873
FNUS55 KPSR 180752
FWFPSR
FIRE WEATHER PLANNING FORECAST FOR SOUTHWEST AND SOUTH-CENTRAL
ARIZONA AND SOUTHEAST CALIFORNIA
NATIONAL WEATHER SERVICE PHOENIX AZ
1252 AM MST TUE AUG 18 2026
DISCUSSION
ABOVE NORMAL TEMPERATURES WITH A STEADY INCREASE IN LOW-LEVEL
MOISTURE IS ANTICIPATED OVER THE NEXT FEW DAYS. MOST LOWER DESERT
COMMUNITIES WILL SEE TEMPERATURES TOPPING OUT AROUND 110-113
DEGREES. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST
FOR THE HIGH TERRAIN TODAY WITH AN INCREASE IN COVERAGE EXPECTED
WEDNESDAY INTO THURSDAY. RELATIVE HUMIDITY VALUES OF 15-25% TODAY
WILL INCREASE TO 20-30% STARTING WEDNESDAY. OUTSIDE OF GUSTY AND
ERRATIC WINDS NEAR ANY THUNDERSTORM, OVERALL WINDS WILL 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.
AZZ132-182000-
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-
1252 AM MST TUE AUG 18 2026
TODAY
* SKY/WEATHER.....................SUNNY.
* MAX TEMPERATURE.................106-112.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................15-19 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 10 MPH IN THE MORNING
BECOMING SOUTHWEST IN THE AFTERNOON.
* WINDS...10000 FT MSL............SOUTHEAST 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.
* MIXING HEIGHT FOR PHOENIX.......11200 FT AGL.
* TRANSPORT WIND FOR PHOENIX......WEST 4 KNOTS.
* DISPERSION FOR PHOENIX..........FAIR.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLEAR.
* MIN TEMPERATURE.................82-92.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................41-61 PCT.
* 24 HR TREND..................16 PCT WETTER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHWEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............NORTHEAST 5 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
WEDNESDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................104-110.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................19-24 PCT.
* 24 HR TREND..................4 PCT WETTER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 10 MPH IN THE MORNING
BECOMING SOUTHWEST IN THE AFTERNOON.
* WINDS...10000 FT MSL............EAST 5 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
* MIXING HEIGHT FOR PHOENIX.......9000 FT AGL.
* TRANSPORT WIND FOR PHOENIX......WEST 9 KNOTS.
* DISPERSION FOR PHOENIX..........VERY GOOD.
EXTENDED
THURSDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-92. HIGHS 104-110. SOUTHWEST WINDS 5 TO
15 MPH.
FRIDAY
PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-92. HIGHS 105-111. SOUTH WINDS 5 TO
10 MPH.
SATURDAY
PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-92. HIGHS 104-111. SOUTH WINDS 5 TO
10 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 80-90. HIGHS 103-109.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 80-90. HIGHS 101-107.
AZZ131-CAZ231-182000-
YUMA/MARTINEZ LAKE AND VICINITY/LOWER COLORADO RIVER VALLEY AZ-
LOWER COLORADO RIVER VALLEY CA-
1252 AM MST TUE AUG 18 2026 /1252 AM PDT TUE AUG 18 2026/
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................108-113.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................15-21 PCT.
* 24 HR TREND..................3 PCT WETTER.
* 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.
* MIXING HEIGHT FOR YUMA..........7300 FT AGL.
* TRANSPORT WIND FOR YUMA.........SOUTH 8 KNOTS.
* DISPERSION FOR YUMA.............GOOD.
TONIGHT
* SKY/WEATHER.....................PARTLY CLOUDY.
* MIN TEMPERATURE.................83-88.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................46-70 PCT.
* 24 HR TREND..................23 PCT WETTER.
* 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.
WEDNESDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................106-111.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................22-27 PCT.
* 24 HR TREND..................6 PCT WETTER.
* 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..........6200 FT AGL.
* TRANSPORT WIND FOR YUMA.........SOUTH 10 KNOTS.
* DISPERSION FOR YUMA.............GOOD.
EXTENDED
THURSDAY
MOSTLY CLEAR. LOWS 83-88. HIGHS 106-111. SOUTH WINDS
5 TO 15 MPH.
FRIDAY
MOSTLY CLEAR. LOWS 84-89. HIGHS 108-113. SOUTH WINDS
5 TO 15 MPH.
SATURDAY
MOSTLY CLEAR. LOWS 84-89. HIGHS 108-113. SOUTH WINDS
5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR. LOWS 83-88. HIGHS 106-111.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 82-87. HIGHS 104-109.
AZZ133-182000-
SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS-
SOUTHERN TONTO NF/WEST SAN CARLOS BIA/SOUTH PORTION FT APACHE BIA/
CAZ-
1252 AM MST TUE AUG 18 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY. SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.
* MAX TEMPERATURE.................91-107.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................15-25 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHEAST 5 TO 15 MPH.
* WINDS...10000 FT MSL............EAST 5 TO 15 MPH.
* CHANCE OF PRECIP................0 PERCENT IN THE MORNING BECOMING
10 PERCENT IN THE AFTERNOON.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............6 PERCENT.
TONIGHT
* SKY/WEATHER.....................MOSTLY CLEAR.
* MIN TEMPERATURE.................67-84.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................40-59 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..NORTHEAST 5 TO 15 MPH.
* WINDS...10000 FT MSL............LIGHT AND VARIABLE.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
WEDNESDAY
* SKY/WEATHER.....................MOSTLY SUNNY. SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.
* MAX TEMPERATURE.................92-106.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................17-25 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHWEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............NORTH 5 TO 15 MPH IN THE MORNING
BECOMING LIGHT AND VARIABLE IN THE AFTERNOON.
* CHANCE OF PRECIP................0 PERCENT IN THE MORNING BECOMING
20 PERCENT IN THE AFTERNOON.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............17 PERCENT.
EXTENDED
THURSDAY
PARTLY CLOUDY WITH CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 65-84. HIGHS 92-106. NORTHWEST WINDS 5 TO
15 MPH.
FRIDAY
PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 65-83. HIGHS 92-107. NORTHEAST WINDS 5 TO
15 MPH.
SATURDAY
PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 66-83. HIGHS 92-107. NORTHEAST WINDS 5 TO
15 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 66-82. HIGHS 91-105.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 65-82. HIGHS 90-104.
CAZ232-182000-
IMPERIAL COUNTY AND EASTERN RIVERSIDE COUNTY-
1252 AM PDT TUE AUG 18 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................104-113.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................12-18 PCT.
* 24 HR TREND..................LITTLE CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTH 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTH 15 TO 25 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
TONIGHT
* SKY/WEATHER.....................PARTLY CLOUDY.
* MIN TEMPERATURE.................83-89.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................29-70 PCT.
* 24 HR TREND..................19 PCT WETTER.
* 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.
WEDNESDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................102-112.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................19-27 PCT.
* 24 HR TREND..................7 PCT WETTER.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHEAST 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
THURSDAY
MOSTLY CLEAR. LOWS 82-90. HIGHS 102-111. SOUTH WINDS
5 TO 15 MPH.
FRIDAY
MOSTLY CLEAR. LOWS 83-90. HIGHS 102-112. SOUTH WINDS
5 TO 15 MPH.
SATURDAY
MOSTLY CLEAR. LOWS 83-90. HIGHS 102-112. SOUTHWEST
WINDS 5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS. LOWS 82-89.
HIGHS 101-111.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 81-88. HIGHS 100-109.
CAZ230-182000-
JOSHUA TREE NATIONAL PARK-
1252 AM PDT TUE AUG 18 2026
TODAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................94-108.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................14-19 PCT.
* 24 HR TREND..................LITTLE RH CHANGE.
* WINDS - 20 FOOT...SLOPE/VALLEY..SOUTHWEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............SOUTHWEST 15 TO 25 MPH.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
TONIGHT
* SKY/WEATHER.....................PARTLY CLOUDY.
* MIN TEMPERATURE.................74-86.
* 24 HR TREND..................LITTLE CHANGE.
* MAX HUMIDITY....................27-34 PCT.
* 24 HR TREND..................3 PCT WETTER.
* WINDS - 20 FOOT...SLOPE/VALLEY..WEST 5 TO 15 MPH.
* WINDS...10000 FT MSL............LIGHT AND VARIABLE IN THE EVENING
BECOMING SOUTH 5 TO 15 MPH AFTER MIDNIGHT.
* CHANCE OF PRECIP................0 PERCENT.
* CWR (>= 0.10 IN)................0 PERCENT.
* CHANCE OF THUNDER...............0 PERCENT.
WEDNESDAY
* SKY/WEATHER.....................MOSTLY SUNNY.
* MAX TEMPERATURE.................93-107.
* 24 HR TREND..................LITTLE CHANGE.
* MIN HUMIDITY....................16-23 PCT.
* 24 HR TREND..................3 PCT WETTER.
* 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
THURSDAY
MOSTLY CLEAR. LOWS 74-86. HIGHS 92-106. SOUTHWEST
WINDS 5 TO 15 MPH.
FRIDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 74-86. HIGHS 92-106. SOUTHWEST WINDS 5 TO
15 MPH.
SATURDAY
MOSTLY CLEAR. LOWS 73-86. HIGHS 92-106. SOUTHWEST
WINDS 5 TO 15 MPH.
SUNDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 72-85. HIGHS 91-105.
MONDAY
MOSTLY CLEAR WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS 71-84. HIGHS 89-103.
8 TO 10 DAY OUTLOOK
TUESDAY AUGUST 25TH THROUGH THURSDAY AUGUST
27TH: ABOVE NORMAL TEMPERATURES AND NEAR TO ABOVE MEDIAN PRECIPITATION.
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