High temperatures climb well above normal this week. In fact, an Extreme Heat Warning has been issued for the Yuma area for Wednesday and Thursday. Atmospheric humidity trends upward as well before decreasing significantly toward the end of the week. Temperatures trend closer to normal by the end of the week as well. As an aside, a weak weather disturbance will brush western and northern Arizona today and Wednesday for an increase in cloudiness. Pockets of virga are possible in the vicinity of Yuma but measurable rain is not likely. Winds will follow familiar warm season patterns today favoring southerly directions before shifting to southwesterly in the afternoon Wednesday and Thursday followed by an uptick in the wind speeds Friday and Saturday.

Peak 8 hour average Ozone levels are expected to continue in the Good range today due to the southerly winds. Levels trend up to the Moderate range Wednesday and Thursday with a subtle change in the winds. An improving trend is anticipated Friday and Saturday and ventilation increases.

Daily average Particulates are expected to remain in the Good range. Of note, there will be times in the evenings during the latter part of this week with elevated readings due to some blowing dust wafting in from Imperial County. At this time, those episodes are not expected to be strong enough to push the daily average out of the Good range.

Ventilation will be Very Good to Excellent Wednesday through Saturday.

- A. Jamison
ADEQ Meteorologist