Flagstaff, AZ
Weather Forecast Office
FXUS65 KFGZ 211642 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 942 AM MST Fri May 21 2021 .SYNOPSIS...A low pressure system will bring strong southwest winds into Saturday with a fire weather threat continuing in some areas. 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. && .UPDATE...A welcome surprise for some of us this morning. While we had anticipated a few morning showers several locations across the area extending from Flagstaff to Show Low received around 0.50 inches of rain through the morning hours with many more locations seeing 0.10 to 0.20 inches of rain. The threat of showers will continue until around Noon MST along and east of a line extending from Heber to the Four Corners then end except for the White Mountains region from about Show Low southeastward. Otherwise, stronger winds today than seen on Thursday with the fire weather threat continuing across west-central and northwest Arizona where a Red Flag Warning is in effect. && .PREV DISCUSSION /404 AM MST/...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 18Z package...Isolated to scattered rain showers possible through about 00Z mostly east of the line KPAN-KBDG with MVFR conditions near shower activity. Otherwise, VFR conditions and gusty south to southwest winds at 25-35 kts gusting 35-50 kts. Winds will decrease after 03Z. Areas of low-level wind shear with some minor turbulence likely along and northeast of higher terrain tonight into early Saturday morning. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A few thunderstorms and showers today along the eastern Mogollon Rim, and in the White and Chuska Mountains through this afternoon with south to southwest winds gusting 40-50 mph. Red Flag Warning in effect today for zones 104-108, 112 and 137, with near critical fire weather conditions expected elsewhere. 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 until 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...McCollum/MCT AVIATION...DB/LaGuardia FIRE WEATHER...DB/LaGuardia For Northern Arizona weather information visit weather.gov/flagstaff
