Severe Thunderstorm Warning 3, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
926 AM MST Sat Jun 25 2022

.SYNOPSIS...Monsoonal flow will continue to bring showers and
thunderstorms to central and northern Arizona through the weekend
and into next week. Gusty winds, localized heavy rainfall, and
lightning will be the primary concerns.

&&

.UPDATE...Satellite this morning shows mostly clear skies west of
I-17 and mid-level debris clouds (and perhaps a few light
showers) over the east. 0-6km steering flow will be much lighter
today, which should result in slow (outflow-oriented) storm
motion with a preference for convective initiation and
maintenance over the higher terrain. Upper level winds are
reasonable, and should move the storm anvils away to the NE, thus
encouraging maintenance of the slow-moving storms (especially if
they propagate to the SW). Instability and available moisture are
a bit lower today than yesterday. With this, expect another round
of storms today, most active along and south of the Mogollon Rim,
with the strongest storms in Yavapai and Gila counties where the
instability is the greatest. This is all in line with this
morning's CAMs (high-resolution Convection-Allowing Models).
Greatest impacts today will be locally heavy rain due to slow
moving storms - those near fresh burn scars should be alert for
rapidly changing conditions this afternoon.

&&

.PREV DISCUSSION /203 AM MST/...Moisture remains over the weekend
for the weekend, with riding resulting in monsoonal flow in place
over Arizona. Showers and thunderstorms are expected to develop
over the area again this afternoon as a result. The greatest
surface-based CAPE looks to be over Yavapai County, particularly
near the I-17 corridor, with around 750-1000 J/Kg with lesser
amounts of 250-500 J/Kg over the remainder of the area. Though,
flow aloft  remains fairly week across the region, thus limiting
to overall severe threat but adding to the flash flood threat
with slow storm motions. The slower storm motion combined with
PWATs around 0.60" to 0.80", will continue to make localized flash
flooding the primary threat, especially if storms remain over the
same area for an extended period of time. Deeper moisture begins
to move into the area late Sunday, thus the potential for flash
flooding looks to expand across the area. In addition to heavy
rainfall, strong gusty outflow winds will be possible with
thunderstorms.

The ridge remains in control over the southwest for much of the
upcoming week. Heights do begin to gradually decrease, however as
the ridge begins to wobble eastward. Consequently, a continued
monsoonal pattern dominates the forecast through much of next
week; with daily chances for showers and thunderstorms along with
near-normal temperatures and light winds. Thus, flash flooding
remains a concern across the area into next week as well.

&&

.AVIATION...For the 18Z TAF package...Scattered TSRA will develop
once again over northern Arizona aft 18Z. TEMPO MVFR conditions,
erratic wind gusts, and locally heavy rain will be possible in and
near storms. Storms should dissipate after 01Z.

&&

.FIRE WEATHER...Scattered showers and thunderstorms will
develop across the entire region today and Sunday afternoons.
Lightning, gusty outflow winds, and flash flooding are all possible
with these storms. Outside of storm activity, expect typical
afternoon breezes and near to below average temperatures.

Monday through Wednesday...A moderate monsoonal pattern will
continue with daily chances for thunderstorms. Lightning, gusty
outflow winds, and flash flooding will continue to be the main
threats. Outside of storm activity, generally light winds will
continue.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...BAK/Humphreys
AVIATION...BAK
FIRE WEATHER...BAK

For Northern Arizona weather information visit
weather.gov/flagstaff