929
FNUS55 KPSR 200800
FWFPSR
FIRE WEATHER PLANNING FORECAST FOR SOUTHWEST AND SOUTH-CENTRAL
ARIZONA AND SOUTHEAST CALIFORNIA
NATIONAL WEATHER SERVICE PHOENIX AZ
100 AM MST THU AUG 20 2026
DISCUSSION
ELEVATED MOISTURE LEVELS WILL PERSIST TODAY WITH A TEMPORARY
REPRIEVE FROM THE EXTREME HEAT ACROSS THE EASTERN DISTRICTS.
EXPECT MOSTLY ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EARLY EVENING OVER THE HIGH TERRAIN AREAS. DRIER AIR WILL THEN
WORK ITS WAY IN FOR FRIDAY AND SATURDAY WITH EVEN LOWER CHANCES
FOR RAIN WHILE TEMPERATURES HEAT BACK UP TO EXTREME LEVELS.
MINRHS OF 20-30% TODAY WILL LOWER TO 15-25% BEGINNING FRIDAY.
WINDS SHOULD OVERALL FOLLOW THE TYPICAL DIURNAL TENDENCIES WITH
SOME MODEST AFTERNOON UPSLOPE GUSTINESS.
..THUNDERSTORMS IMPLY GUSTY WINDS
NOTE...ADDITIONAL FIRE WEATHER FORECAST INFORMATION CAN BE FOUND
IN THE AREA FORECAST DISCUSSION. SEE PRODUCT PHXAFDPSR.
AZZ132-202000-
WEST CENTRAL DESERTS/NORTHWEST MARICOPA COUNTY/GREATER PHOENIX
AREA/SOUTHWEST DESERTS/SOUTHWEST MARICOPA COUNTY/
NORTHWEST AND NORTH-CENTRAL PINAL COUNTY-
PHOENIX BLM/YUM BLM/CAZ-CRZ-
100 AM MST THU AUG 20 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................103-109.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................20-24 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 10 MPH IN THE MORNING
BECOMING WEST IN THE AFTERNOON.
* WINDS...10000 FT MSL............EAST 5 TO 15 MPH IN THE MORNING
BECOMING LIGHT AND VARIABLE IN THE AFTERNOON.
* CHANCE OF PRECIP................10 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............12 PERCENT.
* MIXING HEIGHT FOR PHOENIX.......8100 FT AGL.
* TRANSPORT WIND FOR PHOENIX......WEST 6 KNOTS.
* DISPERSION FOR PHOENIX..........GOOD.
TONIGHT
* SKY/WEATHER.....................PARTLY CLOUDY. SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE EVENING.
* MIN TEMPERATURE.................82-92.
* 24 HR TREND..................4 DEGREES WARMER.
* MAX HUMIDITY....................41-49 PCT.
* 24 HR TREND..................12 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..NORTHWEST 5 TO 10 MPH IN THE
EVENING BECOMING EAST AFTER MIDNIGHT.
* WINDS...10000 FT MSL............SOUTH 5 TO 15 MPH.
* CHANCE OF PRECIP................10 PERCENT IN THE EVENING
BECOMING 0 PERCENT AFTER MIDNIGHT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............12 PERCENT.
FRIDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................105-112.
* 24 HR TREND..................3 DEGREES WARMER.
* MIN HUMIDITY....................16-20 PCT.
* 24 HR TREND..................4 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..EAST 5 TO 10 MPH IN THE MORNING
BECOMING WEST IN THE AFTERNOON.
* WINDS...10000 FT MSL............SOUTHWEST 10 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
* MIXING HEIGHT FOR PHOENIX.......12500 FT AGL.
* TRANSPORT WIND FOR PHOENIX......WEST 5 KNOTS.
* DISPERSION FOR PHOENIX..........GOOD.
EXTENDED
SATURDAY
PARTLY CLOUDY. LOWS 82-92. HIGHS 106-113. SOUTHWEST
WINDS 5 TO 10 MPH.
SUNDAY
PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-92. HIGHS 104-110. SOUTHWEST WINDS 5 TO
15 MPH.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-92. HIGHS 104-110. SOUTHWEST WINDS 5 TO
15 MPH.
TUESDAY
MOSTLY CLEAR. LOWS 82-92. HIGHS 105-112.
WEDNESDAY
MOSTLY CLEAR. LOWS 83-93. HIGHS 106-112.
AZZ131-CAZ231-202000-
YUMA/MARTINEZ LAKE AND VICINITY/LOWER COLORADO RIVER VALLEY AZ-
LOWER COLORADO RIVER VALLEY CA-
100 AM MST THU AUG 20 2026 /100 AM PDT THU AUG 20 2026/
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................107-112.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................20-24 PCT.
* 24 HR TREND..................4 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............LIGHT AND VARIABLE IN THE MORNING
BECOMING SOUTHEAST 5 TO 15 MPH IN THE AFTERNOON.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
* MIXING HEIGHT FOR YUMA..........9200 FT AGL.
* TRANSPORT WIND FOR YUMA.........SOUTH 9 KNOTS.
* DISPERSION FOR YUMA.............GOOD.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLEAR.
* MIN TEMPERATURE.................83-88.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................41-51 PCT.
* 24 HR TREND..................8 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTHEAST 10 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
FRIDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................108-113.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................17-21 PCT.
* 24 HR TREND..................3 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 10 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
* MIXING HEIGHT FOR YUMA..........13700 FT AGL.
* TRANSPORT WIND FOR YUMA.........SOUTH 8 KNOTS.
* DISPERSION FOR YUMA.............EXCELLENT.
EXTENDED
SATURDAY
MOSTLY CLEAR. LOWS 84-89. HIGHS 109-114. SOUTH WINDS
5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 84-89. HIGHS 107-112. SOUTH WINDS 10 TO
20 MPH.
MONDAY
MOSTLY CLEAR. LOWS 83-88. HIGHS 106-111. SOUTH WINDS
5 TO 15 MPH.
TUESDAY
MOSTLY CLEAR. LOWS 84-89. HIGHS 108-113.
WEDNESDAY
MOSTLY CLEAR. LOWS 84-89. HIGHS 108-113.
AZZ133-202000-
SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS-
SOUTHERN TONTO NF/WEST SAN CARLOS BIA/SOUTH PORTION FT APACHE BIA/
CAZ-
100 AM MST THU AUG 20 2026
TODAY
* SKY/WEATHER.....................PARTLY SUNNY. SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.
* MAX TEMPERATURE.................88-103.
* 24 HR TREND..................3 DEGREES COOLER.
* MIN HUMIDITY....................22-33 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..WEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............NORTHEAST 5 TO 15 MPH IN THE
MORNING BECOMING LIGHT AND VARIABLE IN THE AFTERNOON.
* CHANCE OF PRECIP................0 PERCENT IN THE MORNING BECOMING
30 PERCENT IN THE AFTERNOON.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............28 PERCENT.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLOUDY IN THE EVENING
BECOMING PARTLY CLOUDY AFTER MIDNIGHT. SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS IN THE EVENING.
* MIN TEMPERATURE.................65-82.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................49-73 PCT.
* 24 HR TREND..................6 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..NORTHEAST 5 TO 15 MPH.
* WINDS...10000 FT MSL............WEST 5 TO 15 MPH.
* CHANCE OF PRECIP................20 PERCENT IN THE EVENING
BECOMING 0 PERCENT AFTER MIDNIGHT.
* CWR (>= 0.10 IN)................10 PERCENT.
* CHANCE OF THUNDER...............17 PERCENT.
FRIDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................91-107.
* 24 HR TREND..................3 DEGREES WARMER.
* MIN HUMIDITY....................17-25 PCT.
* 24 HR TREND..................7 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..EAST 5 TO 10 MPH IN THE MORNING
BECOMING SOUTHWEST IN THE AFTERNOON.
* WINDS...10000 FT MSL............LIGHT AND VARIABLE IN THE MORNING
BECOMING WEST 5 TO 15 MPH IN THE AFTERNOON.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
EXTENDED
SATURDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 65-83. HIGHS 91-107. NORTHEAST WINDS 5 TO
10 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 66-83. HIGHS 92-107. NORTH WINDS 5 TO 15 MPH.
MONDAY
PARTLY CLOUDY. LOWS 66-83. HIGHS 92-106. NORTHWEST
WINDS 5 TO 15 MPH.
TUESDAY
MOSTLY CLEAR. LOWS 66-84. HIGHS 93-108.
WEDNESDAY
MOSTLY CLEAR. LOWS 67-84. HIGHS 94-108.
CAZ232-202000-
IMPERIAL COUNTY AND EASTERN RIVERSIDE COUNTY-
100 AM PDT THU AUG 20 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................102-112.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................19-26 PCT.
* 24 HR TREND..................3 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTHEAST 10 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLEAR.
* MIN TEMPERATURE.................84-90.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................36-52 PCT.
* 24 HR TREND..................10 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 10 TO 20 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
FRIDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................103-113.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................15-22 PCT.
* 24 HR TREND..................4 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 10 TO 20 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
EXTENDED
SATURDAY
MOSTLY CLEAR. LOWS 83-90. HIGHS 104-113. SOUTHWEST
WINDS 5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 83-90. HIGHS 102-112. SOUTH WINDS 5 TO
15 MPH.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS. LOWS 83-89.
HIGHS 101-111. SOUTH WINDS 5 TO 15 MPH.
TUESDAY
MOSTLY CLEAR. LOWS 83-90. HIGHS 103-112.
WEDNESDAY
MOSTLY CLEAR. LOWS 83-90. HIGHS 103-112.
CAZ230-202000-
JOSHUA TREE NATIONAL PARK-
100 AM PDT THU AUG 20 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................93-106.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................20-28 PCT.
* 24 HR TREND..................LITTLE CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 5 TO 15 MPH IN THE MORNING
BECOMING LIGHT AND VARIABLE IN THE AFTERNOON.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLEAR.
* MIN TEMPERATURE.................74-86.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................37-47 PCT.
* 24 HR TREND..................5 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHWEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............LIGHT AND VARIABLE IN THE EVENING
BECOMING SOUTH 10 TO 20 MPH AFTER MIDNIGHT.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
FRIDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................93-107.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................16-24 PCT.
* 24 HR TREND..................4 PCT DRIER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 10 TO 20 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
EXTENDED
SATURDAY
MOSTLY CLEAR. LOWS 73-86. HIGHS 93-107. WEST WINDS
5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR. LOWS 72-86. HIGHS 92-106. SOUTHWEST WINDS
10 TO 20 MPH.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS. LOWS 72-85.
HIGHS 91-105. SOUTHWEST WINDS 5 TO 15 MPH.
TUESDAY
MOSTLY CLEAR. LOWS 72-86. HIGHS 93-106.
WEDNESDAY
MOSTLY CLEAR. LOWS 73-86. HIGHS 93-107.
8 TO 10 DAY OUTLOOK
THURSDAY AUGUST 27TH THROUGH SATURDAY
AUGUST 29TH: ABOVE NORMAL TEMPERATURES AND NEAR MEDIAN PRECIPITATION.
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