Another Big Storm Event

Another severe thunderstorm event yesterday afternoon with damaging winds and heavy rains, especially across south portion of city. View north from campus at 5 pm MST shows leading edge of storms coming into view from the right (east). A gust to 77 mph was recorded at DM AFB, the Atmo roof-top anemometer went over 80 mph, and the newspaper and SPC have reports of 70 mph at airport. This must have been from a different anemometer down there, since the official NWS ASOS recorded gusts to only 49 mph. Art Douglas reported from Arivaca area: "Called to tell you we had about 50-60 mph winds this afternoon with a downburst....lots of blowing dust followed by 0.64 at the Noon Ranch and 0.56 at the Arivaca Library, but much heavier rains to our SE."

As is often observed, the storms appeared to split as they moved into the city - strongest storms went across south portion of area, with a different cell moving along the south flanks of the Catalinas. The ALERT rainfall maps above show some of this split. The cells merged into a single line as they moved west of I-10. A good research question is: why does this happen fairly often here? Yesterday there could have been several things in play: on Monday the central and northern parts of city had the heavy rains, thus less heating possible in the afternoon Tuesday; this part of city was shaded by an anvil much of the early afternoon from a storm on west part of the Catalinas; and the northwest diurnal flow seemed much weaker here at house prior to the storms. End result here at house was wind, dust, lightning and thunder but only 0.03" of rain.

Photo by Paul Iniguez from the NWS Office at SRP looking toward where South Mountain sits.

 

The Phoenix area had a major dust storm yesterday with near zero visibilities as the above pictured haboob rolled across town,The Phoenix rainfall index map (below) shows that rainfall was sparse with the duststorm.