487
FXUS65 KFGZ 121658
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
958 AM MST Fri Jul 12 2024

.SYNOPSIS...Hot temperatures will continue today, with a slight
cooling trend over the weekend. Increasing moisture each day with
widespread chances for afternoon showers and thunderstorms
continuing into early next week.

&&

.UPDATE...The current forecast is on track. Look for some increase
in thunderstorm coverage today, most numerous along the Mogollon
Rim and locations further south. In the lower desert regions south
of the Rim would not be surprised to see wind gusts in excess of
50 mph. The monsoon works it`s way back over the weekend.

&&

.PREV DISCUSSION /433 AM MST/...Strong high pressure is currently
over southern UT and northern AZ early this morning. This slight
shift in position from where the high was yesterday should allow
for better moisture advection leading to increased chances for
showers and thunderstorms across the region today. The steering
flow should turn a bit more east to northeast today. This will
keep the initial storm development along and south of the Mogollon
Rim, though expect there to be a bit more activity from the Grand
Canyon eastward through Window Rock than there was on Thursday.
Modest instability (500-1000 J/kg CAPE) and some shear (15-30 kts)
will be present today so anticipate that a few storms may be
strong to severe and capable of producing damaging winds, hail,
and brief heavy rainfall this afternoon.

Heat will remain an issue, especially in Grand/Glen Canyons today.
Excessive Heat Warnings remain in effect for areas below 4000 feet
through 8 PM tonight. With the increased cloud cover expected across
central Arizona, temperatures should be slightly cooler and fall
below warning criteria across Yavapai county.

By Saturday, the high sets up near Four Corners in a typical monsoon
pattern leading to more widespread storms across the region. With
the increasing moisture, we should see things shift from a severe
threat to more of a flash flood threat through the weekend. PWATs
don`t look anomalous for mid-July but storms will be capable of
producing torrential rainfall which could result in flash flooding.
Something we will will need to keep an eye on as we head through
the weekend. While still hot, cloud cover will be higher due to
the increase in moisture and should keep things slightly cooler
over the weekend.

The monsoon pattern looks to change little as we head into the new
week, keeping good chances for showers and thunderstorms across
northern and central Arizona. The high starts to wobble a bit to the
west early in the week which will likely start to decrease the
coverage of storms as we head into the latter half of next week.

&&

.AVIATION...Friday 12/18Z through Saturday 13/18Z...Mainly VFR
conditions are forecast outside of thunderstorms. Scattered
showers and thunderstorms are anticipated from 19Z-03Z with
greatest chances along and south of a KGCN-KFLG-KSOW line. Outside
of gusty/erratic thunderstorm outflow winds of 25-40 kts, expect
southerly winds of 10-15 kts through 03Z. Light and variable winds
after 03Z.

OUTLOOK...Saturday 13/18Z through Monday 15/18Z...Widespread
showers and thunderstorms are expected each afternoon and evening.
Besides gusty outflows from storms, west-southwest winds 5-15 kts
are forecast each day.


&&

.FIRE WEATHER....FIRE WEATHER...Today and Saturday...Hot temperatures
will persist for today, followed by a slight cooling trend
beginning on Saturday. Monsoonal moisture will increase each day
with scattered showers and thunderstorms expected along and south
of the Mogollon Rim for this afternoon and evening, isolated
further north. Showers and storms becoming more widespread for
Saturday. Outside of erratic outflow winds from storms, anticipate
a return of southerly winds, 5 to 15 mph, each afternoon.

Sunday through Tuesday...Widespread showers and thunderstorms are
likely Sunday and Monday with the greatest chances along and south
of the Mogollon Rim and the White Mountains. Coverage becomes more
scattered on Tuesday as moisture decreases slightly. Near average
temperatures are forecast each day along with west-northwest winds,
5 to 15 mph.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM MST /9 PM MDT/ this evening
for AZZ005-006.

&&

$$

PUBLIC...McCollum/Meola
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff