325
FXUS65 KPSR 112122
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
222 PM MST THU JUN 11 2026
KEY MESSAGES
- FAIRLY STABLE TEMPERATURES AROUND 4 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.
- AN INCREASE IN MOISTURE BY THE END OF THE WEEK INTO THE WEEKEND
WILL LEAD TO SLIGHT CHANCES FOR SHOWERS AND STORMS, WITH BETTER
CHANCES CURRENTLY FOCUSED DURING MORNING AND OVERNIGHT PERIODS.
- OVERNIGHT LOW TEMPERATURES WILL BE NOTICEABLY WARMER AS A RESULT
OF INCREASED HUMIDITY, WITH THE TYPICALLY WARMER LOWER DESERT
LOCALES STRUGGLING TO COOL BELOW 80 DEGREES BY THE WEEKEND.
SHORT TERM /TODAY THROUGH SATURDAY/
CURRENT RAP ANALYSIS AND SATELLITE IMAGERY SHOWS BROAD RIDGING
OVER THE EASTERN PACIFIC AND AN UPPER LEVEL LOW OFF THE WESTERN
COASTLINE OF THE BAJA PENINSULA. WITH THIS UPPER LEVEL LOW A SWATH
OF MOISTURE CAN ALREADY BE SEEN PUSHING INTO THE DESERT SW FROM
THE GULF OF CALIFORNIA. MODELS REMAIN IN GOOD AGREEMENT THAT THIS
UPPER LEVEL LOW WILL CONTINUE TO TRACK NORTHEASTWARDS ALONG THE
BAJA PENINSULA CAUSING PWATS TO CLIMB TO 1.0-1.5" OR NEAR 200-250%
OF NORMAL, THROUGHOUT THE WEEKEND.
THE FIRST CHANCE OF ACTIVITY WILL BE FRIDAY MORNING IN
SOUTHEASTERN CA AND SOUTHWESTERN AZ. DURING THIS TIME, IN
ADDITION TO THE PLENTIFUL MOISTURE, DETERMINISTIC RUNS SIGNAL FOR
DECENT POCKET OF CYCLONIC VORTICITY RIDING UP ALONG THE COLORADO
RIVER VALLEY FRIDAY, WITH THE HREF SHOWING MUCAPES BETWEEN
250-500 J/KG. THESE CONDITIONS WILL BE FAVORABLE FOR THE
DEVELOPMENT IN ISOLATED SHOWERS STARTING EARLY FRIDAY MORNING
BEFORE DISSIPATING HEADING INTO THE AFTERNOON HOURS. BY SATURDAY
MUCH OF THE LIFTING MECHANISMS IN PLACE FROM FRIDAY WILL HAVE
DWINDLED, HOWEVER MIXING RATIOS OVER SOUTHCENTRAL AZ AND THE
PHOENIX METRO WILL BEGIN TO INCREASE FROM 7-8 G/KG TO BETWEEN
8-10 G/KG BY SATURDAY AFTERNOON/EVENING, AND MINIMAL MUCAPE
(~100-250 J/KG) WILL REMAIN OVER THE REGION. THIS CAN BE ENOUGH
TO FACILITATE THE DEVELOPMENT OF ISOLATED SHOWERS IN THE LOWER
DESERTS, HOWEVER MODELS HINT AT THE BULK OF THE ACTIVITY REMAINING
EAST OF THE PHOENIX METRO IN THE EASTERN HIGHER TERRAIN AREAS
WHERE POPS ARE CURRENTLY ONLY AROUND 10-15%.
TEMPERATURES THROUGH THE REMAINDER OF THE WORKWEEK AND INTO THE
BEGINNING OF THE WEEKEND WILL REMAIN FAIRLY STABLE BETWEEN
104F-110F ACROSS THE LOWER DESERTS. THIS IS A RESULT IN H5 HEIGHTS
REMAINING FAIRLY STABLE AS WELL, WITH HEIGHTS BETWEEN 588-591 DAM
PERSISTING OVER THE DESERT SW. ONE NOTABLE DIFFERENCE WILL BE
WARMER OVERNIGHT LOWS, THANKS TO THE INCREASE IN MOISTURE AND
SOME INFLUENCE FROM CLOUD COVER FRIDAY-SATURDAY LEADING TO LOWS IN
THE UPPER 70S TO MID 80S. ALL THAT BEING SAID, WIDESPREAD
MODERATE TO LOCALIZED AREAS OF MAJOR HEATRISK WILL IN PLACE
THROUGH THE WEEKEND AND INTO NEXT WEEK. SO ENSURE TO STAY HYDRATED
AND FOLLOW PROPER HEAT SAFETY PROTOCOL.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
A FEW CHANGES ARE NOTED IN THE LATEST ENSEMBLES AND GLOBAL MODEL
RUNS: MEASURES OF MOISTURE OVER THE FORECAST AREA (E.G., PWATS,
MIXING RATIOS) ARE PEAKING AT SLIGHTLY LOWER VALUES, HOWEVER,
MOISTURE IS NOT EFFECTIVELY SCOURED OUT AND WILL LIKELY LINGER
INTO EARLY NEXT WEEK, PROVIDING FURTHER CHANCES FOR AFTERNOON AZ
HIGH TERRAIN THUNDERSTORMS. THE LIMITED INSTABILITY WITH LARGE
T/TD SPREADS AND DRY SUB-CLOUD LAYER WILL FAVOR DRY LIGHTNING AND
GUSTY OUTFLOW WINDS VERSUS HEAVY RAINFALL, AS IS TYPICAL WITH
CONVECTIVE ACTIVITY IN JUNE. THESE CHANGES COME AS ENSEMBLES NOW
SHOW THE CYCLONICALLY CURVED POLAR JET, AND ANY ATTENDANT
SHORTWAVE TROUGHS ROTATING THROUGH THE BASE OF THE MEAN TROUGH
OVER THE NORTH-CENTRAL CONUS, REMAINING FURTHER EAST OF THE
REGION. WHILE FLOW ALOFT WILL TURN OUT OF A DRIER WESTERLY OR
NORTHWESTERLY DIRECTION SUNDAY, THE MORE DISTANT INFLUENCE OF
POLAR JET WILL MEAN THAT THE FLOW STAYS FAIRLY WEAK OVER REGION,
MUCH LESS EFFECTIVE AT SCOURING OUT LINGERING MOISTURE. POSITIVE
MIDLEVEL HEIGHT ANOMALIES REMAINING FAIRLY STAGNANT THROUGH THE
MIDDLE OF THE WEEK WILL ALLOW FOR STEADY TEMPERATURES IN A 4 TO 8
DEGREE ABOVE NORMAL RANGE. TEMPERATURES WILL BE SLIGHTLY HIGHER IN
THE WESTERN DESERTS, BUT REGARDLESS, LOWER DESERT HIGHS WILL PEAK
NEAR OR JUST ABOVE 110F FOR THE TYPICALLY HOTTER SPOTS.
AVIATION
UPDATED AT 1814Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH FRIDAY
AFTERNOON UNDER INCREASING MID/HIGH CLOUD DECKS. WESTERLY WINDS
WILL TAKE HOLD HEADING INTO THIS AFTERNOON AND PERSISTING
THROUGHOUT MUCH OF THE TAF PERIOD. CONFIDENCE IN A TYPICAL DIURNAL
EASTERLY SHIFT OVERNIGHT TONIGHT IS LOWER WITH VARIABLE WINDS OR
A BRIEF EASTERLY SWITCH EXPECTED AT KPHX. PERIODIC GUSTS UPWARDS
OF 20 KTS WILL BE POSSIBLE THIS AFTERNOON AND POTENTIALLY
EXTENDING INTO THE EVENING/OVERNIGHT HOURS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH FRIDAY
MORNING UNDER INCREASING MID/HIGH CLOUD DECKS. WINDS AT KIPL WILL
FAVOR THE E/SE THROUGH THIS AFTERNOON BEFORE SWITCHING AROUND TO
THE W FOR A FEW HOURS THIS EVENING. AT KBLH, WINDS WILL FLUCTUATE
BETWEEN THE SE AND SW. OVERALL WIND SPEEDS WILL GENERALLY BE AOB
10 KTS. A FEW VICINITY SHOWERS WILL BE POSSIBLE FRIDAY MORNING
NEAR THE TERMINALS WITH NO IMPACTS EXPECTED.
FIRE WEATHER
TEMPERATURES 3-6 DEGREES ABOVE NORMAL WILL PREVAIL WITH LOWER
DESERT HIGHS NEAR 110F IN SOME OF THE HOTTER SPOTS, ESPECIALLY BY
THE WEEKEND. DRY CONDITIONS WILL CONTINUE TODAY WITH RELATIVE
HUMIDITY BOTTOMING OUT AROUND 8-15%. LOW LEVEL MOISTURE WILL
CONTINUE TO IMPROVE IMPROVE THROUGH THIS WEEKEND WITH MINIMUM
HUMIDITY LARGELY ABOVE 15% AND OVERNIGHT RECOVERIES GENERALLY
IMPROVING FROM POOR TO FAIR. WITH THE INCREASING MOISTURE WILL
ALSO COME INCREASING CHANCES FOR ISOLATED SHOWER/T-STORM ACTIVITY
STARTING FRIDAY MORNING ALONG THE COLORADO RIVER VALLEY AND THEN
AGAIN ACROSS THE AZ HIGH TERRAIN OVER THE WEEKEND, WITH GUSTY
OUTFLOW WINDS AND DRY LIGHTNING POTENTIALLY LEADING TO NATURAL
FIRE STARTS BEING THE MAIN HAZARDS. THE OVERALL WIND PATTERN WILL
REMAIN DIURNAL WITH SPEEDS AT OR BELOW 15 MPH AND LIMITED
AFTERNOON UPSLOPE GUSTINESS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...RYAN
LONG TERM...WHITTOCK
AVIATION...SMITH
FIRE WEATHER...SALERNO/RYAN
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