Rio Rico, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

051
FXUS65 KTWC 072120
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
220 PM MST Mon Jul 7 2025

.SYNOPSIS...Expect scattered storm coverage this afternoon
focused on locales generally south and southeast of Tucson. The
main hazard from the storms today will be their capability to
produce strong gusty outflow winds to 40-45 mph. The threat of
heavy rainfall will also be present near Santa Cruz county this
afternoon. Otherwise, temperatures will be above normal this week
with the potential for extreme heat across Southeast Arizona by
the middle of the week.

&&

.DISCUSSION...The upper pattern today is defined by an elongated
upper high at 500 mb extending across the Southeast Arizona into
central New Mexico with the high center at 300 mb a little farther
south extending from southern Sonora Mexico into the Big Bend
areas of far west Texas. The latest GOES TPW imagery indicted
drier values est of Tucson with PWAT values around an inch across
Cochise and Graham counties, around 1.30 inches near the Tucson
Metro Area with higher values around 1.35-1.45 inches across
western Pima county. Surface dewpoints range this afternoon from
the mid to upper 40s east of Tucson to the mid to upper 50s across
central and western Pima county. The 07/18Z KTWC upper air sounding
this morning indicated a PWAT of 1.36 inches. This sounding was a
little more unstable than I was thinking it was going to look with
a little less warm air aloft and a little deeper, well mixed moisture
between the SFC and 700 mb. The steering flow between 700 mb and
500 mb was very weak today. I guess that is what explains why
storms are hesitant to move off of the higher terrain early this
afternoon.

In general, we are expecting a below normal Monsoon day across
the majority of Southeast Arizona today, with higher more typical
Monsoon activity across Cochise and Santa Cruz counties. The upper
high at 500 mb will be a limiting factor again today as the warm
layer will choke off the majority of deep sustained updrafts. With
the high center positioned near Nogales this afternoon, we see a
slightly diffluent field develop aloft east of Tucson this
afternoon. The thing is that this area is drier than other areas,
increasing the potential for evaporating downdrafts to accelerate
outflows. In fact, the SPC Mesoscale Analysis this morning
indicated DCAPE values of 1200-1800 J/kg across Graham, southern
Greenlee and Cochise counties this afternoon. The 07/12Z HREF this
same area with a 50-70% neighborhood (40-km) probability for wind
gusts exceeding 30 kts this afternoon SE of Tucson this
afternoon, with even a 10% chance of outflows exceeding 50 kts
down in Sonora where all of the CAMS are indicating a large
convective system to develop early this evening along the SE
periphery of the 500 mb high. As these storms eventually continue
to build toward the SW today toward the deeper moisture that is
available, the threat of heavy rain increases. The 07/12Z HREF
indicated a 30% neighborhood (40 km) probability of exceeding an
inch in the 3-hr ensemble probability matched mean for QPF across
Santa Cruz county this afternoon. Agree with the previous forecast
discussion that mentioned that we will have to watch rainfall
totals if storms move thru Nogales Sonora for possible flash
flooding of the Nogales Wash.

Otherwise, the main weather story this week will be the expanding
strong ridge of high pressure aloft over the state resulting in
very hot, near record high temperatures mid-week with a low grade
Monsoon pattern. The high centers at 300 mb, 500 mb and 700 mb
continue to drift northward, resulting in stacked mid and high
level ridge on Wednesday. As was the case yesterday, there is
still not much variation in 07/14Z NBM ensemble members Wednesday
with only 2 degrees of variation (109-111 degrees) between the
25th-75th percentile at KTUS. The overall probability of exceeding
110 degrees at KTUS is 3% Tuesday, 47% Wednesday and back down to
a 17% Thursday. Despite the fact these percentages keep going down
with each run, I still am confident in the Extreme Heat Warning
for Pima, SE Pinal and Graham counties Wednesday.

We will see the ridge shift the second half of the week into this
weekend resulting in a general uptick in thunderstorm coverage,
especially across the eastern half of our forecast area. The 500
mb high center is progged to shift into southern California by
Friday and even nudge off the southern California Coastline the
first half of next week. This location will allow for a stronger
diffluent upper flow east of Tucson driving storms that develop
in the Whites and along the AZ/NM border in the afternoon SSW
into northern Sonora during the evening. I suspect that large
day-to-day thunderstorm complexes developing in Sonora will
reinforce the surface moisture back into Southeast Arizona behind
organized outflows. The first half of next week looks like an
active high-grade Monsoon pattern as the flow is not only
favorable, but additional deep atmospheric moisture will move its
way northward up the Gulf of California thanks to a nearby tropical
system progged to move NW up along the Mexican coast.

&&

.AVIATION...Valid through 08/00Z. SKC to FEW-SCT 12-15k ft AGL
thru 07/18z, then SCT-BKN 7-12k ft AGL with ISOLD-SCT -SHRA/-TSRA
mainly S/SE of KTUS thru 08/04Z with CIGS BKN 5-8k ft AGL and
gusty outflow winds up to 45 kts. Skies will then become SKC-FEW
12-15k ft AGL overnight, then SCT-BKN 7-12k ft AGL again Tuesday
afternoon with ISOLD-SCT -SHRA/-TSRA mainly S/SE of KTUS. SFC
winds generally WLY 8-13 kts. Aviation discussion not updated for
TAF amendments.

&&

.FIRE WEATHER...Although Southeast Arizona will be experiencing a
low-grade monsoon pattern the first half of the week, isolated to
low-end scattered thunderstorm coverage is expected to the south
and southeast of Tucson for the next several days. The main threat
for storms will be the potential for strong gusty and erratic
outflow winds 40-45 mph. Otherwise, an eventual uptick in monsoon
activity is possible the second half of the week into next
weekend as the upper high shifts to a more favorable location
aloft. Temperatures will be above normal this week with hottest
temperatures mid- week. Winds generally light and under 15 mph
with the exception of gusty and erratic winds up to 35-45 mph near
any thunderstorms.

&&

.CLIMATE...RECORD OR NEAR RECORD HIGH TEMPERATURES WEDNESDAY

DATE                         Jul 09
                          FCST RCD/YR
TUCSON INTL AIRPORT       110  111/2024
AJO                       112  116/2024
ORGAN PIPE CACTUS         111  116/1958
PICACHO PEAK              109  113/1994
SAFFORD AG STATION        110  108/2024
SIERRA VISTA FD           101  104/2024
TOMBSTONE                 102  106/1979
WILLCOX                   105  109/2003
DOUGLAS   103  108/2003

&&

.TWC WATCHES/WARNINGS/ADVISORIES...

Extreme Heat Warning from 10 AM to 8 PM MST Wednesday for AZZ501-
502-504>506-509.

&&

$$

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