608
FXUS65 KFGZ 111740
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1040 AM MST Sat May 11 2024

.SYNOPSIS...Seasonal temperatures are expected today with isolated
to scattered afternoon showers and thunderstorms along and north
of I-40. Warmer temperatures arrive starting Sunday, with slight
chances for a few showers and storms each afternoon through
Thursday. Anticipate typical afternoon breezes through the
period.

&&

.UPDATE...Only a few minor changes to the forecast package.
Introduced a bit higher chance of precipitation east of Flagstaff
where advection will likely push any stronger showers towards
Winslow. Also, introduced a slight chance of thunder in and around
the Flagstaff area starting around 11 AM MST as the air mass
looks unstable enough for such activity. Otherwise, the forecast
remains the same.

&&

.PREV DISCUSSION /538 AM MST/...The upper low is centered over
NW Arizona early this morning, with clouds and a few light
showers over northwest Coconino County. This low will slide
eastward through the day, reaching 4 corners by sunset and then
ejecting east into the Plains states by Sunday. Instability
associated with daytime heating will lead to isolated to scattered
showers and thunderstorms this afternoon and early evening with
the highest coverage along and north of I-40. This will be high-
based activity as low levels remain dry. So the main threats will
be a few lightning strikes and wind gusts 30-40 mph. Shower
chances dwindle by mid evening.

Sunday and Monday - brief ridging over the state will lead to
warmer daytime temperatures, finally reaching above normal after a
cool stretch over the past week. Warmer temperatures aloft will
diminish afternoon instability, but enough mid level moisture
remains to keep a slight chance (10-20%) of a shower or storm both
days along the higher terrain from the Mogollon Rim/White Mtns
northward. Daytime west to northwest wind 10-20 mph.

Tuesday through Thursday - a weak low from off the Pacific is
forecast to drift east over the state, as another trough dives
southeast through the Rocky Mountain states. Slight cooling aloft
and continued mid level moisture availability will lead to a
10-30% chance of light showers and a few thunderstorms each day,
with the better chances on Wednesday. Thursday`s forecast is more
uncertain as there are differences in the guidance regarding how
fast the trough moves east of the state. Temperatures will remain
near normal. Dry weather and a warming trend are favored for
Friday.

&&

.AVIATION...Saturday 11/18Z through Sunday 12/18Z...Mainly VFR
conditions persist through this afternoon and evening. Periods of
MVFR VIS and mountain obscuration are forecast from 18Z-02Z today
due to scattered -TSRA/-SHRA. Greatest chances (30-60%) are along
and north of a KCMR-KFLG-KINW-KRQE line during this time. Anticipate
BKN-OVC sky coverage at or above 10,000 feet AGL, becoming clear
overnight. Outside of any outflow gusts of up to 25 kts from
showers and storms this afternoon, expect westerly winds of 10-20
kts, becoming light and variable after 02Z.

OUTLOOK...Sunday 12/18Z through Tuesday 14/18Z...Chances for
isolated to scattered showers and thunderstorms are forecast each
afternoon through Tuesday, mainly confined to the high terrain.
Brief periods of MVFR conditions are possible in any storms, with
much of the region remaining in VFR. Northwest winds, 10-20 kts,
are anticipated for Sunday, followed by west-southwest winds for
Monday and Tuesday.

&&

.FIRE WEATHER...Today and Sunday...An area of low pressure
moving over northern Arizona will bring a chance (20-50%) for
afternoon showers and high-based thunderstorms from the Mogollon Rim
northward, especially today. Little precipitation is expected (less
than 0.10"), however gusty outflow winds of up to 40 mph are
possible. Outside of showers, expect west to northwest winds 10 to
25 mph.

Monday through Wednesday...Temperatures will warm to above average.
A low chance (10-30%) for mountain showers and thunderstorms will
continue each afternoon through the week. Very little precipitation
is expected. Generally west winds of 10 to 20 mph are forecast
through the week.

&&

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

&&

$$

PUBLIC...McCollum/JJ
AVIATION...LaGuardia
FIRE WEATHER...LaGuardia

For Northern Arizona weather information visit
weather.gov/flagstaff