Area Forecast Discussion
Issued by NWS Flagstaff, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

FXUS65 KFGZ 221754

Area Forecast Discussion
National Weather Service Flagstaff AZ
1054 AM MST Wed Mar 22 2017

.SYNOPSIS...Showers will spread from west to east this afternoon
through Thursday morning along a cold front, with rain changing to
snow at the higher elevations by early Thursday morning. Some
thunderstorms are also possible. 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...Some minor updates were made to the precip amount and
snow amount forecasts for this afternoon through the overnight
period, as well as taking a chance of thunder through the
overnight hours. Timing of the frontal passage looks good for
entering the CWA late tonight, moving across northern Arizona
during the early morning hours. Plenty of wind shear will exist
both ahead of and along the cold front to support some
thunderstorms becoming strong this afternoon and this evening,
though somewhat low instability will be a limiting factor with
MUCAPE on the order of a few hundred J/kg.


.PREV DISCUSSION /429 AM MST/...Southwest flow will increase today
ahead of a trough moving onto the west coast. Winds of 15-25 mph
with gusts up to 35 mph are expected this afternoon. Increasing
moisture and steepening lapse rates over Coconino and Yavapai
counties will lead to the development of showers and thunderstorms
by mid to late afternoon, spreading eastward overnight and into
Thursday morning. A few thunderstorms could produce wind gusts
over 45 mph, especially western Coconino and Yavapai counties.
Current projections are for snow levels to fall to 6000-6500 feet
west of a Page-Flagstaff-Payson line after midnight with some
snow accumulation possible, generally in the 1-3 inch range
through Thursday morning. By Thursday afternoon, the trough axis
will be over or just east of the area, with cold and somewhat
unstable northwest flow. There will be a good chance of additional
showers and a few thunderstorms, with snow levels in the
6000-7000 ft range. Most locations will be a bit too warm for much
additional snow accumulation, but a few areas that experience
persistent or heavier showers could see some light accumulation.

The system moves east of the state Thursday night with clearing
conditions continuing through Friday. The next fast-moving system
is forecast to move through the region Saturday and Saturday
night, with the greatest impacts likely remaining north of the
state. Some light precipitation and cooler temperatures will be
possible south to around Flagstaff. Fair weather should return
Sunday, then another system could affect the area early next work
week, but there is significant model spread concerning timing. We
included low precip chances for now until model agreement


.AVIATION...For the 18Z Package...Scattered SHRA/TSRA will develop
west of a KPGA-KFLG line aft 21Z this afternoon. This line will
increase in coverage and 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. Snow
levels lowering behind the front to 6000-6500 ft MSL with snow
affecting the KFLG and KGCN terminals aft 06Z.

Surface winds SW 10-20 kts gusting to 30 kts...shifting to W on
Thursday. Aviation discussion not updated for TAF amendments.






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.