622
FXUS65 KPSR 130507
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1005 PM MST FRI JUN 12 2026
UPDATE
UPDATED AVIATION
KEY MESSAGES
- TEMPERATURES HOVERING AROUND 3 TO 8 DEGREES ABOVE DAILY NORMALS
WILL RESULT IN WIDESPREAD MODERATE HEATRISK WITH ISOLATED POCKETS OF
MAJOR HEATRISK THROUGH THE MIDDLE OF NEXT WEEK.
- AN INCREASE IN MOISTURE THROUGH THE WEEKEND WILL LEAD TO SLIGHT
CHANCES FOR SHOWERS AND STORMS WITH BETTER CHANCES FOCUSED DURING
MORNING AND OVERNIGHT TIME FRAME.
- OVERNIGHT LOW TEMPERATURES WILL BE NOTICEABLY WARMER AS A RESULT
OF THE INCREASED HUMIDITY WITH MANY OF THE TYPICALLY WARMER LOWER
DESERT LOCALES STRUGGLING TO COOL BELOW 80 DEGREES.
SHORT TERM /TODAY THROUGH SUNDAY/
GOES MID-LEVEL WV IMAGERY SHOWS THE EASTERN PACIFIC REMAINING UNDER
BROAD RIDGING WITH TWO TROUGHING FEATURES ON EITHER SIDE. ONE WELL
DEFINED SYSTEM IN THE GULF OF ALASKA, WHILE THE SECOND FEATURE IS
CENTERED WELL OVER CANADA, HOWEVER AFFECTING THE BORDERING STATES
(ND, MN, WI & MI). MEANWHILE, HERE IN THE DESERT SW, THE UPPER LEVEL
LOW CONTINUES TO TRACK NORTHWARDS ALONG THE BAJA PENINSULA WITH
AMPLE MOISTURE. THIS SYSTEM, TO THE REGION'S SW, IS WHAT BROUGHT
SOME SPRINKLES EARLY THIS MORNING ACROSS THE PHOENIX METRO AND WILL
CONTINUE TO BRING SPOTTY ACTIVITY THROUGHOUT THE WEEKEND. CURRENTLY
ISOLATED THUNDERSTORMS CAN BE SEEN ON RADAR OVER YUMA COUNTY, AND
THANKS TO AN 18Z BALLOON LAUNCH OUT OF YUMA WE CAN TAKE A CLOSER
LOOK AT THE CONDITIONS THAT HELPED FUEL THE ACTIVITY THIS AFTERNOON.
AS OF THE 18Z SOUNDING, PWATS WERE AT 1.48", AND MUCAPE WAS AT 457
J/KG, ENOUGH FOR CONVECTION TO CONTINUE THE DEVELOPMENT OF SOME
ISOLATED STORMS. HOWEVER, WITH CIN AT -300 J/KG AND VERY DRY LOWER
ATMOSPHERE CONTINUED DEVELOPMENT WILL STRUGGLE TO REALLY BLOSSOM,
ALBEIT NOT IMPOSSIBLE, AS THE AFTERNOON PROGRESSES. ACROSS WESTERN
MARICOPA COUNTY AND SOUTH CENTRAL AZ A BAND OF ACTIVITY CAN ALSO BE
SEEN ON RADAR THAT ORIGINALLY DEVELOPED JUST SOUTH OF MARICOPA
COUNTY AND IS STREAMING OVERHEAD MOVING TO THE NE IN THE FORM OF
MOSTLY VIRGA SHOWERS. DUE TO THIS MOST OF THE AREAS CAN EXPECT TO
RECEIVE NO MEASURABLE RAINFALL THROUGHOUT THE REST OF TODAY.
BY SATURDAY PWATS REMAIN ELEVATED WITH MOST OF THE LOWER DESERTS
EXPECTING VALUES BETWEEN 1.2-1.5" OR ROUGHLY 200-250% OF NORMAL, AND
WITH 1000-700 MB MIXING RATIOS FLOATING BETWEEN 8-10 G/KG ACROSS
SOUTHWEST AND SOUTH-CENTRAL AZ. ADDITIONALLY, THE ECMWF
DETERMINISTIC SHOWS ANOTHER POCKET OF VORTICITY MOVING SW TO NE
ACROSS THE STATE EARLY SATURDAY MORNING. THIS CAN BE ENOUGH TO SET
OF ANOTHER ROUND OF EARLY MORNING VIRGA SHOWERS WITH AREAS OF
ISOLATED SHOWERS. UNFORTUNATELY, SIMILAR TO FRIDAY MORNING
ACCUMULATION TOTALS ARE EXPECTED TO BE NEAR IF NOT AT ZERO IN THE
LOWER DESERTS AND THE PHOENIX METRO. BY THE AFTERNOON HOURS ACTIVITY
IS EXPECTED TO SHIFT FURTHER EASTWARDS INTO THE FOOTHILLS AND THE
NORTHERN AZ HIGH TERRAIN.
TEMPERATURES OVER THE WEEKEND WILL REMAIN IN THE MID 100S TO UPPER
100S BY SUNDAY AS THE SUBTROPICAL HIGH BEGINS TO INCH CLOSER TO THE
REGION. CURRENT H5 HEIGHTS ARE SITTING BETWEEN 589-590 DAM AND
EXPECTED TO CLIMB SLIGHTLY BY SUNDAY HEADING INTO NEXT WEEK TO NEAR
590-591 DAM. OVERNIGHT LOW TEMPERATURES WILL ALSO BE ABOVE NORMAL
OVER THE WEEKEND, BY 5F-8F, PUTTING OVERNIGHT LOWS IN THE UPPER 70S
TO MID 80S ACROSS THE LOWER DESERT AREAS. THIS HAS LEAD TO
WIDESPREAD MODERATE TO LOCALIZED MAJOR HEATRISK. WITH THE ABSENCE OF
MUCH OVERNIGHT/ EARLY MORNING RELIEF FROM THE HEAT ENSURE TO STAY
HYDRATED AND FOLLOW HEAT SAFETY PRECAUTIONS.
LONG TERM /MONDAY THROUGH THURSDAY/
ALTHOUGH UNCERTAINTY REMAINS IN THE UPPER LEVEL PATTERN NEXT WEEK
AND ESPECIALLY BY THE END OF THE WEEK, ENSEMBLES CONTINUE TO
ADVERTISE H5 HEIGHT ALOFT REMAINING FAIRLY STABLE THROUGH AT LEAST
THE FIRST HALF OF THE WEEK AND DRY (ALBEIT WEAK) WESTERLY OR
NORTHWESTERLY FLOW BEING MAINTAINED. TEMPERATURES MAY WARM A FEW
DEGREES TUESDAY AND/OR WEDNESDAY UNDER SLIGHTLY DRIER CONDITIONS AND
A PERIOD OF STRONGER SUBSIDENCE, AS SUGGESTED BY DEEPER MIDLEVEL
INVERSIONS IN MODEL SOUNDINGS, RESULTING IN SLIGHTLY HIGHER COVERAGE
OF MAJOR HEATRISK FOR A DAY OR TWO. EXTREME HEAT PRODUCTS MAY NEED
TO BE CONSIDERED FOR THIS TIMEFRAME, BUT CONFIDENCE IS CURRENTLY
LOWER THAN USUAL ON THE TEMPERATURE FORECAST, AS IT HAS BEEN
FLUCTUATING A FEW DEGREES UP OR DOWN WITH EACH RUN OVER THE LAST FEW
DAYS. REGARDLESS, TEMPERATURES 3F-8F ABOVE NORMAL WILL PERSIST
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK, AND MODERATE HEATRISK WILL
BE WIDESPREAD.
AVIATION
UPDATED AT 0505Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE POTENTIAL FOR ISOLATED SHRA AND UNUSUAL WIND SHIFT TIMING AND
DIRECTIONS WILL BE THE MAIN WEATHER CONCERNS THROUGH SATURDAY NIGHT
UNDER PERIODS OF MID/HIGH CIGS. CONFIDENCE IS GOOD THE TYPICAL
NOCTURNAL EASTERLY WIND SHIFT WILL EITHER BE DELAYED OR ABSENT
OVERNIGHT/EARLY MORNING AND WIND DIRECTIONS MAY JUST BECOME
VARIABLE. ISOLATED SHRA MAY SWEEP THROUGH THE AREA THROUGH SATURDAY
MORNING; WHILE MOST ACTIVITY WILL BE VIRGA OR LIMITED DURATION SHRA,
THIS MAY CREATE A PERIOD OF ERRATIC WIND DIRECTIONS IN THE MORNING
BEFORE REVERTING BACK TO A WEST DIRECTION BY AFTERNOON. MODELS
CONTINUE TO SUGGEST SHRA/TSRA WELL NORTH OF THE TERMINALS LATE
AFTERNOON SENDING AN OUTFLOW BOUNDARY SOUTH INTO THE PHOENIX METRO.
MODELS ARE LESS RESOLUTE WITH THIS OUTCOME, AND CONFIDENCE IS VERY
LOW, BUT KSDL AND KDVT WOULD BE THE MOST LIKELY TO EXPERIENCE AN
ABRUPT WIND SHIFT FROM THIS OUTFLOW SATURDAY EVENING.
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 SE 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, ESPECIALLY OVER THE
WEEKEND. IMPROVED HUMIDITY LEVELS WILL PREVAIL THROUGH THE WEEKEND,
WITH AFTERNOON MINIMUMS BETWEEN 15-20% AND OVERNIGHT RECOVERIES IN A
POOR TO FAIR CATEGORY, WITH VALUES 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. THERE IS A SLIGHT CHANCE OF
ISOLATED SHOWERS SATURDAY MORNING ACROSS SOUTHCENTRAL AZ BUT CHANCES
WILL THEN BECOME ALMOST ENTIRELY CONFINED TO THE HIGH TERRAIN OF THE
EASTERN DISTRICTS BY SATURDAY AFTERNOON. RAINFALL POTENTIAL WILL BE
LIMITED, SO LOCALLY GUSTY OUTFLOW WINDS AND DRY LIGHTNING
POTENTIALLY LEADING TO NATURAL FIRE STARTS ARE THE MAIN CONCERNS.
THE OVERALL WIND PATTERN WILL REMAIN DIURNAL 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
FIRE WEATHER...WHITTOCK/RYAN
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