236
FXUS65 KPSR 200011
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
511 PM MST SUN JUL 19 2026
UPDATE
UPDATED AVIATION DISCUSSION
KEY MESSAGES
- DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS WILL EXIST THROUGH
THE UPCOMING WEEK, MOST FAVORABLE IN THE ARIZONA HIGH COUNTRY.
- THUNDERSTORM CHANCES MAY BE MORE FAVORABLE (30-40%) FOR THE LOWER
DESERTS ON TUESDAY THROUGH THURSDAY.
- TEMPERATURES WILL GRADUALLY CLIMB TO NEAR NORMAL THROUGH THE
UPCOMING WORKWEEK WITH AREAS ALONG AND WEST OF THE COLORADO
RIVER VALLEY TOPPING OUT ABOVE 110 DEGREES BY MID-WEEK,
RESULTING IN A LOCALLY MAJOR HEATRISK.
SHORT TERM /TODAY THROUGH MONDAY/
LATEST SATELLITE IMAGERY SHOWING WELL DEFINED MCV CIRCULATION MOVING
SLOWLY WEST ACROSS YAVAPAI COUNTY. THIS HAS RESULTED IN
CONSIDERABLE CLOUDINESS ACROSS CENTRAL AND SOUTHWEST AZ TO START
THE DAY. NOT MUCH RAINFALL OUTSIDE OF SOME LIGHT SHOWERS OR
SPRINKLES ACROSS PORTIONS OF MARICOPA, LA PAZ AND YUMA COUNTIES. LOW
LEVEL WATER VAPOR IMAGERY AND 500 MB STREAMLINE ANALYSIS REVEALS
AN ELONGATED AREA OF HIGH PRESSURE ENCOMPASSING THE INTERMOUNTAIN
WEST AND THE CENTRAL PLAINS. MEANWHILE, THE DESERT SOUTHWEST
REMAINS TO THE SOUTH OF THE HIGH PRESSURE CENTER ALLOWING DEEP
EASTERLY FLOW TO PREVAIL WITH EMBEDDED SHORT WAVES TO ENHANCE
STORM CHANCES AT TIMES. ANOTHER ROUND OF STORMS WILL MATERIALIZE
THIS AFTERNOON, BUT ARE EXPECTED TO AGAIN REMAIN RELEGATED TO THE
HIGHER TERRAIN OF S GILA AND YAVAPAI COUNTIES WITH ONLY A 10-30%
CHANCE OF A WEAK OUTFLOW MAKING IT DOWN TO THE LOWER DESERTS.
REMNANT CLOUDS AND MAYBE SPRINKLES/LIGHT SHOWERS EXPECTED AGAIN
ACROSS THE LOWER DESERTS LATE TONIGHT, MOVING OUT TO WEST EARLY
MONDAY MORNING.
ON MONDAY, THE POSITING OF THE SUBTROPICAL HIGH WILL NOT
CHANGE MUCH, REMAINING CENTERED OVER THE INTERMOUNTAIN WEST AND
SOUTHERN ROCKIES. THIS WILL ALLOW DEEP EASTERLY FLOW TO CONTINUE
OVER AZ. THE MOST NOTICEABLE DIFFERENCE WILL BE A SLIGHT SHIFT WWD
OF AN EASTERLY WAVE/INVERTED TROUGH WHICH HAS BEEN SITTING OVER W
TX. THIS FEATURE WILL CONTINUE TO SLOWLY PROGRESS INTO FAR W TX
AND N MX BY MONDAY AFTERNOON. AHEAD OF THIS FEATURE, WE COULD SEE
A MORE ROBUST VORT MAX PROGRESSING WWD INTO N AZ WHICH WILL
PROMOTE ANOTHER ROUND OF CONVECTION ACROSS THE MOGOLLON RIM AND
EASTERN AZ WHERE THE HIGHEST INSTABILITY WILL BE PRESENT. CAPE
VALUES IN THE LOWER DESERTS WILL STILL BE MODERATE AT BEST,
UPWARDS OF 500 J/KG WITH A CAPPING INVERSION PRESENT SO IT MAY BE
DIFFICULT FOR STORMS TO SURVIVE OFF THE HIGHER TERRAIN MONDAY
EVENING. A LONGER LIVED OUTFLOW BOUNDARY IS MORE LIKELY WHICH
COULD AT LEAST FOSTER ISOLATED STORMS OVER FAR E MARICOPA AND
PINAL COUNTIES. DUE TO THE STRENGTHENING OF THE 500 MB HIGH OVER
THE INTERMOUNTAIN WEST AND RESPONDING LOW-LVL THERMAL PROFILES,
TEMPERATURES WILL TICK UP A COUPLE MORE DEGREES MONDAY AFTERNOON
WITH MOST LOWER DESERT LOCATIONS REACHING THE TRIPLE DIGITS.
LONG TERM /TUESDAY THROUGH SATURDAY/
DETERMINISTIC GUIDANCE AND ENSEMBLE MEMBERS CONTINUE TO INDICATE
THAT THE SUBTROPICAL HIGH WILL SHIFT SOUTHEAST OVER THE SOUTHERN
PLAINS BEGINNING ON TUESDAY. THIS WILL CAUSE STEERING FLOW OVER
THE DESERT SOUTHWEST TO SHIFT FROM EASTERLY TO MORE OF A
SOUTHEASTERLY DIRECTION. THE AFOMENTIONED INVERTED TROUGH WILL
SLOWLY PROGRESS THROUGH N MX AND INTO S AZ TUESDAY INTO WEDNESDAY.
THIS FEATURE WILL ENHANCE LARGE SCALE LIFT OVER THE REGION AND
PROMOTE ADDITIONAL MOISTURE TRANSPORT FROM N MX INTO AZ. IN
RESPONSE, SHOWER AND THUNDERSTORM ACTIVITY WILL LIKELY INCREASE IN
COVERAGE AND INTENSITY WITH MUCH BETTER CHANCES FOR THE LOWER
DESERTS TO RECEIVE MEASURABLE RAINFALL. CURRENTLY NBM POPS ARE
HIGHEST DURING THE LATE EVENING ON TUESDAY THROUGH THE OVERNIGHT
PERIOD, PEAKING AROUND 20-40% ACROSS THE PHOENIX METRO. IF
CONVECTION IS MORE ROBUST ON TUESDAY, THEN WEDNESDAY MAY BE A
QUIETER DAY OVERALL. CONFIDENCE DECREASES IN TIMING AND OVERALL
COVERAGE OF THUNDERSTORM ACTIVITY LATER NEXT WEEK AS RIDGING ALOFT
EXPANDS OVER THE FORECAST AREA AND DRIER AIR BEGINS TO INTRUDE
INTO SOUTHEAST PORTIONS OF AZ.
MODEL CONSENSUS INDICATES AN OVERALL EXPANSION AND STRENGTHENING
OF THE SUBTROPICAL HIGH, ALLOWING POSITIVE HEIGHT ANOMALIES TO
BUILD OVER THE FORECAST AREA FROM THURSDAY INTO NEXT WEEKEND. THE
GEFS AND EPS INDICATE MEAN HGHTS APPROACHING 594-596 DAM WHICH
AROUND THE 90TH PERCENTILE OF CLIMATOLOGY FOR LATE JULY. THUS WE
WILL LIKELY SEE TEMPERATURES INCREASING BACK ABOVE NORMAL STARTING
THURSDAY. UNFORTUNATELY THIS MEANS THE RETURN OF MAJOR HEATRISK,
ESPECIALLY ACROSS SE CALIFORNIA AND SW ARIZONA ON THURSDAY AND
FRIDAY. TEMPERATURES WILL INCREASE FURTHER ACROSS THE LOWER
DESERTS BY NEXT WEEKEND WITH GOOD INDICATIONS THAT HIGHS WILL
REACH 110+F IN PHOENIX BEGINNING SATURDAY.
AVIATION
UPDATED AT 0010Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
A FAIRLY TYPICAL DIURNAL WIND PATTERN IS EXPECTED THROUGH MONDAY
AFTERNOON WITH LITTLE TO NO SHRA IMPACTS ANTICIPATED BESIDES
PERHAPS SOME WEAK SPOTTY SHOWERS DURING THE OVERNIGHT AND MORNING
HOURS. W WINDS AT 5-10 KTS ARE EXPECTED THROUGH THIS EVENING
BEFORE SHIFTING E AND/OR VRB AND THEN WINDS WILL VEER BACK W/SW BY
LATE MORNING-NOON MONDAY. THERE WILL BE BETTER ODDS FOR A GUSTY
OUTFLOW FROM THE EAST AND/OR NORTH MONDAY EVENING, BUT POTENTIAL
FOR SHRA/TSRA SPARKING WITH THE OUTFLOWS WILL BE LOW (10-20%). FEW
TO BKN CLOUDS WILL BE COMMON THROUGH THE TAF PERIOD WITH LOWEST
BASES AROUND 8-10K FT AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER IMPACTS ARE EXPECTED THROUGH MONDAY. AT
KBLH, 7-12 KT SSW-SSE WINDS WILL BE PREVAIL. AT KIPL, WINDS WILL
FOLLOW TYPICAL DIURNAL TRENDS WITH A PERIOD OF GUSTY W WINDS THIS
EVENING (G UP TO 20-25 KTS) AND THEN RETURN TO A SE WIND BY MONDAY
AFTERNOON. SPOTTY VCSH/-SHRA MAY DEVELOP IN THE TERMINAL AREAS
TONIGHT THROUGH MONDAY MORNING, MAINLY BETWEEN 07-19Z, BUT
CONFIDENCE ON SPECIFIC TIMINGS IS LOW. FEW TO BKN CLOUDS AOA 10K
FT AGL WILL BE COMMON THROUGHOUT THE PERIOD.
FIRE WEATHER
RECENT WETTING RAINFALL HAS RESULTED IN DRASTIC IMPROVEMENTS IN
FUEL MOISTURE ACROSS SOUTH-CENTRAL AZ WHERE ERC VALUES HAVE FALLEN
BELOW THE 25TH PERCENTILE. ADDITIONAL ROUNDS OF BENEFICIAL WETTING
RAINFALL WILL BE POSSIBLE EACH DAY THROUGH AT LEAST THE MIDDLE OF
THIS WEEK, ESPECIALLY OVER THE FOOTHILLS AND HIGH TERRAIN OF THE
EASTERN DISTRICTS. WINDS WILL REMAIN LIGHT, MOSTLY BELOW 15 MPH
AND FOLLOW TYPICAL DIURNAL UPSLOPE AND DOWNVALLEY PATTERNS, THE
MAIN EXCEPTION BEING GUSTY AND ERRATIC WINDS IN THE VICINITY OF
THUNDERSTORMS. ELEVATED MOISTURE LEVELS WILL KEEP MINIMUM
AFTERNOON HUMIDITY ABOVE 20% ACROSS THE WESTERN DISTRICTS AND
BETWEEN 30-40% OVER THE EASTERN DISTRICTS. OVERNIGHT RECOVERY WILL
RANGE FROM FAIR TO GOOD ACROSS THE WESTERN DISTRICTS AND VERY
GOOD TO EXCELLENT FOR THE EASTERN DISTRICTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...SALERNO/FRIEDERS
LONG TERM...SALERNO
AVIATION...BENEDICT
FIRE WEATHER...SALERNO
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