Flagstaff, AZ
Weather Forecast Office
FXUS65 KFGZ 211104 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 404 AM MST Fri May 21 2021 .SYNOPSIS...A low pressure system will bring strong southwest winds into Saturday, along with areas of critical fire weather. In addition, there will be a chance for showers primarily along and south of the Mogollon Rim today. Temperatures will remain cool through the weekend with warmer temperatures returning next week. && .DISCUSSION...Strong upper level low pressure is positioned over the California/Nevada border this morning with a strong southwest flow over Arizona. A leading shortwave feature has tapped into sufficient moisture to generate an area of showers across central Arizona. Rainfall amounts so far have ranged from a few hundredths to near a tenth of an inch. These showers will favor areas along and south of the Mogollon Rim through the morning hours, before drier air begins to push in from the west this afternoon. We have made adjustments accordingly to the Red Flag Warnings for today based on morning rainfall and expected humidity trends. Strong southerly winds gusting from 40 to 50 mph will continue today and Wind Advisories remain in effect for nearly all of northern Arizona. Drier air overspreads the area from west to east later this afternoon bringing an end to shower chances. The dry southerly flow continues through Saturday leading to additional fire weather and wind concerns. We have issued Fire Weather Watches and Wind Advisories for Saturday for areas from Flagstaff eastward. The greatest uncertainty in the fire weather watch is today`s rainfall and how it will affect current fuel moisture. Temperatures will remain cool through the weekend in response to the trough passage. The trough axis finally moves through the area on Sunday leading to much less wind and a chance for temperatures to begin warming. Look for a period of warmer temperatures, dry conditions and lighter winds through much of next week. There is some potential for additional troughing to bring increased winds sometime late next week but confidence is low at this time. && .AVIATION...For the 12Z package...Based on high-res model guidance, light to moderate rain showers look to continue through this morning for KFLG, KPRC, and KSEZ tapering around 18Z. VFR to MVFR conditions can be expected for the aforementioned sites depending on overall shower activity. KINW could see some light spillover sprinkles during this time, however not enough to limit visibility. Winds remain breezy this morning with some gusty outflows from the rain showers. Strong southwest winds at 25-35 kts redevelop after 14Z, with gusts 35-50 kts. Winds are expected to decrease after 03Z Saturday across the region. Areas of low-level wind shear with some minor turbulence are possible along the Mogollon Rim tonight into early Saturday morning. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Winds remain breezy this morning with light to moderate rain showers along and south of the Mogollon Rim. Another round of strong, 40-50 mph southwest gusts develops later this morning, with critical fire weather conditions over much of northwestern Arizona through the early evening hours. Near-critical conditions are expected in eastern Arizona where RH values will be higher. A few thunderstorms and showers are possible in the eastern zones during the afternoon. Expect strong winds again on Saturday with critical fire weather conditions possible in eastern Arizona. Sunday through Tuesday...Lighter winds and gradual warming, with dry conditions to start next week. && .FGZ WATCHES/WARNINGS/ADVISORIES...Red Flag Warning from 11 AM this morning to 8 PM MST this evening FOR AZZ104>109-112-137-138. Wind Advisory until 8 PM MST this evening FOR AZZ004>017-037>040. Fire Weather Watch from Saturday morning through Saturday evening FOR AZZ109>117-139-140. Wind Advisory from 11 AM to 8 PM MST Saturday FOR AZZ009>017-039- 040. && PUBLIC...MCT AVIATION...LaGuardia FIRE WEATHER...LaGuardia For Northern Arizona weather information visit weather.gov/flagstaff
