Red Flag Warning 20, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
933 AM MST Thu Jun 16 2022

.SYNOPSIS...Hot temperatures today, especially for the lower
elevations where Excessive Heat Warnings are in effect. Isolated
to scattered storms Friday will become more widespread Saturday. A
break in storms is expected to start next week.

&&

.UPDATE...Clear skies across much of the region this morning with
smoke still visible across the Flagstaff area. Smoke will push to
the north and east today as the south to southwest winds pick up
through this afternoon. Additionally, smoke and haze are also
possible over the White Mountains as the Fish Fire continues to
burn just to the south of there. Only minor adjustments made
account for the smoke/haze plumes and to reflect current
observations and trends. Otherwise, the forecast for today looks
to be on track.

&&

.PREV DISCUSSION /422 AM MST/...An area of high pressure
strengthens over Arizona today with temperatures climbing rapidly
this morning under sunny skies. High temperatures are expected to
reach triple digits in the lower elevations with temperatures
being roughly 8 to 12 degrees above seasonal averages across
northern Arizona. By the afternoon, scattered clouds could
provide some relief from the heat in localized areas. An
Excessive Heat Warning is in effect for the lower elevations of
Yavapai and Gila Counties as well as for the Grand Canyon, Marble
Canyon, Glen Canyon, and Lake Powell. Prepare properly by
hydrating, and avoid strenuous outdoor activities from late
morning into the early evening. The heat will be accompanied by
breezy south to southwest winds with peak afternoon gusts of 20
to 25 mph, potentially slightly stronger over high terrain.

Friday through Sunday...With Arizona between a trough to the west
and a ridge to the east, strong, gusty winds will return as these
synoptic features converge. Consistent south to southwesterly
winds of 15 to 20 mph, gusting 30 to 35 mph will create near-
critical fire weather conditions along western Coconino and
Yavapai Counties. Ample moisture is expected to surge into the
region Friday and Saturday as these winds tap into humidity from
the Gulf of California. Additional moisture has already begun
moving into eastern Arizona from New Mexico. Scattered
thunderstorms along the Arizona-New Mexico border are expected
Friday with a chance for a few isolated showers or storms
stretching along the Mogollon Rim. While Friday will be hot,
temperatures will be substantially cooler than Thursday. Moving
into Saturday, temperatures will decrease once again to near
seasonal norms. Saturday will be the most active day for showers
and thunderstorms with the chance of precipitation in portions of
eastern Arizona and the White Mountains currently forecasted at 70
to 85 percent. Widespread thunderstorm activity is possible with
CAPE values of 250 to 500 J/kg. Higher CAPE values near 1000 J/kg
in central Arizona including the central Mogollon Rim, and White
Mountains could lead to stronger convection. While severe
thunderstorms are not anticipated at this time due to limited
shear, any thunderstorm could produce hazardous conditions with
flash flooding being the primary threat. The threat for flash
flooding will be especially high if storms form in the vicinity of
burn scars. Models are in good agreement with 0.75" to 1.0" of
precipitable water across much of central to northern Arizona by
Saturday. The climatological maximum moving average for
precipitable water in Flagstaff for the middle of June is right
around 1.0" while maximum values throughout the entire monsoon
season are near 1.25". Thunderstorm and shower activity will
continue Sunday, but coverage will be primarily over the eastern
Arizona. The longwave trough to the west will move through the
area, pulling much of the moisture from western Arizona out of the
state. Windy conditions will continue as temperatures remain
average for this time of year.

Monday through Wednesday...Another warming trend begins at the
start of next week as high pressure builds once again over the
region. Minimal to no preciptation is in the forecast for Monday
outside of the White Mountains. However for Tuesday and Wednesday,
just enough moisture will remain for isolated showers and storms
to form in the afternoons as the atmosphere destabilizes. The best
chances will be in the White Mountains, but models indicate
slight chances elsewhere across northern Arizona.

&&

.AVIATION...For the 18Z TAF package...VFR conditions persist for the
next 24 hours. Southwest winds 10-15 kts with gusts up to 25 kts
until  03Z. Winds becoming light and variable overnight. Expect
smoke from wildfires to extend north/northeast of KFLG. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Hot temperatures and dry conditions today with
Haines Indices around 5 to 6. Expect SW winds 15-25 mph this
afternoon. Humidity will increase slightly Friday with stronger
afternoon southerly winds gusting around 30-35 mph. Critical fire
weather conditions are possible in western Coconino and Yavapai
counties. Scattered showers and thunderstorms are possible Friday,
mainly east of I-17 & HWY 89.

Saturday through Monday...Seasonably warm temperatures with
increasing afternoon humidity through Sunday. Gusty southerly winds
of 25 to 35 mph each afternoon with chances for scattered
thunderstorms. Main threats include cloud-to-ground lightning,
erratic outflow gusts, and flash flood concerns on new area burn
scars. Lighter winds expected on Monday with lower humidity.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Excessive Heat Warning until
8 PM MST this evening FOR AZZ005-018-037.

Excessive Heat Warning until 8 PM MST this evening FOR AZZ006.

&&

PUBLIC...Meola/JM
AVIATION...Kobold
FIRE WEATHER...Kobold

For Northern Arizona weather information visit
weather.gov/flagstaff