textproduct: NWS Flagstaff

SYNOPSIS

Expect temperatures 5-10 degrees above average on Friday, with temperatures cooling back to near normal over the weekend. Thunderstorm chances continue with an active monsoon pattern expected through the weekend.

DISCUSSION

High pressure has shifted to the east and is centered over the Four Corners which is a good position to import more moisture into the area through the weekend. The first wave of thunderstorms today has developed along the Mogollon Rim and pushes westward to Yavapai County. Short term models show a second wave developing over the northeast mountains and mountains of western New Mexico in the mid to late afternoon pushing to the west through eastern and northeastern Arizona during the evening hours. With plenty of moisture to work with and some wet soils in parts of the area from yesterday's activity, will definitely have to watch for the potential for some flash flooding. A few storms will likely become briefly severe with strong winds and quarter sized hail.

Friday's activity will be dependent on how Thursday's activity works over the atmosphere. It looks like storm motion may be towards the northwest which often means lower POPs for the middle and lower elevations as storms are not as likely to move off the Rim and that's reflected in the forecast at this time. POPs for the northern half of the state remain elevated as storms may move off the higher terrain into the northern deserts.

Saturday through Monday looks like a moderately active monsoon pattern for the higher terrain with lesser chances for the lower deserts as steering flow remains unfavorable for storms to move off the higher terrain. Model suites are split for next week. The GFS ensemble wants to keep monsoon moisture in, while the ECMWF wants to bring in drier air from the west by midweek. Temperatures will also tick back up a few degrees if drier air is in place with highs rising about 5 degrees above average.

AVIATION...Friday 21/06Z through Saturday 22/06Z

Isolated showers and thunderstorms will continue through early Friday morning, around 10Z. Another round of scattered thunderstorms developing after 18Z Friday and continuing into early evening. Daytime winds SW-NW 5-15 kts Friday. Localized/brief MVFR and gusty/erratic winds to 40 kts in heavier storms.

OUTLOOK...Saturday 22/06Z through Monday 24/06Z...Scattered thunderstorm activity becomes more focused on the higher terrain areas for Saturday and Sunday afternoons. Daytime winds SW-W 5-15 kts Saturday and Sunday. Light and variable or terrain driven wind overnight. Gusty and erratic winds near thunderstorms.

FIRE WEATHER...Today through Saturday

Scattered to numerous showers and thunderstorms each day across northern AZ. Storms may continue into the late evening/overnight hours tonight and Friday night. Stronger storms will bring hail, gusty and erratic winds, and localized heavy rainfall. Away from storms, winds are variable 5-15 mph each day.

Sunday through Tuesday...Scattered showers and thunderstorms on Sunday and Monday, becoming isolated on Tuesday. Stronger storms will bring hail, gusty and erratic winds, and localized heavy rainfall. Winds are SW-W 5-15 mph each day, with gusty and erratic winds possible near storms.

FGZ WATCHES/WARNINGS/ADVISORIES

None.