Severe Thunderstorm Warning 16, NWS Phoenix, AZ

344 
WWUS55 KPSR 150356
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
856 PM MST FRI JUL 14 2017

AZC013-027-150403-
/O.EXP.KPSR.SV.W.0016.000000T0000Z-170715T0400Z/
Yuma AZ-Maricopa AZ-
856 PM MST FRI JUL 14 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL YUMA AND MARICOPA
COUNTIES WILL EXPIRE AT 900 PM MST...

The severe thunderstorm warning issued earlier for portions of 
Interstate 8 near Dateland will expire at 9 pm.  Thunderstorms in 
the area have weakened considerably, and severe weather is no longer 
a threat.  However gusty winds will continue in the area through 
late evening with periods of blowing dust along Interstate 8. 
    
LAT...LON 3298 11342 3283 11330 3267 11361 3285 11372
TIME...MOT...LOC 0353Z 058DEG 25KT 3282 11357 

$$

HV

Area Forecast Discussion
National Weather Service Phoenix AZ
339 PM MST Fri Jul 14 2017

.UPDATE...To Aviation Discussion...

&&

.SYNOPSIS...
Temperatures will remain near average through the weekend as high
pressure sits over the Great Basin. Thunderstorms will be common
over higher terrain areas and more scattered at lower elevations of
central Arizona. Areas of blowing dust and gusty winds will likely
accompany any thunderstorms. Moisture levels will gradually increase
over weekend which could lead to an increase in thunderstorm
coverage into the beginning of next week.

&&

.DISCUSSION...

500 mb analysis this afternoon shows a high pressure circulation
near the southern tip of Nevada with a cyclonic easterly wave
just to our south and east over northern Mexico. This puts Phoenix
under a northeasterly steering flow this afternoon and under more
shear (0-6km:~20kts) than what was observed yesterday. Convection
is currently being observed over the White Mountains and rim this
afternoon with a lack of convection, or at least a late start,
further south around Tucson. Models are in fairly good agreement
of limited convective activity in the valley tonight and this
evening. The one notable exception is the UA WRFs which bring
storms into Phoenix, however, these were erroneous outliers
yesterday as well. While convection should be limited at lower
elevations this evening, it is expected to be more widespread than
yesterday since the H5 high has moved off to our northwest and
the aforementioned shear has increase.

Chances for convection over the lower deserts increase for
tomorrow as the easterly wave inches towards our area. While this
happens, PWs and subsequently CAPE are slow to increase over
south-central Arizona and in SE California which may limit overall
activity. Nonetheless, conditions will be more favorable than
even today for convection. The high pressure circulation is
expected to gradually lift north and east into southern Utah by
Sunday while the easterly wave will be position just to our south.
This will put us under a more favorable easterly flow at mid
levels. Lower levels show high theta-e moving in from the south
Saturday night pushing GEFS CAPE values near 1,000 J/kg on Sunday
afternoon. As of right now, Sunday looks to be particularly active
thanks to this and the easterly shortwave passing to our south.
However, if Sunday doesn't pan out, Monday look to be equally
favorable as instability remains elevated. The difficulty of
pinpointing the most active day arises from the fact that outflows
and remnant clouds from the previous days convection influences
the next. So if Saturday happens to be more active than expected,
Sunday might not be particularly active. However, confidence is
high that moisture will increase over our area and overall
thunderstorm activity will increase. With the increase moisture,
storms are expected to drop more rain and flash flooding will be a
concern of ours, especially starting Sunday.

Forecast confidence for the remainder of next week is still rather
tenuous, though the primary message from ensemble means is towards
positive height anomalies only slowly edging east into the central
high plains and keeping the SW Conus in a favorably wet monsoon
pattern. There are some members attempting to retrograde the ridge
towards the end of the week slowing down convective activity, though
these are more the outliers at this point. While repeated robust
thunderstorms days are not likely, have kept POPs within a range of
climatology feeling action will eventually settle back into a more
typical daily evolution.

&&

.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Line of scattered thunderstorms will continue to track off the
Mogollon Rim, likely grazing far eastern portions of the Phoenix
Metro with some isolated shower and storm activity. Outflow winds
from a north to northeast heading are possible into the terminals
from these storms, along with additional isolated storm develop
along and in the wake of the outflows. SCT to BKN clouds 8-10kft
will develop into the evening along the outflows with BKN to OVC
debris/cirrus clouds AOA 20kft. Included mention of VCTS into the
TAFs with afternoon amendments for a few evening hours to account
for the early approach of activity along the Rim. Post outflow
winds will be tricky to determine, but overall thoughts would be
easterly winds through Friday morning. Given the direction the
storms are traveling from, concerns for widespread blowing dust is
lower than in previous evenings.

Southeast California/Southwest Arizona including KIPL and KBLH:

Very little threat for convection over the western deserts today
through this evening and cloud cover should not be especially
significant either with just a few mid/high cloud decks at times
with bases mostly aoa 14k feet. Expect persistent south winds next
24 hours at KBLH with speeds mostly below 15kt and mostly southeast
winds at KIPL; thus the one-line TAFS for both locations.

Aviation discussion not updated for amended TAFs.

&&

.FIRE WEATHER...
Monday through Friday:
Higher humidity and chances for thunderstorms are the key
takeaways for the period. Minimum relative humidities will stay
18-30 percent with good overnight recoveries. The best
thunderstorm chances will remain over the mountainous areas north
and east of Phoenix, but most desert locations, including
southeast California, will also have slight chances for storms
each evening. Sunday and Monday look to be the wettest days of the
period with a good chance for thunderstorms across much of the
lower desert as well as the higher terrain. Outside of the typical
thunderstorm threats, the storms are also likely to generate
strong outflow winds that could impact distant locations.
Otherwise, expect light and typical winds and temperatures.
Finally, as moisture increases, temperatures will decrease and we
can expect below normal high temperatures, especially over south-
central Arizona for most of the period. Possibly the coolest day
of the period will be Monday when high temperatures in the central
deserts fall to near 100 or even into the 90s.

&&

.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

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DISCUSSION...Wilson/MO
AVIATION...Nolte/CB
FIRE WEATHER...Deemer/CB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
521 PM MST FRI JUL 14 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0506 PM     DUST STORM       2 NE LUKE AFB           33.55N 112.34W
07/14/2017                   MARICOPA           AZ   PUBLIC

            ESTIMATED VISIBILITY OF 1/4 MILE.

&&

PI

Special Weather Statement
National Weather Service Phoenix AZ
522 PM MST FRI JUL 14 2017

AZZ534-537-538-150100-
Aguila Valley-Tonopah Desert-Northwest Valley-
522 PM MST FRI JUL 14 2017

...A STRONG THUNDERSTORM WILL AFFECT MARICOPA COUNTY NEAR
WICKENBURG...MORRISTOWN...AND CIRCLE CITY...

At 520 PM MST, a few strong thunderstorms were located near
Wickenburg, moving south at 10 mph. These storms were moving toward
the towns of Morristown and Circle City.

Wind gusts up to 50 mph and torrential rainfall are possible with
these storms.

Locations impacted include...
Surprise, Wickenburg, Wittmann, Circle City, Sun City West and
Morristown.

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

LAT...LON 3394 11251 3369 11237 3357 11274 3398 11293
      3401 11284
TIME...MOT...LOC 0020Z 359DEG 10KT 3395 11265

HV

Special Weather Statement
National Weather Service Phoenix AZ
548 PM MST FRI JUL 14 2017

AZZ551>553-555-558-150130-
Northwest Pinal County-Southeast Valley/Queen Creek-Apache
Junction/Gold Canyon-Superior-Pinal/Superstition Mountains-
548 PM MST FRI JUL 14 2017

...A FEW STRONG THUNDERSTORMS WILL AFFECT MARICOPA AND PINAL
COUNTIES...GENERALLY IN THE PHOENIX FAR SOUTHEAST VALLEY...AND IN
THE SAN TAN VALLEY COOLIDGE AREAS...

At 544 PM MST, a few strong thunderstorms were located near Florence
Junction, moving southwest at 20 mph. These storms will continue to
move southwest into the far Phoenix southeast valley, and into the
San Tan Valley Coolidge areas.  Winds gusts between 35 and 45 mph
area possible, along with visibilities under 4 miles in blowing dust.

Locations impacted include...
Casa Grande, Apache Junction, Florence, Coolidge, Superior, Queen
Creek, La Palma, Gold Camp, San Tan Valley, Florence Junction, Queen
Valley, Olberg, Arizola, Boyce Thompson Arboretum, San Tan Mountain
Park, Randolph, Blackwater, Chandler Heights, Toltec and Magma.

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

LAT...LON 3308 11190 3345 11138 3326 11092 3290 11145
      3275 11164
TIME...MOT...LOC 0044Z 040DEG 19KT 3319 11140

HV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
632 PM MST FRI JUL 14 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND GST     6 WNW DEER VALLEY       33.71N 112.20W
07/14/2017  E60 MPH          MARICOPA           AZ   PUBLIC

            DELAYED REPORT. VISIBILITY ABOVE 1/4 MILE.

&&

PI

Special Weather Statement
National Weather Service Phoenix AZ
641 PM MST FRI JUL 14 2017

AZZ553-554-150215-
Northwest Pinal County-West Pinal County-
641 PM MST FRI JUL 14 2017

...A STRONG THUNDERSTORM WILL AFFECT PINAL COUNTY...

At 639 PM MST/639 PM PDT/, a few strong thunderstorms were located
near Olberg, or 11 miles northwest of Casa Grande. Other storms will
develop between Casa Grande and Maricopa the remainder of the
evening.

Wind gusts up to 50 mph are possible with this storm.

Locations impacted include...
Casa Grande, Olberg and Stanfield.

LAT...LON 3290 11219 3311 11186 3297 11174 3280 11177
      3279 11187 3277 11189 3276 11205 3272 11207
      3272 11214 3268 11215 3268 11219
TIME...MOT...LOC 0139Z 057DEG 2KT 3301 11188

HV

Special Weather Statement
National Weather Service Phoenix AZ
759 PM MST FRI JUL 14 2017

AZZ531-535-536-539-150400-
Gila River Valley-Southeast Yuma County-Kofa-Gila Bend-
759 PM MST FRI JUL 14 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN YUMA AND MARICOPA
COUNTIES NEAR INTERSTATE 8 BETWEEN TACNA AND SENTINEL...

At 755 PM MST, an area of strong thunderstorms were located 10 miles
west of Sundad, or 35 miles southwest of Tonopah, moving southwest
at 20 mph.

These storms were moving southwest toward the Interstate 8 towns of
Sentinel, Dateland, Mohawk, and Tacna..

Thunderstorms have the capability of producing wind gusts between 35
and 45 mph, and areas of blowing dust with visibilities under 2
miles.

Locations impacted include...
Wellton, Tacna, Paloma, Tyson, Dateland, Mohawk and Roll.

LAT...LON 3321 11352 3273 11310 3235 11396 3288 11426
TIME...MOT...LOC 0255Z 032DEG 16KT 3318 11342

HV