Severe Thunderstorm Warning 136, NWS Tucson, AZ

184 
WWUS55 KTWC 132251
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
351 PM MST Fri Aug 13 2021

AZC009-021-132315-
/O.CON.KTWC.SV.W.0136.000000T0000Z-210813T2315Z/
Graham-Pinal-
351 PM MST Fri Aug 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM MST
FOR WEST CENTRAL GRAHAM AND NORTHEASTERN PINAL COUNTIES...

At 351 PM MST, a severe thunderstorm was located over San Carlos, or
17 miles east of Globe, moving southwest at 5 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
San Carlos Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3340 11026 3312 11028 3318 11051 3318 11047
      3320 11046 3319 11041 3320 11040 3328 11046
      3333 11044 3336 11045 3339 11044 3340 11036
      3343 11034
TIME...MOT...LOC 2251Z 043DEG 6KT 3334 11046 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AH

921 
WWUS55 KTWC 132308
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
408 PM MST Fri Aug 13 2021

AZC009-021-132318-
/O.EXP.KTWC.SV.W.0136.000000T0000Z-210813T2315Z/
Graham-Pinal-
408 PM MST Fri Aug 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL GRAHAM AND
NORTHEASTERN PINAL COUNTIES WILL EXPIRE AT 415 PM MST...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds are still possible with
this thunderstorm.

LAT...LON 3340 11026 3312 11028 3318 11051 3318 11047
      3320 11046 3319 11041 3320 11040 3328 11046
      3333 11044 3336 11045 3339 11044 3340 11036
      3343 11034
TIME...MOT...LOC 2308Z 043DEG 6KT 3332 11048 

$$

AH

Area Forecast Discussion
National Weather Service Tucson AZ
203 PM MST Fri Aug 13 2021

.SYNOPSIS...A disturbance moving in from the east today into the
weekend will increase convection for much of southeast Arizona.
Some storms will generate strong winds and very heavy rain which
will result in continued flooding concerns.

&&

.DISCUSSION...Current radar shows isolated thunderstorms along the
international border and the White Mountains. Through the
afternoon expect further development in these areas with coverage
expanding. There is ample moisture and instability for storms to
tap into along with a small upper level disturbance moving in from
New Mexico. Hi-res guidance shows the storms forming over the
Whites propagating southwestward late this afternoon into the
evening. These storms will likely make it into the Tucson metro by
this evening and possibly propagate into far western Pima County.
Colliding outflows from storms along the border will also lead to
further storm formation. The main threats will be heavy rainfall
and strong to severe wind gusts. The SPC has most of the CWA in a
marginal severe risk for wind. Storms will also be capable of
1"-2" per hour rainfall rates. The soil is already saturated from
previous rains so washes and rivers will be quick to start flowing.
Through tonight the HREF PMM QPF shows some of the sky islands
receiving up to 3 inches of rain. Flash and areal flooding will be
a threat today and tomorrow especially over area burn scars.
Tonight there could be a few lingering storms especially in
western Pima County.

The forecast Saturday is a little more uncertain than today and
will depend on how much nocturnal activity there is tonight. The
ingredients for storms with heavy rainfall will be there but the
atmosphere could be worked over leading to a later start. The
ECMWF EFI for QPF does show a chance for anomalously high
rainfall especially for eastern areas. A weak disturbance will
still be moving through which could lend some upper level support
Saturday as well. The main threat looks to be heavy rainfall with
severe winds taking a back seat, although winds in excess of 40
mph will still be possible. Areas that receive rainfall today
will be especially susceptible to flooding Saturday. Sunday
eastern areas begin to dry some with slightly reduced PWAT values,
but ample moisture will still be in place from Tucson westward.
Expect another round of scattered convection with heavy rainfall
being the primary threat.

Monday PWAT values will be back down to around normal for this
time of year, so expect more isolated to scattered showers and
thunderstorms. The steering flow will be out of the northwest
leading to the chance for a Rim shot. Little too early to tell how
far storms will propagate off the Rim. Tuesday and Wednesday look
to be low to mid grade monsoon days. Thereafter a trough moves
through to the north turning our flow southwesterly, which will
likely dry us out a little bit.

&&

.AVIATION...Valid through 15/00Z.
Isolated to scattered SHRA/TSRA this afternoon along the
international border and the White Mountains. Storms expand in
coverage by late afternoon into the evening covering most of
southeast Arizona. There is a chance some storms remain overnight
with another round of convection Saturday afternoon. Some of the
storms today could be severe with gusty winds and small hail.
Otherwise expect sfc winds 10 kts or less. Clouds will be SCT-BKN
7k-10k ft MSL through the period with occasional MVFR conditions
in SHRA/TSRA. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Ample moisture this weekend along with periodic
mid level disturbances will result in scattered to numerous
showers and thunderstorms across southeastern Arizona. Storm
coverage then reduces starting Monday to isolated to scattered.
Given the higher levels of moisture and cloud coverage, temperatures
will be cooler this weekend into next. Strong, erratic winds and
locally heavy rainfall will be possible with any stronger storms
that develop. 20-foot winds will generally be less than 15 mph
when not influenced by thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Sunday afternoon for AZZ501>515.

&&

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

Special Weather Statement
National Weather Service Tucson AZ
225 PM MST Fri Aug 13 2021

AZZ509>511-132215-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-White
Mountains of Graham and Greenlee Counties including Hannagan
Meadow-Galiuro and Pinaleno Mountains including Mount Graham-
225 PM MST Fri Aug 13 2021

...A strong thunderstorm will impact portions of central Graham and
west central Greenlee Counties through 315 PM MST...

At 225 PM MST, Doppler radar was tracking a strong thunderstorm 9
miles north of Safford Regional Airport, or 12 miles northeast of
Safford, moving southwest at 15 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Safford, Thatcher, Solomon, Morenci, Roper Lake State Park, Safford
Regional Airport, Pima, Bylas, Central, Fort Thomas, Point-Of-Pines,
Calva and Swift Trail Junction.

This includes the following highways...
 Route 70 between mile markers 281 and 350.
 Route 191 between mile markers 112 and 132, near mile marker 166,
and between mile markers 169 and 184.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3265 10963 3313 11040 3347 11014 3346 11001
      3352 11000 3317 10925
TIME...MOT...LOC 2125Z 037DEG 13KT 3299 10959

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

AH

Special Weather Statement
National Weather Service Tucson AZ
314 PM MST Fri Aug 13 2021

AZZ506-509-510-132300-
Upper Gila River and Aravaipa Valleys including
Clifton/Safford-Southeast Pinal County including
Kearny/Mammoth/Oracle-White Mountains of Graham and Greenlee Counties
including Hannagan Meadow-
314 PM MST Fri Aug 13 2021

...A strong thunderstorm will impact portions of northwestern Graham
and northeastern Pinal Counties through 400 PM MST...

At 314 PM MST, Doppler radar was tracking a strong thunderstorm 9
miles east of San Carlos, or 25 miles east of Globe, moving southwest
at 15 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Bylas, Calva and San Carlos Reservoir.

This includes Route 70 between mile markers 272 and 295.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3347 10994 3313 11011 3319 11045 3320 11040
      3328 11046 3339 11044 3340 11036 3343 11032
      3343 11029 3344 11028 3345 11018 3346 11017
TIME...MOT...LOC 2214Z 037DEG 13KT 3339 11030

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

AH

Special Weather Statement
National Weather Service Tucson AZ
320 PM MST Fri Aug 13 2021

AZZ508-509-512-132300-
Upper Gila River and Aravaipa Valleys including
Clifton/Safford-Chiricahua Mountains including Chiricahua National
Monument-Eastern Cochise County Below 5000 Feet including
Douglas/Willcox-
320 PM MST Fri Aug 13 2021

...Strong thunderstorms will impact portions of southeastern Graham,
northeastern Cochise and southeastern Greenlee Counties through 400
PM MST...

At 320 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending from 13 miles southwest of Virden to near Portal.
Movement was west at 10 mph.

HAZARD...Winds in excess of 45 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...
Portal, Bowie, Chiricahua National Monument, San Simon and Paradise.

This includes the following highways...
 Interstate 10 between mile markers 362 and 391.
 Route 181 between mile markers 51 and 64.
 Route 186 between mile markers 353 and 359.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3187 10905 3174 10949 3252 10955 3264 10905
TIME...MOT...LOC 2220Z 074DEG 8KT 3255 10916 3195 10913

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

JRM