799 FXUS65 KFGZ 230307 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 807 PM MST Wed May 22 2019 .SYNOPSIS...Cool, winter-like weather is forecast through Thursday as an unseasonably cold low pressure system continues to impact the area. Expect periods of rain and mountain snow, with the greatest potential for travel impacts above 6500 feet late tonight and early Thursday. Dry, breezy, and cool conditions are forecast Friday and Saturday, with unsettled weather returning by Memorial Day. && .DISCUSSION...Accumulating snow remains on track for the high country late tonight into Thursday morning as a cold trough rotates through the region. Latest model guidance continues to indicate a 4-7 hour period of significant, accumulating snow above 6500 feet for the higher terrain of the Western and Central Mogollon Rim and higher terrain near the Grand Canyon. We are still expecting a general 1-5 inches of snow accumulation for these locations. Expect a hazardous morning commute in these areas with low visibility and slippery roadways making travel difficult. It will be best to delay travel until midday when temperatures climb above freezing and melting begins. While there will be lingering showers into the afternoon, the most significant, widespread precipitation will end in the mid-late morning hours. No changes will be made to the Winter Weather Advisory this evening and remainder of the forecast is in good shape. && .PREV DISCUSSION /308 PM MST/...Scattered light rain, snow, and occasional graupel showers continue across the Northland, generally across NW Arizona north and west of Flagstaff. Precipitation totals have been greatest over the Coconino Plateau where 0.2 - 0.4" has fallen today. Scattered showers will continue this evening ahead of the trough continuing to dig over S. California. Snow levels over Central and NW Arizona will hover between 7200-7600 feet until midnight. The axis of the shortwave will rotate through and shear across N. Arizona tonight, bringing colder temperatures, lower snow levels, and a 4 to 7 hour period of heavier precipitation late tonight and early Thursday as the shortwave shears through the area. Current forecast profiles provide saturation to about -25C and 700mb temperatures dropping to -5C, which should allow for efficient snow production and accumulations above 6500 feet. A Snow Advisory has been issued for the higher terrain of the Western and Central Mogollon Rim and higher terrain near the Grand Canyon, where 1-5 inches of snow are forecast late tonight and early Thursday. Expect challenging driving conditions on icy roadways during the Thursday morning commute. The low will quickly move northeast out of the state on Thursday, with clearing skies and diminishing showers in the afternoon. Very cold, near record low temperatures are forecast on Friday morning, with a hard freeze expected in the high country. Expect generally fair weather and warmer temperatures Friday afternoon and Saturday as a weak trough remains over the West Coast. Winds will increase again on Sunday as the West Coast trough strengthens and moves toward Arizona. Expect cooler, unsettled weather on Memorial Day and early next week as this system continues to impact Northern Arizona. && .AVIATION...For the 06Z package...Scattered rain and mountain snow showers may produce local MVFR/IFR conditions this evening. Expect showers to increase substantially after 06Z Thurs with more widespread MVFR to IFR conditions from KSEZ to KSOW northward. Snow levels lowering to 6500 ft MSL with accumulating snow at and above this level. Rain/snow persisting through 15-18Z Thurs before conditions improve from west to east through the afternoon. Winds through the period will be S to SW 10-20 kts with gusts near 30 kts Thurs afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect widespread rain and mountain snow to develop tonight into early Thursday morning. Snow levels will be around 6000- 6500 ft with main accumulations expected above 6500 ft. Showers will clear west to east Thursday morning with breezy southwest winds again Thursday afternoon. Expect dry and cool conditions for Friday. Saturday through Monday...Expect cool dry weather with breezy southwest afternoon winds Saturday. Southwest winds will increase again on Sunday. Next chance of showers returns late Sunday into Monday mainly north of the Mogollon Rim. && .FGZ WATCHES/WARNINGS/ADVISORIES...Winter Weather Advisory until 11 AM MST Thursday FOR AZZ004-006-015-016. && $$ PUBLIC...TPS/BAK AVIATION...MCT FIRE WEATHER...MCT For Northern Arizona weather information visit weather.gov/flagstaff