328
FXUS65 KPSR 100529
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1029 PM MST SAT MAY 9 2026
UPDATE...UPDATED 06Z AVIATION DISCUSSION
KEY MESSAGES
- AN EXTREME HEAT WARNING WILL BE IN EFFECT FOR THE PHOENIX METRO
SUNDAY THROUGH TUESDAY AND PORTIONS OF THE WESTERN DESERTS
SUNDAY AND MONDAY.
- MODERATE HEATRISK WILL IMPACT THE MAJORITY OF THE AREA THROUGH
THE FIRST HALF OF NEXT WEEK WITH ISOLATED MAJOR HEATRISK SUNDAY
THROUGH TUESDAY.
- MONDAY IS EXPECTED TO BE THE HOTTEST DAY WITH LOWER DESERT HIGH
TEMPERATURES PEAKING BETWEEN 105 AND 110 DEGREES.
SHORT TERM /TODAY THROUGH MONDAY/
UPPER LEVEL RIDGING IS NOW FULLY IN PLACE OVER WESTERN CONUS, WITH
THE AXIS CENTERED OVER THE PACIFIC NW STATES (WA,OR,CA). THROUGHOUT
THIS WEEKEND THE RIDGE WILL MOVE FURTHER INLAND AND IS EXPECTED TO
BE FULLY OVER THE DESERT SW BY LATE SUNDAY INTO MONDAY. H5 HEIGHTS
WILL STEADILY CLIMB FROM 582-584 TODAY TO BETWEEN 588-591 BY
SUNDAY/MONDAY, IN RESPONSE TEMPERATURES WILL ALSO STEADILY WARM,
WITH READINGS TODAY BETWEEN 102-104 DEGREES IN THE PHOENIX AREA TO
103-106 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA.
BY SUNDAY TEMPERATURES WILL INCREASE 1-3 DEGREES FROM TODAY, AND
HIGHS ARE EXPECTED TO PEAK ON MONDAY TO BE BETWEEN 106-109 DEGREES
IN THE PHOENIX AREA TO 108-110 DEGREES ACROSS SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA. BOTH SUNDAY AND MONDAY WILL
REPRESENT A HIGH-END MODERATE HEATRISK FOR NEARLY ALL LOCATIONS
ACROSS SOUTHEAST CALIFORNIA THROUGH SOUTHERN AND CENTRAL ARIZONA
WITH MONDAY HAVING THE HIGHEST AREAL COVERAGE (~25%) OF MAJOR
HEATRISK. WITH THAT BEING SAID, AN EXTREME HEAT WARNING REMAINS IN
EFFECT FOR WESTERN PORTIONS OF IMPERIAL COUNTY AND FOR THE
PHOENIX METRO FOR SUNDAY AND MONDAY, WITH THE IMPERIAL VALLEY AND
THE LOWER COLORADO RIVER VALLEY ZONES INCLUDED IN THE WARNING FOR
JUST MONDAY.
LONG TERM /TUESDAY THROUGH FRIDAY/
A GRADUAL CHANGE IN THE UPPER LEVEL PATTERN WILL HELP TO BRING
SOME MODEST HEAT RELIEF BY THE LATTER HALF OF NEXT WEEK. THE FIRST
CHANGE WILL BE A WEAK TROUGH THAT IS FORECAST TO DEVELOP JUST
WEST OF SOUTHERN BAJA ON SUNDAY BEFORE TRACKING NORTHWARD ALONG
THE CALIFORNIA COASTLINE ON TUESDAY. THIS FEATURE IS NOT EXPECTED
TO BRING BIG CHANGES TO OUR REGION, BUT IT WILL LEAD TO INCREASED
SOUTHERLY FLOW AND MOISTURE WHILE ALSO SOMEWHAT DISPLACING THE
RIDGE TO OUR EAST. MODELS SHOW DECENT MOISTURE ADVECTION MAINLY
ABOVE 15K FEET INTO OUR REGION STARTING MONDAY NIGHT, BUT MORE SO
TUESDAY NIGHT INTO WEDNESDAY. TUESDAY MAY BRING SOME SPARSE
HIGHER LEVEL CLOUDS, BEFORE THICKER AND MORE CLOUD COVERAGE IS
LIKELY TO MOVE IN ON WEDNESDAY.
THE TRACK OF THE SHORTWAVE TROUGH ACROSS CALIFORNIA TUESDAY AND
WEDNESDAY IS ALSO EXPECTED TO LOWER HEIGHTS ACROSS THE DESERT
SOUTHWEST, BUT ANY COOLING WILL BE SLOW TO OCCUR. TUESDAY'S
FORECAST HIGHS ARE VERY SIMILAR TO SUNDAY'S EXPECTED READINGS, BUT
BY WEDNESDAY HIGHS ARE LIKELY TO FALL BACK TO JUST ABOVE 100
DEGREES. THE LATEST NBM HAS COME IN SLIGHTLY WARMER FOR AFTERNOON
HIGHS ON TUESDAY FOR THE PHOENIX METRO, RESULTING IN AREAS OF
MAJOR HEATRISK CONTINUING. THUS, WE HAVE ELECTED TO EXTEND THE
EXTREME HEAT WARNING FOR THE PHOENIX METRO THROUGH TUESDAY
EVENING. A LARGER, BUT WEAKENING PACIFIC LOW IS THEN EXPECTED TO
REACH THE CALIFORNIA COAST SOMETIME WEDNESDAY INTO WEDNESDAY NIGHT
BEFORE MOVING EAST NORTHEAST THROUGH NEVADA AND UTAH ON THURSDAY
AND/OR FRIDAY OF NEXT WEEK. THIS DISTURBANCE SHOULD CONTINUE TO
AID IN WEAK HEIGHT FALLS ACROSS THE DESERT SOUTHWEST LATE NEXT
WEEK POTENTIALLY DROPPING DAYTIME HIGHS INTO THE UPPER 90S, OR
AROUND FIVE DEGREES ABOVE NORMAL.
AVIATION
UPDATED AT 0525Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION WEATHER CONCERNS UNDER MOSTLY CLEAR SKIES CAN BE
EXPECTED THROUGHOUT THE TAF PERIOD. THE OVERALL WIND PATTERN WILL
CONTINUE TO EXHIBIT THE TYPICAL DIURNAL TENDENCIES WITH SPEEDS
GENERALLY AOB 10 KTS, ALTHOUGH SOME OCCASIONAL AFTERNOON/EARLY
EVENING GUSTS UPWARDS OF 20 KTS WILL BE POSSIBLE ONCE AGAIN ON
SUNDAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION WEATHER CONCERNS UNDER CLEAR SKIES CAN BE EXPECTED
THROUGHOUT THE TAF PERIOD. AT KIPL, WINDS WILL GENERALLY BE OUT OF
THE WEST, WITH A PERIOD OF SOUTHEASTERLY WINDS DURING THE
AFTERNOON. AT KBLH, WINDS WILL GENERALLY FLUCTUATE BETWEEN THE
SOUTH AND SOUTHWEST WITH PERIODS OF LIGHT VARIABILITY DURING THE
OVERNIGHT AND MORNING HOURS. OVERALL WIND SPEEDS WILL BE AOB 10
KTS.
FIRE WEATHER
HOT AND DRY CONDITIONS WILL PREVAIL THROUGH THIS WEEKEND AND WELL
INTO NEXT WEEK WITH THE LOWER DESERT HIGHS TOPPING 100 DEGREES
THROUGH AT LEAST TUESDAY. WITH AFTERNOON HIGHS WARMING 10-15
DEGREES ABOVE NORMAL, MINIMUM HUMIDITY LEVELS WILL MOSTLY FALL
INTO THE SINGLE DIGITS EACH DAY. CORRESPONDINGLY, OVERNIGHT
RECOVERY WILL ONLY BE IN A POOR TO FAIR 20-35% RANGE. WINDS WILL
BE VERY TYPICAL FOR MID MAY THROUGH MONDAY WITH SOME GUSTS AROUND
20 MPH COMMON DURING MID/LATE AFTERNOON. THE COMBINATION OF THE
HOT TEMPERATURES, VERY LOW RHS, DRY FUELS, AND BREEZY CONDITIONS
FOCUSED DURING THE LATE AFTERNOON HOURS SHOULD RESULT IN ELEVATED
FIRE WEATHER CONDITIONS FOR PORTIONS OF THE AREA.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING FROM 11 AM TO 8 PM MST MONDAY FOR AZZ530-
532.
EXTREME HEAT WARNING FROM 10 AM SUNDAY TO 8 PM MST TUESDAY FOR
AZZ537-540-542>544-546-548-550-551.
CA...EXTREME HEAT WARNING FROM 11 AM TO 8 PM PDT MONDAY FOR CAZ567-
569-570.
EXTREME HEAT WARNING FROM 10 AM SUNDAY TO 8 PM PDT MONDAY FOR
CAZ562-563-566.
SHORT TERM...RYAN/KUHLMAN
LONG TERM...KUHLMAN
AVIATION...LOJERO
FIRE WEATHER...KUHLMAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page