Date & Time: 09/18/2017 8:50 AM MST
Forecaster: Henz, D.
Officially speaking, we’ve got a couple more weeks left to the summer Monsoon, though it appears we will continue the transition into fall as dictated by the upper-level pattern. Looking at the big picture, general westerly flow remains in place across the Desert Southwest with a developing system moving into the Pac-NW and high pressure suppressed south of TX. In the near term (through Wednesday), plan mostly sunny skies, dry conditions, and daily highs around normal. Looking ahead, our next disturbance will affect the region Thursday into Friday bringing another cold front, gusty winds, and a shot for showers/rain. A colder air mass is then forecast to settle over the region Friday into the weekend.
For today plan on clear and sunny skies across the region. Afternoon temperatures will warm into the 97˚F-100˚F range around the Valley. Variable winds will generally remain in the 2-7mph range with no gusts of any consequence throughout the day. Overnight low temperatures will once again dip into the mid to low 70s around the Valley under clear skies and light winds.
For tomorrow plan on a near repeat of today. Daytime highs will reach the 97˚F-100˚F range around the Valley under mostly sunny skies (expect a few passing afternoon high clouds). Light and variable winds early on will give way to developing breezier conditions into the evening (gusts around 10-20mph). Wednesday will be a transition day as the next weather disturbance approaches AZ from the west. High temperatures are still forecast to reach the upper 90s under mostly sunny skies. South/southwest winds will be breezy through most of the day with gusts around 15-25mph. A short period of unsettled weather should follow during the Thursday/Friday time period and we’ll have more on this in tomorrow’s Outlook.
|Air Quality (O3)||Moderate||Moderate||Moderate|