384
FXUS65 KPSR 290539
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1039 PM MST SAT MAR 28 2026
UPDATE
UPDATED 06Z AVIATION DISCUSSION.
KEY MESSAGES
- UNSEASONABLY HOT TEMPERATURES WILL CONTINUE TO CHALLENGE DAILY
RECORDS THROUGH MONDAY BEFORE NOTICEABLE COOLING OCCURS DURING
THE MIDDLE OF NEXT WEEK.
- ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER PORTIONS
OF SOUTHCENTRAL AND SOUTHEASTERN ARIZONA ON SUNDAY AND MONDAY.
ANY STORM THAT DEVELOPS COULD PRODUCE GUSTY OUTFLOW WINDS.
SHORT TERM /TODAY THROUGH SUNDAY/
RIDGING ALOFT REMAINS THE PREDOMINANT FEATURE OVER THE DESERT
SOUTHWEST, ALTHOUGH THE CENTER OF THE RIDGE AXIS IS NOW FOCUSED
WELL TO THE EAST OVER THE SOUTHERN PLAINS. 500 MB HGHTS HAVE
LOWERED SLIGHTLY TO AROUND 582-584 DAM ACROSS OUR FORECAST AREA,
HOWEVER HGHTS OF THIS MAGNITUDE ARE STILL AROUND THE 98TH
PERCENTILE OF CLIMATOLOGY FOR LATE MARCH. THEREFORE, WE ARE STILL
EXPECTING TO SEE RECORD BREAKING HIGH TEMPERATURES IN THE UPPER
90S TO AROUND 100 DEGREES BOTH TODAY AND SUNDAY FOR MOST DESERT
COMMUNITIES INCLUDING PHOENIX, YUMA, AND EL CENTRO.
THERE WAS A NOTICEABLE INCREASE IN WINDS THIS MORNING AS A BACKDOOR
FRONT PROGRESSED THROUGH THE FORECAST AREA. MAXIMUM GUSTS WERE
AROUND 35-40 MPH ACROSS THE FOOTHILLS AND HIGH TERRAIN AREAS EAST OF
PHOENIX WHILE THE LOWER DESERTS DID SEE GUSTS REACHING INTO THE 20-
30 MPH RANGE. THESE STRONGER EASTERLY WINDS KICKED UP DUST WHICH
TEMPORARILY REDUCED VISIBILITIES TO AROUND 3-5 MILES IN SOME
AREAS, HOWEVER VISIBILITY WILL CONTINUE TO IMPROVE THROUGH THIS
AFTERNOON AS WINDS DIMINISH AND THE DUST SETTLES. IT SHOULD BE A
MUCH QUIETER NIGHT REGION-WIDE WITH LOW TEMPERATURES SETTLING INTO
THE MID 60S TO AROUND 70 DEGREES.
ON SUNDAY, MID-LVL RIDGING WILL CONTINUE TO BREAK DOWN AND SHIFT
EVEN FARTHER EAST WHICH WILL ALLOW A SHORTWAVE TROUGH TO PROGRESS
THROUGH THE GREAT BASIN AND N AZ BY THE LATE AFTERNOON TO EARLY
EVENING TIME PERIOD. ALTHOUGH MOISTURE PROFILES ARE NOT IDEAL, THERE
WILL BE AT LEAST A MODEST INCREASE IN LOW LEVEL MOISTURE ON SUNDAY,
ESPECIALLY ACROSS SOUTHERN AZ WHERE PWATS WILL RISE TO AROUND
0.80- 1.00". AS THE SHORTWAVE TROUGH APPROACHES FROM THE WEST,
INCREASING INSTABILITY AND STEEPENING LAPSE RATES WILL CREATE AN
ENVIRONMENT CONDUCIVE FOR ISOLATED SHOWERS AND A FEW WEAK
THUNDERSTORMS. THE MAIN AREA OF FOCUS FOR CONVECTION ACCORDING TO
LATEST HIGH-RES GUIDANCE LOOKS TO BE ALONG AND SOUTH OF THE I-8
CORRIDOR INCLUDING THE TABLE TOP WILDERNESS AREA OF SW MARICOPA
COUNTY. IF A FEW HIGH-BASED STORMS DO INITIATE, THERE COULD BE A
THREAT OF GUSTY OUTFLOW WINDS. LATEST HREF PROBABILITIES FOR GUSTS
GREATER THAN 35 MPH ARE BETWEEN 30-50% IN SW MARICOPA AND E PINAL
COUNTIES. THERE IS ALSO A CHANCE THAT A RESIDUAL OUTFLOW COULD
MAKE IT INTO THE PHOENIX METRO AREA AROUND SUNSET WHICH COULD
RESULT IN GUSTY WINDS AND BLOWING DUST.
LONG TERM /MONDAY THROUGH FRIDAY/
MOISTURE ADVECTION WILL STRENGTHEN SUNDAY NIGHT INTO MONDAY,
ESPECIALLY IN THE LOW TO MID LEVELS AS A GULF SURGE IS FORECAST FOR
SUNDAY NIGHT. THIS WILL TEMPORARILY RAISE SURFACE DEW POINTS WELL
INTO THE 50S FOR MONDAY MORNING BEFORE DROPPING BACK DOWN INTO THE
40S AS DRIER WESTERLY FLOW ALOFT MIXES DOWN INTO THE BOUNDARY LAYER
MONDAY AFTERNOON. THE LACK OF FORCING ON MONDAY AND DRYING ALREADY
SETTLING BACK IN SHOULD LIMIT SHOWER AND THUNDERSTORM CHANCES TO THE
EASTERN ARIZONA HIGH TERRAIN. LOW LEVEL MIXING RATIOS MAY BRIEFLY
INCREASE TO AROUND 7 G/KG MONDAY AFTERNOON, BUT THIS AMOUNT OF
MOISTURE SHOULD ONLY BE ENOUGH FOR ISOLATED TO SCATTERED WEAK HIGH
TERRAIN CONVECTION. THE WEST SOUTHWESTERLY FLOW SHOULD THEN CONTINUE
TO KEEP THE DRIER AIR IN PLACE FOR TUESDAY DECREASING POPS TO ONLY
AROUND 10% FOR THE EASTERN ARIZONA HIGH TERRAIN. A SECOND SHORTWAVE
IS THEN FORECAST TO MOVE THROUGH OUR REGION FROM THE NORTHWEST ON
WEDNESDAY BRINGING A WEAK COLD FRONT AND PERHAPS ANOTHER ROUND OF 10-
20% POPS FOCUSED OVER THE ARIZONA HIGH TERRAIN. HOWEVER, THESE
NBM/WPC MANDATED POPS ON WEDNESDAY ARE VERY LIKELY TOO HIGH BASED ON
LOCAL FORECASTER PATTERN RECOGNITION/EXPERIENCE. ENSEMBLE GUIDANCE
THEN GENERALLY AGREES OUR REGION WILL STAY UNDER ZONAL TO QUASI-
ZONAL DRY WESTERLY FLOW THROUGH THE REST OF NEXT WEEK, ENDING ANY
VERY MINIMAL RAIN CHANCES.
TEMPERATURES EARLY NEXT WEEK WILL START OFF QUITE WARM WITH HIGHS
MOSTLY IN THE LOW TO MID 90S ON MONDAY AND THE LOWER 90S ON TUESDAY.
HOWEVER, BOTH OF THESE WELL-ABOVE NORMAL DAYS SHOULD HAVE A GOOD
DEAL OF HIGH CLOUDINESS TAKING THE EDGE OFF THE HEAT. ONCE THE COLD
FRONT PASSES THROUGH LATER TUESDAY AND TUESDAY NIGHT, TEMPERATURES
WILL FINALLY DROP BACK TO WITHIN A FEW DEGREES OF NORMAL STARTING
WEDNESDAY. THE LATEST NBM/WPC FORECAST TEMPERATURES FOR WEDNESDAY-
FRIDAY SHOW HIGHS MOSTLY IN THE MID 80S AND LOWS MOSTLY IN THE 50S.
AVIATION
UPDATED AT 0539Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
EAST WINDS WILL PREVAIL THROUGH TONIGHT WITH SPEEDS AROUND 8 KTS
OR LESS. CONFIDENCE IS GOOD THAT WINDS WILL SHIFT W/SW SUNDAY
AFTERNOON, WITH A FEW HOURS OF LIGHT VARIABILITY MIDDAY. SHOWERS
AND STORMS DEVELOPING WELL SOUTH OF PHOENIX LATER SUNDAY AFTERNOON
WILL BE CAPABLE OF PUSHING OUTFLOW BOUNDARIES INTO PHOENIX IN THE
EVENING, LIKELY AFTER 01Z, WITH AROUND A 10% CHANCE FOR GUSTS
GREATER THAN 30 KTS. ODDS OF VCSH/VCTS SUNDAY EVENING ARE TOO LOW
(5-10%) TO INCLUDE IN THE TAF. VFR CONDITIONS ARE EXPECTED THROUGH
THE TAF PERIOD WITH SCT TO BKN MID AND HIGH CLOUDS STAYING MOSTLY
ABOVE 15K FT AGL TO AS LOW AS 10K FT AGL SUNDAY EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER ISSUES WILL EXIST THROUGH SUNDAY UNDER PERSISTENT
MID/HIGH CLOUD DECKS. WINDS WILL GENERALLY OSCILLATE BETWEEN A SE
AND SW DIRECTION WITH SPEEDS UP TO AROUND 12 KT. HOWEVER, PERIODS
OF VARIABLE DIRECTIONS WILL ALSO BE COMMON.
FIRE WEATHER
UNSEASONABLY HOT TEMPERATURES WITH MOSTLY DRY CONDITIONS CAN BE
ANTICIPATED THROUGH THIS WEEKEND, HOWEVER A GRADUAL COOLING TREND
WILL TRANSPIRE BY EARLY NEXT WEEK. MINRH VALUES WILL INCREASE
FROM 10-20% TODAY UP TO 15-20% SUNDAY AND MONDAY, WHILE MAXRHS
WILL ALSO INCREASE FROM 20-40% TONIGHT TO 40-70% SUNDAY NIGHT. DUE
TO THE INCREASE IN LOW-LEVEL MOISTURE, THERE WILL BE AT SLIGHT
CHANCE FOR RAIN (10-30%) ACROSS SOUTHCENTRAL AZ SUNDAY AND MONDAY,
BUT THE CWR WILL REMAIN UNDER 10%. ANY STORMS THAT DO DEVELOP
WILL BE CAPABLE OF PRODUCING GUSTY AND ERRATIC OUTFLOW WINDS AND
DRY LIGHTNING, WHICH COULD LEAD TO NEW FIRE STARTS. WINDS WILL
CONTINUE TO TAPER OFF BELOW 15 MPH THROUGH THIS AFTERNOON AND
REMAIN OUT OF THE E-SE OVERNIGHT. WINDS WILL RESUME A DIURNAL
PATTERN ON SUNDAY WITH AFTERNOON UPSLOPE BREEZINESS EXPECTED TO
INCREASE EARLY NEXT WEEK.
CLIMATE
DAILY RECORD HIGHS:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
3/28 95 IN 2015 98 IN 2015 98 IN 2015
3/29 97 IN 2015 100 IN 1897 97 IN 1969
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...SALERNO
LONG TERM...KUHLMAN
AVIATION...BENEDICT/18
FIRE WEATHER...SALERNO
CLIMATE...RW/18
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