NWS records highest-ever instability readings in Phoenix area, based on weather balloon data

PHOENIX (KSAZ) -- The National Weather Service is breaking out a high-flying, high-tech way to measure weather conditions, especially during the monsoon.

It helps the weather service stay ahead of the storms.

Twice a day, every day during the monsoon season, the NWS sends up a balloon from its offices at tje SRP headquarters in Tempe. The balloon carries instruments to take scientific readings of the atmosphere, measuring what meteorologists call "instability."

"Instability is what thunderstorms need to grow," said Jaret Rogers with the National Weather Service in Phoenix. "It is the difference in temperatures. As you get higher up, it cools off very quickly. The higher up you go, there is also a lot of moisture in the atmosphere, so those two things contribute to instability."

It takes about an hour or two for the balloon to rise up to 100,000 feet (30,480 meters) where it eventually pops, and the instruments float back down to the ground. On Thursday the weather balloon and its little payload made history.

"So, what was measured this morning was the most ever measured at 5:00 a.m. in Phoenix," said Rogers. "So it just means the instability is there. Doesn't mean a thunderstorm will occur, but the environment is actually supportive for a thunderstorm."

Sure enough, the instruments on board the balloon got it right, as there were heavy rain up in Northern Arizona on Thursday, especially in and around Flagstaff.