Heat in Arizona, August 13, 2023

Area Forecast Discussion
National Weather Service Tucson AZ
854 AM MST Sun Aug 13 2023

.SYNOPSIS...Seasonable monsoon weather is expected with
temperatures running slightly above normal with the potential for
scattered afternoon and evening thunderstorms across southeast
Arizona. Better chances for thunderstorms on Monday, and then
expect hotter temperatures with fewer thunderstorms by mid week.

&&

.DISCUSSION...A push of moisture from the south has kept
temperatures at or below normal this morning making the 24 hour
change in low temperatures 2-3 degrees F cooler than yesterday
morning. There are some lingering mid- to upper-level, partly
cloudy skies from yesterday mainly over Cochise and southern
Graham and Greenlee Counties. Today, there is a 20-30% chance for
thunderstorms and showers focused along the International Border
and then west of Graham County. Convection will start to brew
around 19-20z (noon-1:00 PM MST). High temperatures will be at or
slightly above normal as the high temperature for Tucson is
forecasted to be 100F while the climatological normal for today is
99F. Please see the previous discussion for details in the long
term.

&&

.PREV DISCUSSION... /issued 146 AM MST Sun Aug 13 2023/
This morning, there are mostly clear skies with pockets of
locations having partly cloudy skies, mainly mid level clouds.
There will be plenty of sunshine to help fire up thunderstorms in
the afternoon across the region. There is not much of upper level
support to keep storms going in their life cycle but there is
enough moisture and instability to get some going. Storms can form
in the early afternoon and diminish by the early evening.

The high pressure is still pushing towards Arizona with a low off
the southern California coast. By Monday, the south-southeast
flow will bring in more moisture with a small upper level
disturbance to support a little more widespread convection than
previous days. The ensemble models show the precipitable water
increasing to 1.4-1.6 inches by Monday afternoon. These are
slightly higher values than what Southeast Arizona saw a few days
ago.

As the high pressure continues to move westward, it will slowly
turn off the moisture and suppressing storm development.
The higher terrain and a few locations may see some afternoon storms
through the rest of the week. Otherwise, temperatures will trend
hotter and peaking by Thursday.

And looking at next weekend, the high will start to shift back
east a bit and allowing for tropical moisture to funnel into
Southern California and Arizona. This will likely lead to more
thunderstorms, in terms of coverage and intensity, and keeping
temperatures near normal through the weekend.

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.AVIATION...valid through 14/12z.
FEW-SCT 10-14k ft MSL through 13/18Z and then SCT-BKN 10-14k ft
MSL with SCT-BKN layers above 20k MSL through the rest of the
forecast period. Isold to SCT -SHRA/-TSRA after 13/19Z through
14/03Z. Erratic wind gusts of 35-45 kts with any TSRA. Otherwise
light SFC winds overnight with daytime SFC winds of NW-WLY 8-12
kts gusting up to 20 kts at times. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Daily rounds of showers and thunderstorms each
afternoon into early next week, with the best coverage on Monday.
Any storms that do form are capable of producing strong, erratic,
and gusty outflows. Otherwise, expect normal diurnal 20-foot winds
except for east-southeast winds 10-20 mph Monday and Tuesday.
Daytime temperatures will be around normal through Monday then
increase to above normal midweek. Minimum RH in the lower
elevations will generally range from 15-25% and 25-40% in the
higher elevations except 45-55% Monday and Tuesday.

&&

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

Public...Malarkey
Aviation...Malarkey
Fire Weather....Malarkey

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