526
FXUS65 KPSR 132212
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
312 PM MST SAT JUN 13 2026
KEY MESSAGES
- TEMPERATURES AROUND 3 TO 8 DEGREES ABOVE DAILY NORMALS WILL
RESULT IN WIDESPREAD MODERATE HEAT RISK, WITH ISOLATED POCKETS
OF MAJOR HEAT RISK AT TIMES, THROUGH THE MIDDLE OF NEXT WEEK.
- CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MOSTLY BE FOCUSED
OVER THE NORTHERN ARIZONA HIGH TERRAIN AND PORTIONS OF SOUTHEAST
ARIZONA THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
- BRIEF GUSTY WINDS FROM DISTANT OUTFLOWS AND LOW PROBABILITIES
FOR A THUNDERSTORM OR TWO OVER THE NORTHERN AND EASTERN
FOOTHILLS OF MARICOPA COUNTY CANNOT BE RULED OUT TODAY AND
SUNDAY IN THE LATE AFTERNOON TO EVENING TIME FRAME.
SHORT TERM /TODAY THROUGH SUNDAY/
THE UPPER LEVEL PATTERN REMAINS STAGNANT WITH BROAD RIDGING OVER THE
EASTERN PACIFIC AND TROUGHING FEATURES STRADDLING THE RIDGE IN
THE NORTHERN STREAM. MEANWHILE, GOES WV IMAGERY SHOWS DRY AIR
BEGINNING TO INFILTRATE THE REGION FROM THE SOUTHWEST, BUT MODELS
SUGGEST THE RECENT INFLUX OF MOISTURE WON'T BE COMPLETELY
DISPLACED UNTIL MID TO LATE NEXT WEEK. WITH THAT SAID YOU MAY HAVE
STILL FELT THE LINGERING MOISTURE THIS MORNING AS PWATS FROM THE
12Z SOUNDING WERE AT 1.22" AND DEW POINTS ACROSS THE LOWER
DESSERTS THIS MORNING WERE IN THE UPPER 50S TO LOWER 60S. THIS
MOISTURE HAS ALSO BEEN A KEY COMPONENT IN DRIVING OVERNIGHT LOWS
TO BE IN THE UPPER 70S TO MID 80S, OR ROUGHLY 5F-10F DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR. AFTERNOON HIGHS ARE IN A SIMILAR
BOAT AT ~5F ABOVE NORMAL AS POSITIVE HEIGHT ANOMALIES ARE DOMINANT
ACROSS THE DESERT SW. THIS IS IN PART OF THE BROAD RIDGING
MENTIONED EARLIER BUT ALSO A SUBTROPICAL HIGH TO THE REGION'S SE
HAS BEEN BUILDING AND SLOWLY SHIFTING WESTWARDS WITH H5 HEIGHTS
BETWEEN 590-591DAM. UNFORTUNATELY THIS SUBTROPICAL HIGH IS
POSITIONED TO FAR TO OUR SOUTHEAST, RESULTING IN SOUTHWEST FLOW
ALOFT. THIS SOUTHWEST FLOW WILL MEAN DRIER AIR CONTINUING TO BE
ADVECTED INTO THE REGION OVER THE NEXT WEEK, AND AFTERNOON HIGHS
WILL CONTINUE TO BE BETWEEN 105F-110F. THESE TEMPERATURES WILL
KEEP THE REGION UNDER MODERATE TO LOCALIZED AREAS OF MAJOR
HEATRISK.
WITH THE SUBTROPICAL HIGH PUSHING FURTHER WESTWARDS THE LIFTING
MECHANISMS THAT CAME FROM THE UPPER LEVEL LOW HAVE ALSO BEEN
DISPLACED FURTHER WESTWARDS OFF THE BAJA COASTLINE AND SUBSIDENCE
WILL BEGIN TO TAKE HOLD. HOPE IS NOT COMPLETELY GONE THOUGH, AS
STORMS CAN ALREADY BE SEEN ON SATELLITE IN THE NORTHERN AZ HIGH
TERRAIN AND FAR SOUTHEAST AZ. THOUGH MOST OF THESE STORMS ARE WELL
OUTSIDE OUR CWA AN OUTFLOW COULD FORM AND MOVE INTO SOUTH-CENTRAL
AZ BY THE LATE AFTERNOON/EVENING. IF THIS BOUNDARY DOES MANIFEST
IT COULD BE ENOUGH TO TRIGGER AN ISOLATED STORM IN THE NORTHERN/
NORTHEASTERN FOOTHILLS AS HREF MUCAPE IN THE AFTERNOON RANGES
BETWEEN 250-500 J/KG, ENOUGH TO SUSTAIN CONVECTIVE ASCENT. CONDITIONS
SUNDAY WILL BE MUCH OF THE SAME AS CAMS SUGGEST STORM DEVELOPMENT
MOSTLY REMAINING IN THE NORTHERN AZ HIGH TERRAIN AND FAR SOUTHEAST
AZ.
LONG TERM /MONDAY THROUGH FRIDAY/
LOW LEVEL MOISTURE WILL NOT BE SCOURED OUT HEADING INTO NEXT
WEEK, ESPECIALLY FOR THE SOUTHEASTERN CORNER OF THE STATE, AND SO
A CONTINUATION OF DIURNALLY DRIVEN, HIGH TERRAIN SHOWERS/STORMS
LOOKS LIKELY. ACTIVITY WILL BE REDUCED AT TIMES DUE TO PERIODS OF
STRONGER SUBSIDENCE, ONE OF WHICH IS CAPTURED AS A STRONGER
MIDLEVEL INVERSION IN GFS BUFR SOUNDINGS DURING THE TUESDAY-
WEDNESDAY TIMEFRAME. THIS STRONGER ANTICYCLONIC SUBSIDENCE IS ALSO
EXPECTED TO SUPPORT TEMPERATURES A FEW DEGREES WARMER, DESPITE
FAIRLY STABLE H5 HEIGHTS, RESULTING IN A VERY MODEST EXPANSION OF
MAJOR HEATRISK ACROSS THE WESTERN DESERTS. THE PATTERN WILL CHANGE
MORE NOTICEABLY BY THE END OF THE WORK WEEK, AS ENSEMBLES ARE
POINTING TOWARDS A STRONGER SUBTROPICAL JET STREAK MOVING CLOSER
TO AND EVENTUALLY ONSHORE SOMEWHERE ALONG CALIFORNIA/NORTHERN BAJA
(NORTH/SOUTH DISCREPANCIES ARE APPARENT BETWEEN THE DIFFERENT
ENSEMBLE SUITES). THIS WILL INCREASE WINDS REGIONALLY AS THE
SUBTROPICAL JET IMPARTS DEEP SOUTHWESTERLY FLOW, DECREASE HEIGHTS
ALOFT, AND SUBSTANTIALLY SCOUR OUT THE LOW LEVEL MOISTURE ACROSS
THE REGION. AS A RESULT, ANTICIPATE ELEVATED FIRE WEATHER
CONCERNS, ESPECIALLY FOR SOUTHEAST CA AND SOUTHWEST AZ,
TEMPERATURES MODERATING CLOSER TO DAILY NORMALS, AND THE DIURNALLY
DRIVEN SHOWER/STORM CHANCES OVER AZ HIGH TERRAIN TO END.
AVIATION
UPDATED AT 1110Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE POTENTIAL FOR WEAK OUTFLOWS THIS EVENING WILL BE THE MAIN
AVIATION QUESTION DURING THE PERIOD. IT APPEARS NOW THAT THE USUAL
E'RLY SHIFT AT KPHX HAS BETTER POTENTIAL OF TAKING PLACE, BUT A
VRB GROUP REMAINS IN THE TAF TO INDICATE LINGERING UNCERTAINTY.
OUTSIDE OF THIS WINDOW, W'RLY FLOW WILL BE COMMON DURING THE
MAJORITY OF THE FORECAST. THE ONLY INTERRUPTION TO THIS PATTERN
MAY BE THE PRESENCE OF WEAK OUTFLOWS, MENTIONED ABOVE,
ORIGINATING FROM DISTANT CONVECTION. HOWEVER, GUIDANCE CONTINUES
TO BACK AWAY FROM THIS OUTCOME, SO NE'RLY SHIFTS AT KDVT AND KSDL
HAVE BEEN REPLACED WITH TYPICAL EVENING VRB GROUPS. THE POTENTIAL
FOR AN OUTFLOW IS NOT ZERO, BUT THEY WILL HIGHLY DEPENDENT ON
CONVECTIVE LOCATION, THEREFORE, AMENDMENTS MAY BE NEEDED AS WE
MOVE THROUGH THE DAY. KDVT AND KSDL WOULD BE THE MOST LIKELY TO
OBSERVE ANY OUTFLOW SWITCHES. FEW-SCT MID-LEVEL CLOUDS WILL BE
PRESENT BUT SHOULD GRADUALLY CLEAR THROUGH TODAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER CONCERNS SHOULD EXIST THROUGH SATURDAY NIGHT
UNDER MOSTLY CLEAR SKIES. CONFIDENCE IS GOOD THAT A SOUTHERLY WIND
COMPONENT WITH OCCASIONAL GUSTINESS WILL BE MAINTAINED AT KBLH
WHILE DIRECTIONS OSCILLATE BETWEEN SSE AND SW AT KIPL. SOME
STRONGER 20-30KT SUNDOWNER GUSTS WILL BE POSSIBLE AT KIPL
SATURDAY EVENING, THOUGH CONFIDENCE IS ONLY LOW TO MODERATE.
FIRE WEATHER
TEMPERATURES 3-8 DEGREES ABOVE NORMAL WILL PREVAIL WITH LOWER DESERT
HIGHS NEAR 110F IN SOME OF THE HOTTER SPOTS THROUGH THE MIDDLE OF
NEXT WEEK. IMPROVED HUMIDITY LEVELS WILL PREVAIL THROUGH THE
WEEKEND, WITH AFTERNOON MINIMUMS GENERALLY BETWEEN 15-20% AND
OVERNIGHT RECOVERIES AS LOW AS 25% IN THE FAR WESTERN DISTRICTS AND
BETWEEN 35-50% FOR MOST OTHER AREAS. WITH THE INCREASING MOISTURE
WILL ALSO COME SLIGHT CHANCES FOR ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY. CHANCES WILL BECOME ALMOST ENTIRELY
CONFINED TO THE HIGH TERRAIN OF THE EASTERN DISTRICTS BY THIS
AFTERNOON. RAINFALL POTENTIAL WILL BE LIMITED, SO LOCALLY GUSTY
OUTFLOW WINDS AND DRY LIGHTNING POTENTIALLY LEADING TO NATURAL
FIRE STARTS ARE THE MAIN CONCERNS. WINDS WILL GENERALLY REMAIN
TERRAIN-DRIVEN OUTSIDE THE INFLUENCE OF THUNDERSTORM OUTFLOWS,
WITH SPEEDS AT OR BELOW 15 MPH AND AFTERNOON/EARLY EVENING UPSLOPE
AND UPVALLEY GUSTS UP TO 25 MPH.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...RYAN
LONG TERM...WHITTOCK
AVIATION...18/RW
FIRE WEATHER...WHITTOCK/RYAN
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