248
FXUS65 KTWC 162145
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
245 PM MST Wed Jul 16 2025

.SYNOPSIS... A more quiet monsoon pattern will begin today.
Slight chance for isolated showers and storms today mainly south
and east of Tucson. Near normal temperatures today with highs in
the upper 80s to 90s, gradually increasing over the next 7 to 10
days.

&&

.KEY MESSAGES...
- Slight chance for isolated showers and storms today mainly
  south and east of Tucson. Marginal risk for excessive rainfall
  noted by WPC and general risk for thunderstorms noted by SPC.

- Near normal temperatures today with highs in the upper 80s to
  90s, gradually increasing over the next 7 to 10 days.

- Low-grade monsoon pattern returns this weekend.


&&

.DISCUSSION... The MCS that lead to widespread rain showers and
isolated thundershowers, continues to move westward and is now
located over the Tohono O`odham Nation. This system will slowly
shift westward reaching Yuma overnight. As of now, the system is
bringing light showers to far western Pima county and western
Pinal county with a small thundershower forming in the center of
the MCS near Sells. There are some isolated weak thunderstorms
developing along the Chiricahuas, the Huachucas and slightly
stronger in the White Mountains in far northern Graham and
Greenlee counties. Storms and showers are expected to stay south
and east of Tucson today with a very slight chance for showers to
pass through the Tucson area late this afternoon into the early
evening hours. The 18Z upper air sounding launched at Tucson shows
a fairly saturated atmosphere with PWATs around 1.68 inches.
SBCAPE and DCAPE are fairly weak around 500 and 300 respectively.
The main concern with storms that develop today will be heavy
precipitation and locally gusty winds.

Tomorrow, a low pressure center aloft with move northeastward from
off the coast of northern Baja into southern Arizona as high
pressure located over central Texas intensifies. This will lead to
southerly flow aloft and a weak 45-50 kt jet streak over central
Pima county tomorrow afternoon. The low pressure will also push
some moisture out of our area sending into into northern Arizona
and New Mexico decreasing PWATs to 1.1 to 1.4 inches. The bulk of
instability will be focused to areas west of Tucson, leading to a
chance for isolated to scattered showers and thunderstorms in the
late afternoon to early evening hours. There is a still a chance
for isolated showers and thunderstorms to form east of Tucson.

Towards the end of the week into the weekend, the low pressure
center aloft will weaken and push northward into central
California. The high pressure over central Texas will continue to
intensify shifting wind directions to the southwest in southern
Arizona. This upcoming pattern is not the most favorable for
thunderstorm development, thus low-grade monsoon will begin as
early as Friday. Daytime high temperatures will gradually
increase to near or slightly above normal temperatures over the
next 7 to 10 days. The CPC 8-14 day outlook shows a 40 to 60
percent probability for leaning above normal temperatures and a 33
to 40 percent chance for leaning below normal precipitation.

&&

.AVIATION... Valid 18/00Z
BKN-OVC clouds AOA 9 to 11k ft KTUS westward. FEW to SCT clouds
AOA 10 to 12k ft from KOLS to KSAD and southeastward. Clouds will
continue to develop across the area becoming SCT to OVC by 17/00Z.
Isolated weak thunderstorms are developing on the Chiricahuas and
Huachucas as of 16/21Z. Showers and thunderstorms are expected to
remain isolated this afternoon focused to areas south and east of
KTUS. There may be some isolated showers and storms pop up near
or west of KTUS between 16/23 to 17/03Z. With stronger storms,
expect gusty and erratic outflow winds between 30-40 kts with
heavy rainfall. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...
Temperatures will be slightly cooler than normal today and
Thursday, then near normal late this week. Deep moisture in the
area today will move northward tomorrow, decreasing moisture
over the weekend into early next week. Afternoon winds will
remain westerly from 10-15 mph, with occasional gusts at or above
25 mph. Afternoon RH values in the low lying areas will be 20-30%
through Friday decreasing to 17-25% over the weekend.

&&

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Malarkey

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