the lack of upper level dynamics, especially in the summer, to push any system out of the way. Up in Kentucky, storms usually travel along the jet stream year round... down here, we find it hard pressed for it to make a visit.

Last summer, most of south was under the influence of the same ridge that we're under now... however, we had enough rain to have somewhat of a weakness in the atmosphere allowing for disturbances to sneak into our area one after the other. That's part of the reason why Erin came through here.. had the high been stronger, she probably would have been pushed into Mexico.

[ryneone]

Tonight we have to have an 8 day?

Where are?

[AnthonySA]

Originally Posted by ryneone

Tonight we have to have an 8 day?

Where are?

Definitely..