582
FXUS65 KTWC 152200
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
300 PM MST Wed Jul 15 2026

.SYNOPSIS...Scattered thunderstorms this evening with heavy rain
and strong gusty winds possible near any thunderstorm. More
widespread chances for showers and thunderstorms are forecast on
Thursday and potentially Friday with an increased risk of flash
flooding. High temperatures will be below normal for the next 7
days.

&&

.DISCUSSION...A very active monsoon pattern will continue for
the foreseeable future. Rather chaotic upper air pattern via
water vapor imagery which shows an upper low over srn Baja, an
upper low over cntrl TX, large expansive upper ridge that
extends from ern CONUS west to the interior west with a high
centered near Salt Lake City. And in the tropics, there is TS
Elida, which was located 570 miles SSW off the srn tip of Baja
per the latest NHC advisory.

We have NE flow over the area today between the upper high near
Salt Lake City and the cntrl TX upper low. Ample moisture is in
place for scattered showers and thunderstorms as they propagate
NE-SW. Main threats will be strong gusty outflow winds, some of
which may briefly be severe, localized heavy rain and flash
flooding.

Thursday: Flash flooding concerns will be heightened thanks to
additional moisture advection into the area with PWATs ranging
from 1.25" far east to over 2" west of Tucson and sufficient
dynamics over the area. Thunderstorms developing over the
mountains will propagate to the SW under NE flow aloft. Outflow
interactions will continue to develop strong wet microbursts
from Tucson west late Thursday afternoon into Thursday night.
Localized rainfall rates up to 2"/hr are possible with some of
the very wet storms leading to flash flooding. From WPC,
HREF/REFS guidance had low end chances, (10-30%), of rainfall
totals exceeding 5", especially west of Tucson. With that said,
and in coordination with WPC, added a rare Moderate Risk (MDT,
at least 40%) in the Excessive Rainfall Outlook (ERO) for
excessive rainfall within 25 miles of a point, for SW Cochise
county, all of Santa Cruz county, ern Pima county (mainly S of
Tucson at this time) and central Pima county. A Flash Flood
watch was issued for most of the area Thursday afternoon into
early Friday morning. We may see some interesting average
recurrence intervals (ARI) on Thursday. Of note: the last time
SE AZ had an area MDT ERO was on Sept 21, 2022.

Friday has the potential to be another active day but confidence
is low due to what happens on Thursday. Could end up with an MCV
moving thru which will diminish chances.

Wet monsoon pattern continues this weekend into the first half
of next week with daily chance of showers and thunderstorms.

High temperatures will run below normal for the next 7 days.

&&

.AVIATION...Valid through 17/00Z.
Widely SCTD -SHRA/-TS thru 16/04z then SCTD -SHRA/TS aft 16/19z.
Ceilings mostly 9k-12k ft. Hvy rain, mtn OBSCN and erratic
strong wind gusts of 35-45 kts psbl with any TS. Outside of TS,
SFC winds generally under 10 kts. Aviation discussion not updated
for TAF amendments.

&&

.FIRE WEATHER...Daily chances for thunderstorms will continue
each afternoon and evening through the next 7 days with day to
day variability. More widespread chances for showers and
thunderstorms are likely Thursday and potentially Friday.
Minimum relative humidity 25-30 percent in the lower desert
locations and above 40 percent in the mountains this week. Winds
this week will remain mainly light and under 15 mph, though
strong and erratic winds will be possible with any thunderstorm.

&&

.HYDROLOGY...The heavy rains on Thursday may lead to some
significant rises in washes, creeks and rivers, especially from
western Cochise county west into central Pima county.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flood Watch from Thursday afternoon through late Thursday
  night for AZZ502>506-514-515.
 Flood Watch from Thursday afternoon through Thursday evening
  for AZZ507>509-511>513.

&&

$$

Visit us on Facebook, X, YouTube, and at weather.gov/Tucson