612
FXUS65 KPSR 211058
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
358 AM MST SUN JUN 21 2026
UPDATE
UPDATED 12Z AVIATION DISCUSSION.
KEY MESSAGES
- TEMPERATURES WILL SLOWLY RISE TO ABOVE NORMAL LEVELS OVER THE
NEXT FEW DAYS CREATING WIDESPREAD MODERATE HEAT RISK BY TUESDAY.
- STRONG HIGH PRESSURE WILL PEAK ACROSS THE REGION MIDWEEK WITH
DAYTIME HIGHS REACHING THEIR PEAK ON THURSDAY AT BETWEEN 110 TO
114 DEGREES ACROSS THE LOWER DESERTS.
- LOCALIZED MAJOR HEAT RISK WILL BE POSSIBLE ON WEDNESDAY AND
THURSDAY BEFORE A COOLING PERIOD BEGINS STARTING FRIDAY.
SHORT TERM /TODAY THROUGH MONDAY/
THE NOT SO HOT TEMPERATURES OVER THE PAST COUPLE OF DAYS HAS BEEN
DUE TO A SLOW MOVING TROUGH PASSING TO OUR NORTH, BUT THAT SYSTEM
IS ABOUT TO EJECT INTO THE CENTRAL AND NORTHERN PLAINS. AS THIS
OCCURS LATER TODAY INTO MONDAY, THE SUBTROPICAL HIGH CENTERED JUST
TO THE SOUTH OF ARIZONA AND NEW MEXICO WILL SHIFT NORTHWARD FULLY
INTO OUR REGION. TEMPERATURES WILL RESPOND SLIGHTLY TODAY WITH
READINGS A DEGREE OR TWO WARMER THAN YESTERDAY, BEFORE BECOMING
MORE NOTICEABLY HOT BEGINNING MONDAY. ADDITIONALLY, AS THE HIGH
CENTER MOVES CLOSER TO OUR AREA IT WILL SHIFT OUR WINDS OUT OF THE
SOUTH BEGINNING TONIGHT ALLOWING FOR SOME MOISTURE TO SEEP
NORTHWARD OFF THE GULF OF CALIFORNIA. BETWEEN THE RISING HEIGHTS
FROM THE HIGH PRESSURE RIDGE GRADUALLY RAISING TEMPERATURES AND
THE INCREASING HUMIDITIES, THE AIR WILL BECOME MUCH MORE
UNCOMFORTABLE STARTING MONDAY. DAYTIME HIGHS ARE FORECAST TO RISE
TO BETWEEN 105-109 DEGREES ON MONDAY PUTTING THE BULK OF THE AREA
INTO THE MODERATE HEATRISK CATEGORY. THE INCREASING HUMIDITIES
WILL HAVE A BIGGER IMPACT ON OVERNIGHT TEMPERATURES STARTING
MONDAY NIGHT WITH LOWS STAYING ABOVE 80 DEGREES IN THE PHOENIX
AREA TO ONLY DOWN IN THE MID 70S FOR RURAL DESERT LOCATIONS.
LONG TERM /TUESDAY THROUGH SATURDAY/
THE MAIN FORECAST CONCERN FOR THE REST OF THE COMING WEEK IS THE
POTENTIAL FOR MAJOR HEATRISK TO DEVELOP ACROSS PORTIONS OF THE
AREA AS EARLY AS WEDNESDAY AND REMAINING A POSSIBILITY THROUGH
FRIDAY. GUIDANCE IS IN GOOD AGREEMENT SHOWING THE SUBTROPICAL
HIGH STRENGTHENING INTO WEDNESDAY, LIKELY REACHING PEAK H5 HEIGHTS
OF 595-597DM LATE TUESDAY AND WEDNESDAY. ADDITIONAL GULF MOISTURE
SURGES ARE ALSO EXPECTED MONDAY NIGHT AND TUESDAY NIGHT
INCREASING LOW LEVEL MOISTURE ENOUGH TO POTENTIALLY BRING SOME
ISOLATED SHOWERS AND THUNDERSTORMS STARTING TUESDAY ACROSS
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. THE HIGHEST POPS ARE
BETWEEN 10-15% ACROSS THE HIGHER TERRAIN AREAS OF SOUTHWEST
ARIZONA, WHILE CHANCES SHOULD REMAIN WELL BELOW 10% ACROSS SOUTH-
CENTRAL ARIZONA DUE TO THE STRONGER SUBSIDENCE CLOSER TO THE HIGH
CENTER.
MODELS ARE SOMEWHAT TRENDING AWAY FROM EVEN HIGHER HEIGHTS THAT
LOOKED POSSIBLE A COUPLE OF DAYS AGO, BUT THEY ARE STILL RIGHT
NEAR THE THRESHOLD OF POTENTIALLY NEEDING EXTREME HEAT HEADLINES.
THE LATEST NBM STILL SHOWS SOME VERY LOCALIZED MAJOR HEATRISK
DEVELOPING BY WEDNESDAY BEFORE REACHING ITS PEAK COVERAGE OF
ROUGHLY 20-30% OF THE LOWER DESERTS ON THURSDAY. FORECAST HIGHS
ARE ALSO 1-2 DEGREES LOWER THAN PREVIOUSLY ADVERTISED WITH PEAK
READINGS OF 111-114 DEGREES ON THURSDAY. DUE TO THE REMAINING
UNCERTAINTY IN THE STRENGTH OF THE RIDGE, WE WILL HOLD OFF FOR NOW
ON ANY EXTREME HEAT WATCHES. MODELS ARE ALSO NOW TRENDING TOWARD
A QUICKER DECLINE IN HEIGHTS LATER THIS WEEK, STARTING AS EARLY AS
WEDNESDAY NIGHT. HEIGHTS ARE FAVORED TO SLOWLY DECREASE ON
THURSDAY AND LIKELY CONTINUING THROUGH NEXT WEEKEND AS ANOTHER
TROUGH IS FORECAST TO PASS BY TO OUR NORTH. DAYTIME HIGHS SHOULD
FALL BELOW 110 DEGREES BY SATURDAY AND POTENTIALLY GO BACK INTO
THE NORMAL RANGE BY NEXT SUNDAY. MOISTURE LEVELS ARE ALSO EXPECTED
TO BEGIN TO DROP OFF STARTING THURSDAY WITH ANY ISOLATED
CONVECTIVE POTENTIAL DISAPPEARING BY FRIDAY.
AVIATION
UPDATED AT 1058Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION WEATHER CONCERNS EXPECTED THROUGHOUT THE TAF PERIOD.
THE OVERALL WIND PATTERN WILL CONTINUE TO FOLLOW THE TYPICAL
DIURNAL TENDENCIES WITH OVERALL SPEEDS AOB 10 KTS. SOME OCCASIONAL
AFTERNOON/EARLY EVENING GUSTS INTO THE MID/UPPER TEENS WILL BE
POSSIBLE ONCE AGAIN. CLEAR SKIES WILL PERSIST INTO THIS AFTERNOON
BEFORE FEW-SCT HIGH CIRRUS CLOUD DECKS MOVE IN THIS EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS EXPECTED THROUGHOUT THE TAF
PERIOD. AT KIPL, WEST WINDS CONTINUE EARLY THIS MORNING BEFORE A
BRIEF PERIOD OF LIGHT AND VARIABLE WINDS PRIOR TO SHIFTING OUT OF
THE SOUTH THIS AFTERNOON AND THEN BACK OUT OF THE WEST THIS
EVENING. AT KBLH, WINDS WILL GENERALLY FLUCTUATE BETWEEN THE SOUTH
AND SOUTHWEST. OVERALL WIND SPEEDS WILL GENERALLY REMAIN AOB 12
KTS ALONG WITH SOME MINOR AFTERNOON/EVENING GUSTINESS. CLEAR SKIES
WILL PERSIST INTO THIS AFTERNOON BEFORE FEW-SCT HIGH CIRRUS CLOUD
DECKS MOVE IN THIS EVENING.
FIRE WEATHER
NEAR NORMAL TEMPERATURES AND VERY DRY CONDITIONS WILL CONTINUE
THROUGH MONDAY WITH FAIRLY LIGHT WINDS. MINRHS WILL BE IN THE
SINGLE DIGITS EACH DAY, WHILE OVERNIGHT RECOVERIES WILL BE POOR,
RANGING BETWEEN 15-35%. SOME AFTERNOON AND EARLY EVENING UPSLOPE
BREEZINESS WILL BE COMMON, BUT GUSTS WILL MOSTLY STAY BELOW 20
MPH. EVEN WITH THE LIGHT BREEZES, THE VERY LOW RHS SHOULD STILL
LEAD TO ELEVATED FIRE WEATHER CONDITIONS DURING THE LATTER HALF OF
THE AFTERNOON/EARLY EVENING HOURS. GOING INTO THE MIDDLE PART OF
NEXT WEEK, MOISTURE WILL IMPROVE RAISING MINRHS TO BETWEEN 10-15%
BY WEDNESDAY, BUT TEMPERATURES WILL ALSO WARM TO ABOVE NORMAL.
DAYTIME BREEZINESS SHOULD ALSO INCREASE WITH MORE GUSTS REACHING
THE 20-25 MPH RANGE.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...BERISLAVICH/LOJERO
FIRE WEATHER...KUHLMAN
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