145
FXUS65 KPSR 100520
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 PM MST THU JUL 9 2026
UPDATE
UPDATED 06Z AVIATION DISCUSSION.
KEY MESSAGES
- HOT TEMPERATURES WILL CONTINUE THIS WEEK RESULTING IN AREAS OF
ISOLATED MAJOR HEAT RISK AND LINGERING EXTREME HEAT WARNINGS.
- THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL MAINLY BE CONFINED
TO HIGHER TERRAIN AREAS OF FAR EASTERN ARIZONA THROUGH SATURDAY.
- DEEPER MOISTURE WILL MOVE INTO THE REGION EARLY NEXT WEEK
RESULTING IN BETTER CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS.
SHORT TERM /TODAY THROUGH FRIDAY/
EARLY AFTERNOON WV IMAGERY DEPICTS THE EASTERN EDGE OF A SUBTROPICAL
ANTI-CYCLONE OVER ARIZONA WITH THE CORE HIGH PRESSURE CENTER ALONG
THE SOUTHERN CALIFORNIA COAST. MEANWHILE, SHORTWAVE ENERGY IN THE
NORTHERN STREAM ACROSS THE GREAT BASIN WAS ACTING TO DAMPEN AND
PARTIALLY ERODE THIS RIDGE ALOFT. WHILE H5 HEIGHTS HAVE RETREATED
SOMEWHAT TO AROUND 594DM, THERMAL PROFILES THROUGH THE MIDDLE
TROPOSPHERE ARE STEADY OR EVEN WARMING AS A RESULT OF MIDLEVEL
SUBSIDENCE WARMING SOUTH OF A WESTERLY JET STREAK ACROSS UTAH. THIS
EVOLUTION WILL YIELD A CONTINUATION OF SURFACE TEMPERATURES 5F-10F
ABOVE NORMAL TODAY AND PATCHY AREAS OF MAJOR HEATRISK. ON FRIDAY,
THE HIGH PRESSURE CENTER WILL MOVE BACK INTO ARIZONA AS THE NORTHERN
STREAM SHORTWAVE EXITS INTO THE PLAINS. TEMPERATURES SHOULD COOL
VERY SLIGHTLY IN RESPONSE TO THE LOSS OF SUBSIDENT WARMING, HOWEVER
LOCALIZED AREAS IN SE CALIFORNIA CONTINUE WITH MAJOR HEATRISK AND
CONTINUATION OF EXTREME HEAT WARNINGS.
GIVEN INCREASED SUBSIDENCE, WARMING ALOFT, AND A MODEST REDUCTION IN
LOW LEVEL MIXING RATIOS, DEEP CONVECTION WILL BE REDUCED THROUGH
FRIDAY, THOUGH NOT COMPLETELY ELIMINATED ACROSS EASTERN ARIZONA HIGH
TERRAIN. CONCEIVABLY, A WEAKENING OUTFLOW COULD PROPAGATE INTO PARTS
OF THE CWA THIS EVENING, HOWEVER WANING INSTABILITY AND GREATER
INHIBITION SHOULD LIMIT CONVECTIVE COVERAGE AND INTENSITY. EVEN MORE
SPARSE AND WEAKER THUNDERSTORMS WOULD BE EXPECTED FRIDAY UNDER A
SIMILAR HOSTILE ENVIRONMENT, AND NOT EVEN JUSTIFYING POPS ABOVE
10%. A FAR MORE CONDUCIVE ENVIRONMENT WILL MATERIALIZE OVER NORTHERN
SONORA FRIDAY EVENING WITH MODELS HINTING AT AN WELL ORGANIZED,
INTENSE MCS. WITH MEAN FLOW TURNING SE BY THIS TIME, THIS WILL SET
THE STAGE FOR DEEP MOISTURE ADVECTION INTO THE FORECAST AREA
SATURDAY WITH SFC-H7 MIXING RATIOS 10-11 G/KG AND TOTAL COLUMN PWATS
OVER 1.50" SURGING THROUGH SOUTH-CENTRAL ARIZONA. THESE MOISTURE
PARAMETERS ALONG WITH THE EVOLVING SYNOPTIC PATTERN WILL BECOME
FAVORABLE FOR SCATTERED STORMS, MULTIPLE STRONG OUTFLOW BOUNDARIES,
AND LOCALLY HEAVY RAINFALL INTO LOWER ELEVATION COMMUNITIES INTO
EARLY NEXT WEEK.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS MENTIONED, THE OVERALL WEATHER PATTERN HEADING INTO THE WEEKEND
AND NEXT WEEK WILL BECOME MORE FAVORABLE FOR A MORE ACTIVE MONSOONAL
PATTERN TO SET UP. THE SUBTROPICAL RIDGE WILL QUICKLY MIGRATE
NORTHEASTWARD INTO THE ROCKIES OVER THE WEEKEND AND THEN SET UP OVER
THE CENTRAL PLAINS EARLY NEXT WEEK WHILE STRENGTHENING IN THE
PROCESS. AS THIS WHOLE PATTERN EVOLUTION MATERIALIZES, THE MID-LEVEL
FLOW WILL SHIFT OUT OF THE EAST TO SOUTHEAST. THIS WILL INTRODUCE
STRONG MOISTURE TRANSPORT INTO THE DESERT SOUTHWEST WITH THE LATEST
EPS AND GEFS SHOWING PWATS INCREASING TO AT LEAST 1.4-1.5" STARTING
AS EARLY AS SUNDAY AND REMAINING ABOVE 1.5" INTO NEXT WEEK.
MOISTURE ON SATURDAY WILL LIKELY REMAIN FAIRLY LIMITED ACROSS SOUTH-
CENTRAL AZ WITH LOW-LEVEL MIXING RATIOS REMAINING BETWEEN 9-10 G/KG,
WITH THE BETTER MOISTURE AND THUS THE BEST CONVECTIVE POTENTIAL
REMAINING RELEGATED TO THE HIGHER TERRAIN AND SOUTHEASTERN AZ. THERE
ARE STRONG INDICATIONS FROM THE LATEST GUIDANCE OF A STRONG
CONVECTIVE COMPLEX LIKELY TO DEVELOP OVER NORTHERN SONORA SATURDAY
EVENING, WHICH WILL LIKELY SEND OF POOL OF HIGHER MOISTURE INTO
CENTRAL AZ HEADING INTO SUNDAY WITH MIXING RATIOS SOLIDLY ABOVE 10
G/KG. AS A RESULT, SUNDAY LOOKS TO BE THE FIRST REAL POTENTIAL FOR
GREATER THUNDERSTORM ACTIVITY TO MATERIALIZE ACROSS THE SOUTH-
CENTRAL AZ LOWER DESERTS WITH NBM POPS SOLIDLY IN THE 30-50% RANGE.
WITH PWATS VALUES REMAINING ABOVE 1.5" ALONG WITH MIXING RATIOS
ABOVE 10 G/KG THROUGH THE FIRST HALF OF NEXT WEEK, THE POTENTIAL FOR
ADDITIONAL CONVECTIVE ACTIVITY WILL REMAIN IN PLACE AND LIKELY
EXPAND FURTHER WEST TO INCLUDE THE WESTERN DESERTS AS WELL WITH NBM
POPS RANGING BETWEEN 20-40% EACH DAY. WE WILL ALSO HAVE TO BE ON THE
LOOKOUT FOR ANY POTENTIAL EASTERLY WAVES THAT COULD ENHANCE THE
CONVECTIVE ACTIVITY, HOWEVER, PINPOINTING THE TRACK AND TIMING OF
THESE WAVES THIS FAR OUT IS VERY DIFFICULT. THEREFORE, HIGH
UNCERTAINTY EXISTS OF WHICH PARTICULAR DAYS NEXT WEEK HAVE THE
POTENTIAL TO BE MORE CONVECTIVELY ACTIVE. WITH THE INCREASING
MOISTURE AND POTENTIAL CLOUD COVER, AFTERNOON HIGH TEMPERATURES THIS
WEEKEND INTO EARLY NEXT WEEK WILL GRADUALLY RETREAT TO NEAR TO
SLIGHTLY ABOVE NORMAL LEVELS WITH WIDESPREAD MODERATE HEATRISK IN
PLACE.
AVIATION
UPDATED AT 0520Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE MAIN AVIATION FORECAST UNCERTAINTY REMAINS TO BE THE POTENTIAL
FOR AN OUTFLOW FROM DISTANT CONVECTION IN SE AZ MOVING THROUGH
REGION TONIGHT. THE OUTFLOW IS FAIRLY WEAK CURRENTLY AND COULD
WASH OUT PRIOR TO REACHING ANY OF THE TERMINALS. HAVE GONE AHEAD
AND REMOVED THE TEMPS AT KSDL AND KDVT, BUT KEPT THEM IN AT KPHX
AND KIWA. CURRENT TIMING LOOKS TO BE BETWEEN 0730-0900Z WITH SOME
OCCASIONAL GUSTS IN THE UPPER TEENS TO AROUND 20 KT POSSIBLE.
ADDITIONALLY A GULF SURGE COULD OVERPOWER THE OUTFLOW AND HELP TO
KEEP WINDS WESTERLY UNTIL THE EASTERLY SHIFT AROUND 10Z. ONCE
WINDS GO EASTERLY TONIGHT THEY ARE EXPECTED TO REMAIN EASTERLY
UNTIL THE TYPICAL WESTERLY SHIFT LATE TOMORROW MORNING. SOME GUSTS
INTO THE UPPER TEENS TO AROUND 20 KT IS AGAIN EXPECTED TOMORROW
AFTERNOON AND EARLY EVENING. BY LATE TOMORROW EVENING A SIMILAR
SET UP AND AMOUNT OF UNCERTAINTY TO TONIGHT'S SET UP EXISTS.
MODELS SHOW A DISTANT OUTFLOW POSSIBLY MOVING THROUGH LATE
TOMORROW EVENING OR SHOW THE GULF SURGE OVERPOWERING ANY OUTFLOWS
KEEPING WINDS ELEVATED (10-15 KT) OUT OF THE WEST. SKIES WILL
REMAIN MOSTLY CLEAR WITH FEW HIGH CLOUDS EXPECTED DURING THE
MORNING HOURS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
AT KIPL, CURRENT SW'RLY WINDS WILL GO SE'RLY BY 07Z AND ARE
EXPECTED TO REMAIN SE'RLY FOR THE REMAINDER OF THE TAF PERIOD.
WIND SPEEDS AT KIPL WILL GENERALLY BE AOB 10 KT. AT KBLH, MULTIPLE
ROUNDS OF BREEZY CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
WINDS ARE EXPECTED TO REMAIN S'RLY THE WHOLE PERIOD. WIND SPEEDS
WILL REMAIN ELEVATED THROUGH THE WHOLE PERIOD (NOT EXPECTED TO
DROP BELOW 10 KT). A PERIOD OF BREEZY WINDS IS EXPECTED TO BEGIN
AROUND 09Z FROM A GULF SURGE, WITH GUSTS OF 20-25 KT. WINDS WILL
THEN DROP SLIGHTLY DURING THE MID-MORNING HOURS BEFORE GUSTS OF
20-25 KT PICK UP AGAIN TOMORROW AFTERNOON. WINDS WILL THEN DROP
OFF SLIGHTLY AGAIN AROUND SUNSET. SKIES WILL BE MOSTLY CLEAR.
FIRE WEATHER
GUSTY AND ERRATIC THUNDERSTORM WINDS WITH ISOLATED LIGHTNING OVER
THE FAR EASTERN DISTRICTS THROUGH FRIDAY WILL BE THE MAIN FIRE
WEATHER CONCERN. OUTSIDE OF ANY POTENTIAL OUTFLOWS, WINDS SHOULD
FAVOR DIURNAL TRENDS WITH TYPICAL AFTERNOON BREEZINESS AROUND 20
MPH. SOME STRONGER AFTERNOON GUSTS BETWEEN 20-30 MPH WILL BE COMMON
THROUGH FRIDAY ALONG THE LOWER COLORADO RIVER VALLEY. AFTERNOON RH
VALUES BETWEEN 10-20% WILL BE COMMON ACROSS THE REGION THROUGH
SATURDAY. OVERNIGHT RECOVERIES WILL GENERALLY RANGE BETWEEN 30-60%
WITH THE UPPER END OF THE RANGE ACROSS THE IMPERIAL VALLEY AND THE
EASTERN DISTRICTS. TEMPERATURES ARE EXPECTED TO RUN WELL ABOVE
NORMAL TODAY, WITH THE LOWEST ELEVATIONS REACHING BETWEEN 110-115
DEGREES BEFORE A VERY GRADUAL COOL DOWN TAKES PLACE STARTING FRIDAY.
MORE WIDESPREAD MONSOONAL ACTIVITY IS LIKELY STARTING LATE THIS
WEEKEND AND CONTINUING INTO NEXT WEEK. MOISTURE LEVELS AND
HUMIDITIES SHOULD ALSO IMPROVE CONSIDERABLY HEADING INTO NEXT WEEK,
ALLEVIATING MUCH OF THE FIRE WEATHER CONCERNS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST FRIDAY FOR AZZ530-537-540-
542>544-546-548-550-551.
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT FRIDAY FOR CAZ562-566-567-
569-570.
SHORT TERM...18
LONG TERM...LOJERO
AVIATION...BERISLAVICH
FIRE WEATHER...LOJERO/KUHLMAN
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