Severe Thunderstorm Warning 6, NWS Tucson, AZ

675 
WWUS55 KTWC 090137
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
637 PM MST SUN JUL 8 2018

AZC019-090215-
/O.CON.KTWC.SV.W.0006.000000T0000Z-180709T0215Z/
Pima-
637 PM MST SUN JUL 8 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM MST
FOR NORTHWESTERN PIMA COUNTY...

At 635 PM MST, a severe thunderstorm was located near Highway 86 
between San Simon Village and Why, or 46 miles northwest of Sells, 
moving west at 15 to 20 mph.

This is a very dangerous storm.

HAZARD...80 mph wind gusts and ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

Locations impacted include...
Why, Gunsight, Kuakatch, Gu Vo and San Simon Village. 

This includes the following highways...
 Route 85 between mile markers 52 and 71.
 Route 86 between mile markers 53 and 76.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People 
outside should move to a shelter, inside a strong building and away 
from windows.

&&

LAT...LON 3229 11240 3211 11234 3201 11281 3234 11273
TIME...MOT...LOC 0135Z 093DEG 12KT 3221 11259 

HAIL...1.50IN
WIND...80MPH
 
$$

Meyer

Area Forecast Discussion
National Weather Service Tucson AZ
147 PM MST Sun Jul 8 2018

.SYNOPSIS...More plentiful moisture through the coming week will
result in an increase in shower and thunderstorm activity. Slightly
above normal temperatures today will trend below normal through the
work week thanks to abundant moisture and enhanced thunderstorm
activity.

&&

.DISCUSSION...The upper high continues to remain centered north of
the four corners region along the central Utah/Colorado state line.
Northeast flow around the high circulation has pulled some drier air
into the region, as seen on both the GOES-16 water vapor channels
and on various satellite Pwat imagery. At 20Z, PW values ranged from
around 0.6" over the White Mountains and eastern Rim to greater than
1.4" west of a Douglas to Tucson to Casa Grande line. Convection was
slow to fire today, with just some isolated cells over the White
Mountains and along the International Border east of Nogales attm.

The main focus today was going to be along the eastern Rim, with
movement into the lower deserts on brisk northeast flow at the mid
levels. The thinking was that outflow boundaries would sustain
themselves and interact with deeper moisture as the cells tracked
southwest. However, the entrainment of drier air into the region has
put a squash on some of this development. There is still time for
this development to take place, but as the afternoon wears on my
confidence for this scenario to unfold continues to diminish. For
the time being, will keep higher pops and Blowing Dust Advisory in
effect for the remainder of the afternoon and early evening hours.
May need to make some adjustments late this afternoon/early evening
based on the amount of development at that time.

Otherwise, the GFS/ECMWF are very similar through the upcoming week,
as they move the center of the upper high northeast into the central
high plains Wednesday and then back westward to north of the four
corners region by next weekend. The mid level flow will switch to an
east/southeast direction late Monday. This will allow deeper
moisture to work into the area, as model PW values approach 1.5"
Monday night into Tuesday. The models also track two distinct
inverted troughs into the region, one mid-week and the other next
weekend. These features will likely increase the threat for
thunderstorms as they move into the region and with the higher PW's
in place expect some flooding concerns as the week progresses.

Model guidance numbers continue to indicate convective activity this
upcoming week will occur primarily during the evening/late night
hours. At this time, especially from Tucson eastward, have high end
scattered valley pops Monday through Thursday, with numerous showers
and thunderstorms in the mountains. Daytime temperatures of 1-3
degrees above normal today will lower to a couple of degrees below
normal most of the upcoming week as deeper moisture moves into the
region resulting in increased precipitation chances and cloud cover.

&&

.AVIATION...Valid through 10/00Z.
Isolated to scattered -TSRA/-SHRA will be possible at all terminals
through the late evening. Isolated to scattered storms will again be
possible Monday early afternoon through the end of the TAF period.
Expect SCT to BKN clouds at 8k-10k ft AGL and BKN clouds above 20k
ft AGL. Occasional MVFR ceilings near -TSRA with gusts up to 45 kts
possible. Outside of thunderstorm winds, sfc winds will be out of
the east/southeast at 8-15 kts with some afternoon gusts. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Moisture will continue to increase today and remain
high during the next 7 days. Scattered showers and thunderstorms
each day with storms lingering into the overnight hours. 20 ft
surface winds will generally be 15 mph or less from an easterly
direction through midweek, and thereafter follow a more typical
diurnal pattern. In the vicinity of thunderstorms expect strong and
variable winds.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
  Blowing Dust Advisory until 8 PM MST this evening for
  AZZ501-502-504>506-515.

&&

DISCUSSION...Zell
AVIATION/FIRE WEATHER...Hardin

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Special Weather Statement
National Weather Service Tucson AZ
333 PM MST SUN JUL 8 2018

AZZ502-515-082300-
Tohono O'odham Nation including Sells-Baboquivari Mountains including
Kitt Peak-
333 PM MST SUN JUL 8 2018

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

At 333 PM MST, Doppler radar was tracking a strong thunderstorm 24
miles south of Sells, moving west at 25 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
South Komelik, Newfields, San Miguel, Cowlic, Vamori and Choulic.

LAT...LON 3169 11219 3185 11210 3172 11160 3153 11170
TIME...MOT...LOC 2233Z 090DEG 21KT 3157 11182

HARDIN