Area Forecast Discussion
Issued by NWS Flagstaff, AZ
FXUS65 KFGZ 230443
Area Forecast Discussion
National Weather Service Flagstaff AZ
943 PM MST Wed Mar 22 2017
.SYNOPSIS...Showers and thunderstorms will spread from west to
east through Thursday morning along a cold front, with rain
changing to snow at the higher elevations by early Thursday
morning. Showers and a few thunderstorms will continue Thursday
afternoon. Dry conditions are forecast Friday with another low
pressure system possibly affecting the region Saturday.
.UPDATE...Current radar imagery shows a north to south oriented
line of storms roughly from Pine to Leupp. This is the leading
edge of a cold front that is forecast to move eastward across the
region through the morning hours. Wind gusts between 20 to 30
knots, as well as lots of small hail, where observed as the front
moved though Flagstaff area. In addition, surface temperatures
dropped by several degrees behind the line of convection.
Cold air will continue to move into the area behind the front.
Snow has already been observed at the South Rim of the Grand
Canyon and in Williams. Snow levels will continue to decrease
overnight, bottoming out in the 6000 to 7000 foot range by
Aside from lowering snow levels a bit to account for a slightly
earlier switch over from rain to snow in northwest Arizona, the
current forecast is on track. 1-3" of snow are still expected
between 6500-7500 feet on Thursday morning, with greater amounts
possible above 7500 feet.
.PREV DISCUSSION /209 PM MST/...
SHORT TERM...through Friday afternoon.
There may be a lull in shower activity for much of Thursday
morning after 8-9 am or so. Rain and snow showers are forecast to
redevelop on Thursday afternoon as cold temperatures aloft will be
in place as the trough axis passes. 700 mb temperatures are
forecast to range from -5 to -8C. Expect this shower activity to
decrease through Thursday evening.
After temperatures several degrees below average on Thursday,
expect temperatures to return to slightly above average on Friday
as a short-wave ridge translates across northern Arizona, with no
LONG TERM...Friday night through Wednesday.
A shortwave ridge centered over Arizona Friday afternoon will
quickly shift east Friday night. The progressive pattern then
continues with another shortwave trough forecast to move across
the state on Saturday. This trough will bring additional chances
for showers to the area, particularly favoring far northern AZ
near the UT border. This will also help keep temperatures closer
to normal over the weekend.
Our forecast confidence begins to decrease by Monday of next week
as models in the extended range show widely varying solutions of
another potential low pressure system impacting the southwest. The
overall pattern favors cooler and showery weather with a general
long wave trough across the west, but the details are yet to be
.AVIATION...For the 06Z Package...Scattered SHRA/TSRA will spread
east through the evening and overnight hours reaching the New Mexico
border by around 15Z Thurs. Expect MVFR to IFR conditions during
this period of showers/storms. A few storms could produce hail and
strong winds. Snow levels will lower behind the front to 6000-6500
ft MSL with snow affecting the KFLG and KGCN terminals Thursday.
Occasionally gusty winds to continue overnight and Thursday as well.
Aviation discussion not updated for TAF amendments.
For Northern Arizona weather information visit