847
FXUS65 KPSR 300612
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1112 PM MST SUN MAR 29 2026
UPDATE
UPDATED 06Z AVIATION DISCUSSION.
KEY MESSAGES
- UNSEASONABLY HOT TEMPERATURES WILL CONTINUE TO CHALLENGE DAILY
RECORDS MONDAY BEFORE NOTICEABLE COOLING ARRIVES DURING THE
MIDDLE OF THE WEEK.
- ISOLATED SHOWERS AND POTENTIALLY AN EMBEDDED THUNDERSTORMS WILL
BE POSSIBLE OVER PORTIONS OF SOUTH-CENTRAL ARIZONA THIS
AFTERNOON AND MONDAY PRODUCING GUSTY OUTFLOW WINDS.
SHORT TERM /TODAY THROUGH TUESDAY/
THE CONUS FLOW PATTERN HAS BECOME FAR MORE ZONAL IN NATURE WITH
SUBTROPICAL RIDGING BECOMING DAMPENED EQUATORWARD WHILE FAST MOVING,
LOW AMPLITUDE FEATURES REMAIN NORTH OF THE FORECAST AREA. EARLY
AFTERNOON WV IMAGERY REVEALS A WEAK CYCLONIC SIGNATURE AND VORTICITY
CENTER ALONG THE SOUTHERN CA/BAJA COAST CREATING LOCAL SOUTHERLY
FLOW TAPPING BETTER DEEP MOISTURE PROFILES AIDED BY CONVECTIVE
OVERTURNING ACROSS THE INTERNATIONAL BORDER. CONFIDENCE IS
INCREASING VIA OBJECTIVE ANALYSIS AND HREF OUTPUT THAT 7-8 G/KG
MIXING RATIOS WILL ADVECT NORTH WITH WEAK ASCENT MECHANISMS SPARKING
ISOLATED DEEP CONVECTION ACROSS PORTIONS OF SOUTHERN ARIZONA.
LOCATIONS ALONG I-8 NEAR THE TABLE TOP WILDERNESS APPEAR MOST POISED
FOR LATE AFTERNOON CONVECTIVE INITIATION TAPPING ~500 J/KG MLCAPE.
HOWEVER, RAINFALL PROSPECTS WILL BE QUITE REMOTE AND ISOLATED GIVEN
THE PREDOMINANT INVERTED-V SOUNDINGS AND LARGE T/TD SPREADS, AND
INSTEAD WILL YIELD DCAPE VALUES IN EXCESS OF 1200 J/KG PROMOTING
ENHANCED DOWNDRAFT WINDS AND ORGANIZED OUTFLOW BOUNDARIES. THE
PREPONDERANCE OF HREF OUTPUT SUGGESTS OUTFLOW WINDS 30-40 MPH
CAPABLE OF PRODUCING AREAS OF BLOWING DUST IN THE I-8/I-10 VICINITY
LATE AFTERNOON/EARLY EVENING WITH RESIDUAL STRONGER WINDS/GUSTS
ENTERING THE PHOENIX METRO BEFORE QUICKLY SUBSIDING DURING THE MID
EVENING.
WHILE SLIGHTLY BETTER QUALITY MOISTURE CONTINUES TO ADVECT INTO
SOUTH-CENTRAL ARIZONA MONDAY MORNING, FLOW TRAJECTORIES WILL
STEADILY TURN MORE WESTERLY DURING THE DAY ERODING MOISTURE DEPTH
AND MAGNITUDE RESULTING IN A SOMEWHAT MORE CONVECTIVELY HOSTILE
ENVIRONMENT. SOME MODEST INSTABILITY WILL EXIST ACROSS THE EASTERN
FORECAST AREA MONDAY AFTERNOON, HOWEVER WEAKER ASCENT STRUCTURE AND
NOTABLE CINH WILL LIKELY CONSTRICT DEEP CONVECTION TO ISOLATED
OROGRAPHIC LOCATIONS. SIMILAR TO TODAY, OUTFLOW WINDS WILL BE MORE
PREFERRED THAN ACTUAL ACCUMULATING RAINFALL GIVEN THE THERMODYNAMIC
PROFILES, AND ANY ACTIVITY SHOULD QUICKLY WANE WITH LOSS OF DAYTIME
HEATING. BY TUESDAY, MOISTURE WILL BE SCOURED EVEN FURTHER WITH
DEEPENING WESTERLY FLOW PRECLUDING ANY ADDITIONAL POPS. OTHERWISE,
H5 HEIGHTS RETREATING FROM NEAR 582DM TODAY TO AROUND 574DM TUESDAY
WILL FORCE A MODEST COOLING TREND WITH TEMPERATURES STILL
CHALLENGING RECORD HIGHS TODAY FALLING CLOSER TO A +10F ANOMALY
TUESDAY AFTERNOON.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
A MOSTLY ZONAL WESTERLY FLOW PATTERN WILL CONTINUE MIDWEEK WITH A
WEAK SHORTWAVE TROUGH TRACKING ACROSS CENTRAL CALIFORNIA BEFORE
MOVING THROUGH OUR REGION ON WEDNESDAY. DRYING CONDITIONS WILL
PERSIST DURING THIS TIME WITH LOW LEVEL MIXING RATIOS DROPPING 3-5
G/KG, BUT ALSO WITH THE PASSING SHORTWAVE ON WEDNESDAY, SOME HIGH
TERRAIN SHOWERS MAY DEVELOP. NBM POPS STILL SEEM TOO HIGH FOR
WEDNESDAY, SO HAVE LOWERED CHANCES MORE INTO THE 5-10% RANGE FOR THE
LOWER DESERTS AND 10-20% FOR THE HIGHER TERRAIN.
TEMPERATURES WILL ALSO FINALLY COOL OFF DURING THE MIDDLE OF THE
WEEK WITH HIGHS FALLING INTO THE MID 80S WEDNESDAY. ONCE THE
SHORTWAVE TROUGH MOVES TO THE EAST OF THE REGION WEDNESDAY NIGHT,
EVEN MORE DRY AIR WILL FILTER IN FROM THE NORTHWEST. DRY CONDITIONS
WITH TEMPERATURES ON AVERAGE 3-6 DEGREES ABOVE NORMAL ARE EXPECTED
LATE IN THE WEEK AS A ANOTHER PACIFIC TROUGH PASSES WELL TO OUR
NORTH. ENSEMBLE GUIDANCE THEN MOSTLY AGREES A MODEST RIDGE IS LIKELY
TO DEVELOP OFF THE WEST COAST LATE IN THE WEEK BEFORE MOVING INTO
OUR REGION NEXT WEEKEND. THIS SHOULD PRODUCE ANOTHER WARMING TREND
WITH NBM FORECAST HIGHS BACK INTO THE 90S BY AROUND NEXT SUNDAY.
AVIATION
UPDATED AT 0612Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
GUSTY SOUTHERLY WINDS SHOULD SUBSIDE OVER THE NEXT COUPLE OF
HOURS. CONFIDENCE ON TIMING OF EASTERLY WIND SHIFT IS LOW, BUT
ANTICIPATED WITHIN AN HOUR OR TWO AFTER SOUTHERLY WINDS SUBSIDE.
LIGHT VARIABILITY MAY ALSO DEVELOP AND PERSIST THROUGH EARLY TO
MID MORNING. DIURNAL WESTERLY WINDS ARE EXPECTED TO DEVELOP BY
NOON MONDAY, WITH LIGHT VARIABILITY DURING THE WIND SHIFT. WIND
SPEEDS INCREASE UP TO 7-12 KTS IN THE AFTERNOON WITH GUSTS UP TO
15-20 KTS. AN OUTFLOW IS LESS LIKELY MONDAY AFTERNOON AND NO
VCSH/VCTS ARE EXPECTED. SCT TO BKN MID AND HIGH CLOUDS WILL
CONTINUE TO PASS OVER THE AREA.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER ISSUES WILL EXIST THROUGH THE TAF PERIOD UNDER
PERSISTENT MID/HIGH CLOUD DECKS. WINDS WILL REMAIN PREDOMINANTLY
SOUTHEASTERLY AT KIPL THROUGH MONDAY AFTERNOON, FOLLOWED BY A
WESTERLY SUNDOWNER WIND IN THE EVENING. WINDS AT KBLH WILL MOSTLY
FLUCTUATE BETWEEN SE AND SW THROUGH MONDAY WITH PERIODS OF LIGHT
VARIABILITY. A BRIEF UPTICK IN S/SE WINDS TONIGHT IS ANTICIPATED
BEHIND AN OUTFLOW BOUNDARY. WINDS WILL THEN BE LIGHT MONDAY
MORNING AND INCREASE UP TO 7-12 KTS, WITH GUSTS UP TO 15-20 KTS,
IN THE AFTERNOON AT KBLH AND EVENING AT KIPL. SCT TO BKN MID AND
HIGH CLOUDS WILL CONTINUE TO PASS OVER THE AREA.
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
---- ------- ---- ---------
3/29 97 IN 2015 100 IN 1897 97 IN 1969
3/30 97 IN 2004 99 IN 1934 101 IN 1934
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...18
LONG TERM...KUHLMAN
AVIATION...BENEDICT
FIRE WEATHER...SALERNO/KUHLMAN
CLIMATE...KUHLMAN
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