Bit More Interesting Today

Scenic skies this morning at a bit after 8:00 am MST.

It was quite suppressed locally yesterday, and I don't think there was even a sprinkle around. The plot of detected CGs (below - from Atmo and Vaisala) for 24 hours ending at 8:03 am this morning shows almost all the thunderstorm activity was far to our west. There were however one or two detections over the Huachuca Mountains, and a check of the radar does indicate a couple of small, short-lived storms over the mountains.

The morning forecast from the NWS indicates POPs at 30% for measurable rain at the airport through around midnight tonight. The 12 UTC run of the WRF-RR is a bit more optimistic. Model's forecast of composite radar echoes valid at 5:30 pm this afternoon is above, and rainfall through midnight is below - with fairly large areal coverage across eastern Pima County.

The morning sounding plot (above) for the TUS/TWC  upper-air data indicates little CAPE because of a nasty inversion at around 400 mb. The forecast sounding from the same WRF run (below, valid at 5:30 pm) however indicates a lifted parcel (red) that gets past the inversion, allowing the storms that are forecast. 

The 400 mb analysis (second below) doesn't seem to indicate cooling that would weaken the inversion by late afternoon. However, the model forecast increases low-level moisture during the day, taking the inversion out of play. The PW in the WRF-RR forecast increases from 31 to about 41 mm and the 850 mb Td increases from 11 to 13 C. So, the more moist air out to our west is forecast to slosh eastward this afternoon, bringing us a better chance for showers. Will be interesting to watch how this all evolves.