Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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FXUS65 KFGZ 201618

Area Forecast Discussion
National Weather Service Flagstaff AZ
918 AM MST Sun May 20 2018

.SYNOPSIS...A strong but mainly dry weather system will approach
northern Arizona today and move across the area on Monday and
Tuesday. Look for gusty afternoon south to southwest winds each
day, strongest on Monday. Limited moisture will result in a
slight chance of afternoon showers and thunderstorms over portions
of the area. From Wednesday onward, expect the usual afternoon
spring breezes with temperatures warming to above normal levels.


.UPDATE...Another day of pleasant weather is in store for northern
Arizona. Southerly breezes will be on the increase this afternoon
as troughing continues to develop to our west. Temperatures will
be similar to yesterday - a few degrees warmer than average. A few
showers or a thunderstorm will remain possible mainly over the
Kaibab Plateau and adjacent to the Utah border. The current
forecast is in good shape with no updates needed.


.PREV DISCUSSION /300 AM MST/...Low pressure was in the process of
forming over California during the early morning hours. The low
will continue to deepen through the day producing strengthening
pressure gradients across northern Arizona. The result will be
afternoon south to southwest winds of 10 to 20 mph gusting to 30
mph. Temperatures will remain seasonable. Limited moisture will
once again result in a slight chance of showers and thunderstorms
north of Interstate-40.

On Monday and Tuesday...The California low strengthens further and
then swings across the Nevada/Utah/Arizona region. Look for even
stronger winds on Monday afternoon generally from the south to
southwest at 15 to 25 mph gusting to 35 mph. Conditions will be
dry enough for heightened fire danger across most of northern
Arizona. The most critical conditions on Monday are forecast from
Winslow and Happy Jack east and south where a Fire Weather Watch
is in effect. Winds will weaken some on Tuesday but fire danger
will remain heightened. Limited moisture and instability will
continue to produce a slight chance of showers and thunderstorms
across northern Arizona. The best chance for storms will be across
the Arizona/New Mexico border on Monday shifting to the four
corners and the Arizona/Utah border on Tuesday. Cooling a bit with
the coolest temperatures on Tuesday.

From Wednesday onward...Models in better agreement with both
models showing building high pressure across Arizona into
Saturday. The result will be daytime temperatures warming to well
above normal along with the usual afternoon spring breezes.


.AVIATION...For the 18Z package...Expect VFR conditions for the next
24 hours.  Higher terrain areas along the Utah broder to see some
mid level convection again with a slight chance of afternoon -tsra.
Winds SW 10-20kts gusts 30kts through 02z, then variable to 10 kt.
Aviation discussion not updated for TAF amendments.


Low pressure aloft and to our west today will form a
closed low centered over southern California on Monday. Northern
Arizona can expect variable cirrus cloud cover through tonight,
though lingering mid level moisture and instability along the Utah
border brings a slight chance of a high based thunderstorm this
afternoon. On Monday, The exceedence of critical fire weather
condition is looking better across east central Arizona, and a
fire weather watch has been issued. Additionally, increasing
southerly flow should bring mid level moisture and high based
thunderstorm chances to Apache county.

.Tuesday through Thursday...On Tuesday, breezy south to southwest
winds continue as the closed low weakens over northwest Arizona. A
slight chance of high based showers or thunderstorms is forecast for
western Coconino County and the Four Corners area. Fair weather
returns for Wednesday and Thursday.


.FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Monday
afternoon through Monday evening FOR AZZ113-114-116-117.




For Northern Arizona weather information visit is the U.S. government's official web portal to all federal, state and local government web resources and services.