Morning 12 July 2010

Very Brief Discussion

Have early morning appointments on east side of town and thus don’t have much time –

Yesterday – Even given the moisture and instability of early yesterday, the day turned out to be yet another serious disappointment locally. The remnants of TD-02 mostly pulled out to the northeast, although an elongated, sheared and weak trough remains at 500 mb to our south. Only one brief, late morning shower formed on the eastern Catalinas. No thunder, lightning, or rain observed here at the house. Best storms, and some were cold-top convection with quite a bit of lightning, were to the southeast to southwest and up in the White Mountains. Outflows from several different directions converged in the Tucson area before dusk, but the evening sounding was CAPEless, so a nice convergence event went wanting. Only 17 of the ALERT stations had rainfall but most of the RAWS stations had at least a bit of rain. Ft. Huachuca reported 0.54” and other notable amounts were: Sasabe 0.98”, Rucker 0.61”, Haystack Mountain 0.59”, and Carr 0.57”. So, a really feeble start of the season here in the metro Tucson area – and we remain “high” and dry here at house. Note that Art Douglas reported yesterday that it has been a very slow start to the rains down in Ash Canyon, with him recording only 0.57” for the month – although, it looked like there were several storms down there yesterday afternoon.

Today – Very moist conditions continue in lower-half of troposphere with PWs at low elevations around 40 to 45 mm. Sky this morning clear and very hazy, almost like a Midwest summer morning (see view of Catalinas). The TWC morning sounding (above) has moistened some below 700 mb and dried above 400 mb. If the morning conditions persist and mix out by mid-afternoon, it appears that mean boundary layer mixing ratio would be around 10 g/kg and that there’d be a nice bit of CAPE (however, yesterday mixed out at 8 g/kg with no CAPE). Winds in troposphere are mostly light and variable, so today’s steering appears even more uncertain than yesterday (yesterday the steering flow clearly became northeasterly). Ordinarily, I’d say that there was an excellent chance for a storm from Catalinas to drift over the house today. But, we seem to be snake bit and models keep most activity in the borderlands again. So, I’ll just sit and watch.