Area Forecast Discussion
Issued by NWS Tucson, AZ

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052
FXUS65 KTWC 141634
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
934 AM MST Mon Sep 14 2026

.SYNOPSIS...An active week ahead with daily chances of showers
and thunderstorms. Elevated precipitation chances today with a
Flash Flood Watch for portions of southeast Arizona. Daily high
temperatures will fluctuate between near normal and a few
degrees below normal.

&&

.UPDATE...Latest visible satellite imagery shows mostly clear to
partly cloudy skies across southeast Arizona with some residual
early morning shower and thunderstorm activity dissipating over
Graham County at this time. Cumulus clouds are already starting to
form which portends to an active day with SPC mesoanalysis indicating
MLCAPE values as high as 2000 to 3000 J/KG with dissipating CIN over
the next few hours as daytime heating continues. Latest CAMs focus
on locales from Tucson north and eastward for the highest storm
chances this afternoon which is reasonable based on latest trends.
Main concern will continue to be locally heavy rainfall with flash
flooding potential with a secondary wind threat. Current forecast is
in good shape. No updates this morning. See previous discussion for
additional information.


&&

.DISCUSSION...A persistent moist southerly flow aloft on the
western flank of the upper ridge to our east will keep
anomalously high PWAT values for September across the area
through at least Thursday. There will be daily threats of
rainfall rates between 1-2"/hr, possibly higher, with some of
the stronger thunderstorms that develop this week leading to
elevated chances of flash flooding each day through Thursday.
WPC EROs for Days 1-4 (Mon-Thu) have slight risk for excessive
rain each day across much of the forecast area. The potential
wet week ahead may lead to some enhanced flows in washes,
creeks, and rivers that are already saturated.

Today: Early morning satellite imagery showed considerable
cloud cover across the eastern half of the forecast area with
clear skies across western half of Pima county. There will be
isolated weak, not long lived, showers popping up this morning.
With the increased threat for heavy rain and localized flash
flooding from scattered showers and thunderstorms, a Flash
Flood Watch is in effect for much of the area today from 11 am
to 11 pm.

Tuesday: Areal coverage of storms likely down versus today.

Wednesday: A disturbance moving out of Sonora MX will bring a
more active day versus Tuesday.

Thursday: Not as active as Wednesday.

Friday into this weekend: Drier air pushes in under westerly
flow aloft, resulting in reduced precipitation chances. High
temperatures will be right around normal.

8 to 14 day outlooks (Mon Sep 21 to Sun Sep 27)
Temperature: Leaning above normal, 44-45% chance
Precipitation: Likely above, 49-52% chance

&&

.AVIATION...Valid thru 15/12Z.
SCT-BKN clouds 8k-10k ft AGL for much of valid pd with layers
clouds above. ISOLD -SHRA thru 14/17z, then SCT SHRA/TSRA aft
14/18z thru 15/04z. Outflow winds nr TSRA of 35-45 kts. VSBYs
down to 1SM nr strongest TS. SFC winds terrain driven less than
10 kts thru 14/16z then again after 15/04z thru end of valid
pd. Btwn 14/16z and 15/04z SFC winds SLY/SWLY SFC winds 6-12 kt.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...An active week ahead with daily chances of
showers and thunderstorms. High temperatures will fluctuate
between near normal and a few degrees below normal. Min RH
values mainly 20 to 45 percent in the valleys and 35 to 65
percent in the mountains over the next week. RH recoveries will
continue to be excellent overnight. Winds will generally remain
less than 15 mph and terrain driven. Gusty and erratic winds
will accompany thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flood Watch from 11 AM MST this morning through this evening
  for AZZ503>509-511>514.

&&

$$

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