PHOENIX - No advisory or warning was issued when the first dust event of monsoon 2016 took over the Valley sky late June of last year. Being the first of the season, it got everyone's attention and took the lead as breaking news in 12 News evening newscasts.
While it may have seemed "big," it wasn't enough to prompt a dust storm warning or even a blowing dust advisory.
When the National Weather Service in Phoenix makes the call, it all comes down to how widespread the dust wall is, the visibility and if it's a threat to life or property.
A blowing dust advisory is put in place when visibility drops between a mile and a quarter-of-a-mile and people and property may be at risk.
A dust storm warning is issued when the dust cloud takes on an even larger area, reduces visibility to a quarter-of-a-mile or less and puts people and property in harm's way.
In this case, the blowing dust wasn't as extensive as the "traditional" dust storms that slam Phoenix every monsoon. There were only a few unconfirmed reports of visibility getting down to a mile. The event also wasn't a danger to people or property, according to the National Weather Service.
Earlier on Thursday, winds were already forecast to be gusty in the Valley, then distant, weak storms in southeastern Arizona took the winds to the next level with outflow winds. The cranked up winds kicked up dust as they headed northwest over dry, dusty land. The dust event that resulted just didn't pack the punch a true-to-form dust storm would.
The dust storm Phoenix is known for is usually generated by a much stronger storm and outflow boundary.
Think of it this way, our excessive heat warning expired at 8 p.m. Thursday but it's still going to be very hot with 110-degree temperature readings for the next several days. It just falls short of satisfying the criteria.