726
FXUS65 KPSR 142039
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
139 PM MST SUN SEP 14 2025
KEY MESSAGES
- NEAR TO SLIGHTLY BELOW-AVERAGE TEMPERATURES TODAY BEFORE GRADUALLY
WARMING THROUGH THE MIDDLE OF THE WORK WEEK.
- NO SHOWERS OR STORMS EXPECTED TODAY THROUGH THE FIRST HALF OF THE
WEEK, WITH MOSTLY SUNNY SKIES AND LIGHT WINDS.
- POTENTIAL FOR A WIDESPREAD RAIN EVENT LATE WEEK INTO NEXT WEEKEND
WITH A PUSH OF MOISTURE, BUT THERE IS STILL A HIGH DEGREE OF
VARIABILITY WITH THIS FORECAST.
SHORT TERM /TODAY THROUGH MONDAY/
WATER VAPOR SATELLITE IMAGERY EARLY THIS AFTERNOON SHOWS WESTERLY
FLOW ALOFT AND AN ABUNDANCE OF DRY AIR ACROSS THE REGION THAT WAS
BROUGHT IN FROM THE TROUGH THAT MOVED THROUGH OVER THE PAST
COUPLE OF DAYS, WHICH IS NOW IN THE PLAINS. THE ABUNDANCE OF DRY
AIR IS ALSO PRESENT ON THE SPC MESOANALYSIS, WHERE PWAT VALUES ARE
AROUND 0.5" OR LESS ACROSS MUCH OF THE REGION. OBJECTIVE ANALYSIS
ALSO SHOWS WEAK TROUGHING OVER THE AREA WITH A SHORTWAVE IN
CENTRAL CA AND ANOTHER SHORTWAVE OVER SONORA, MEXICO. TC MARIO AND
ANOTHER TROPICAL WAVE ARE JUST OFF THE WEST COAST OF MEXICO,
WHICH WILL NEED TO BE WATCHED AS THEIR TRACK COULD PLAY A ROLE IN
OUR WEATHER FOR THE END OF THE WEEK AND NEXT WEEKEND. THERE IS
ALSO A SUBTROPICAL HIGH OVER CENTRAL MEXICO, WHICH WILL PLAY A
ROLE IN OUR WEATHER OVER THE NEXT COUPLE OF DAYS AS IT BUILDS INTO
OUR REGION.
WITH THE DRY CONDITIONS IN PLACE, SHOWER AND STORM CHANCES WILL
CONTINUE TO BE AROUND 0% ACROSS THE REGION THROUGH AT LEAST
TOMORROW. AS PREVIOUSLY MENTIONED, THE SUBTROPICAL RIDGE WILL BE
BUILDING INTO OUR REGION WHICH WILL ALLOW FOR A GRADUAL WARMING OF
TEMPERATURES. TEMPERATURES EARLY THIS AFTERNOON ARE A COUPLE DEGREES
WARMER THAN THEY WERE AT THIS TIME YESTERDAY AND ARE ALSO FORECASTED
TO TOP OUT A FEW DEGREES WARMER THAN YESTERDAY. MOST LOWER DESERT
LOCATIONS ARE FORECASTED TO SEE HIGHS IN THE UPPER 90S TO NEAR 100
DEGREES TODAY WITH HIGHER TERRAIN AREAS IN THE UPPER 80S TO LOW 90S.
FURTHER WARMING IS EXPECTED TOMORROW AS THE HIGH BUILDS FURTHER INTO
OUR AREA, WITH AFTERNOON HIGH TEMPERATURES FORECASTED TO BE NEAR TO
SLIGHTLY ABOVE NORMAL (100-105 DEGREES ACROSS THE LOWER DESERTS AND
IN THE 90S IN THE HIGHER TERRAIN). THE DRY CONDITIONS AND CLEAR
SKIES WILL CONTINUE TO ALLOW FOR TEMPERATURES TO COOL OFF RATHER
NICELY FOR THE OVERNIGHT AND EARLY MORNING PERIOD. EARLY MORNING
LOWS WILL CONTINUE TO BE PLEASANT WITH MONDAY MORNING LOWS
FORECASTED TO BE A COUPLE DEGREES WARMER THAN THIS MORNING, BUT
STILL IN THE 70S ACROSS THE LOWER DESERTS AND IN THE 60S IN THE
HIGHER TERRAIN. KEEP PRACTICING SMART HEAT SAFETY IN THE AFTERNOONS
AS LONG EXPOSURE TO 90+ DEGREE HEAT CAN STILL HAVE NEGATIVE HEALTH
IMPACTS WITHOUT THE PROPER HEAT SAFETY ACTIONS.
LONG TERM /TUESDAY THROUGH SUNDAY/
FORECAST CONFIDENCE THROUGH THE FIRST HALF OF THIS COMING WORK
WEEK REMAINS HIGH. HIGH PRESSURE WILL CONTINUE TO NUDGE INTO THE
REGION, LEADING TO A GRADUAL RISE IN 500MB HEIGHTS. GLOBAL
ENSEMBLES HAVE H5 HEIGHTS PEAK AROUND 590DAM ON TUESDAY, WHICH IS
AROUND 80TH PERCENTILE OF CLIMATOLOGY FOR THIS TIME OF YEAR. AS A
RESULT SURFACE TEMPERATURES WILL CLIMB SLIGHTLY ABOVE NORMAL FOR
AT LEAST TUESDAY AND WEDNESDAY. LATEST NBM FORECAST HAS AFTERNOON
HIGHS REACHING 101-105 DEGREES BOTH DAYS. THERE WILL BE A SLOW
RETURN OF MOISTURE THROUGH WEDNESDAY, ENOUGH FOR SOME CLOUDS TO
DEVELOP, BUT LIKELY NOT ENOUGH STILL FOR SHOWERS OR STORMS IN
SOUTH-CENTRAL AZ TO SOUTHEAST CA. LATEST NBM POPS ARE AT <5%
TUESDAY AND <10% WEDNESDAY.
FOR LATE-WEEK INTO NEXT WEEKEND, CONFIDENCE IS SLOWLY INCREASING
IN FAVOR OF A - POTENTIALLY WIDESPREAD - RAINFALL EVENT. HOWEVER,
THERE STILL REMAINS A LARGE SPREAD IN OUTCOMES ACROSS THE 3
PRIMARY GLOBAL ENSEMBLES AND THERE ARE SOME UNCERTAINTIES IN THE
SYNOPTIC SCALE FORCING. THE INTERQUARTILE RANGES FOR PWAT,
ACCUMULATED PRECIP, AND TEMPERATURES ARE STILL QUITE LARGE WITH
THE MOST RECENT 00Z ENSEMBLE RUNS. SO IT IS STILL TOO EARLY TO PUT
ANY STOCK IN FORECAST RAINFALL AMOUNTS AND IMPACTS. THE
CONFIDENCE IS INCREASING THOUGH, LARGELY DUE TO THE LOWER QUARTILE
PWAT FORECASTS AND POTENTIAL FOR JET STREAK SUPPORT. THE 10TH
PERCENTILE PWAT FORECAST IS NEAR TO ABOVE NORMAL AT 1.1-1.2"
ACROSS THE LOWER DESERTS BY FRIDAY. TYPICAL PWAT LEVELS THIS TIME
OF YEAR ARE AROUND 0.9-1.0". GREATEST PWAT ANOMALIES (>150%)
CONTINUE TO FAVOR WESTERN AREAS, IN SOCAL AND JUST OFFSHORE. THESE
AREAS, AND ALONG THE COLORADO RIVER, LOOK LIKE THE MORE FAVORABLE
AREAS FOR JET SUPPORT AS WELL. SO, THESE MENTIONED AREAS
CURRENTLY HAVE THE HIGHER ODDS FOR RAINFALL AND THIS LINES UP WITH
THE LATEST CPC 6-10 OUTLOOK'S HIGHLIGHTED AREAS WITH THE HIGHEST
ODDS OF ABOVE NORMAL PRECIP.
AS FOR POTENTIAL RAINFALL, IT IS AT LEAST WORTH MENTIONING THERE
ARE SEVERAL ENSEMBLE MEMBERS WITH HIGH RAINFALL AMOUNTS. AROUND
5-10% OF THE GLOBAL ENSEMBLE MEMBERS HAVE 1.00-2.00" RAINFALL
AMOUNTS. HOWEVER, A LOT OF THESE EXTREME MEMBERS INVOLVE A
TROPICAL CIRCULATION MOVING UP THE BAJA. RIGHT NOW THIS DEFINITELY
SEEMS LIKE QUITE A STRETCH GIVEN THE MAJORITY OF MEMBERS WILL
HAVE HIGH PRESSURE STILL FIRMLY IN PLACE OVER NORTHWEST MX AND
TURN ANY TROPICAL CIRCULATIONS MORE OUT TO SEA. ON THE OTHER END
OF THE FORECAST SPECTRUM, THERE ARE STILL AROUND 25% OF MODEL
MEMBERS WITH 0.05" OR LESS. THIS FAR OUT IN THE FORECAST THE
EXTREME RAINFALL FORECASTS ARE DRIVING UP THE ENSEMBLE MEANS AND
WITH TIME THE FORECAST MAY TREND MORE TOWARD THE LOWER MEDIAN
FORECASTS. ALSO, DON'T BE SURPRISED IF COME LATE NEXT WEEK THE
RAINFALL FORECAST HAS BACKED OFF OR BECOME MORE FOCUSED TO A
PARTICULAR AREA AND/OR MOST AREAS RECEIVE JUST CLOUD-COVER. STILL
A LOT TO PARSE OUT WITH THIS FORECAST.
AVIATION
UPDATED AT 1705Z.
SOUTH CENTRAL ARIZONA AND SOUTHEAST CA INCLUDING KPHX, KIWA,
KSDL, KDVT, KBLH AND KIPL:
NO AVIATION CONCERNS ARE EXPECTED THROUGH MONDAY MORNING UNDER
MOSTLY CLEAR SKIES. WINDS WILL OVERALL FAVOR DIURNAL TRENDS, WITH
EXTENDED PERIODS OF VARIABILITY, ESPECIALLY FOR THE WESTERN
TERMINALS. EXPECT A PERIOD OF SOUTHERLY WINDS MIDDAY TODAY BEFORE
GRADUALLY VEERING TOWARD THE W-SW BY MID-LATE AFTERNOON FOR THE
PHOENIX TERMINALS. SPEEDS WILL REMAIN GENERALLY LESS THAN 10 KTS
THROUGH THE PERIOD.
FIRE WEATHER
NEAR TO SLIGHTLY BELOW AVERAGE TEMPERATURES WILL BE COMMON ACROSS
THE REGION TODAY, WITH A GRADUAL WARM-UP TO SLIGHTLY ABOVE
AVERAGE BY TUESDAY-WEDNESDAY. WINDS WILL BE LIGHT NEARLY EVERY
DAY, FOLLOWING TYPICAL DIURNAL TENDENCIES, WITH OCCASIONAL
AFTERNOON GUSTS UP TO 10-20 MPH. DRY CONDITIONS WILL PREVAIL
THROUGH THE FIRST HALF THIS WEEK WITH NO CHANCES FOR WETTING
RAINS. MINRHS THROUGH WEDNESDAY WILL MOSTLY RANGE FROM 15-25%
(10-15% TODAY) ACROSS ALL DISTRICTS WITH FAIR OVERNIGHT RECOVERIES
AT 30-50%. THE FORECAST FOR LATE IN THE WEEK AND INTO THE WEEKEND
IS STILL HIGHLY UNCERTAIN. HOWEVER, A GOOD PUSH OF MOISTURE IS
EXPECTED TO MOVE INTO THE REGION BEGINNING THURSDAY, WHICH WILL
INCREASE THE RH LEVELS AND WILL INCREASE ODDS FOR SHOWERS AND
STORMS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...BERISLAVICH
LONG TERM...BENEDICT
AVIATION...RW/FRIEDERS
FIRE WEATHER...BENEDICT/BERISLAVICH
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