textproduct: NWS Flagstaff

SYNOPSIS

Isolated afternoon showers and thunderstorms, along with warming temperatures are expected through Tuesday. Later in the week, increasing moisture and monsoon activity is forecast.

DISCUSSION

Troughing remained just off the California coast with high pressure centered over Texas/Oklahoma Sunday afternoon. The westward movement of the high center in combination with the California trough has resulted in deeper moisture being directed toward the Lower Colorado Valley/southern Nevada and away from northern Arizona. In addition, the nudging of the high center toward Arizona continues to produce subsidence aloft resulting in a capping/stabilizing layer in the mid-levels.

For tonight...A few showers and thunderstorms could linger into the early evening hours but after that we are anticipating a nearly complete shutdown in activity as subsidence and further stabilization occurs as the high pressure center continues to approach Arizona.

For Monday and Tuesday...The high pressure center gradually builds from over Texas/Oklahoma to over Arizona. Monsoon moisture will remain on the low side along with a stabilizing capping layer aloft. As a result, most of northern Arizona will see only isolated afternoon and early evening showers and thunderstorms through Tuesday. The exception, moisture values will remain just high enough over the mountains of far eastern Arizona for scattered afternoon showers and thunderstorms, primarily the White Mountains region. Otherwise, look for warmer temperatures and light winds under the influence of the building high.

From Wednesday onward...Models continue to show the eventual shift of high pressure aloft to over the Four Corners opening the door to increasing monsoon moisture and much better chances for showers and thunderstorms.

AVIATION...Monday 17/00Z through Tuesday 18/00Z

Mainly VFR conditions, with brief MVFR conditions possible near ISOLD -SHRA/-TSRA over and near higher terrain. Current ISOLD -SHRA/TSRA activity will continue until about 03Z. Winds will be VRB 5-10 kt or terrain driven through about 18Z, then SW-W. Shower/storm coverage will remain limited to the higher terrain tomorrow, with the best chances around the White Mountains and along portions of the Rim, with storms beginning around 18-22Z. Gusty and erratic winds near storms.

OUTLOOK...Tuesday 18/00Z through Thursday 20/00Z...VFR conditions, MVFR possible near heavier storms. Chance of isolated showers/storms over higher terrain between 18Z-03Z each afternoon. Winds SW-W 5-15 kts daytime, light and variable or terrain driven overnight. Gusty and erratic winds near storms.

FIRE WEATHER...Monday and Tuesday

Turning warmer. Isolated to scattered showers and thunderstorms each day, best coverage over the eastern Mogollon Rim and White Mountains. Outside of storms, winds are generally southwest through west at 10 mph or less each day.

Wednesday through Friday...Continued warmer temperatures. Scattered showers over the Mogollon Rim and White Mountains on Wednesday, with coverage increasing and spreading westward on Thursday and Friday. Outside of storms, winds are generally southwest through west 5-10 mph each day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.