Severe Thunderstorm Warning 30, NWS Tucson, AZ

064 
WWUS55 KTWC 202026
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
126 PM MST FRI JUL 20 2018

AZC023-202100-
/O.CON.KTWC.SV.W.0030.000000T0000Z-180720T2100Z/
Santa Cruz-
126 PM MST FRI JUL 20 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM MST
FOR SOUTH CENTRAL SANTA CRUZ COUNTY...

At 121 PM MST, a severe thunderstorm was located near Nogales, 
moving southwest at 20 mph. A weather spotter near Kino Springs 
reported very heavy rainfall along with dime size hail at 118 PM 
MST. 

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. Minor street flooding and 
         elevated flows in normally dry washes my also accompany 
         this storm. 

Locations impacted include...
Nogales, Rio Rico Southeast, Rio Rico Southwest and Kino Springs. 

This includes the following highways...
 Interstate 19 between mile markers 1 and 7.
 Route 82 between mile markers 1 and 12.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3134 11109 3137 11116 3148 11079 3134 11071
      3133 11108
TIME...MOT...LOC 2021Z 063DEG 16KT 3135 11087 

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

301 
WWUS55 KTWC 202054
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
154 PM MST FRI JUL 20 2018

AZC023-202104-
/O.EXP.KTWC.SV.W.0030.000000T0000Z-180720T2100Z/
Santa Cruz-
154 PM MST FRI JUL 20 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL SANTA CRUZ
COUNTY WILL EXPIRE AT 200 PM MST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 3134 11109 3137 11116 3148 11079 3134 11071
      3133 11108
TIME...MOT...LOC 2054Z 084DEG 12KT 3136 11098 

$$

Area Forecast Discussion
National Weather Service Tucson AZ
932 AM MST Fri Jul 20 2018

.SYNOPSIS...Isolated to scattered thunderstorms today into Saturday.
As high pressure strengthens over the desert southwest late this
weekend into early next week, the number of storms will decrease and
temperatures will climb to well above normal with near record heat
possible early next week.

&&

.DISCUSSION...Another day and another round of thunderstorms.
Moisture levels today on par with yesterday as far as PW values go
with only slightly lower dewpoints. This has resulted in lower CAPE
values than yesterday but still in excess of 2000 this morning which
is more than enough. We have a triggering feature moving NW out of
Mexico which should help support convection with a couple of storms
now moving into the Douglas area. Should be a good afternoon and
evening convection wise with the setup that we have. No changes
needed to the short-term forecast. The heat next week is well
addressed in the previous discussion below.

&&

.AVIATION...Valid through 21/12Z.
A few TSRA nr KDUG this morning otherwise ISOLD-SCT TSRA today after
20/19z with cloud bases 8-10k ft AGL. Outside of strong and erratic
TSRA outflows, surface winds remain below 12 kts through the period.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to occasionally scattered afternoon and
evening storms are forecast today and Saturday. Heat will build
Sunday into early next week with potential for record high
temperatures. Outside of thunderstorms, 20-ft winds remain below
15 mph, although the Upper Gila River Valley will experience
gustier northwesterly winds at times.

&&

.PREV DISCUSSION... /issued 322 AM MST Fri Jul 20 2018/
Clear to partly cloudy sky prevailed this morning across southeast
Arizona. A weak upper level disturbance moving across northern
Chihuahua has kicked off a few thunderstorms southeast of the New
Mexico boot. May see a few of these storms move into far southeast
Cochise county around sunrise. Otherwise the above mentioned feature
will be the driver in storms today as it moves W-NW northern Sonora
and southern Arizona. Outflow interactions will keep storms going
into the late evening hours west of Tucson. Locally heavy rainers
with PW values in the 1.3" to 1.6" range.

Plenty of debris cloudiness Saturday will delay thunderstorm
development. Areal coverage down a bit compared to today due to the
clouds and warming temperatures aloft. Highs at or slightly warmer
than today.

Strengthening high pressure aloft along with continued warm mid-
level temperatures will limit thunderstorm coverage on Sunday to
mainly the high terrain.

Main weather story early next week will be the late July heat
wave with most areas below 5000 feet meeting heat warning
criteria both Monday and Tuesday with record or near record highs.
Based on coordination between the SW offices, went ahead and
upgraded the Excessive Heat Watch to Warning. Later shifts may
need to add Wednesday to the Warning along with the possibility of
warmer highs as model thickness values are warmer than current
forecast. Both EC/Canadian hinting that Tucson could approach July
all-time high either Tuesday or Wednesday. Still holding on to
some moisture for slight chance of mainly mountain storms early
next week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning from 10 AM Monday to 8 PM MST Tuesday for
AZZ501>509.

&&

PUBLIC...Cerniglia
AVIATION....Rasmussen
FIRE WEATHER...Rasmussen

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Special Weather Statement
National Weather Service Tucson AZ
1232 PM MST FRI JUL 20 2018

AZZ503-513-202015-
Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Upper Santa Cruz River and Altar
Valleys including Nogales-
1232 PM MST FRI JUL 20 2018

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN SANTA CRUZ COUNTY UNTIL
115 PM MST...

At 1229 PM MST, Doppler radar was tracking a strong thunderstorm 5
miles east of Patagonia, or 18 miles west of Sierra Vista, moving
west at 10 mph.

Winds in excess of 40 mph and pea-size hail will be possible with
this storm.

Locations impacted include...
Patagonia and southern Sonoita.

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 3154 11052 3142 11049 3142 11076 3167 11078
      3162 11060
TIME...MOT...LOC 1929Z 100DEG 10KT 3148 11060

JKP

Special Weather Statement
National Weather Service Tucson AZ
1241 PM MST FRI JUL 20 2018

AZZ503-515-202030-
Upper Santa Cruz River and Altar Valleys including
Nogales-Baboquivari Mountains including Kitt Peak-
1241 PM MST FRI JUL 20 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL PIMA AND
NORTHWESTERN SANTA CRUZ COUNTIES UNTIL 130 PM MST...

At 1240 PM MST, Doppler radar was tracking a strong thunderstorm 15
miles west of Tubac, or 22 miles southwest of Green Valley, moving
northwest at 15 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm. Locally heavy rain is also likely with this storm.

Locations impacted include...
Arivaca, Junction Of Highway 286 And Arivaca Road 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.

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

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 3165 11107 3148 11121 3164 11162 3189 11141
TIME...MOT...LOC 1940Z 122DEG 13KT 3165 11131

Cerniglia