250
FXUS65 KFGZ 130320
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
820 PM MST Sun May 12 2024

.SYNOPSIS...An unsettled pattern continues across much of the
Southwest this week. Expect warm temperatures, breezy winds, and
chances for isolated showers and thunderstorms each afternoon.

&&

.UPDATE...The forecast remains on track this evening with skies
quickly clearing and winds becoming light. Today`s precipitation
amounts ranged from trace to a few hundredths for the lucky spots
in northern Arizona that received rain. As previously mentioned,
expect partly cloudy skies to return over high terrain by mid-
morning tomorrow. CAMs are indicating isolated to widely scattered
showers beginning sometime from late morning to early afternoon
with the best chances along the Mogollon Rim and near the Arizona/New
Mexico border. Isolated thunderstorms are possible as well.

&&

.PREV DISCUSSION /513 PM MST/...Tranquil weather conditions are
taking place across northern Arizona this afternoon with mild
temperatures and breezy, 10-20 mph, northerly winds. Even with a
similar moisture profile in place as yesterday afternoon`s, shower
and thunderstorm development for this afternoon has been lacking
thanks to increasing heights and warm air aloft as a shortwave
ridge moves in from the west. A light rain shower or two is not
out of the question by this evening near the Kaibab Plateau, the
eastern Mogollon Rim, and White Mountains according to the HREF,
however, chances remain quite low (10-15%).

Expect clearing skies overnight with near average low temperatures
and little to no wind. On Monday, with the shortwave ridge axis
directly over Arizona, daytime temperatures become 5-10 degrees
above average with west-northwest winds, 10-20 mph. Isolated
shower and thunderstorm coverage remains in the forecast with
10-20% chances along the high terrain for Monday afternoon.
Confidence is quite low at this time, hence the very slight
chances, however, hi-res guidance does suggest a few showers and a
thunderstorm or two developing over the Mogollon Rim, Kaibab, and
White Mountains.

As we head into the middle of the week, the ridge looks to break
down as a weak area of low pressure from the west phases with a
shortwave trough likely to sweep across the Rockies. Moisture
advection looks to gradually increase each day, peaking on
Wednesday according to GEFS and ECMWF Ens guidances, with PWAT
values slightly above average for this time of year. With the
increase in moisture and conditions becoming more unstable aloft
as cooling takes place, chances for showers and thunderstorms
increase each afternoon for Tuesday and Wednesday. The greatest
coverage is expected on Wednesday as the low moves across Arizona.
At this time, scattered showers and thunderstorms are forecast
across much of northern Arizona on Wednesday as temperatures
return to average.

After Wednesday, precipitation chances begin a decreasing trend as
drier northwest flow develops Thursday into Friday. Temperatures
warm into the weekend with breezy southwest winds returning.
Something to keep our eye on in regards to the long term forecast
is the chance for a drier and windier pattern to develop across
the Southwest after next weekend. Ensemble model guidance suggests
this trend as the overall synoptic pattern looks to remain active
across the West.

&&

.AVIATION...Monday 13/00Z through Tuesday 14/00Z...VFR conditions
will prevail through the TAF period with light winds, with an
isolated shower possible over the higher terrain through 02Z.

.OUTLOOK...Tuesday 14/00Z through Thursday 16/00Z...Generally VFR
conditions are forecast through the period. Look for isolated
afternoon showers with a stray thunderstorm or two possible over
the mountains. Daytime winds are forecast to be from the west to
southwest at 5-15 kts gusting 25 kts but gusty and erratic winds
will be produced by any showers/storms.

&&

.FIRE WEATHER...Monday and Tuesday...Isolated afternoon showers and
a few high-based thunderstorms mainly confined to the Mogollon Rim,
Kaibab Plateau, White Mountains, and the Chuska Mountains. Wetting
rain is unlikely. Outside of any erratic outflow gusts from storms,
expect west to southwest winds at 5 to 15 mph gusting to 25 mph each
afternoon. Look for Warm temperatures each day with minimum humidity
of 10 to 20%.

Wednesday through Friday...Shower and thunderstorm chances persist
each afternoon through Friday with the greatest coverage likely on
Wednesday. Afternoon winds will be out of the west each day at 5 to
15 mph gusting to 25 mph.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

PUBLIC...Mazon/LaGuardia
AVIATION...BAK
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff