Tuesday, June 28, 2016
Increasing Thunderstorm Activity Today and Tomorrow
Yesterday was a mostly down day, only 9 ALERT stations had very light rainfall, with these mostly at higher elevations. However, the models forecast a significant upturn in activity through the next couple of days as a distinct inverted trough moves westward across southern Arizona.
This morning's sounding (above) continues to have some CAPE at low elevations, although steering level winds continue to be chopped-up. The PW is nearly an inch and a half, which is quite good for late June. The 8:00 MST analysis of blended PW from CIRA at Colorado State (below) indicates values reaching toward two inches along the Borderlands - again this is quite impressive wrt the calendar.
I've just peeked at the 12 UTC WRF-NAM forecasts. The model forecasts some afternoon storms over the eastern half of Pima county, but it is interesting that the model forecasts additional thunderstorms during the early morning hours - forecast of composite radar echoes above is valid at 1:00 am. The model really increases activity during the afternoon tomorrow, as the inverted trough moves by. The radar forecast below is quite something for 4:00 pm MST. However, the way things evolve during the early morning hours has the potential to impact the details of the afternoon forecast.
Posted by Bob Maddox at 11:10 AM