Flooding in Arizona, August 22 to 23, 2022

Area Forecast Discussion
National Weather Service Tucson AZ
225 AM MST Mon Aug 22 2022

.SYNOPSIS...Daily showers and thunderstorms will continue this
coming week into next weekend although the heavy rainfall threat
will be much less than this past weekend. Temperatures will be
warmer but remain a bit below below normal during the work week.

&&

.DISCUSSION...Storms ran well into the night across western Pima
county before finally sliding into Mexico. Plenty of rain left behind
with elevated flows remaining on many area rivers and washes. Of note
is the Gila river with a significant surge of water entering AZ with
the gauge at Duncan showing a quadrupling of the flow over the last
several hours. This flow will slowly work its way down river today.
Several other areas seeing high flows and will need to keep an eye on
them.

As far as today goes, we will have north to northeast flow aloft with
plenty of moisture and enough instability for storms. As is typical
in this flow pattern, convection will fire up south and southeast of
Tucson and over the White mountains. After storms develop they will
travel to the SSW through the afternoon into the evening hours.
Mainly an 'east of Tucson' show today with convection a bit more
widely scattered than has been the case over previous days. Storms
should be moving along nicely but will still need to watch for heavy
rains over very wet soils for additional flood worries.

The upper level high migrates from NW of the area today to near the
4-corners area by Wednesday, a more preferred location for us.
Atmospheric moisture remains elevated and with the more favorable
flow regime we should see an uptick in convection across much of the
area once again for the middle of the week.

Beyond that the flow gradually becomes westerly as the high opens up
into a longer wave ridge through the weekend which will allow for
some atmospheric drying to occur. Still will have afternoon/early
evening convection around, just less of it across the forecast area.

Through this entire period afternoon temperatures will be warmer than
they have been recently, however still remaining a bit below the
long term average.

&&

.AVIATION...Valid through 23/12Z.
Isolated to scattered storms developing again this afternoon mainly
east and south of Tucson with SCT cloud decks at 6k-9k ft AGL thru
23/04Z. The stronger SHRA/TSRA could reduce visibilities in heavy
downpours, briefly lower CIGS to 3k-6k ft AGL and produce gusts to
40+ kts. Expect skies to slowly clear aft 23/04Z. Storms developing
again Tuesday afternoon. Otherwise, winds will follow diurnal trends
at speeds of 10 kts or less. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Daily chances of showers and thunderstorms through
next weekend. Primary threats will be strong winds, lightning, and
flash flooding. Outside of thunderstorm activity, wind trends will
remain light and follow typical diurnal trends.

&&

.HYDROLOGY...Rainfall over the Gila Basin in New Mexico over the
past 48+ hours has led to a significant increase in the flow in the
Gila River. River Flood warnings and advisories have been posted
along the Gila in AZ as a result. The surge has been slow moving down
the river, however the gauge at Duncan has shown a significant rise
as of 1:30 am and the latest forecast from the Colorado Basin River
Forecast Center (CBRFC) has water levels peaking around flood stage
at Duncan with the water level cresting between 5 am and 7 am then
gradually falling through the day at that location. This crest will
continue moving downstream today with significant rises expected
downstream of Duncan.

&&

.TWC NON-FLOOD WATCHES/WARNINGS/ADVISORIES...
None.
&&

Public...Cerniglia
Aviation...Cerniglia
Fire Weather...Cerniglia
Hydrology...Cerniglia

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