Flash Flood Warning 4, NWS Phoenix, AZ

119 
WGUS75 KPSR 250921
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
221 AM MST Sat Jun 25 2022

AZC013-250931-
/O.CAN.KPSR.FF.W.0004.000000T0000Z-220625T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
221 AM MST Sat Jun 25 2022

...FLASH FLOOD WARNING IS CANCELLED FOR MARICOPA COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3399 11271 3392 11244 3378 11251 3379 11281
      3400 11274 3400 11273

$$

GL

Area Forecast Discussion
National Weather Service Phoenix AZ
1144 PM MST Fri Jun 24 2022

.UPDATE...
Scattered thunderstorms have developed over the last couple hours
across mainly Maricopa and Pinal Counties. This appears to be in
response to multiple outflow boundaries colliding within a
slightly to moderately unstable environment. PW values are
currently between 1.25 and 1.5 inches across Central Arizona. Main
threats continue to be torrential rainfall, brief gusty winds
over 40 mph, and pockets of blowing dust. Localized areas near
Chandler and Sun Lakes are approaching 2" of rain, so a FFW is in
effect until 1:30AM. Will continue to monitor radar trends through
the night.

&&

.SYNOPSIS...
Moisture will hang around with an even more favorable monsoon
pattern setting up Sunday into next week. Today and tomorrow, winds
and blowing dust will be the main weather risks, especially along I-
8 and I-10 in Maricopa, Pinal, and Yuma counties. Sunday and Monday,
the flooding potential increases across the lower deserts as more
moisture from soon to be Hurricane Celia advances towards the
region. Low to moderate HeatRisk remains in place through next week.

&&

.DISCUSSION...
This morning, the 12Z sounding at Phoenix and Yuma, showed 1.37
inches and 1.23 inches of precipitable water respectively. This is a
lot of moisture for this time of year with both of these values
exceeding the daily maximum according to sounding climatology. The
synoptic pattern remains nearly the same today, with slightly more
westerly flow. An unstable atmosphere will be in place again today
with mesoanalysis depicting MLCape values rising into the 500-1000
J/kg range across much of Maricopa, Pinal, and La Paz counties this
afternoon. In these areas, DCape values will also be extremely high,
in the 1800-2000 J/kg range.

Convection will continue to develop across northern and eastern
Arizona this afternoon, including southern Gila County, and be a
little delayed across southern AZ (compared to yesterday). There is
also a chance for lower desert storms, with a ~25% chance in the
Wickenburg area, ~20% chance across the Phoenix and Casa Grande
area, and <10% chance in Parker and Quartzite areas. Strong
downburst/outflow winds and blowing dust will be the biggest risks
today, especially along I-8 and I-10 in Maricopa and Pinal counties.
The HREF probability of wind speeds exceeding 35 mph today is
greater than 70% in southern Gila county, 50-70% in Maricopa and
Pinal counties and 30-50% in La Paz county. Most areas will likely
see less than a quarter inch of rain with storms. However, with
plenty of moisture in the atmosphere to tap into, some cells may
produce upwards of 0.5-1.0 inch of rain.

Tomorrow, the area of focus shifts westward into western Pima,
southern Maricopa, and Yuma counties, as this is where the best
instability will be. The probability of greater than 35 mph wind
speeds in this area is greater than 50%. HRRR 80m wind is also
showing a decent outflow boundary developing and traveling northwest
and potentially moving through southeast California. Strong
downburst/outflow winds and blowing dust will be the biggest risks
tomorrow in these areas, especially along I-8 in Yuma, Maricopa, and
Pinal counties.

We are still expecting a more favorable monsoon pattern to set up
Sunday and last much of next week. It also appears that Sunday into
Tuesday, we will see an increase in moisture from the tropics,
thanks to soon to be Hurricane Celia. Thunderstorm chances in the
Phoenix area rise to 25% each day Sunday into next week. Heavy rain,
strong winds, and blowing dust will be the main risks each day.
Moderate HeatRisk will remain in place for the lower deserts of our
CWA through at least early next week.

&&

.AVIATION...Updated at 0555Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Erratic winds from an isolated thunderstorm in the Chandler area to
produce erratic winds for the next hour or so at KIWA and KPHX, with
KIWA having the greatest risk for strong winds being at KIWA. There
is a lesser chance for TS impacts at KSDL and KDVT, with winds at
both these terminals remaining mainly from a northerly direction for
the next hour or so. More typical easterly drainage winds return
later this evening/overnight as the shower/TS activity diminishes.
As far as Saturday is concerned, after light easterly winds in the
morning, the typical westerly switch is expected to occur around
midday/early afternoon. Winds are expected to become rather gusty by
late afternoon as more showers/T-storms develop, mainly to the
south/southwest of the Phoenix metro. Outflows from these storms
could briefly produce (50-70% chance) of winds gusts aoa
35kts/blowing dust by late afternoon, with even a 20-30% chance that
a thunderstorm will directly impact one (or more) of the terminals.
However, confidence is still too low at this point to include
anything more than VCSH in the TAFs at this point. Convective
activity is likely to diminish rather rapidly by mid-evening
Saturday with winds likely switching to a southeasterly direction.

Southeast California/Southwest Arizona including KIPL and KBLH:
Little to no weather concerns will exist through Saturday evening
under clear skies. Current southwesterly winds to become light
southerly to southeasterly by late tonight/early Sat morning. A bit
stronger winds can be anticipated by Saturday afternoon.

&&

.FIRE WEATHER...
Moisture will remain entrenched across the desert southwest through
next week. There will be daily opportunities for afternoon and early
evening shower and thunderstorm activity, especially across Arizona
and high terrain locations. With the increased moisture, MinRH
values will remain above 15% across most areas through tomorrow and
above 20% Sunday into all of next week. Great overnight recoveries.
Apart from frequent late afternoon/early evening thunderstorm
downburst and/or outflow winds, no other significant winds are
expected.

&&

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

UPDATE...Heil
DISCUSSION...Feldkircher
AVIATION...Percha/18
FIRE WEATHER...Feldkircher

Special Weather Statement
National Weather Service Phoenix AZ
829 PM MST Fri Jun 24 2022

AZZ531-533-538-250400-
Kofa AZ-Tonopah Desert AZ-Central La Paz AZ-
829 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of east central La Paz,
northeastern Yuma and Maricopa Counties through 900 PM MST...

At 829 PM MST, Doppler radar was tracking a strong thunderstorm 17
miles north of Sundad, or 22 miles west of Tonopah, moving east at 10
mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

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

This storm will remain over mainly rural areas of east central La
Paz, northeastern Yuma and Maricopa Counties.

This includes AZ Interstate 10 between mile markers 67 and 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3331 11342 3346 11350 3360 11338 3357 11322
      3343 11315 3337 11320
TIME...MOT...LOC 0329Z 261DEG 7KT 3343 11331

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

INS

Special Weather Statement
National Weather Service Phoenix AZ
901 PM MST Fri Jun 24 2022

AZZ534-250445-
Aguila Valley AZ-
901 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of Maricopa County
through 945 PM MST...

At 901 PM MST, Doppler radar was tracking a strong thunderstorm near
Aguila, or 20 miles west of Wickenburg, moving northeast at 10 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...
Gladden and Aguila.

This includes US Highway 60 between mile markers 75 and 95.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3384 11298 3377 11323 3377 11333 3400 11333
      3400 11298
TIME...MOT...LOC 0401Z 239DEG 8KT 3394 11310

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

INS

Special Weather Statement
National Weather Service Phoenix AZ
948 PM MST Fri Jun 24 2022

AZZ548-550-551-553-250515-
South Mountain/Ahwatukee AZ-Northwest Pinal County AZ-
Southeast Valley/Queen Creek AZ-East Valley AZ-
948 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of Maricopa and Pinal
Counties through 1015 PM MST...

At 947 PM MST, Doppler radar was tracking a strong thunderstorm over
Chandler, moving northeast at 10 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...
Mesa, Chandler, Gilbert, Tempe, Sun Lakes, Queen Creek, Gilbert City
Hall, Tumbleweed Park, Chandler City Hall, San Tan Village Mall,
Fiesta Mall, Chandler Fashion Center Mall, Guadalupe, Firebird Lake
and Higley.

This includes the following highways...
AZ Interstate 10 between mile markers 157 and 172.
US Highway 60 between mile markers 173 and 180.
AZ Route 87 between mile markers 158 and 172.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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 3313 11193 3328 11208 3344 11189 3326 11166
TIME...MOT...LOC 0447Z 239DEG 8KT 3328 11189

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

INS

Special Weather Statement
National Weather Service Phoenix AZ
1032 PM MST Fri Jun 24 2022

AZZ548-550-551-553-250600-
South Mountain/Ahwatukee AZ-Northwest Pinal County AZ-
Southeast Valley/Queen Creek AZ-East Valley AZ-
1032 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of Maricopa and Pinal
Counties through 1100 PM MST...

At 1031 PM MST, Doppler radar was tracking a strong thunderstorm over
Tumbleweed Park, or over Sun Lakes. This storm was nearly stationary.

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...
Mesa, Chandler, Gilbert, Tempe, Sun Lakes, Queen Creek, Mesa
Riverview Mall, Gilbert City Hall, Downtown Mesa, Tumbleweed Park,
Chandler City Hall, San Tan Village Mall, Seville, Freestone Park,
Bapchule, Fiesta Mall, Chandler Fashion Center Mall, Phoenix Mesa
Gateway Airport, Guadalupe and Firebird Lake.

This includes the following highways...
AZ Interstate 10 between mile markers 157 and 174.
US Highway 60 between mile markers 174 and 183.
AZ Route 87 between mile markers 157 and 174.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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.

&&

LAT...LON 3310 11192 3328 11208 3345 11186 3328 11163
TIME...MOT...LOC 0531Z 241DEG 2KT 3325 11185

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

INS

Special Weather Statement
National Weather Service Phoenix AZ
1103 PM MST Fri Jun 24 2022

AZZ534-537-250645-
Aguila Valley AZ-Northwest Valley AZ-
1103 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of Maricopa County
through 1145 PM MST...

At 1103 PM MST, Doppler radar was tracking a strong thunderstorm over
Morristown, or near Circle City, moving north at 10 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...
Wickenburg, Wittmann, Circle City and Morristown.

This includes the following highways...
US Highway 60 between mile markers 106 and 129.
AZ Route 74 between mile markers 1 and 10.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3398 11269 3392 11243 3377 11249 3377 11273
      3400 11282 3400 11273
TIME...MOT...LOC 0603Z 169DEG 10KT 3386 11264

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

GL

Special Weather Statement
National Weather Service Phoenix AZ
1129 PM MST Fri Jun 24 2022

AZZ550-551-553-250715-
South Mountain/Ahwatukee AZ-Northwest Pinal County AZ-
Southeast Valley/Queen Creek AZ-
1129 PM MST Fri Jun 24 2022

...A strong thunderstorm will impact portions of Maricopa and Pinal
Counties through 1215 AM MST...

At 1129 PM MST, Doppler radar was tracking a strong thunderstorm over
Bapchule, or near Sun Lakes. This storm was nearly stationary.

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...
Chandler, Casa Grande, Sun Lakes, Bapchule, Tumbleweed Park, Olberg,
Santan and Sacaton.

This includes the following highways...
AZ Interstate 10 between mile markers 166 and 181.
AZ Route 87 between mile markers 152 and 164.
AZ Route 347 between mile markers 176 and 184.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in Phoenix.

&&

LAT...LON 3296 11195 3314 11208 3328 11189 3328 11181
      3314 11173 3295 11186
TIME...MOT...LOC 0629Z 040DEG 2KT 3315 11187

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

INS