Sunday, October 02, 2016

Moisture Increase Brings Some Chances For Showers

We were out at Santa Rita Abbey Friday evening and Saturday. The roads in were very wet and muddy ,but weather cool and pleasant (note - as usual the grid point forecasts for this area 5 miles north-northwest of Sonoita were considerably too warm - forecast low for Saturday morning was 59 F but by 7:00 pm MST Friday evening temperature out there was already down to 59 F). Night skies were spectacular, with the Milky Way hanging across the sky from Nogales to overhead. I did notice that light pollution seems noticeably worse than a decade or so ago - especially that coming from the Sierra Vista/Ft. Huachuca area. Photo above is of the Santa Ritas at sunrise Saturday.

A strong 500 mb short wave is impacting the Great Basin and Northwest today and tomorrow, and as the south end of this feature affects southeastern Arizona today we're experiencing an increase in low-level moisture from the GoC. The CIRA blended PW analysis above is from 4:00 am and shows the moisture intrusion into Arizona. Forecast below of PW is from the 00 UTC WRF-GFS forecast (no 06 UTC forecasts available) and is valid at 4:00 pm this afternoon. 

The TUS GEFS plumes for 06 UTC indicate fairly high chances for light showers this afternoon and evening (above). However, CAPE remains quite low, due to warm air at middle levels, in the plumes (below) and also in the WRF-GFS forecast from 00 UTC. So a decent chance for showers today but thunderstorms may be limited to high elevations. No sounding as of yet from TWC and this, along with the lack of 06 UTC WRF forecasts, leaves us with little current data at sunrise.

We squeezed in a quick drive over to Rancho Rossa vineyards east-southeast of Sonoita - photo below is of 2016 cabernet still ripening on the vine.

1 comment:

  1. Hi Bob,
    I've noticed light pollution has gotten worse over the last few years in Tucson also due to the conversion to LED lighting. LED has more light in the shorter spectrum which is easier to scatter and they are generally brighter. I was shocked the other night when there were low clouds of how bright it was due to the light. The only real dark sky sites are out in the middle of nowhere (like Paradise!).

    The 6Z runs have been missing as I'm still working the bugs out from upgrading WRF.