294
FXUS65 KPSR 292349
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
449 PM MST TUE JUL 29 2025
UPDATE
00Z AVIATION DISCUSSION.
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES WITH LOWER DESERT HIGHS AROUND 110
DEGREES WILL RESULT IN A DAILY MODERATE HEATRISK.
- LIMITED MONSOON MOISTURE WILL BRING DAILY CHANCES OF EASTERN
ARIZONA HIGH TERRAIN STORMS THROUGH FRIDAY. A FEW SHOWERS OR
STORMS MAY BE POSSIBLE INTO THE SOUTH-CENTRAL ARIZONA LOWER
DESERTS ON THURSDAY.
SHORT TERM /TODAY THROUGH WEDNESDAY/
THE SEEMINGLY UNENDING LATE-SPRING/EARLY-SUMMER LIKE PATTERN
CONTINUES ACROSS THE DESERT SOUTHWEST, WITH DRY SOUTHWESTERLY FLOW
ACROSS MUCH OF THE SOUTHWEST. THIS HAS BEEN MAKING IT VERY
DIFFICULT TO GET DEEP MOISTURE INTO THE REGION, AND STICK AROUND.
WATER VAPOR SATELLITE THIS AFTERNOON SHOWS THE DEEPER MOISTURE IS
LOCATED ALONG AN AXIS FROM CHIHUAHUA, MX UP THROUGH NM, WITH
NOTABLY DRIER AIR ACROSS AZ AND SOCAL. TOTAL COLUMN PWAT AND
LOWEST 100MB MIXING RATIOS DID INCREASE A SMIDGE IN SOUTH-CENTRAL
AZ, FROM 0.7" AND 4 G/KG YESTERDAY MORNING TO 0.9" AND 6 G/KG, BUT
THIS IS STILL NOT WHAT YOU ARE LOOKING FOR TO GET ANY STORMS INTO
THE LOWER DESERTS OF SOUTH-CENTRAL AZ. ON TOP OF THAT, A NEW AND
WEAK ANTICYLONIC CIRCULATION HAS DEVELOPED OVER NORTHERN BAJA AND
HAS HELPED INDUCE A NORTHERLY MID-LEVEL WIND OVER PRIMARILY
SOUTHEAST AZ, WHICH IS NOT AN IDEAL WIND SETUP TO GET STORM MOTION
TOWARD THE LOWER DESERTS OF SOUTH-CENTRAL AZ. AFTERNOON
CONVECTION TODAY WILL AGAIN FAVOR HIGH TERRAIN AREAS AND SKY
ISLANDS OF EASTERN AREA. ONCE AGAIN TODAY, THE GREATEST SENSIBLE
WEATHER IMPACT WILL BE THE HEAT, WITH SUNNY SKIES AND ABOVE NORMAL
AFTERNOON TEMPERATURES, AS LOWER DESERT HIGHS ARE FORECAST TO
REACH 107-112 DEGREES. THIS IS LEADING TO WIDESPREAD MODERATE
HEATRISK, SO AVOID LONG OUTDOOR EXPOSURE THIS AFTERNOON.
MORE OF THE SAME IS EXPECTED AGAIN TOMORROW, DRY AND HOT AGAIN
WITH SIMILAR TEMPERATURES. THE SYNOPTIC PATTERN AND ENVIRONMENTAL
CONDITIONS ARE NOT FORECAST TO CHANGE VERY MUCH, BESIDES PERHAPS
ANOTHER SMIDGEN INCREASE OF MOISTURE UP TO PWATS AROUND 1.0" AND
MIXING RATIOS TO AROUND 7 G/KG IN SOUTH- CENTRAL AZ. LATEST HREF
SHOWS AFTERNOON CONVECTION TOMORROW MAY NOT GET ANY CLOSER TO THE
SOUTH- CENTRAL AZ LOWER DESERTS THAN SOUTHERN GILA AND SOUTHEAST
PINAL COUNTIES. WITH THE STORM MOTION BEING MORE OF A SOUTHERLY
DIRECTION IN EASTERN AZ THIS IS NOT EVEN FAVORABLE FOR MUCH IN THE
WAY OF OUTFLOW BOUNDARIES MOVING TOWARD THE LOWER DESERTS.
LONG TERM /THURSDAY THROUGH MONDAY/
MOISTURE IS STILL LIKELY TO IMPROVE SOME LATER THIS WEEK AND
SPREAD WESTWARD INTO THE LOWER DESERTS, BUT TO A LESSER DEGREE
THAN PREVIOUSLY ADVERTISED. THE LATEST GEFS ONLY SHOWS PWATS
RISING TO 1.0-1.1" INTO THE LOWER DESERTS LATE THURSDAY AND FRIDAY
MORNING, WHEREAS THE EPS SHOWS 1.2-1.3". LOW LEVEL MIXING RATIOS
ALSO REMAIN FAIRLY LIMITED MUCH OF THE TIME, MAINLY STAYING
BETWEEN 6-8 G/KG BUT THERE LOOKS TO BE A BRIEF PERIOD OF 8-10 G/KG
CENTERED ON THURSDAY NIGHT. BESIDES THE LIMITED MOISTURE, WE ARE
ALSO LIKELY TO FALL WITHIN A MORE SUBSIDENT RIGHT EXIT REGION OF
AN UPPER LEVEL JET. POPS HAVE BEEN SCALED BACK A GOOD AMOUNT WITH
CHANCES MAINLY STILL OVER THE EASTERN ARIZONA HIGHER TERRAIN
THURSDAY AFTERNOON WITH 10-20% CHANCES INTO THE SOUTH-CENTRAL
ARIZONA LOWER DESERTS THURSDAY EVENING AND THURSDAY NIGHT. GIVEN
THE LATEST LOOK AT THE POTENTIAL MOISTURE, THESE POPS ARE LIKELY
TOO OPTIMISTIC.
LINGERING MOISTURE INTO FRIDAY MAY BE ENOUGH FOR ANOTHER ROUND OF
AFTERNOON SCATTERED SHOWERS AND ISOLATED STORMS, BUT BY THIS TIME
DRIER AIR WILL ALREADY BE USHERING INTO THE AREA FROM THE
SOUTHWEST WHILE THE CENTER OF THE SUBTROPICAL HIGH WILL BE NEARLY
OVERHEAD. THE STRONGER SUBSIDENCE FROM THE HIGH CENTER WILL LIKELY
COUNTERACT ANY LINGERING MOISTURE OVER THE LOWER DESERTS LEAVING
ONLY CHANCES FOR CONVECTION OVER THE EASTERN ARIZONA HIGHER
TERRAIN. THE RAPID DRYING TREND IS EXPECTED TO CONTINUE THROUGH
THE WEEKEND WITH PWATS DROPPING TO WELL BELOW 1" AREAWIDE BY
SATURDAY NIGHT. OTHER THAN A VERY LIMITED POTENTIAL FOR AN
ISOLATED STORM OR TWO OVER EASTERN ARIZONA ON SATURDAY, RAIN
CHANCES ARE LIKELY TO COME TO AN END FOR A COUPLE DAYS. GUIDANCE
DOES HINT AT MAYBE A RETURN OF SOME LIMITED CONVECTION AT SOME
POINT EARLY NEXT WEEK, BUT ONLY ACROSS THE HIGHER TERRAIN.
TEMPERATURES THROUGH THE REST OF THE WEEK INTO NEXT WEEK ARE
EXPECTED TO REMAIN AT LEAST A FEW DEGREES ABOVE NORMAL EACH DAY.
HIGHS AROUND 110 DEGREES ACROSS THE LOWER DESERTS ARE LIKELY MOST
DAYS. LUCKILY, GUIDANCE INDICATES THE TROUGH TO OUR NORTHWEST
SHOULD SHIFT CLOSER TO OUR AREA OVER THE WEEKEND TO SUPPRESS THE
SUBTROPICAL RIDGE. THIS IS DEFINITELY THE MOST FAVORED SOLUTION,
BUT THERE REMAINS AROUND 10-20% OF THE MEMBERS SHOWING THE RIDGE
HAVING MORE INFLUENCE. IF THIS WERE TO OCCUR, WE MAY END UP SEEING
HIGHS CLOSER TO 115 DEGREES. BEYOND THE FORECAST PERIOD (LATTER
HALF OF NEXT WEEK), ENSEMBLES ARE POINTING AT THE RIDGE REBUILDING
WITH AT LEAST SOME POTENTIAL FOR AN EARLY AUGUST EXTREME HEAT
EVENT.
AVIATION
UPDATED AT 2350Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH THE FORECAST
PERIOD. WINDS WILL CONTINUE TO FOLLOW TYPICAL DIURNAL PATTERNS
WITH A FEW GUSTS IN THE THE UPPER TEENS THROUGH EARLY THIS
EVENING. WINDS WILL SHIFT BACK AROUND TO THE ESE BY 06Z AT KIWA
AND 09Z AT KPHX TONIGHT. ONLY FEW MID-HIGH LVL CLOUDS CAN BE
EXPECTED ACROSS THE REGION.
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 SHOULD BECOME
ESTABLISHED OUT OF THE WEST THIS EVENING AND REMAIN WESTERLY
THROUGH THE OVERNIGHT PERIOD. AT KBLH, WINDS WILL FLUCTUATE OUT OF
THE SOUTH TO SOUTHWEST. BOTH TERMINALS WILL ALSO EXPERIENCE
PERIODS OF CALM AND VRB WINDS, ESPECIALLY CLOSER TO SUNRISE
WEDNESDAY MORNING.
FIRE WEATHER
LIMITED MONSOON MOISTURE WILL PROVIDE FOR DAILY CHANCES OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE EASTERN
ARIZONA HIGH TERRAIN, BUT CHANCES FOR WETTING RAINS WILL MOSTLY BE
10% OR LESS. BY THURSDAY, THE LIMITED CHANCES MAY EXTEND INTO THE
SOUTH-CENTRAL ARIZONA LOWER DESERTS. THE LACK OF GOOD MOISTURE
SHOULD RESULT IN AT LEAST MINOR RISK OF DRY LIGHTNING. AFTERNOON
MINRHS FOR THE LOWER DESERTS WILL REMAIN BETWEEN 5-15% TODAY AND
WEDNESDAY, WITH 15-20% IN SOUTHERN GILA COUNTY. OUTSIDE OF THE
INFLUENCE OF THUNDERSTORMS, WINDS WILL GENERALLY FOLLOW DIURNAL
TENDENCIES WITH TYPICAL AFTERNOON UPSLOPE GUSTINESS. TEMPERATURES
WILL MOSTLY RUN 3-6 DEGREES ABOVE NORMAL THROUGH THE REST OF THE
WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...BENEDICT
LONG TERM...KUHLMAN
AVIATION...SALERNO
FIRE WEATHER...KUHLMAN
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