There were two different dust events today. The first occurred around 1:45pm when a strong thunderstorm went through the valley. Winds gusted to 60mph at the airport and visibility dropped to 4km, but the event only lasted about 10 minutes. The airport did report blowing dust so this will go into the books as an official event.
Dust events associated with convective downdrafts are informally known as "Haboobs." They originate from local sources, do not last very long, and are quite common in Utah. The second event is going on now...
This dust is not associated with a thunderstorm but rather the strong pre-frontal southerly winds. Unfortunately the concentrations are too weak and it is too late in the day to determine where the dust is coming from. Frontal passage tonight should put an end to this dusty weather.
Couple of thoughts on yesterday's radar returns and dust:
ReplyDeleteFrom the 4th floor of the DEQ office we have a good view of Valley rain shafts and some dust events.
While the radar returns looked impressive yesterday the actual rain shafts were not overwhelming. We noted here that the radar sure lit things up but the ground impact was minor. The large droplet size likely contributed to the strong returns. Even 2 or 3K meters off the deck the rain shafts just didnt look that impressive. The pavement near cars and trees never even got wet here at DEQ.
We did note an unusual dust event that blew from west to east in the vicinity of I80. It was odd because it picked up dramatically and it was unclear if it was smoke from a lightning hit minutes before or if it was dust. Then, we jokingly said maybe its a tornado. This particular event was contained, but was impactful for the few moments that it lived right at the leading edge of the rain.