Nice view of Baboquivari from Kitt Peak this morning.
This morning's sounding from TWC (above) is the most favorable for deep convection and thunderstorms in quite a long time. Moisture and CAPE are good, and afternoon heating should produce a well-mixed and deep BL with cloud bases up around 600 mb. Winds however are light and variable through 300 mb, so storms that develop won't be moving very much, unless an organized, mesoscale outflow develops.
This time of year, when thunderstorms are occurring, it is not realistic to try to forecast beyond a couple of days, since the evolution of each day's storms affects what is likely to happen the next day. The NWS forecast for today through Friday night is shown below, and is basically the same each day. This outlook is essentially low-grade climatology for the airport, so it conveys little in the way of actual forecast information.
In contrast, I show here three forecasts of afternoon/evening radar echo coverage from the 12 UTC WRF-RR run this morning. Forecast above is valid at 6:00 pm MST this afternoon. Forecast below is valid at 8:00 pm tomorrow afternoon; and forecast at bottom is valid at 6:00 pm on the 17th. Basically, the model forecasts each afternoon's thunderstorm activity to shift west and southward.
The model-based POPs for the metro area are quite low today and Friday, but significant tomorrow (appears like perhaps 50% or greater). The information content, in my opinion, is much greater in the model forecasts than that provided by the NWS forecast of climatology for the entire coming week.
Of course, only time will tell how accurate the WRF forecasts actually are.
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