aslkahuna Posted June 30, 2011 Share Posted June 30, 2011 Tucson's 81 day spell without any rain (tied for 4 longest) ended this morning with a thunderstorm dropping light rain at the airport. Davis-Monthan had 0.14 in while we caught the core with 0.48in. Storms formed as a result of an outflow boundary from an MCS that developed last night over Cochise County which interacted with a dryline just to our east. This is at least a pre monsoonal pattern and the monsoon itself is expected to develop soon. Steve Link to comment Share on other sites More sharing options...
A-L-E-K Posted June 30, 2011 Share Posted June 30, 2011 Nice and probably not a moment too soon. Link to comment Share on other sites More sharing options...
Ed Lizard Posted June 30, 2011 Share Posted June 30, 2011 That reminds me, I don't subscribe to JB anymore, but he always argued the only true monsoon in North America was in the mountains of Western Mexico where storms developed every night in the Summer. I never cared enough to really think about it. If Arizona winds up South of the ridge axis and with Easterly flow aloft, that would seem to be a windshift. I saw something on the interwebs about a 55ºF dewpoint at Phoenix as an indicator. BTW, that isn't quite Southeast Texas humidity, but then we rarely exceed 100ºF. Not exactly a dry heat... Link to comment Share on other sites More sharing options...
tacoman25 Posted June 30, 2011 Share Posted June 30, 2011 Tucson's 81 day spell without any rain (tied for 4 longest) ended this morning with a thunderstorm dropping light rain at the airport. Davis-Monthan had 0.14 in while we caught the core with 0.48in. Storms formed as a result of an outflow boundary from an MCS that developed last night over Cochise County which interacted with a dryline just to our east. This is at least a pre monsoonal pattern and the monsoon itself is expected to develop soon. Steve Woohoo. Link to comment Share on other sites More sharing options...
aslkahuna Posted July 1, 2011 Author Share Posted July 1, 2011 That reminds me, I don't subscribe to JB anymore, but he always argued the only true monsoon in North America was in the mountains of Western Mexico where storms developed every night in the Summer. I never cared enough to really think about it. If Arizona winds up South of the ridge axis and with Easterly flow aloft, that would seem to be a windshift. I saw something on the interwebs about a 55ºF dewpoint at Phoenix as an indicator. BTW, that isn't quite Southeast Texas humidity, but then we rarely exceed 100ºF. Not exactly a dry heat... JB is either being stubborn or does not follow current monsoon research to any great extent. He's right about the storms over the Sierra Madre but overlooks the precip and convective maximum that extends northward from there. A paper entitled The North American Monsoon by Comrie (UofAZ) et.al. in the BAMS for October 1997 gives a good definition of why what we see in SE AZ is part of that monsoon as well as reviewing the research up to then. The 55 degree dewpoint rule at PHX was an abortion based upon poor understanding of what a monsoon is and though applied statewide was really invalid for anywhere except PHX. The criteria I used for determing the presence of the monsoon when I was putting out outlooks for it are posted on my homepage is Special Topics. That easterly flow pattern (actually E-SE) is in fact the monsoon flow and happens every Summer during July into early September. Incidentally, dewpoints in Tucson and Sierra Vista are usually in the 60's at the peak of the monsoon which for Sierra Vista yields a surface mixing ratio equal to that at sea level with a 70 degree dewpoint so it does get humid. Yuma, in fact, sees dewpoints near 80 during moisture surges from the Sea of Cortez with dews in the 70's reaching PHX and TUS on occasion and even (rarely) Sierra Vista. Dr. Comrie is my son's principal Advisor as he works on PhD dissertation regarding a particular aspect of monsoon climatology. My son also wrote a paper on the role of Transient Inverted Troughs during the monsoon. Steve Link to comment Share on other sites More sharing options...
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