How real is the rain shield over Austin?

Answering the question is there a rain shield over Austin?

AUSTIN (KXAN) -- Is there an actual rain shield over Austin? Some people think there is. Some people who live outside of Austin will swear there is something that happens when rain is approaching that makes it bypass their locale.

Our weather office receives emails about this after rain events asking, "Why didn't my city get rain when it looked so promising?"

It can be frustrating.

That frustration is made more when rain and storms coming out of the Hill Country get weaker moving into our metro counties (Hays, Travis, and Williamson). Sometimes these storms just completely end resulting in "not a drop" in Austin.

It's akin to a "why does this happen" question. It goes like this: why, when clouds clear from west to east, does the clearing seem to stop at Lake Travis resulting in afternoon high temperatures being less than the forecast because the clearing never made it here?

But it's the rain we're addressing here. Does science accept this or not?

Once again, we can look at the Balcones Escarpment. The Escarpment separates the higher elevation in the Hill Country to the flat topography east of Austin. We know warm surface wind get that lift into the higher levels of the atmosphere from the Hills. There are times that, for whatever reason, these updrafts fall apart when reaching the escarpment. The rain may bypass the city only to re-intensify when the inflow is established a second time.

The opposite is true, too. At times we will get more rain than we bargain for with all that moisture feeding into the area at the surface from the Gulf and at higher elevations from the Pacific. This will happen when a cold front stalls.

More than that, we have many tall buildings in Austin. Too many. These structures will take the wind and contribute to an alteration to their speed and direction. They deter the creation of clouds to generate rain. They can affect changes in winds and temperatures by trapping heat.

In addition, we have a lot of concrete creating the urban eat island effect. The makeup of a thunderstorm will change as it approaches this city. This accounts for, at times, a storm passing detouring the city because of the urban heat island, then becoming one again after it passes.

One reason that there really isn't that proverbial hole over Austin is greenhouse gas emissions. A study shows they cause an increase in rainfall.

So, all this said, while a storm may be hindered by temperatures, and available moisture, there really isn't a rain shield over the Austin area. It only seems that way because, yes, there are times when a promising storm moving east out of, say, Marble Falls, seems to die off when it crosses into Travis County.

It's just another one of the wonderful urban legends that make up this beautiful part of the country called Central Texas.