160
FXUS65 KPSR 172351
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
451 PM MST WED JUN 17 2026
UPDATE...UPDATED 00Z AVIATION DISCUSSION
KEY MESSAGES
- ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL RETURN THIS
AFTERNOON, MAINLY OVER THE FOOTHILLS OF MARICOPA COUNTY, BUT A
FEW STORMS COULD FORM IN THE LOWER DESERTS WITH THE MAIN THREATS
BEING GUSTY OUTFLOW WINDS AND BLOWING DUST.
- TEMPERATURES UP TO 8 DEGREES ABOVE NORMAL WILL COOL CLOSER TO
THE SEASONAL AVERAGE BY THE END OF THE WEEK ALLOWING MODERATE
HEATRISK TO BE REDUCED TOWARDS A MINOR CATEGORY.
- AN APPROACHING EAST PACIFIC WEATHER DISTURBANCE LATE THIS WEEK
WILL DRY OUT THE REGION, WHILE BRINGING INCREASINGLY BREEZY
CONDITIONS AND COOLING TEMPERATURES.
SHORT TERM /TODAY THROUGH THURSDAY/
LATEST MID-LVL WV IMAGERY AND 500 MB STREAMLINE ANALYSIS REVEALS
AN AREA OF LOW PRESSURE SITUATED OVER THE AZ/CA BORDER ALLOWING
MUCH DRIER AIR TO ADVECT INTO THE WESTERN HALF OF THE FORECAST
AREA. OUT AHEAD OF THIS FEATURES IN SOUTH-CENTRAL AND SOUTHEASTERN
AZ, SFC MOISTURE REMAINS RELATIVELY HIGH WITH DEWPOINTS HOVERING
IN THE MID 50S. PWAT VALUES ARE ALSO AROUND 1.2"-1.5" OR AROUND
175% OF NORMAL FOR MID-JUNE. THE MOISTURE IN PLACE COUPLED WITH
DIFFLUENCE ALOFT AHEAD OF THE APPROACHING LOW WILL PROVIDE A FOCUS
FOR WIDELY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY BY THIS
AFTERNOON. LATEST HIGH-RES GUIDANCE, ESPECIALLY THE HRRR DOES
SUGGEST HIGHER COVERAGE THAN PREVIOUS RUNS WITH THE MAIN FOCUS
AREAS FOR INITIATION IN SOUTHERN YAVAPAI AND CENTRAL PINAL
COUNTIES. LATEST VISIBLE SATELLITE IMAGERY DOES CONFIRM INITIATION
UNDERWAY IN THESE AREAS. CAPE VALUES IN EXCESS OF 1500 J/KG
ACROSS THE LOWER DESERTS MAY SUPPORT WELL DEFINED OUTFLOW
BOUNDARIES WHICH COULD GENERATE ADDITIONAL SHOWERS AND STORMS BY
THIS EVENING, HOWEVER COVERAGE STILL LOOKS TO REMAIN LIMITED. THE
MAIN THREATS WITH ANY STORM WILL BE STRONG, GUSTY WINDS WITH
AROUND A 30-50% CHANCE OF GUSTS EXCEEDING 35 MPH IN MARICOPA AND N
PINAL COUNTIES THIS AFTERNOON/EVENING. BY THURSDAY, ACTIVITY
SHOULD BECOME RELEGATED TO THE WHITE MOUNTAINS OF EASTERN ARIZONA,
ONLY POTENTIALLY CLIPPING FAR EASTERN GILA COUNTY AS DRY AIR
CONTINUES TO FILTER INTO THE STATE FROM W TO E.
OVERALL 500 MB HGHTS WILL CONTINUE A DOWNWARD TREND OVER THE NEXT
24 HOURS AS THE RIDGE AXIS SHIFTS EWD INTO NM AND THE WEAK AREA OF
LOW PRESSURE MOVES OVER CENTRAL AZ. THIS REDUCTION IN HEIGHTS/THICKNESS
WILL RESULT IN TEMPERATURES ACROSS THE LOWER DESERTS DECREASING
FROM 105-111F TODAY TO AROUND 102-107F ON THURSDAY. WITH DRIER AIR
OVERSPREADING THE FORECAST AREA, OVERNIGHT LOWS WILL NOT BE AS
WARM AS PREVIOUS NIGHTS, MAINLY IN THE UPPER 70S TO MID 80S ON
THURSDAY MORNING WITH FURTHER COOLING ANTICIPATED BY THE END OF
THIS WEEK.
LONG TERM /FRIDAY THROUGH TUESDAY/
THERE IS EXCELLENT AGREEMENT AMONG ENSEMBLE MEMBERSHIP THAT MORE
PRONOUNCED EAST PACIFIC TROUGHING WILL EJECT INTO THE GREAT BASIN
RESULTING IN STRONG ZONAL FLOW ACROSS THE FORECAST AREA. THIS FLOW
PATTERN WILL COMPLETELY SCOUR AWAY MOISTURE SUCH THAT MIXING RATIOS
FALL CLOSER TO 2-3 G/KG ELIMINATING ALL CHANCES FOR PRECIPITATION.
WHILE H5 HEIGHTS WILL NOT DROP MARKEDLY, SUBTLE COOLING ALONG WITH
THE INTRODUCTION OF THIS MUCH DRIER AIRMASS WILL RESULT IN
TEMPERATURES FALLING TO NEAR NORMAL LEVELS OVER THE WEEKEND. THE
INITIAL ROUND OF MODEST HEIGHT FALLS COMBINED WITH SEASONABLY DEEP
MIXING DEPTHS WILL PROMOTE REPEATED CHANCES OF GUSTY AFTERNOON WINDS
LATE IN THE WEEK. JUXTAPOSED WITH THE INCOMING DRY AIRMASS AND
RECEPTIVE, DESSICATED FUELS, FIRE DANGER WILL BECOME QUITE ELEVATED.
ENSEMBLE SPREADS GROWS SOMEWHAT TOWARDS THE MIDDLE OF NEXT WEEK,
HOWEVER THE MAJORITY OF MEMBERS INDICATE BUILDING SUBTROPICAL
RIDGING OVER THE CWA AFTER THE TROUGH PASSAGE. H5 HEIGHTS SHOULD
REBOUND OVER 594DM WITH THE ANTI-CYCLONE CENTER BECOMING POSITIONED
DIRECTLY OVER ARIZONA. SOME OF THE MORE AGGRESSIVE MODELING IN THE
UPPER QUARTILE OF THE MODEL DISTRIBUTION EVEN SUGGESTS HEIGHTS
BREACHING 597DM BY THE MIDDLE OF THE WEEK WHICH WOULD EQUATE TO
LOWER ELEVATION TEMPERATURES REACHING 115F YIELDING EXPANSIVE MAJOR
HEATRISK.
AVIATION
UPDATED AT 2345Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NEAR THE SHORT TERM, AN NORTHWARD SURGING OUTFLOW BOUNDARY
CARRYING BLOWING DUST WILL AFFECT KPHX AND KIWA THROUGH 01Z BEFORE
CONDITIONS IMPROVE AFTERWARDS. OTHERWISE, GUSTY WINDS UPWARDS OF
20-25 KTS OUT OF THE WEST WILL CONTINUE THROUGH THE EVENING HOURS.
GUSTS WILL SUBSIDE DURING THE OVERNIGHT PERIOD WITH WINDS BACKING
OUT OF THE EAST THROUGH THURSDAY MORNING BEFORE SHIFTING OUT OF
THE WEST BY THE LATE MORNING HOURS. SOME AFTERNOON GUSTS NEAR 20
KTS WILL ONCE AGAIN MATERIALIZE. NO THREAT OF TS/OUTFLOWS EXPECTED
FOR THURSDAY. FEW MID TO HIGH CLOUDS WILL BE COMMON THROUGHOUT THE
TAF PERIOD.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
THE MAIN AVIATION CONCERN WILL BE GUSTY WINDS THAT WILL CONTINUE
THROUGH THIS EVENING AND ONCE AGAIN MATERIALIZE THURSDAY
AFTERNOON/EARLY EVENING. AT KIPL, WINDS WILL GENERALLY PREVAIL OUT
OF THE WEST WHILE AT KBLH, WINDS WILL FLUCTUATE OUT OF THE SOUTH
TO SOUTHWEST. AFTERNOON/EARLY EVENING GUSTS UPWARDS OF 25 KTS WILL
BE COMMON AT KBLH AND UPWARDS OF 25-30 KTS AT KIPL. HEADING INTO
THURSDAY, ANOTHER ROUND OF AFTERNOON GUSTS UPWARDS OF 20-25 KTS
CAN BE EXPECTED AT KBLH WHILE GUSTS AT KIPL MAY EXCEED 25 KTS LATE
AFTERNOON/EARLY EVENING. SKIES WILL REMAIN CLEAR THROUGHOUT THE
TAF PERIOD.
FIRE WEATHER
A PRONOUNCED DRYING TREND WILL TRANSPIRE ACROSS THE REGION THROUGH
THE REMAINDER OF THIS WEEK WITH TERRAIN INDUCED SHOWERS/STORMS
BECOMING COMPLETELY ELIMINATED FROM THE FORECAST BY FRIDAY.
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE OVER HIGHER TERRAIN FEATURES THIS AFTERNOON, HOWEVER
CHANCES OF WETTING RAINFALL WILL BE REMOTE. THE MAIN IMPACTS WITH
ANY STORM WILL BE GUSTY AND ERRATIC WINDS AND DRY LIGHTNING.
DESPITE TEMPERATURES COOLING CLOSER TO NORMAL LATER THIS WEEK, A
MUCH DRIER AIRMASS WILL ALLOW MINIMUM HUMIDITY LEVELS PRIMARILY IN
A 10-20% RANGE TO DETERIORATE INTO WIDESPREAD SINGLE DIGITS OVER
THE WEEKEND AND EARLY NEXT WEEK. CORRESPONDINGLY, OVERNIGHT
RECOVERY WILL DETERIORATE INTO A POOR TO FAIR 15-40% RANGE. WINDS
WILL FREQUENTLY BECOME GUSTY THE REMAINDER OF THE WEEK YIELDING A
WIDESPREAD ELEVATED FIRE DANGER, HOWEVER AT THIS TIME, SPEEDS
APPEAR TO REMAIN BELOW CRITICAL THRESHOLDS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...SALERNO
LONG TERM...18
AVIATION...LOJERO
FIRE WEATHER...SALERNO/18
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