Severe Thunderstorm Warning 39, NWS Phoenix, AZ

207 
WWUS55 KPSR 030159
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
659 PM MST THU AUG 2 2018

AZC013-021-030215-
/O.CON.KPSR.SV.W.0039.000000T0000Z-180803T0215Z/
Maricopa AZ-Pinal AZ-
659 PM MST THU AUG 2 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM MST
FOR MARICOPA AND PINAL COUNTIES...

At 659 PM MST, severe thunderstorms were located along a line
extending from near Palo Verde to 7 miles southwest of South Mountain
Park, moving northeast at 15 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Avondale, Goodyear, Buckeye, Palo Verde, Perryville, Liberty, Phoenix
International Raceway, Estrella Mountain Park, Estrella Mountain
Ranch, Hassayampa, Rainbow Valley, Komatke and Arlington.

This includes the following highways...
AZ Interstate 10 between mile markers 111 and 119.
AZ Route 85 between mile markers 140 and 154.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3349 11261 3331 11208 3309 11229 3327 11282
TIME...MOT...LOC 0159Z 242DEG 11KT 3329 11265 3326 11217 

HAIL...0.75IN
WIND...60MPH
 
$$

Hernandez

106 
WWUS55 KPSR 030214
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
714 PM MST THU AUG 2 2018

AZC013-021-030223-
/O.EXP.KPSR.SV.W.0039.000000T0000Z-180803T0215Z/
Maricopa AZ-Pinal AZ-
714 PM MST THU AUG 2 2018

...THE SEVERE THUNDERSTORM WARNING FOR MARICOPA AND PINAL COUNTIES
WILL EXPIRE AT 715 PM MST...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with these
thunderstorms.

LAT...LON 3349 11261 3331 11208 3309 11229 3327 11282
TIME...MOT...LOC 0213Z 242DEG 11KT 3331 11261 3328 11213 

$$

Hernandez

Area Forecast Discussion
National Weather Service Phoenix AZ
1242 PM MST Thu Aug 2 2018

.SYNOPSIS...
High pressure will meander across the southwest United States
resulting in slightly above average temperatures, but a gradual
decrease in thunderstorm chances through the weekend, especially
across the lower deserts. More significant moisture will return to
the region by early next week as high pressure builds to the
northwest. Temperatures will consistently remain a few degrees
above normal.

&&

.DISCUSSION...

Visible satellite shows thunderstorm activity gradually increasing
area-wide early this afternoon, and continues to reveal a few
notable features that may support an increase in thunderstorm
potential later this afternoon and evenings. A fast-moving
gravity wave is moving across south-central Arizona, and has
appeared to already enhance convection across south of the Tucson
area. Earlier mid-level cloudiness continues to diminish near the
Phoenix area, while convection becomes more widespread across the
Rim and White Mountains.

The latest hi-res convective allowing guidance continues to
indicate a cluster or two of storms developing across Pima County
into southwest Maricopa and Pinal Counties later this afternoon.
Although steering flow is quite weak, thunderstorms are expected
to propagate and develop towards the Phoenix area later this
afternoon and evening. With weak large-scale forcing for ascent
and new thunderstorm convective development largely dependent on
outflow boundaries, coverage is still uncertain. Can't rule out a
few strong wind gusts, locally heavy rain, and patchy blowing
dust with any thunderstorms/outflows that develop. Farther west,
thunderstorms developing over the higher terrain of northern Baja
County are approaching western Imperial County in association with
a remnant MCV. Additional convection has been noted across JTNP.
Blowing dust and locally strong wind gusts will accompany any
storms that develop.

The upper ridge across the western CONUS will
remain dampened through the weekend by a belt of moderate
westerlies across the Great Basin, which will keep our
temperatures slightly above normal. Within this regime, drier air
aloft will also overspread the region this weekend and result in a
downtick in thunderstorm activity area-wide. However, there will
still be enough moisture around to support a few thunderstorms
over southern Gila County.

By next week, a seasonably strong upper trough will develop off
the Pacific Northwest coast, and correspond with a significant
amplification of the upper ridge over the western CONUS. The
parent anticyclone will shift northwestward towards the Great
Basin while simultaneously strengthening. While this may result in
a gradual warming trend for southeast California, it should be far
enough removed to keep excessive heat concerns at bay for the time
being. During this time period, moisture will return back closer
to seasonal normals for August, and bring back daily chances for
thunderstorms. This should set up a Type II monsoonal pattern and
place south-central Arizona within east-northeast flow aloft.
Temperatures should also remain fairly consistent during this
period.

&&

.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Based on observational data and preponderance of latest high
resolution model output, it looks far more likely that sct
thunderstorms will impact the Phoenix metro, and particularly KPHX.
The pattern conceptually matches storms forming over SW Maricopa Co
generating outflow and blowing dust moving north towards the
terminals. Potentially aided by lift from the Estrellas, storms
could directly impact KPHX and have added a Tempo group around 02Z.

The most likely time frame of IFR conditions due to TSRA and BLDU
looks to be 02Z-05Z with showers lingering for a few more hours
afterwards. Gusty SSW winds with the outflow would become extremely
variable in direction with the passage of any storms, and wake low
development could cause a period of gusty north winds washing back
into terminal locations. Not convinced coverage will be that
extensive throughout the metro and only included VCTS for KIWA and
KSDL sites, though BLDU could become a problem at these location as
well.

Southeast California/Southwest Arizona including KIPL and KBLH:
Thunderstorm chances and associated impacts are the primary aviation
concerns this afternoon and evening. Storms were already developing
along the Baja spine this morning, and steering flow could drive
TSRA into KIPL this afternoon. Chances of directly impacting the
terminal location is too small to include in this TAF package, with
only a wind shift currently noted. Storm chances at KBLH are much
less, and the typical south winds should prevail.

Aviation Discussion not updated for amended TAFs.

&&

.FIRE WEATHER...
Sunday through Thursday:
Thunderstorm chances will be more relegated to higher terrain
areas of Gila County on Sunday as the overall atmospheric moisture
content declines. As high pressure redevelops to the northwest,
moisture will return to the area and bring an increase in
thunderstorm chances to the lower deserts. Otherwise, minimum
humidities will remain in a 15-30% range following fair to good
overnight recovery. Apart from thunderstorms, winds will be light
except for typical afternoon and evening upslope breeziness.
Little temperature trend expected during the five day period, with
high temperatures remaining a few degrees or so above seasonal
normals each day.

&&

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

&&

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

DISCUSSION...Rogers
AVIATION...MO
FIRE WEATHER...Rogers/CB

Special Weather Statement
National Weather Service Phoenix AZ
637 PM MST THU AUG 2 2018

AZZ533-030215-
Central La Paz AZ-
637 PM MST THU AUG 2 2018

...SPECIAL WEATHER STATEMENT...

At 637 PM MST, Doppler radar was tracking a strong thunderstorm 8
miles east of Bouse, or 28 miles southwest of Alamo Lake, moving
north at 30 mph.

Winds in excess of 30 mph will be possible with this storm.

This storm will remain over mainly rural areas of northeastern La Paz
County.
This includes AZ Route 72 between mile markers 31 and 34.

LAT...LON 3382 11372 3387 11397 3422 11394 3421 11353
TIME...MOT...LOC 0137Z 192DEG 26KT 3393 11385

Hernandez

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
638 PM MST THU AUG 2 2018

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

0624 PM     DUST STORM       4 E AHWATUKEE FOOTHILLS 33.31N 111.99W
08/02/2018                   MARICOPA           AZ   TRAINED SPOTTER

            SPOTTER REPORTS VISIBILITY OF LESS THAN 1/4
            MILE AND DROPPING.

&&

TD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
639 PM MST THU AUG 2 2018

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

0635 PM     DUST STORM       3 WNW GILBERT           33.36N 111.84W
08/02/2018                   MARICOPA           AZ   TRAINED SPOTTER

            TRAINED SPOTTER REPORTS 1/4 MILE VISIBILITY
            IN BLOWING DUST.

&&

MP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
640 PM MST THU AUG 2 2018

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

0626 PM     DUST STORM       2 E CHANDLER            33.29N 111.82W
08/02/2018                   MARICOPA           AZ   TRAINED SPOTTER

            SPOTTER REPORTS VISIBILITY LESS THAN 1/4
            MILE DUE TO DUST AND WINDS OF ABOUT 20MPH.

&&

TD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
641 PM MST THU AUG 2 2018

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

0627 PM     DUST STORM       PHOENIX MESA GATEWAY    33.31N 111.66W
08/02/2018                   MARICOPA           AZ   AWOS

            MESA GATEWAY AWOS REPORTS 1/8 MILE
            VISIBILITY IN BLOWING DUST.

&&

MP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
642 PM MST THU AUG 2 2018

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

0629 PM     DUST STORM       3 NNW CHANDLER          33.33N 111.89W
08/02/2018                   MARICOPA           AZ   TRAINED SPOTTER

            SPOTTER REPORTS NEAR ZERO VISIBILITY DUE TO
            DUST.

&&

TD