087
FXUS65 KPSR 041004
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
304 AM MST SAT JUL 4 2026
KEY MESSAGES
- NEAR NORMAL TEMPERATURES WITH A DECENT AMOUNT OF CLOUDS ARE
EXPECTED THIS WEEKEND.
- HOTTER TEMPERATURES WILL RETURN EARLY NEXT WEEK CREATING
MODERATE TO MAJOR HEAT RISK BY TUESDAY AND LASTING THROUGH AT
LEAST THURSDAY.
- AN EXTREME HEAT WATCH HAS BEEN ISSUED FOR TUESDAY THROUGH
THURSDAY ACROSS THE LOWER DESERTS, INCLUDING PHOENIX, YUMA, AND
EL CENTRO. FORECAST HIGHS ARE CURRENTLY 111 TO 116 DEGREES.
- DRY CONDITIONS WILL PREVAIL, ALTHOUGH A SPRINKLE CANNOT BE RULED
OUT SATURDAY INTO SUNDAY, BEFORE ISOLATED STORM CHANCES RETURN
OVER THE ARIZONA HIGH TERRAIN LATER NEXT WEEK.
SHORT TERM /TODAY THROUGH SUNDAY/
UPPER LEVEL RIDGING HAS MOSTLY TAKEN OVER ACROSS THE DESERT
SOUTHWEST, BUT A DECAYING TROPICAL SYSTEM WEST OF BAJA WILL
CONTINUE TO BRING CONSIDERABLE HIGH LEVEL CLOUDINESS TO THE REGION
TODAY INTO EARLY SUNDAY. H5 HEIGHTS HAVE RISEN OVER THE PAST
COUPLE OF DAYS LEADING TO RISING TEMPERATURES, BUT READINGS TODAY
MAY END UP FALLING SHORT OF FRIDAY'S HIGHS DUE TO THE CLOUDS.
GUIDANCE ALSO SHOWS A WING OF VORTICITY SWINGING NORTHWARD THROUGH
THE AREA THIS AFTERNOON WHILE MOISTURE ALOFT DESCENDS MORE INTO A
14-20K FEET LAYER. THE RESULTANT WEAK FORCING FROM THE VORTICITY
AXIS IS EXPECTED TO BE ENOUGH TO BRING SOME VERY HIGH BASED VIRGA
SHOWERS FOCUSED DURING THE AFTERNOON AND EARLY EVENING HOURS
TODAY. SOME LOCATIONS ARE EXPECTED TO FEEL SOME SPRINKLES AT
TIMES, BUT THE CHANCES OF ANY ACTUAL MEASURABLE RAINFALL REMAINS
NEAR ZERO.
AFTER THE TROUGH AXIS SHIFTS NORTHWARD OUT OF THE AREA BY EARLY
SUNDAY, SOME DRYING ALOFT WILL HELP TO GRADUALLY DISPERSE THE HIGH
CLOUDS FROM WEST TO EAST. THE INCREASED INSOLATION ON SUNDAY
SHOULD RESULT IN DAYTIME HIGHS REACHING NEAR 110 DEGREES FOR SOME
LOCATIONS. THE SUBTROPICAL HIGH INTO SUNDAY WILL ALSO REMAIN
CENTERED WELL TO OUR EAST SOUTHEAST CREATING A MORE FAVORABLE
FETCH OF SOUTHERLY FLOW AND LEADING TO SOME IMPROVING BOUNDARY
LAYER MOISTURE. EVEN THOUGH MOISTURE WILL IMPROVE OVER THE NEXT
FEW DAYS, IT WILL STILL FALL WELL SHORT OF WHAT WOULD BE NEEDED
FOR ANY MONSOON CONVECTION TO DEVELOP.
LONG TERM /MONDAY THROUGH FRIDAY/
FORECAST CONFIDENCE HAS INCREASED IN A MORE PRONOUNCED PERIOD OF
VERY HOT CONDITIONS FOR NEXT WEEK. THE SUBTROPICAL RIDGE IS
EXPECTED TO GRADUALLY SHIFT RIGHT OVER THE REGION MONDAY INTO
TUESDAY WITH GUIDANCE NOW FAVORING SOME STRENGTHENING OF THE HIGH
GOING INTO MID WEEK. FORECAST H5 HEIGHTS ARE SHOWN RISING TO
BETWEEN 594-596DM BY TUESDAY BEFORE PEAKING BETWEEN 595-597DM, OR
WELL WITHIN THE 90TH PERCENTILE OF CLIMATOLOGY.
NBM GUIDANCE OVER THE PAST 24 HOURS HAS TRENDED NOTICEABLY WARMER
FOR THE MIDDLE PART OF NEXT WEEK, MOSTLY DUE TO THE HIGHER
HEIGHTS BUT ALSO SOMEWHAT DUE TO LESS THAN PREVIOUSLY EXPECTED
MOISTURE MOVING INTO THE AREA. NBM FORECAST HIGHS HAVE INCREASED
BY AROUND 2F FOR TUESDAY-THURSDAY PUTTING MUCH OF THE LOWER
DESERTS INTO A 112-116 DEGREE RANGE. THIS HEAT EPISODE IS VERY
LIKELY TO BRING OUR HOTTEST TEMPERATURES SO FAR THIS SUMMER. THE
UPTICK IN FORECAST TEMPERATURES HAS LED US TO ISSUE AN EXTREME
HEAT WATCH FOR TUESDAY-THURSDAY FOR ALL OF THE LOWER DESERTS
ACROSS SOUTHEAST CALIFORNIA AND SOUTHERN AND CENTRAL ARIZONA.
MODEL GUIDANCE IS STILL TRYING TO HAVE THE RIDGE SHIFT MORE TO THE
WEST LATER NEXT WEEK, POTENTIALLY RECENTERING TO OFF THE SOUTHERN
CALIFORNIA COAST. IF THIS OCCURS, IT SHOULD LOWER TEMPERATURES A
COUPLE OF DEGREES BY NEXT FRIDAY, BUT JUST AS IMPORTANT IS THE
POTENTIAL FOR ADDITIONAL MOISTURE ADVECTING NORTHWESTWARD INTO THE
AREA. THERE IS STILL A GOOD AMOUNT OF UNCERTAINTY WITH THIS
POTENTIAL MOISTURE INCREASE AS IT WILL LARGELY DEPEND ON THE
POSITION OF THE HIGH CENTER. IF THE HIGH CENTER DOES END UP MOVING
FAR ENOUGH TO THE WEST, THIS SCENARIO SHOULD ALLOW FOR AT LEAST
ENOUGH OF A MOISTURE INCREASE AND WEAKENING SUBSIDENCE TO BRING
SOME HIGH TERRAIN SHOWERS AND STORMS. ANY CHANCES FOR THE LOWER
DESERTS IS MORE LIKELY THAN NOT TO HOLD OFF UNTIL NEXT WEEKEND.
AVIATION
UPDATED AT 0900Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT WEATHER CONCERNS WILL EXIST THROUGH THE TAF PERIOD
UNDER PERIODS OF THICKER MID/HIGH CIGS. WITH THESE CIGS, EXPANSIVE
AREAS OF VIRGA AND POTENTIALLY AN ISOLATED SHRA/SOME AREAS OF
SPRINKLES WILL BE LIKELY AT ANY POINT FROM THE LATE MORNING THROUGH
THE EVENING, BUT WITH LIMITED IMPACT TO OPERATIONS. TRENDS IN WIND
SHIFTS AND SPEEDS SHOULD BE SIMILAR TO THE PAST 24 HOUR WITH WIND
SPEEDS MAINLY AOB 10 KT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER CONCERNS WILL EXIST THROUGH THE TAF PERIOD UNDER
PERIODS OF THICKER MID/HIGH CIGS, OCCASIONAL VIRGA, AND POTENTIALLY
AN ISOLATED SHRA/A FEW AREAS OF SPRINKLES. CHANCES FOR OPERATIONAL
IMPACTS FROM CIGS/SHRA REMAIN TOO LOW TO INCLUDE IN THIS TAF
PACKAGE. CONFIDENCE IS GOOD THAT WINDS WILL GENERALLY SHIFT BETWEEN
SSE AND SW WITH MODEST AFTERNOON/EARLY EVENING GUSTINESS. PERIODS OF
LIGHT AND VARIABLE TO NEAR CALM CONDITIONS ARE EXPECTED THIS
MORNING AT KBLH AND FROM MID MORNING THROUGH THE AFTERNOON AT KIPL.
FIRE WEATHER
HIGH PRESSURE WILL REMAIN IN CONTROL WELL INTO NEXT WEEK WITH NEAR
NORMAL TEMPERATURES THIS WEEKEND WARMING TO ABOVE NORMAL BY MONDAY.
AFTERNOON HUMIDITIES WILL FALL TO AROUND 10% EACH DAY THROUGH
MONDAY WITH OVERNIGHT RECOVERIES GRADUALLY IMPROVING TO 25-40%
EARLY NEXT WEEK. WINDS WILL CONTINUE TO FOLLOW DIURNAL
UPSLOPE/DOWNVALLEY PATTERNS WITH MODEST UPSLOPE AFTERNOON
BREEZINESS. DESPITE THE DIMINISHED WINDS, SEASONABLY ELEVATED
FIRE DANGER WILL LIKELY PERSIST INTO NEXT WEEK DUE TO DRY
CONDITIONS AND DRY FUELS. MOISTURE IS EXPECTED TO GRADUALLY
INCREASE OVER THE REGION NEXT WEEK NEXT WEEK, BUT OVERALL DRY
CONDITIONS SHOULD PERSIST WITH ANY CHANCES FOR WETTING RAINS
HOLDING OFF UNTIL LATE NEXT WEEK AT THE EARLIEST.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WATCH FROM TUESDAY MORNING THROUGH THURSDAY EVENING
FOR AZZ530>534-536>551-553>555-559-560-562.
CA...EXTREME HEAT WATCH FROM TUESDAY MORNING THROUGH THURSDAY EVENING
FOR CAZ562-564>570.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...18/BERISLAVICH
FIRE WEATHER...KUHLMAN
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