359
FXUS65 KPSR 280546
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1046 PM MST MON APR 27 2026
UPDATE
06Z AVIATION DISCUSSION.
KEY MESSAGES
- TEMPERATURES WILL WARM TOWARD SEASONAL NORMALS STARTING
TUESDAY, LIKELY STAYING THERE FOR THE REST OF THE WORKWEEK.
HOTTER TEMPERATURES WITH LOWER DESERT HIGHS INTO THE NINETIES
LOOK POSSIBLE BY THE WEEKEND.
- A WEATHER SYSTEM IS LIKELY TO BRING RAIN CHANCES TO PORTIONS OF
THE REGION ON OR AROUND THURSDAY, BUT THE TIMING AND POTENTIAL
RAINFALL AMOUNTS ARE STILL QUITE UNCERTAIN.
SHORT TERM /TODAY THROUGH WEDNESDAY/
TRANQUIL CONDITIONS WILL BE THE NORM THROUGH THE FRONT HALF OF
THE WEEK UNDER DRY QUASI-ZONAL WESTERLY FLOW. SUB-TROPICAL HIGH
PRESSURE WILL BEGIN TO NUDGE ITS WAY NORTHWARD OVER THE NEXT FEW
DAYS, BUT BEFORE IT BECOMES THE MORE DOMINANT FEATURE, THERE IS
STILL SOME LINGERING TROUGHING AROUND THE GREAT BASIN TO BE DEALT
WITH. AS THIS TRANSITION EVOLVES, THE REGIONAL THERMAL PROFILE
WILL TAKE SOME TIME TO CATCH UP, SO HIGH TEMPERATURES TODAY WILL
ACTUALLY CONTINUE THE BRIEF TREND OF RUNNING BELOW NORMAL FOR THIS
TIME OF YEAR. READINGS FOR THE LOWER DESERTS WILL RANGE FROM THE
UPPER 70S TO LOWER 80S, WHILE HIGHER TERRAIN LOCATIONS CAN EXPECT
LOWER TO MIDDLE 70S.
HEIGHTS ALOFT WILL TREND UPWARDS HEADING INTO TUESDAY AS THE
PREVIOUSLY MENTIONED RIDGE AMPLIFIES SLIGHTLY. HOWEVER, EVEN THOUGH
THERE WILL BE A GOOD 4-7 DEGREE JUMP IN DAY-TO-DAY TEMPERATURES,
AFTERNOON HIGHS SHOULD REMAIN RIGHT AROUND, TO EVEN SLIGHTLY BELOW,
NORMAL. THIS IS IN PART TO THE SCUFFLE BETWEEN THE COOLER AIR THAT
WILL REMAIN TO OUR NORTH AND THAT BUILDING HIGH PRESSURE. NOT MUCH
CHANGE IS EXPECTED IN THE HEIGHT FIELD FOR WEDNESDAY, BUT
TEMPERATURES ALOFT SHOULD BE CAUGHT UP BY THEN TO BUMP REGIONAL
SURFACE READINGS MORE TOWARD THE UPPER 80S TO AROUND 90 DEGREES
FOR LOWER DESERT COMMUNITIES. THE ONLY OTHER NOTABLE CHANGE DURING
THE NEXT THREE DAYS OR SO WILL BE AN INCREASE IN HIGH CLOUDS FOR
THE MIDDLE OF THE WEEK AS A CLOSED LOW MEANDERS OVER THE EASTERN
PACIFIC. THAT DISTURBANCE WILL HAVE A GREATER INFLUENCE ON OUR
FORECAST AREA DURING THE BACK HALF OF THE WEEK.
LONG TERM /THURSDAY THROUGH SUNDAY/
THURSDAY MAY BE SHAPING UP TO BE AN INTERESTING WEATHER DAY ACROSS
PORTIONS OF ARIZONA IF THE PACIFIC WEATHER SYSTEM PASSES CLOSE
ENOUGH OR EVEN ACROSS SOUTHERN ARIZONA. MODEL UNCERTAINTY IS STILL
SOMEWHAT HIGH WITH THE GEFS INDICATING A SLIGHTLY STRONGER SYSTEM
WITH MORE MOISTURE GETTING PULLED NORTHWARD INTO OUR AREA COMPARED
TO THE EPS. TIMING DIFFERENCES ARE ALSO THERE WITH THE EPS BEING
AROUND 12 HOURS BEHIND THE GEFS AND CMCE, BUT FOR NOW SOMETIME
THURSDAY LOOKS TO BE THE BEST CHANCE FOR ANY RAIN CHANCES. THE
TRACK OF THE LOW WILL ALSO COME INTO PLAY AS GUIDANCE SHOWS THE
LOW CENTER MOVING ALONG THE ARIZONA/MEXICO BORDER. ANY SHIFT
TOWARD THE SOUTH WOULD BE DETRIMENTAL FOR RAIN CHANCES, WHILE A
SHIFT MORE INTO ARIZONA WOULD BE MORE IDEAL.
UPPER LEVEL MOISTURE WILL ADVECT INTO THE REGION FROM THE SOUTH
SOUTHWEST ON WEDNESDAY, WITH MOISTURE GRADUALLY LOWERING WITH TIME
AS THE DISTURBANCE NEARS OUR AREA ON THURSDAY. ENSEMBLES DO
MOSTLY AGREE ON PWATS INCREASING ON THURSDAY TO AROUND 0.60-0.75",
OR 150-175% OF NORMAL WITH SOME MEMBERS EXCEEDING 1.00".
INITIALLY, SOME VERY HIGH-BASED SHOWERS SHOULD BECOME POSSIBLE BY
THURSDAY MORNING FROM PHOENIX AND AREAS THE EAST AND SOUTHEAST,
BUT VERY DRY AIR IN THE LOW LEVELS IS LIKELY TO PROHIBIT ANY
MEASURABLE RAINFALL. IT SHOULD NOT BE UNTIL THE AFTERNOON/EVENING
HOURS WHEN MOISTURE IMPROVES ENOUGH WITHIN THE LOW AND MID LEVELS
AND FORCING REACHES ITS PEAK FOR SHOWERS AND POTENTIALLY SOME
THUNDERSTORMS TO AFFECT THE AREA. SO FAR MOISTURE WITHIN THE LOWER
LEVELS LOOKS QUITE MEAGER, BUT IT WOULD NOT BE SURPRISING TO HAVE
ENOUGH MOISTURE AND INSTABILITY IN THE MID-LEVELS FOR SOME
CONVECTIVE ACTIVITY TO OCCUR. SOME ENSEMBLE MEMBERS ARE PICKING UP
ON THE CONVECTIVE POTENTIAL INDICATING A POTENTIAL OF LOCALIZED
QPF AMOUNTS OF A HALF AN INCH OR MORE. ADDITIONALLY, ANY
THUNDERSTORMS THAT MAY DEVELOP COULD BRING STRONG GUSTY WINDS WITH
THE POTENTIAL FOR BLOWING DUST. POPS REMAIN SOMEWHAT LOW DUE TO
THE UNCERTAINTY WITH 10-20% ACROSS THE WESTERN LOWER DESERTS,
25-40% OVER THE SOUTH-CENTRAL ARIZONA LOWER DESERTS TO AS HIGH AS
44-55% OVER THE EASTERN ARIZONA HIGH TERRAIN.
TEMPERATURES SHOULD DIP AGAIN INTO OR JUST BELOW THE NORMAL RANGE
ON THURSDAY DUE TO THE WEATHER SYSTEM SKIRTING BY TO OUR SOUTH,
BUT THE SLIGHT COOL DOWN IS LIKELY TO BE SHORT-LIVED. ONCE THE
SYSTEM MOVES EAST SOUTHEAST OF THE REGION BY AROUND FRIDAY, UPPER
LEVEL RIDGING SHOULD BEGIN TO FILTER IN FROM THE WEST. WHETHER THE
WARMER TEMPERATURES MOVE IN ALREADY ON FRIDAY OR WAIT UNTIL
SATURDAY IS STILL UNCERTAIN, BUT AT THE VERY LEAST THE LOWER
DESERTS SHOULD REACH INTO THE LOW TO MID 90S BY SATURDAY. THE 90S
FOR HIGHS ARE FORECAST TO PERSIST INTO SUNDAY AND POSSIBLY INTO
NEXT MONDAY, BUT NBM GUIDANCE SHOWS ANOTHER SLIGHT COOL DOWN MAY
OCCUR EARLY NEXT WEEK BRINGING TEMPERATURES BACK INTO THE NORMAL
RANGE.
AVIATION
UPDATED AT 0545Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION CONCERNS ARE ANTICIPATED THROUGH THE FORECAST PERIOD.
WINDS WILL FOLLOW TYPICAL DIURNAL TRENDS, WITH A LATER THAN USUAL
EASTERLY SHIFT AT KPHX OVERNIGHT. SPEEDS SHOULD REMAIN AOB 8 KTS
AT ALL TERMINALS. SKIES WILL REMAIN GENERALLY CLEAR THROUGH EARLY
MONDAY BEFORE HIGH CLOUDS INCREASE IN COVERAGE BY THE AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION CONCERNS ARE ANTICIPATED THROUGH THE FORECAST PERIOD.
W-NW WINDS WILL PREVAIL AT KIPL, WHILE S-SW WINDS CONTINUE AT KBLH
OVERNIGHT. DIRECTIONS WILL BECOME MORE N-NW AT BOTH TERMINALS
EARLY TUESDAY MORNING. ANY LINGERING GUSTS SHOULD SUBSIDE LATE
TONIGHT AT KIPL WITH SPEEDS FALLING TO 8 KTS OR LESS AT BOTH
TERMINALS OVERNIGHT. MOSTLY CLEAR SKIES WILL PREVAIL TONIGHT WITH
INCREASING HIGH CLOUDS ANTICIPATED MONDAY MORNING.
FIRE WEATHER
DRYING CONDITIONS ALONG WITH A SLIGHT WARM UP ARE EXPECTED THROUGH
TUESDAY. LOOK FOR MINRHS TO FALL TO 15-20% THIS AFTERNOON AND
10-15% ON TUESDAY, WHILE OVERNIGHT RECOVERIES TRANSITION FROM GOOD
TO POOR TO FAIR (25-40%) BY TUESDAY NIGHT. WINDS WILL BE ON THE
LIGHT SIDE FOLLOWING DIURNAL PATTERNS WITH ONLY SOME OCCASIONAL
UPSLOPE BREEZINESS DURING THE AFTERNOON HOURS. ANOTHER WEATHER
SYSTEM IS THEN FORECAST TO MOVE THROUGH THE REGION DURING THE
LATER HALF OF THE WORKWEEK LEADING TO INCREASED RH AND CHANCES
FOR RAIN AND POSSIBLY SOME ISOLATED THUNDERSTORMS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM..RW
LONG TERM...KUHLMAN
AVIATION...SALERNO
FIRE WEATHER...KUHLMAN
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