Special Weather Statement, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
925 AM MST Fri Aug 12 2022

.SYNOPSIS...A favorable pattern for daily thunderstorms will
persist into next week, with daytime temperatures remaining near
seasonable readings.

&&

.DISCUSSION...This morning visible satellite shows midlevel clouds
across the Southeast Arizona from the Catalina Mountains towards
Sonora. The clouds are starting to clear out for the better
cumulus clouds to form. There are left over bits from the complex
west of Naco that can bring a light shower this morning along the
International border. Otherwise, it is shaping up to a decent day
for thunderstorms across the region.

The 12Z sounding looks promising for thunderstorm development.
The MUCAPE is 1383 J/KG; PWAT is 1.66 inches; modest CIN for the
morning. We do have weak shear, so strong thunderstorms may not be
likely to occur. The convective temperature is 94F and with the
slight clearing of the midlevel clouds for the rest of the
morning, the ground can get more substantial surface heating which
will help break the cap. The forecasted high for Tucson is 99F
and that seems to be on track.

Only a handful of CAMs initialized well with the lingering complex
along the International border and out towards Yuma. With that in
mind, isolated to scattered thunderstorms can start to develop in
the early afternoon and lasting into the evening. The better
chances are along the higher terrain, such as the Mogollon Rim
and the Sky Islands. If the last several days were any indication
of storm evolution, like lasting up to 45 minutes in the
lifecycle, we can get several rounds of storms starting in the
afternoon, another in the evening, and another in the late night.
WPC has the region under a slight risk for excessive rainfall and
it checks out as the soil moisture in the eastern part of the CWA
have been in the 98th percentile from the NASA SPORT. So, the
chance of flash flooding is still here across the region and
washes can get going pretty quick from a good raining storm. Most
likely be isolated cases for flash flooding. The better chances
for widespread flooding can occur next week, please see previous
discussion.

&&

.AVIATION...Valid through 13/12Z.
Isolated SHRA/TSRA have already begun to develop early this
morning primarily east of KTUS and KOLS but a brief VCSH can't be
ruled out at either terminal. Coverage of SHRA/TSRA will increase
after 12/19z remaining SCT throughout the afternoon before
beginning a dissipating trend after 13/02z. With any storms at or
near the terminals, strong wind gusts in excess of 40 kts, cloud
heights dropping to 6k-8k ft, and vsby reductions will be possible
for a brief time. Outside of storms, winds will remain around 10
kts or less. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...An active monsoon period is expected to continue
into early next 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. Flash flooding will also remain
a concern each day. Wind trends are otherwise light following a
diurnal pattern.

&&

.PREV DISCUSSION... /issued 244 AM MST Fri Aug 12 2022/
Isolated showers and even a couple lightning strikes can be seen
across southeast Arizona early this morning. Based on the 12/00Z
sounding, there is quite a bit of elevated instability to tap into
to help generate these overnight storms. A complex over Sonora
inched up toward the southern border of Cochise County, but cloud-
tops are warming and this is now mostly anvil rain.

The monsoon ridge is generally centered over eastern Colorado and
it will gradually sag toward the southeast over the coming days.
Mid and upper-level flow will weaken at times and become less
directionally organized. Today we still have marginal cloud-
layer winds from the south/southeast around 10 kts. Precipitable
water is forecast to remain near to above normal for this time of
year, and PoPs continue to be above climo. With saturated soils
all the recent rains, the biggest threat to keep in mind is flash
flooding, especially as storm motion weakens. WPC has our
forecast area in a slight risk of excessive rainfall and this
theme continues into the weekend.

The most interesting feature on the horizon is the potential for
an easterly wave that approaches toward the middle of next week.
This can be seen on all ensemble guidance and will provide large-
scale lift to an already moist environment. ECMWF EFI and the
GEFS hint at the potential for anomalous rainfall amounts compared
to climatology, but there's still plenty of time to see the
evolution of how this pans out over the coming days.

&&

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

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Special Weather Statement
National Weather Service Tucson AZ
1041 AM MST Fri Aug 12 2022

AZZ504-506-507-514-121830-
Santa Catalina and Rincon Mountains including Mount
Lemmon/Summerhaven-Upper San Pedro River Valley including Sierra
Vista/Benson-Southeast Pinal County including
Kearny/Mammoth/Oracle-Tucson Metro Area including Tucson/Green
Valley/Marana/Vail-
1041 AM MST Fri Aug 12 2022

...A strong thunderstorm will impact portions of northeastern Pima
and southern Pinal Counties through 1130 AM MST...

At 1040 AM MST, Doppler radar was tracking a strong thunderstorm over
Mount Lemmon/Summerhaven, or 9 miles southeast of Catalina. This
storm was nearly stationary.

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...
Catalina, Mount Lemmon/Summerhaven and Seven Falls.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3231 11077 3237 11086 3248 11088 3258 11082
      3251 11067 3238 11061
TIME...MOT...LOC 1740Z 152DEG 2KT 3242 11076

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

GLZ

Special Weather Statement
National Weather Service Tucson AZ
111 PM MST Fri Aug 12 2022

AZZ505-122100-
South Central Pinal County including Eloy/Picacho Peak State Park-
111 PM MST Fri Aug 12 2022

...A strong thunderstorm will impact portions of south central Pinal
County through 200 PM MST...

At 111 PM MST, Doppler radar was tracking a strong thunderstorm over
Picacho Peak State Park, or 19 miles northwest of Marana, moving
northwest at 10 mph.

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...
Eloy, Picacho, Picacho Peak State Park and Red Rock.

This includes the following highways...
 Interstate 10 between mile markers 207 and 227.
 Route 87 between mile markers 116 and 119.

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 3261 11122 3251 11144 3272 11165 3285 11137
TIME...MOT...LOC 2011Z 150DEG 9KT 3261 11139

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

GEL