Severe Thunderstorm Warning 22, NWS Tucson, AZ

573 
WWUS55 KTWC 092217
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
317 PM MST Fri Jul 9 2021

AZC019-092245-
/O.CON.KTWC.SV.W.0022.000000T0000Z-210709T2245Z/
Pima-
317 PM MST Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MST
FOR SOUTH CENTRAL PIMA COUNTY...

At 316 PM MST, a severe thunderstorm was located 8 miles northwest of
Arivaca, or 20 miles west of Tubac, moving northwest at 15 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Arivaca and Arivaca Lake. 

This includes Route 286 between mile markers 3 and 21.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3177 11124 3153 11124 3152 11155 3178 11158
TIME...MOT...LOC 2216Z 113DEG 13KT 3168 11139 

HAIL...1.00IN
WIND...60MPH
 
$$

551 
WWUS55 KTWC 092224
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
324 PM MST Fri Jul 9 2021

AZC019-092245-
/O.CON.KTWC.SV.W.0022.000000T0000Z-210709T2245Z/
Pima-
324 PM MST Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MST
FOR SOUTH CENTRAL PIMA COUNTY...

At 322 PM MST, a severe thunderstorm was located 9 miles northwest of
Arivaca, or 21 miles west of Tubac, moving northwest at 15 mph.

HAZARD...60 mph wind gusts and quarter size hail. Severe 
         thunderstorms of this intensity can also produce small 
         tornadoes with little notice. 

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Arivaca and Arivaca Lake. 

This includes Route 286 between mile markers 3 and 21.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3177 11124 3153 11124 3152 11155 3178 11158
TIME...MOT...LOC 2222Z 113DEG 13KT 3169 11142 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

Area Forecast Discussion
National Weather Service Tucson AZ
223 PM MST Fri Jul 9 2021

.SYNOPSIS...We'll keep enough moisture around for isolated to
scattered thunderstorms the next few days, with temperatures running
several degrees above average for much of the area. Then conditions
look favorable for an increase in thunderstorm activity by early
next week.

&&

.DISCUSSION...Slow start to thunderstorm initiation today. A few
storms have developed over the Rim, with cumulus clouds gradually
increasing over the mountains of Pinal/Pima/Santa Cruz Counties. Dew
points are still in the low 60s to upper 50s in those areas, but
drier area is approaching from the east. This should keep Cochise
County fairly quiet for today. Storm motion is toward the
west/southwest at a decent pace of around 20 kts. SPC Meso Analysis
shows a good amount of instability over the more moisture rich
areas, with a line of low-level convergence along the advancing
easterly dry airmass. HREF favors the region southwest of Tucson for
thunderstorms later this afternoon into the evening along with
whatever tries to move off the Rim. Overall, it's generally a low-
grade monsoon day.

Tomorrow is shaping up to be a more organized Rimshot event
resulting in widespread thunderstorm chances as precip propagates
all the way out into the lower deserts overnight. This scenario is
aided by a better moisture profile and some cooling aloft which
helps erode the persistent inversion we've been dealing with the
past few days. Steering winds are a touch more northeasterly as well
as the high repositions a little more to the west over Las Vegas.

Over the next several days the high meanders about this general
area, keeping persistent northeasterly flow for us. Daily
thunderstorm chances will continue, and model guidance is really
hitting the Tuesday-Thursday period. GEFS M-Climate percentiles for
QPF shows a broad portion of our CWA in the 90th percentile and
above. The high weakens at this time and an easterly wave tracking
across Mexico pushes deep moisture into our region. Still hard to
pinpoint which days might be most active, but high temps drop
several degrees and the flash flooding threat is likely to increase
during this time.

&&

.AVIATION...Valid through 11/00Z.
SKC to SCT clouds 9k-14k ft MSL through most of the period except
SCT-BKN with layers above through 10/06z. Isolated-SCT SHRA/TSRA
from the White Mountains southwest to Santa Cruz county potentially
affecting the KTUS and KOLS terminals this evening. Wind gusts to 40
kts possible near any TSRA. Otherwise, surface winds less than 12
kts. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to scattered thunderstorms today into the
evening hours. Saturday has the potential for a stronger rim shot
event with storms propagating to the SW. A further increase is
expected next week with a more favorable environment for storms,
similar to last week. Min RH values will generally be in the 15-25
percent range for lower elevations through Monday with very good
overnight recoveries before increasing Tuesday onward. Surface winds
will be light and follow normal daily trends when not influenced by
storms.

&&

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

&&

Discussion...Howlett
Aviation/Fire Wx...Cerniglia

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson

Special Weather Statement
National Weather Service Tucson AZ
252 PM MST Fri Jul 9 2021

AZZ503-092215-
Upper Santa Cruz River and Altar Valleys including Nogales-
252 PM MST Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL PIMA COUNTY UNTIL
315 PM MST...

At 251 PM MST, Doppler radar was tracking a strong thunderstorm near
Arivaca, or 12 miles west of Tubac, moving west at 5 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Arivaca and Arivaca Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3170 11117 3153 11118 3154 11146 3173 11147
TIME...MOT...LOC 2151Z 094DEG 6KT 3163 11127