385
FXUS65 KPSR 122109
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
209 PM MST FRI JUN 12 2026
KEY MESSAGES
- TEMPERATURES HOVERING AROUND 3 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 TODAY AND 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 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 1809Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
LIGHT SHOWERS/VIRGA CONTINUE TO DRIFT NORTHWARD THROUGH THE
PHOENIX METRO THIS MORNING WITH BKN CIGS MOSTLY AOA 12-15 KFT. NOT
EXPECTING ANY IMPACTS WITH THIS AS IT CONTINUES THROUGH THE REST
OF THE MORNING AND POTENTIALLY LINGERING INTO THE AFTERNOON. WINDS
WILL CONTINUE TO FAVOR A WESTERLY COMPONENT THROUGHOUT MUCH OF THE
TAF PERIOD WITH GUSTS UPWARDS OF 18-20 KTS THIS AFTERNOON. SCT-BKN
MID AND HIGH CLOUDS AOA 12 KFT WILL CONTINUE THROUGH THE PERIOD
WITH ADDITIONAL VICINITY SHOWERS/VIRGA EXPECTED OVERNIGHT TONIGHT
INTO THE MORNING HOURS TOMORROW.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS ARE EXPECTED THROUGH SATURDAY
MORNING UNDER FEW-SCT, AND PERHAPS AT TIMES BKN, MID/HIGH CLOUDS
AOA 12 KFT. WINDS AT KIPL WILL ONCE AGAIN SWITCH AROUND FROM THE
E/SE TO THE W THIS EVENING, WHILE KBLH WILL FAVOR THE SSE-SSW
THROUGH THE PERIOD. OVERALL WIND SPEEDS WILL BE AROUND 7-12 KTS
WITH GUSTS AROUND 20 KTS THIS AFTERNOON AT KBLH. SHOWERS ARE
EXPECTED TO REMAIN EAST OF THE TERMINALS, HOWEVER, CAN'T RULE OUT
AN ISOLATED VICINITY SHOWER NEAR THE TERMINALS DURING THE PERIOD.
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...SMITH
FIRE WEATHER...WHITTOCK/RYAN
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