141
FXUS65 KPSR 150843
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
143 AM MST MON JUN 15 2026
KEY MESSAGES
- TEMPERATURES AROUND 3 TO 8 DEGREES ABOVE DAILY NORMAL WILL
RESULT IN WIDESPREAD MODERATE HEAT RISK WITH ISOLATED POCKETS OF
MAJOR HEAT RISK AT TIMES, THROUGH THE MIDDLE OF THE WEEK.
- CHANCES FOR SHOWERS AND THUNDERSTORMS REMAIN IN THE FORECAST FOR
AT LEAST ONE MORE DAY, WITH THE BEST POTENTIAL FOCUSED OVER
FOOTHILL AND HIGH TERRAIN LOCATIONS, THOUGH LOWER DESERT STORMS
CANNOT BE RULED OUT.
- AN EASTERN PACIFIC ARE OF LOW PRESSURE WILL HELP TO DRY THE
REGION OUT WHILE ALSO PROVIDING COOLER TEMPERATURES DURING THE
BACK HALF OF THE WEEK AND INTO THE WEEKEND.
SHORT TERM /TODAY THROUGH TUESDAY/
CURRENT UPPER-AIR ANALYSIS REVEALS A SLIGHTLY MORE REFINED PATTERN
COMPARED TO THIS TIME 24 HOURS AGO, BUT MULTIPLE DIFFERENT SYSTEMS
REMAIN IN CLOSE PROXIMITY TO THE DESERT SOUTHWEST. THE INTERPLAY
BETWEEN THE WESTWARD PROGRESSING SUB-TROPICAL RIDGE AND A WEAK
EASTERN PACIFIC TROUGH CONTINUES, HELPING TO KEEP MOISTURE LEVELS
AROUND 150-200% OF NORMAL FOR THIS TIME OF YEAR, WHICH TRANSLATES TO
PWATS BETWEEN 1.0-1.4". THIS STILL REMAINS A DECENT WAYS OFF FROM
WHAT WE SEE DURING THE MONSOON SEASON (WHICH OFFICIALLY BEGINS
TODAY), BUT IT HAS BEEN SUFFICIENT ENOUGH TO SPARK SOME ISOLATED TO
SCATTERED CONVECTION ACROSS PORTIONS OF OUR FORECAST AREA. IN FACT,
SOME FOLKS ACROSS EASTERN PORTIONS OF OUR FORECAST AREA MIGHT HAVE
BEEN WOKEN UP BY SOME EARLY MORNING THUNDERSTORM, AND ISOLATED CELLS
CANNOT BE RULED OUT FOR THIS AREA EVEN THROUGH SUNRISE. WITH THIS
MOISTURE LIKELY NOT GOING ANYWHERE FOR ANOTHER 24-36 HOURS, ANOTHER
ROUND OF CONVECTIVE ACTIVITY IS EXPECTED THIS AFTERNOON AND EVENING,
WITH PERHAPS EVEN MORE COVERAGE FOR LOWER DESERT AREAS AND THE
PHOENIX METRO.
EVEN THOUGH MOISTURE LEVELS ARE NOT INCREASING, OUR RAINFALL CHANCES
ARE ACTUALLY A BIT HIGHER (20-40%) COMPARED TO YESTERDAY'S POPS.
CAMS ARE IN AGREEMENT WITH THESE HIGHER CHANCES AS THEY SHOW BETTER
SHOWER AND THUNDERSTORM COVERAGE, BUT WHY IS THIS THE CASE IF
MOISTURE IS NEARLY THE SAME? THE ANSWER LIKELY LIES WITHIN THE
EVOLUTION OF THE UPPER-LEVEL PATTERN. GUIDANCE POINTS TOWARD
INCREASING FLOW ALOFT ACROSS CENTRAL AND EASTERN ARIZONA, CREATING
MASS SPEED DIVERGENCE OVER THE REGION, SETTING UP A FAVORABLE
ENVIRONMENT FOR UPDRAFT MAINTENANCE. OROGRAPHIC LIFT WILL LIKELY BE
THE TRIGGERING MECHANISM, BUT THE SYNOPTIC LIFT WILL ALLOW FOR
STORMS THAT DO POP TO LIVE LONGER. AS FLOW ALOFT INCREASE, IT WILL
ALSO SWITCH FROM MORE WESTERLY TO NORTHWESTERLY, WHICH MAY ALSO AID
IN SEEING BETTER RAINFALL COVERAGE ACROSS LOWER DESERT AREAS.
POTENTIAL HIGH TERRAIN OUTFLOWS WILL BE MORE ALIGNED WITH MEAN FLOW,
WHICH IN TURN COULD CREATE A MORE ADVANTAGEOUS SETUP FOR THESE
BOUNDARIES TO DESCEND TO THE LOWER ELEVATIONS DEPENDING ON WHERE
CELLS INITIATE. IT IS HIGHLY CONDITIONAL, BUT EVEN THE PHOENIX METRO
MAY SEE SOME RAINFALL OUT OF THIS. BESIDES GUSTY OUTFLOW WINDS, THE
MAIN IMPACTS WITH POTENTIAL CONVECTION WILL BE OCCASIONAL LIGHTNING
AND AREAS OF BLOWING DUST, THE LATTER BEING DEPENDENT ON IF WE CAN
GET LOWER DESERT STORMS OVER DUST PRONE AREAS.
WE BEGIN TO SLOWLY DRY OUT STARTING TUESDAY, BUT LINGERING MOISTURE
WILL STILL HOVER CLOSE TO 150-175% OF NORMAL. THIS SLIGHT DROP, WITH
THE ADDITION OF SUBSIDENCE ALOFT THANKS TO GREATER INFLUENCE OF
BROAD RIDGING, WILL TAMP DOWN FURTHER RAIN POTENTIAL IN THE NEAR
TERM. CHANCES FOR PARTS OF OUR AREA ARE NOT ZERO, THERE ARE CAMS
THAT DO HINT AT ISOLATED ACTIVITY, BUT ANY RAINFALL MAY OCCUR WILL
BE HEAVILY BASED ON OROGRAPHIC INTERACTIONS.
IN TERMS OF TEMPERATURES DURING THIS TIMEFRAME, IT WILL BASICALLY
STATUS QUO FROM WHAT WE SAW THIS PAST WEEKEND ACROSS THE REGION.
AFTERNOON READINGS WILL BE AROUND 3-8 DEGREES ABOVE NORMAL FOR THE
MIDDLE OF JUNE, WHICH EQUATES TO OBSERVATIONS RANGING FROM 105-112
FOR LOWER DESERT AREAS. UNFORTUNATELY OVERNIGHT LOWS WILL NOT OFFER
MUCH IN THE WAY OF RELIEF, ESPECIALLY AROUND POPULATION CENTERS, AS
ELEVATED MOISTURE, COMBINED WITH THE URBAN HEAT ISLAND, WILL KEEP
READINGS MOSTLY IN THE 80S. THE NBM HAS ACTUALLY BEEN OFF MY SEVERAL
DEGREES THE PAST FEW NIGHTS AT SKY HARBOR, WHERE WE SAW OUR FIRST 90
DEGREE LOW OF THE YEAR YESTERDAY MORNING, WHICH WAS 4 DEGREES ABOVE
FORECASTS. THE ONE POTENTIAL AVENUE FOR SOME COOLER THAN EXPECTED
READINGS WILL COME FROM THE ABOVE MENTIONED RAINFALL/OUTFLOWS THIS
EVENING, BUT THAT IS NOT A GUARANTEE. NONETHELESS, THIS MIX OF MILD
OVERNIGHT, AND HOT DAYTIME TEMPERATURES WILL RESULT IN WIDESPREAD
MODERATE, TO EVEN POCKETS OF MAJOR HEATRISK. PROPER HEAT PRECAUTIONS
SHOULD BE USED IF PLANS TAKE YOU OUTSIDE FOR EXTENDED PERIODS
DURING THE NEXT FEW DAYS.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
THE REMAINDER OF THE WEEK LOOKS GENERALLY UNEXCITING, AT LEAST FOR
OUR AREA, AS DRY AIR FILTERS IN FROM WEDNESDAY ONWARD. THERE COULD
BE JUST ENOUGH LEFT OVER MOISTURE TO SQUEEZE OUT SOME SHOWERS OVER
SOUTHEAST ARIZONA OR HIGH TERRAIN AREAS TO OUR NORTH AND EAST, BUT
THE MAJORITY OF ACTIVITY SHOULD BE FOCUSED OVER TUCSON AND FLAGSTAFF
CWAS. SOMETHING A BIT PECULIAR IS THE PRESENCE OF POPS AND QPF FOR
THE PHOENIX METRO ON FRIDAY, EVEN THOUGH PWATS WILL BE FALLING
CLOSER TOWARD NEAR AND BELOW NORMAL FOR JUNE. MOISTURE AT THOSE
LEVELS WOULD LIKELY NOT EVEN BE ENOUGH TO GET HIGH TERRAIN STORMS,
LET ALONE LOWER DESERT RAINFALL. THIS COULD BE JUST AN ARTIFACT OF
THE INGESTED WPC RAINFALL FORECAST THAT GETS ADJUSTED WITH TIME, BUT
WE WOULD BE HARD PRESSED TO GET RAINFALL ON FRIDAY WITH DRY AIR
RUSHING IN. WHO KNOWS, MAYBE IF WE CAN GET ENOUGH SYNOPTIC LIFT WITH
AN APPROACHING EASTERN PACIFIC TROUGH TO INTERACT WITH STUBBORN
MOISTURE, SOME RAIN CHANCES CANNOT BE COMPLETELY RULED OUT, BUT AS
OF NOW, I LEAN MORE TOWARD THE DRIER SOLUTION.
SPEAKING OF THAT TROUGH, ITS MIGRATION CLOSER TO THE DESERT
SOUTHWEST BY THE LATTER HALF OF THE WEEK WILL HELP US "COOL" OFF A
BIT AS TEMPERATURES FALL CLOSER TO NORMAL, WITH PERHAPS SOME AREAS
EVEN SEEING BELOW NORMAL READINGS BY THE WEEKEND. NOW, THIS DOES NOT
MEAN WE GET A BREAK FROM THE TRIPLE DIGITS, BUT AT LEAST DAILY
FORECASTED HIGHS FALL CLOSER TO 99-108. NOT A MASSIVE AMOUNT OF
RELIEF, BUT ENOUGH TO BACK REGIONAL HEATRISK DOWN TO THE LOWER END
OF THE MODERATE CATEGORY. HEAT PRECAUTIONS WILL STILL NEED TO REMAIN
IN PLACE REGARDLESS. LOWER MOISTURE WITH THOSE COOLER TEMPS WILL
ALSO ALLOW FOR SOME MORE COMFORTABLE OVERNIGHT LOWS IN THE UPPER 60S
TO NEAR 80 DEGREES. SOMETHING THAT WILL HAVE TO MONITORED IS THE
POTENTIAL FOR ELEVATED FIRE WEATHER CONDITIONS AS THIS FEATURE WILL
INCREASE WINDS REGIONWIDE. STRENGTH OF GUSTS IS STILL UNCERTAIN AT
THIS TIME, BUT WITH VERY DRY AIR EXPECTED TO BE IN PLACE, IT WOULD
NOT TAKE MUCH WIND TO INCREASE FIRE DANGER.
AVIATION
UPDATED AT 0525Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THUNDERSTORM ACTIVITY AND ASSOCIATED STRONG WINDS LATE MONDAY
AFTERNOON/EARLY EVENING WILL BE THE MAIN AVIATION WEATHER
CONCERNS. IN THE MEANTIME, THE OVERALL WIND PATTERN SHOULD FOLLOW
THE TYPICAL DIURNAL TRENDS INTO AT LEAST EARLY MONDAY AFTERNOON
WITH EASTERLY WINDS OVERNIGHT SHIFTING OUT OF THE WEST BY LATE
MORNING/EARLY AFTERNOON. SOME OCCASIONAL GUSTS NEAR 20 KTS WILL BE
POSSIBLE TOMORROW AFTERNOON. THEREAFTER, THUNDERSTORM ACTIVITY
DEVELOPING OVER THE HIGHER TERRAIN AREAS TO THE NORTH WILL LIKELY
DRIFT SOUTHWARD AND ATTEMPT TO REACH THE PHOENIX AREA LATE
AFTERNOON/EARLY EVENING. EVEN THOUGH A HANDFUL OF HI-RES MODEL
GUIDANCE SHOWS AN INCREASE IN CONVECTIVE ACTIVITY, THERE IS HIGH
UNCERTAINTY IN THE OVERALL COVERAGE AND TIMING. THEREFORE, A
PROB30 HAS BEEN INCLUDED FOR ALL SITES BETWEEN 15/23Z TO 16/03Z AT
THIS TIME. GUSTY, ERRATIC WINDS WILL BE THE PRIMARY HAZARD WITH A
70% CHANCE OF GUSTS EXCEEDING 35 MPH. FEW-SCT MID-LEVEL CLOUD
DECKS WILL BE COMMON WITH OCCASIONAL BKN COVERAGE DURING
CONVECTIVE ACTIVITY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER FEW MID-LEVEL CLOUD DECKS
DURING THE DAY MONDAY CAN BE EXPECTED THROUGHOUT THE TAF PERIOD.
AT KIPL, CURRENT WESTERLY WINDS WILL BE SHIFTING BACK OUT OF THE
SOUTHEAST DURING THE OVERNIGHT PERIOD WITH THIS GENERAL DIRECTION
PREVAILING THROUGH THE AFTERNOON HOURS BEFORE SHIFTING BACK OUT
OF THE WEST MONDAY EVENING. AT KBLH, WINDS WILL FLUCTUATE OUT OF
THE SOUTH TO SOUTHWEST. OVERALL WIND SPEEDS WILL GENERALLY REMAIN
UNDER 12 KTS.
FIRE WEATHER
ELEVATED MOISTURE LEVELS WILL RESULT IN ISOLATED TO SCATTERED
THUNDERSTORMS ONCE AGAIN THIS AFTERNOON AND EVENING, MAINLY FOR
HIGHER TERRAIN AREAS, THAT WILL BE CAPABLE OF PRODUCING GUSTY AND
ERRATIC WINDS AND DRY LIGHTNING. OUTSIDE OF ANY THUNDERSTORM
OUTFLOWS, WINDS WILL BE DIURNALLY DRIVEN WITH THE TYPICAL
AFTERNOON AND EVENING UPSLOPE/UPVALLEY BREEZINESS BETWEEN 15-25
MPH. ENHANCED MOISTURE WILL BRING SOME BENEFIT AS MINRHS RANGE
BETWEEN 15-20% FOR THE MAJORITY OF THE REGION, WITH THE EXCEPTION
BEING SE CALIFORNIA WHERE READINGS WILL BE CLOSER TO 10%. FOR
THOSE AREAS WITH BETTER MOISTURE, THE OVERNIGHT PERIOD WILL OFFER
AT LEAST SOME MODEST RELIEF AS MAXRH READINGS RISE TO 30-50% EACH
NIGHT. THOSE DRIER SPOTS FURTHER WEST HOWEVER WILL ONLY SEE
VALUES INCREASE TO AROUND 25%. MOISTURE SCOURS OUT DURING THE BACK
HALF OFF THE WEEK, WHICH WILL DECREASE DRY THUNDERSTORM
POTENTIAL, BUT DROP RHS CLOSER TO 10-15% DURING THE AFTERNOONS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...RW
LONG TERM...RW
AVIATION...LOJERO
FIRE WEATHER...RW
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