017 FXUS65 KFGZ 272221 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 321 PM MST Thu Jul 27 2017 .SYNOPSIS...Expect daily chance for showers and thunderstorms as an active monsoon pattern remains in place across northern Arizona into next week. && .DISCUSSION...So far today, scattered showers and thunderstorms have formed over much of the Mogollon Rim, White Mountains and high terrain in far northeast Arizona. Subsequent outflow boundaries have produced some isolated storms in portions of Yavapai County and the Little Colorado River valley. These storms are slow movers, and the primary hazards have been lightning and heavy rain. The latest hi-res model guidance suggests showers may continue across eastern portions of the area well into the overnight hours. On Friday, most model guidance suggests slightly higher boundary layer moisture. In addition, an inverted trough is forecast to move into southern Navajo and Apache Counties. Forcing from this feature is expected to make eastern portions of the area the most active, and a favorable location for MCS development. Elsewhere, another round of scattered storms are expected, but an extensive mid and upper level cloud deck may limit instability. Flow around the inverted trough will cause storm mostion to switch to a more northerly direction, but will remain quite light - generally 10 knots or less. Given deep layer shear values of 20 knots or less and slow storm movement, flash flooding remains the primary hazard from Friday's storms. Over the weekend, The inverted trough to the south will turn the flow aloft to the southeast over the weekend. This will advect in more moisture over the region keeping good chances for storms in the forecast. Latest model guidance suggest this pattern may persist into early next week. && .AVIATION...For theFor the 18Z package...Scattered showers will develop in the afternoon and evening. Best chances are expected across the mountains of east-central AZ, with MVFR/IFR conditions possible in the stronger storms. Aviation discussion not updated for TAF amendments. 00Z package...Showers and storms will continue this evening. MVFR/IFR conditions possible in the stronger storms. Clearing skies will develop this evening with another round of showers and thunderstorms Friday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Slow moving thunderstorms will continue to develop and move across the area today, Friday afternoon and evening. Some flash flood potential exists due to the high rainfall rates and slow movement of the storms. Saturday through Monday...Moisture is forecast to increase across Arizona with a greater chance for showers and storms expected across the fire district. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...RR AVIATION...Suk FIRE WEATHER...Suk For Northern Arizona weather information visit weather.gov/flagstaff |