Special Weather Statement, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
1044 AM MST Tue Aug 9 2022

.SYNOPSIS...A favorable flow pattern for daily thunderstorms will
persist through the week as the upper high remains centered near the
Four Corners region. Daytime temperature will remain near seasonable
readings.

&&

.DISCUSSION...A Flash Flood Watch has been issued for the entire
area from this afternoon through at least Wednesday morning.

Current water vapor imagery shows a weather disturbance moving
west through NW Chihuahua and NE Sonora. This will be a focus
later today and into the overnight for convection. Looking over
the morning sounding, shows a juiced atmosphere with a weak onion
sounding. The current flow regime will be more than enough to
modify the environment to increase the likelihood of
thunderstorms.

The CAMs are also quite active starting at 2100Z with multiple
rounds of storms through the evening and overnight. With current
analysis and CAMs, the greatest threat fro flash flooding appears
to be from western Cochise County through Santa Cruz, and all of
Pima County. This is the track of the weather disturbance
overlapped with highest moisture and instability. As the storms
fire, there should be enough moisture advection and low level
convergence to focus storms. Cell mergers and backbuilding into
the large/strong instability pool along/south of the International
Border will help with organization and increase the flash
flooding threat. Rainfall rates could easily reach several inches
an hour with 3-6 hr totals of 1-3". Some areas along the
International Border could see locally higher amounts if multiple
storms train over the same area.

One other thing to note is the saturated ground and quick
response for many area washes/rivers. It will not take nearly as
much rain as usual to cause flash flooding like early in the
season.

For severe weather, shear is less than past days. Storm mode
should be more pulse/multicellular cluster like with the
potential for upscale growth into a small MCS. Wind will be the
greatest risk with only small hail expected.

&&

.PREV DISCUSSION... /issued 225 AM MST Tue Aug 9 2022/
Models keep the upper high centered near the Four Corners region
through the middle of the week. Thereafter, the upper high will
shift farther north and eastward by Friday. The overall flow
pattern will remain favorable for daily scattered showers and
thunderstorms, mainly in the afternoon and evening but the rain
chances will continue overnight as well. The position of the high
will be ideal for inverted troughs to track westward and enhance
the thunderstorm activity. Latest models depicted a few shortwaves
rotating around the upper high and impacting the area this week.
One later today with more significant ones passing through
Wednesday and again on Thursday into Friday. That said, soil
moisture content remained high for most of the area, so flash
flooding will continue to be a concern. High temperatures will
remain near seasonable readings.

&&

.AVIATION...Valid through 10/18Z. SCT clouds at 7k-10k ft AGL
with SCT-BKN above 15k ft AGL. CIGS may briefly lower to 4k-6k ft
AGL with the TSRA, along with mountain obscurations and wind gusts
to 40+ kts. Otherwise, SFC wind will generally be less than 12
kts, favoring a NWLY/NLY direction during the afternoon hours and
variable in direction at other times. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...An active monsoon period is expected to continue
through the week, with daily rounds of scattered showers and
thunderstorms. The typical threats of strong gusty winds and heavy
rainfall remain, as well as the potential for precipitation outside
the normal afternoon/evening cycles. Wind trends are otherwise light
following a diurnal pattern.

&&

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for AZZ501>515.

&&

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Special Weather Statement
National Weather Service Tucson AZ
1258 PM MST Tue Aug 9 2022

AZZ502-515-092045-
Tohono O'odham Nation including Sells-Baboquivari Mountains including
Kitt Peak-
1258 PM MST Tue Aug 9 2022

...A strong thunderstorm will impact portions of central Pima County
through 145 PM MST...

At 1258 PM MST, Doppler radar was tracking a strong thunderstorm near
San Isidro, or 8 miles northeast of Sells, moving north at 10 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Sells, San Isidro, Kitt Peak, Ali Chukson, Fresnal, No:ligk,
Comobabi, Cababi, South Comobabi, Santa Rosa Ranch, Sil Nakya, San
Luis - Sells District, Artesia, Rincon and Ali Molina.

This includes Route 86 between mile markers 110 and 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3195 11157 3185 11190 3215 11203 3227 11168
TIME...MOT...LOC 1958Z 162DEG 10KT 3202 11179

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

AWH

Special Weather Statement
National Weather Service Tucson AZ
101 PM MST Tue Aug 9 2022

AZZ503-504-092030-
Upper Santa Cruz River and Altar Valleys including Nogales-Tucson
Metro Area including Tucson/Green Valley/Marana/Vail-
101 PM MST Tue Aug 9 2022

...A strong thunderstorm will impact portions of east central Pima
County through 130 PM MST...

At 100 PM MST, Doppler radar was tracking a strong thunderstorm 10
miles northwest of Green Valley. This storm was nearly stationary.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Three Points.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3201 11106 3177 11108 3178 11133 3204 11130
TIME...MOT...LOC 2000Z 098DEG 3KT 3193 11117

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

KGD