446
FXUS65 KPSR 251021
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
321 AM MST THU JUN 25 2026
KEY MESSAGES
- TEMPERATURES AROUND FIVE DEGREES ABOVE NORMAL WILL RESULT IN
LOCALIZED MAJOR HEAT RISK AGAIN TODAY WITH EXTREME HEAT
WARNINGS REMAINING IN PLACE.
- CRITICAL FIRE WEATHER CONDITIONS ARE THEN EXPECTED OVER MUCH OF
THE REGION FRIDAY THROUGH SUNDAY DUE TO DRY AND WINDY CONDITIONS
DEVELOPING.
- COOLING TEMPERATURES THIS WEEKEND WILL EVENTUALLY PUSH READINGS
TO SLIGHTLY BELOW NORMAL STARTING SUNDAY.
SHORT TERM /TODAY THROUGH FRIDAY/
ABOVE NORMAL TEMPERATURES WILL CONTINUE OVER THE NEXT COUPLE OF
DAYS WHILE THE SUBTROPICAL HIGH CENTERED TO OUR SOUTHEAST SLOWLY
WEAKENS AND EVENTUALLY SHIFTS FARTHER AWAY FROM THE REGION. VERY
WARM EARLY MORNING TEMPERATURES WITH MOST LOCATIONS WELL INTO THE
80S WILL QUICKLY RISE TO ABOVE 100 DEGREES MID MORNING BEFORE
TOPPING OUT BETWEEN 108-112 DEGREES ACROSS THE MAJORITY OF THE
LOWER DESERTS. EXTREME HEAT WARNINGS REMAIN IN EFFECT FOR PORTIONS
OF THE AREA THROUGH EARLY EVENING LARGELY DUE TO THE VERY WARM
OVERNIGHT TEMPERATURES COMBINING WITH HIGHS AROUND FIVE DEGREES
ABOVE NORMAL.
THE MODEST MID-LEVEL MOISTURE THAT HAS BEEN PRESENT OVER THE PAST
DAY OR TWO IS STILL RESULTING IN SOME ISOLATED LIGHT SHOWER
ACTIVITY FROM TIME TO TIME, BUT VERY DRY AIR IN THE LOWER LEVELS
HAS KEPT MUCH OF THE ACTIVITY FROM REACHING THE GROUND. THE
LINGERING MOISTURE MAY HAVE MORE OF AN IMPACT TODAY AS THE HIGH
WEAKENS AND SUBSIDENCE DECREASES. HI-RES GUIDANCE LARGELY AGREES
CONVECTION WILL BE MORE EXPANSIVE TODAY, BUT ONLY ACROSS THE
EASTERN ARIZONA HIGH TERRAIN. ANY CONVECTION IS STILL EXPECTED TO
BE HIGH-BASED AND SHOULD NOT AMOUNT TO MUCH PRECIPITATION. DRIER
AIR IS ALREADY BEGINNING TO WORK ITS WAY ACROSS SOUTHERN
CALIFORNIA AND WILL CONTINUE TO MAKE EASTWARD PROGRESS THROUGH
MUCH OF ARIZONA TONIGHT INTO FRIDAY. AS H5 HEIGHTS CONTINUE TO
LOWER INTO FRIDAY, FORECAST HIGHS DIP A BIT FURTHER WITH READINGS
MORE IN A 106-110 DEGREE RANGE.
THE MAIN FORECAST CONCERN WILL SHIFT AWAY FROM THE HEAT TO
INCREASING FIRE DANGER STARTING FRIDAY. A LARGE PACIFIC TROUGH
WILL SPREAD OVER THE NORTHWESTERN U.S. TODAY AND THEN OVER THE
ENTIRE WESTERN U.S. FRIDAY INTO SATURDAY. THE INCOMING TROUGH WILL
BRING GRADUAL HEIGHT FALLS ACROSS THE DESERT SOUTHWEST STARTING
FRIDAY AS WELL AS A TIGHT PRESSURE GRADIENT WHICH WILL LAST FOR
SEVERAL DAYS. WINDS WILL BECOME BREEZY TO LOCALLY WINDY ON FRIDAY
AND AS THE ATMOSPHERE DRIES OUT, HUMIDITIES WILL DROP TO CRITICAL
LEVELS FRIDAY AFTERNOON. RED FLAG WARNINGS HAVE BEEN POSTED FOR
THE LOWER CO RIVER VALLEY AND OVER THE ARIZONA HIGH TERRAIN WHERE
CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED STARTING LATE FRIDAY
MORNING. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED
ACROSS THE REST OF THE AREA.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
THE LARGE PACIFIC TROUGH WILL BE THE DOMINANT WEATHER FEATURE
ACROSS THE WESTERN U.S. OVER THE WEEKEND AND LIKELY EVEN THROUGH
THE FIRST HALF OF NEXT WEEK. THE DEEP LOW WITH H5 HEIGHTS
BRIEFLY REACHING NEAR CLIMATOLOGICAL RECORD LOWS OVER THE GREAT
BASIN LATE SATURDAY INTO SUNDAY WILL KEEP THE PRESSURE GRADIENT
ABNORMALLY TIGHT FOR LATE JUNE. STRONG GRADIENT WINDS OVER THE
ENTIRE REGION ON SATURDAY AND THEN MORE FOCUSED ACROSS THE EASTERN
HALF OF ARIZONA ON SUNDAY WILL POSE A MAJOR FIRE WEATHER THREAT.
GUSTS OF 25-40 MPH ARE EXPECTED TO IMPACT A GOOD PORTION OF THE
AREA THIS WEEKEND AS HUMIDITIES LOWER INTO A 5-15% RANGE. RED FLAG
CONDITIONS WILL IMPACT MUCH OF THE REGION ON SATURDAY AND THEN
OVER EASTERN ARIZONA ON SUNDAY. EXPECT RAPID SPREAD AND GROWTH OF
ANY NEW OR EXISTING FIRES. GUIDANCE EVENTUALLY SHOWS THE DEEP LOW
GRADUALLY FILLING EARLY NEXT WEEK, BUT REMAINING IN PLACE AT LEAST
THROUGH THE MIDDLE OF NEXT WEEK. WINDS WILL ALSO DIMINISH
SOMEWHAT EARLY NEXT WEEK, BUT BREEZY CONDITIONS ARE LIKELY TO
PERSIST.
THE PRESENCE OF THE LARGE TROUGH WILL BRING SOME RELIEF FROM THE
HEAT STARTING THIS WEEKEND WITH NBM FORECAST HIGHS DROPPING TO
BELOW NORMAL FIRST ACROSS THE WESTERN DESERTS ON SATURDAY AND THEN
AREAWIDE BY SUNDAY. DAYTIME HIGHS ANYWHERE FROM THE UPPER 90S TO
JUST OVER 100 DEGREES ARE EXPECTED ON SUNDAY AND MONDAY BEFORE
TEMPERATURES BEGIN TO SLOWLY RISE BACK CLOSER TO NORMAL AT SOME
POINT DURING THE LATTER HALF OF NEXT WEEK. OVERNIGHT LOWS WILL
ALSO BECOME QUITE PLEASANT WITH READINGS AS LOW AS THE MID 60S
ACROSS THE WESTERN DESERTS TO THE LOW TO MID 70S OVER THE REST OF
THE LOWER DESERTS.
AVIATION
UPDATED AT 1000Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION CONCERNS ARE EXPECTED THROUGH THURSDAY NIGHT.
WINDS WILL FOLLOW DIURNAL TRENDS WITH GUSTS THIS AFTERNOON UPWARDS
OF AROUND 20 KT. CAN'T RULE OUT SOME VERY HIGH BASED ISOLATED
LIGHT SHOWERS THROUGH THIS AFTERNOON, BUT NO IMPACTS ARE EXPECTED
FOR THE AREA TERMINALS. SCT TO SOMETIMES BKN MID-LEVEL CLOUDS WILL
LAST THROUGH THE FIRST PART OF TODAY WITH CLEARING EXPECTED BY
THIS EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
THE MAIN AVIATION CONCERN WILL BE BREEZY TO WINDY CONDITIONS AT
EACH TERMINAL THIS AFTERNOON AND EVENING. UNTIL THEN W'RLY AND
S'RLY WINDS SHOULD BE FAVORED AT KIPL AND KBLH RESPECTIVELY. GUSTS
25-30 KT WILL THEN BECOME COMMON LATER IN THE PERIOD, WITH
STRONGER GUSTS UPWARDS 35 KT POSSIBLE AT KIPL. FEW MID-LEVEL
CLOUDS ARE LIKELY TO CLEAR BY THIS AFTERNOON.
FIRE WEATHER
ELEVATED FIRE DANGER WILL CONTINUE TODAY DUE TO LOW HUMIDITY,
VERY WARM TEMPERATURES, AND AFTERNOON UPSLOPE/UPVALLEY BREEZY
CONDITIONS WITH CRITICAL CONDITIONS DEVELOPING FRIDAY. RED FLAG
WARNINGS HAVE BEEN ISSUED FOR FRIDAY THROUGH SUNDAY FOR MUCH OF
THE AREA. EXPECT MINRHS TODAY INTO THE SINGLE DIGITS ACROSS THE
WESTERN DISTRICTS, BUT CLOSER TO 20% IN THE EAST. THESE VALUES
WILL FALL CLOSER TO 5-15% STARTING FRIDAY AND STAY IN THIS RANGE
FOR SEVERAL DAYS. WINDS WILL GENERALLY REMAIN TERRAIN DRIVEN
TODAY WITH UPSLOPE GUSTS DURING THE LATTER HALF OF THE AFTERNOON
PEAKING AROUND 25 MPH. WINDS WILL INCREASE STARTING FRIDAY WITH
GUSTS INTO A 20-35 MPH RANGE AND LOCALLY HIGHER OVER HIGHER
TERRAIN AREAS. WINDS ARE LIKELY TO PEAK ON SATURDAY WITH GUSTS
COMMONLY REACHING 25-40 MPH. THESE WINDY AND DRY CONDITIONS WILL
COMBINE WITH THE VERY DRY FUELS TO CREATE A RISK OF EXTREME FIRE
BEHAVIOR. TEMPERATURES WILL COOL OFF THIS WEEKEND REACHING TO
SLIGHTLY BELOW NORMAL STARTING SUNDAY. WINDS ARE EXPECTED TO
GRADUALLY DIMINISH NEXT MONDAY INTO TUESDAY.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ530-532-
533-537-540-542>544-546-548-550-551.
RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM MST SATURDAY FOR
AZZ131.
RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM MST SUNDAY FOR AZZ133.
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT THIS EVENING FOR CAZ562-566-
567-569.
RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM PDT SATURDAY FOR
CAZ231.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...RW/KUHLMAN
FIRE WEATHER...KUHLMAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page