One more day of extreme heat is in the forecast for the Valley, before some relief moves in for the first half of the upcoming week. Highs around Metro Phoenix this afternoon will be near 115. In the mountains, highs will range from the low 90s to around 105.
An Excessive Heat Warning remains in effect until 8 p.m. tonight for Metro Phoenix, the southern deserts and the mountains below 5000 feet. Mid-level moisture remains in place for isolated storms to develop this afternoon and evening, mainly east of Flagstaff.
The main threats with these storms will be dry lightning and erratic winds, but some stronger storms may produce rain. While the Valley will stay dry, humidity has increased, with dew points in the 50s, so the heat might feel a little more uncomfortable today.
Westerly winds will be gusty statewide this afternoon, with speeds of 25 to 30 mph possible through this evening. Gusty winds are in the forecast through midweek.
High pressure responsible for our record-breaking heat will continue to shift south towards Mexico, in response to troughing in the Northwest. This will help gradually drop temperatures Monday through Wednesday. Highs around Phoenix will hit 109 Monday, 106 Tuesday and 107 Wednesday. Morning lows should also drop to the 80s.
Dry air from the west will inhibit thunderstorm development in the mountains for Monday, but a disturbance will track into Arizona on Tuesday and Wednesday.
This will create cloudy conditions statewide, bring a slight chance of storms to the Valley Tuesday night through Wednesday morning, and reignite better storm chances in the mountains for Wednesday and Thursday.
High pressure will shift again by the end of the week, and another spell of extreme heat will develop. Valley highs will range from 110 to 115 Thursday through the weekend.