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783
FXUS65 KFGZ 122122
AFDFGZ

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

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

.AVIATION...Sunday 12/18Z through Monday 13/18Z...VFR conditions
will prevail. Afternoon isolated showers or stray thunderstorms
will be confined primarily to the mountain areas. Wind gusts to
35 mph can be expect in the vicinity of any showers/storms.
Otherwise, winds will be from the north to northwest at 5-15 kts.
The shower and storm threat will end after sunset.


OUTLOOK...Monday 13/18Z through Wednesday 15/18Z...Mainly VFR
conditions are forecast. 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...
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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.
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.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

PUBLIC...LaGuardia
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff