Area Forecast Discussion
Issued by NWS Flagstaff, AZ
FXUS65 KFGZ 230434
Area Forecast Discussion
National Weather Service Flagstaff AZ
933 PM MST Sat Oct 22 2016
.SYNOPSIS...Increasing moisture will bring chances for showers
and thunderstorms across portions of northern Arizona from Sunday
through Tuesday. Then, high pressure will lead to warm and dry
conditions on Wednesday and Thursday. By late next work week,
chances for showers returns as a passing weather system clips the
.DISCUSSION...High pressure over east Texas and a strong trough of
low pressure developing off the West Coast started to transport
moisture from northern Mexico into Arizona today. The KFGZ sounding
PWAT increased from 0.25 yesterday afternoon to 0.42 this afternoon.
The KTWC sounding showed 0.84 inches...with showers and
thunderstorms over southeast Arizona this afternoon. There are still
ongoing thunderstorms over northern and southern Sonora this
evening. Moisture (and chances of showers/thunderstorms) will
continue to increase as the trough moves closer to Arizona through
Monday. The current forecast handles this quite well.
.PREV DISCUSSION /349 PM MST/...On Sunday, moisture will begin to
increase as a light south to southwest flow sets up between a ridge
over the southern United States and a trough over the east Pacific.
The bulk of the moisture plume is forecast to pass northward along
the Colorado River, so the best chances for showers and
thunderstorms will be over western portions of the area.
By Monday, moisture is forecast to spread eastward causing chances
for showers and thunderstorms across all of northern Arizona.
Expect shower and thunderstorm activity to continue from Monday
night into Tuesday as a shortwave trough crosses the region. On
Tuesday, chances for storms decrease on the backside of the
trough, but enough instability is expected for at least isolated
storms. Daytime temperatures will be near normal at most places.
On Wednesday and Thursday, heights rebound as an upper-level
ridge builds across northern Arizona. This will cause a period of
dry weather and a return to above normal temperatures by Thursday.
Longer term model forecasts continue to indicate that another
trough will bring the potential for showers back to the region by
the end of the work week.
.AVIATION...For the 06Z forecast...Expect VFR conditions over the
next 24 hours. An approaching storm will bring increasing clouds on
Sunday. After 18Z, breezy southwest winds and a slight chance for
showers and thunderstorms will develop over the higher terrain.
Aviation discussion not updated for TAF amendments.
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