733
FXUS65 KPSR 120048
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
548 PM MST TUE AUG 11 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- BETTER MOISTURE AND MORE FAVORABLE CONDITIONS FOR MONSOON STORM
DEVELOPMENT IS EXPECTED THROUGH MIDWEEK WITH THE MOST
WIDESPREAD ACTIVITY ACROSS SOUTH-CENTRAL AND EASTERN ARIZONA.
- LOCALLY HEAVY RAINFALL AND GUSTY THUNDERSTORM WINDS WILL REMAIN
POSSIBLE THROUGH THURSDAY BEFORE DRYING CONDITIONS ENDS RAIN
CHANCES AS EARLY AS FRIDAY.
- COOLING TEMPERATURES ARE EXPECTED THROUGH MIDWEEK, BRIEFLY
FALLING TO BELOW NORMAL WEDNESDAY THROUGH FRIDAY.
SHORT TERM /TODAY THROUGH THURSDAY/
GOES MID-LEVEL WV IMAGERY AND RAP40 500MB ANALYSIS CONTINUE TO
SHOW THE UPPER LEVEL PATTERN WITH SOUTHEASTERLY FLOW ALOFT AND THE
CORE OF THE HIGH PRESSURE OVER THE FOUR CORNERS REGION. BY
WEDNESDAY THE HIGH WILL BE PUSHED EASTWARDS TOWARDS TEXAS WHILE A
TROUGH DEEPENS ACROSS THE WESTERN COAST, AND IS EXPECTED TO REMAIN
IN PLACE THROUGH THE END OF THE WEEK, BRINGING SOUTHWESTERLY FLOW
ALOFT. THIS WILL HELP GRADUALLY DRY THE REGION OUT ESPECIALLY
TOWARDS THE LATER HALF OF THE WEEK AND HEADING INTO THE WEEKEND.
OTHERWISE FOR THE REST OF TODAY, A MOSTLY OVERTURNED ATMOSPHERE
FROM THE PAST ACTIVE NIGHTS WILL LIKELY TO LIMIT SHOWER AND
THUNDERSTORM ACTIVITY COMPARED TO THE LAST COUPLE OF DAYS. HREF
SHOWS A 30-50% CHANCE OF STORM DEVELOPMENT IN THE EASTERN HIGH
TERRAIN WITH ONLY A 10-20% CHANCE OF ACTIVITY DEVELOPING TONIGHT
AND INTO THE OVERNIGHT PERIOD FOR THE LOWER DESERTS. THAT BEING
SAID THE MAIN IMPACT/CONCERN FOR THE LOWER DESERTS WILL BE BREEZY
TO WINDY CONDITIONS FROM OUTFLOWS, THATS IF THEY CAN SURVIVE INTO
THE LOWER DESERTS.
UNCERTAINTY REMAINS HIGH FOR WEDNESDAY AS THE WEAK TROUGH BEGINS
TO ENTER WESTERN PORTIONS OF THE REGION TURNING THE FLOW OUT OF
THE SOUTH SOUTHWEST. THE INCOMING TROUGH IS EXPECTED TO INCREASE
UPPER LEVEL FORCING ACROSS MUCH OF THE AREA FOR WEDNESDAY INTO
EARLY THURSDAY, BUT AS THE FLOW SHIFTS OUT OF THE SOUTH SOUTHWEST
SOME DRY AIR WILL BEGIN TO FILTER INTO WESTERN AND THEN SOUTH-
CENTRAL ARIZONA. HOWEVER, PLENTY OF MOISTURE WILL REMAIN FROM
AROUND PHOENIX AND AREAS TO THE EAST AND NORTHEAST OF PHOENIX. THE
BIGGEST QUESTION WILL BE THE AREAS OF FOCUS FOR SHOWER AND STORMS
FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING. GUIDANCE
INDICATES THE BEST CHANCES FROM NORTHERN AND EASTERN PORTIONS OF
PHOENIX INTO THE HIGHER TERRAIN WITH POPS OF 50-70% WITH
DECREASING CHANCES TO THE SOUTH AND WEST AS THAT DRIER AIR ENTERS
THE REGION. A FASTER THAN NORMAL STORM MOVEMENT SHOULD HELP TO
LIMIT THE HEAVY RAINFALL THREAT, BUT THE AFOREMENTIONED FACTORS
COULD STILL LEAD TO SOME INSTANCES OF FLASH FLOODING, ESPECIALLY
IN NE AZ. THE ACTIVITY IS LIKELY TO PERSIST DURING THE OVERNIGHT
HOURS/THURSDAY MORNING, BUT THE THREAT FOR HEAVY RAINFALL IS
LIKELY TO GRADUALLY DECREASE.
THE GOOD NEWS, OUTSIDE OF PRECIPITATION POTENTIAL, WILL BE THAT
THIS ACTIVITY WILL LEAD TO AMPLE CLOUD COVERAGE OVER THE NEXT FEW
DAYS, HELPING TEMPERATURES TO BE NEAR NORMAL TODAY, THEN 3F-6F
DEGREES BELOW NORMAL STARTING WEDNESDAY. THIS WILL LEAD TO A LARGE
MAJORITY OF THE REGION DROPPING TO MINOR HEATRISK WITH THE
EXCEPTION OF A SMALL CORNER OF SE CA, WHERE LOCALIZED AREAS OF
MODERATE WILL REMAIN. ADDITIONALLY THE MORNING LOW TEMPERATURES
WILL CONTINUE TO BE NEAR TO SLIGHTLY BELOW NORMAL THROUGH OUT THE
REST OF THE WORK WEEK.
LONG TERM /FRIDAY THROUGH MONDAY/
DRYING IS EXPECTED TO PICK UP ACROSS THE AREA DURING THE LATTER
HALF OF THURSDAY WITH MOST OF THE SHOWER AND THUNDERSTORM
POTENTIAL SHIFTING TO OVER THE ARIZONA HIGH TERRAIN. BY FRIDAY,
ENOUGH DRY AIR IS EXPECTED TO FILTER INTO THE AREA TO COMPLETELY
END RAIN CHANCES ACROSS THE LOWER DESERTS WHILE LIMITED CHANCES
ARE FORECAST FOR THE HIGH TERRAIN. THE SUBTROPICAL HIGH IS
EXPECTED TO STAY CENTERED ACROSS THE SOUTHEASTERN U.S. THROUGH AT
LEAST THE WEEKEND WITH BROAD TROUGHING OVER MUCH OF THE WESTERN
U.S. THIS WILL KEEP DRY AIR IN PLACE THROUGH AT LEAST THE UPCOMING
WEEKEND WITH AT MOST SLIGHT CHANCES FOR AFTERNOON CONVECTION OVER
THE FAR EASTERN ARIZONA HIGH TERRAIN. ENSEMBLES DO SHOW THE
SUBTROPICAL HIGH BECOMING MORE ELONGATED LATE THIS WEEKEND WITH
HEIGHTS GRADUALLY INCREASING OVER OUR REGION. AS A RESULT,
TEMPERATURES ARE LIKELY TO CLIMB BACK TO AROUND OR EVEN A FEW
DEGREES ABOVE NORMAL BY SUNDAY OR MONDAY. THE NEXT POTENTIAL FOR
RAIN COULD COME AS EARLY AS NEXT MONDAY OR TUESDAY, BUT
UNCERTAINTY IS QUITE HIGH AT A WEEK AWAY.
AVIATION
UPDATED AT 0047Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
MAIN FORECAST CHALLENGE, AND POTENTIAL AVIATION IMPACT IS WHETHER
VCSH/VCTS WILL DEVELOP AT TERMINALS DURING THE TAF PERIOD.
THUNDERSTORM OUTFLOWS AND VCSH/VCTS ARE NOT EXPECTED THROUGH THIS
EVENING AND EARLY OVERNIGHT HOURS, BUT THERE ARE INDICATIONS HIGH-
BASED SHOWERS AND MAYBE A STORM DEVELOPS BETWEEN 10-18Z WEDNESDAY
MORNING. ADDITIONALLY, ISOLATED STORMS MAY DEVELOP IN THE METRO
AREA WEDNESDAY AFTERNOON. OTHERWISE, STORM ACTIVITY WEDNESDAY
AFTERNOON AND EVENING WILL MOSTLY STAY NORTH AND SOUTHEAST OF THE
METRO, WITH OUTFLOW WINDS MOST FAVORED FROM THE NORTH. PREVAILING
WEST WINDS WILL CONTINUE THROUGH MIDNIGHT AT MOST TERMINALS AND
THEN WILL TREND TOWARD E/SE EARLY WEDNESDAY MORNING. AN EARLY W/SW
WIND SHIFT IS EXPECTED WEDNESDAY, BY AROUND 16-17Z, WITH SPEEDS
INCREASING IN THE AFTERNOON UP TO 7-12 KTS WITH GUSTS UP TO 20
KTS. FEW TO SCT MID AND HIGH CLOUDS WILL BE COMMON THROUGH THE TAF
PERIOD.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
VCSH/VCTS NEAR BOTH TERMINALS WILL DISSIPATE OVER THE NEXT HOUR
AND THE NEXT CHANCE FOR VCSH/VCTS WILL BE BETWEEN 22-03Z WEDNESDAY
(10% CHANCE), WITH POTENTIAL FOR GUSTY OUTFLOW WINDS AS WELL.
OTHERWISE, WINDS WILL CONTINUE TO FAVOR S/SW AT KBLH AND S/SE AT
KIPL. WIND SPEEDS UP TO 7-12 KTS WILL BE COMMON AT BOTH TERMINALS
WITH GUSTS UP TO 20-25 KTS AT KBLH WEDNESDAY AFTERNOON. FEW TO
SCT CLOUDS WILL BE COMMON OVER THE AREA WITH LOWEST BASES DOWN TO
AROUND 10K FT AGL.
FIRE WEATHER
SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED EACH DAY
THROUGH MIDWEEK ACROSS THE HIGHER TERRAIN AREAS OF THE EASTERN
DISTRICTS, WITH SLIGHTLY LOWER CHANCES IN THE LOWER ELEVATIONS.
THE BEST CHANCES WILL FALL DURING THE LATTER HALF OF WEDNESDAY
INTO THURSDAY MORNING. AFTERNOON MINRHS WILL RANGE BETWEEN 25-35%
IN THE LOWER DESERTS AND BETWEEN 40-50% IN THE EASTERN HIGH
TERRAIN THROUGH WEDNESDAY WITH GOOD TO EXCELLENT OVERNIGHT
RECOVERIES. ASIDE FROM GUSTY AND ERRATIC WINDS NEAR THUNDERSTORMS,
THE OVERALL WIND PATTERN WILL FOLLOW THE DIURNAL TRENDS WITH
MODEST AFTERNOON UPSLOPE GUSTS. NEAR TO BELOW NORMAL TEMPERATURES
ARE EXPECTED THROUGH THE REST OF THE WEEK WITH DRYING CONDITIONS
BY FRIDAY AND LASTING THROUGH NEXT WEEKEND.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...RYAN/KUHLMAN
LONG TERM...KUHLMAN
AVIATION...BENEDICT
FIRE WEATHER...KUHLMAN
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