Drought in Arizona, June 1 to 30, 2025

Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST Sat May 31 2025

.SYNOPSIS...Temperatures cool to below normal as a weather system
moves through Sunday and Monday. This system will bring a
substantial moisture increase into the region Sunday. Widespread
showers and isolated thunderstorms will occur Sunday into early
Monday with dry conditions returning thereafter.

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.DISCUSSION...Water vapor imagery this afternoon showed upper low
just west of Guadalupe Island. This system had tapped into the
tropical moisture to our south, thanks of TS Alvin which has
weakened to a remnant low. Afternoon IR/visible imagery showed
increasing mid-level clouds moving into SE AZ while across the
northern Greenlee county there were buildups and a couple
lightning strikes.

Precipitable water values over the next 24 hours will be
increasing into the 1.25" to 1.70" range which is 250% to 325%
above normal for early June. The dynamics associated with the
upper low that will be lifting toward Arizona Sunday morning will
develop showers and isolated thunderstorms west of Tucson Sunday
morning and spread east across the area as the day progresses.
Some of the showers will produce brief periods of heavy rain with
some training of showers/storms possible. With the high content of
moisture and considering the time of year, and after coordinating
with WPC to add SLGT risk of excessive rainfall, I went ahead of
issued a Flash Flood Watch Sunday for southeast Pinal, Pima, and
Santa Cruz counties. In my 30+ years in Tucson, I can't remember
a Flash Flood Watch in early June. We will be keeping an eye on
rainfall totals that occur near/in the Cody burn scar near Oracle.
Rainfall totals mostly less than 0.50" with isolated areas up to
1.25". Below normal highs tomorrow due to the clouds and showers.

Showers will be decreasing from west to east on Monday as the low
weakens to an open wave as it moves into the Four Corners region.
Moisture will quickly decrease behind the low leading to precip
being on the lighter side Monday. Another closed low follows in
behind Tuesday leading to just a slight chance for precip east of
Tucson and breezy winds. For the remainder of the work week
southeast Arizona stays under dry southwest flow with high
pressure becoming centered over northern Mexico and a shortwave
making its way down the West Coast.

Temperatures will be below normal through Wednesday with highs
potentially below 90 degrees Sunday and Monday in Tucson. After
Wednesday highs return to normal or a few degrees above normal.

&&

.AVIATION...Valid through 02/00Z.
SCT 10k-14k AGL bcmg BKN thru 01/12z. -SHRA and isold -TSRA dvlpg
west of KTUS aft 01/12z and spreading E across the remainder of
fcst area by end of valid pd. Isold MVFR conds W of KTUS btwn
01/12z and 02/00z. SWLY/SLY winds 5-15 kts thru much of valid pd.
Isold gusts to 35-40 kts nr any TS that dvlp W of KTUS aft 01/12z.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...A dry thunderstorm threat exists until early this
evening today south and east of Tucson over the higher terrain.
Minimum humidity values will be 12 to 22 percent.

Tropical moves into the area Sunday which will lead to widespread
showers and isolated thunderstorms Sunday into Monday. Rain could
be heavy at times leading to possible debris flows over new area
burn scars. Overall winds remain light but gusty and erratic winds
would occur with any thunderstorm activity. Another weather
system moves through Tuesday with a slight chance for precip east
of Tucson along with breezy winds. Thereafter expect dry and
warming conditions.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flood Watch from Sunday morning through Sunday afternoon for
  AZZ501-502-515.

 Flood Watch from Sunday afternoon through Sunday evening for
  AZZ503>507-513-514.

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