Cloud bases were very warm again yesterday, 15-20 C (59-68 F) paving the way for thunderstorm rainfalls similar to those seen in the Southeast US, inches in an hour or so. Didn’t happen locally, but just to the north of us toward Park Links Road and up toward the Florence area, likely happened as one giant cell after another formed between Saddlebrooke and Florence.
Those were the only clouds that produced thunder yesterday. Less vigorous clouds rained, but didn’t have the ingredients to be thunderstorms, stronger updrafts, apparently. Also, at times it appeared some of the rain, to this eyeball, was “warm” rain, rain formed without ice, a rarity here in Arizona (something that happens all the time in Hawaii, and over the oceans.)
And if you were sharp, you saw something happen yesterday that is also quite rare; the clouds erupt in our vicinity into Cumulonimbus by 9 AM from surface heating (they weren’t those nighttime showers that tend to fade as the sun comes up). That was exciting because when they took off, it seemed like a day destined to have giants here.
But then something happened, drier air began to move in from the east, and pretty soon, the ONLY large clouds were to the west and north, a sure sign a disturbance aloft was moving through and less favorable conditions for rain would follow it, the normal “couplet”, or sequence.
Sure enough, the clouds over the Catalinas, after such an auspicious start, struggled to grow into Cumulonimbus clouds, as they did elsewhere to our southern flank, while we watched one magnificent Cumulonimbus after another rise up to the north.
Fortunately, a moistening and destabilizing regime of air is moving this way from Texas across northern Mexico toward Douglas, and so our day here in Catalina should be more enlightened, by lightning.