336
FXUS65 KPSR 030624
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1124 PM MST SUN AUG 2 2026
UPDATE...UPDATED 06Z AVIATION DISCUSSION
KEY MESSAGES
- EXTREME HEAT WILL PERSIST THROUGH THE START OF THE WEEK WITH
HIGH TEMPERATURES TOPPING OUT IN THE 110 TO 118 DEGREE RANGE
OVER MUCH OF THE LOWER DESERTS, HOVERING RIGHT AROUND RECORD
LEVELS.
- EXTREME HEAT WARNINGS ARE IN EFFECT REGIONWIDE THROUGH TUESDAY.
- HIGH PRESSURE AND DRIER AIR OVER THE REGION WILL CONFINE
SHOWERS AND THUNDERSTORMS PRIMARILY TO FAR EASTERN AND
SOUTHEASTERN ARIZONA AREAS THROUGH AT LEAST MONDAY.
- SHOWER AND THUNDERSTORM CHANCES INCREASE ACROSS SOUTH-CENTRAL
ARIZONA BY THE SECOND HALF OF THE WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
A STRONG RIDGE OF HIGH PRESSURE REMAINS SITUATED OVER THE DESERT
SOUTHWEST AND CONTINUES TO PROMOTE WELL ABOVE NORMAL TEMPERATURES
ACROSS THE REGION THIS AFTERNOON. THIS MORNING'S 12Z PHX AND 18Z
FGZ SOUNDINGS SAMPLED A 500 MB HEIGHT OF 598 DM; THOUGH THE RIDGE
REMAINS QUITE STRONG, A WEAKENING TREND IS UNDERWAY AS A TROUGH
PASSES THROUGH THE PACIFIC NW/BC/ALBERTA. BY TOMORROW, 500 MB
HEIGHTS WILL LOWER TO AROUND 594-595 DM, WHICH IS STILL ABOVE THE
90TH CLIMATOLOGICAL PERCENTILE. AFTERNOON TEMPERATURES MONDAY ARE
FORECAST TO SEE A ~2-4 DEGREE DROP FROM TODAY WITH HIGHS TOPPING
OUT BETWEEN 111-116 DEGREES FOR MOST LOWER DESERT LOCATIONS.
MORNING LOWS WILL ALSO REMAIN QUITE WARM, OFFERING LIMITED RELIEF
FROM THE HEAT AS TEMPERATURES ONLY FALL INTO THE MID/UPPER 80S TO
LOW 90S. AS A RESULT, MAJOR TO EXTREME HEATRISK WILL BE IN PLACE
ACROSS MANY LOWER DESERT LOCALES MONDAY, THOUGH SEEING A NOTABLE
DECREASE FROM THE WIDESPREAD COVERAGE IN PLACE TODAY. AFTERNOON
TEMPERATURES TUESDAY WILL SEE ANOTHER ~2-4 DEGREE DROP, HOWEVER,
GUIDANCE CONTINUE TO FAVOR INCREASING BOUNDARY LAYER MOISTURE
HEADING INTO THE MIDDLE PART OF THE WEEK, WHICH WILL MAKE FOR MORE
HUMID CONDITIONS. THIS ADDED MOISTURE WILL PUSH HEAT INDICES
UPWARDS OF 112-118 DEGREES, PARTICULARLY ACROSS SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA. EXTREME HEAT WARNINGS REMAIN IN
EFFECT FOR MUCH OF THE AREA THROUGH TUESDAY EVENING.
MONSOONAL ACTIVITY IS EXPECTED TO REMAIN LIMITED ACROSS OUR AREA
THROUGH THE START OF THE NEW WORKWEEK WITH LIMITED MOISTURE AND
STRONG HIGH PRESSURE PROMOTING SUBSIDENCE. FOR TODAY, STORMS WILL
AGAIN FAVOR FAR EASTERN AND SOUTHEASTERN ARIZONA. STRONG OUTFLOWS
EMANATING FROM THESE STORMS ARE EXPECTED TO PUSH INTO SOUTHERN
GILA COUNTY AND MAY BE ENOUGH TO POP OFF A FEW ISOLATED SHOWERS
AND STORMS. ANY NEW STORM DEVELOPMENT THAT WERE TO OCCUR WOULD BE
CAPABLE OF PRODUCING STRONG, ERRATIC WINDS. STORM ACTIVITY WILL
CONTINUE TO PRIMARILY FAVOR EASTERN AND SOUTHEASTERN PORTIONS OF
THE STATE AS NORTHEASTERLY STEERING FLOW KEEPS MUCH OF THIS
ACTIVITY OUTSIDE OF OUR CWA. MONDAY LOOKS TO BE A PARTICULARLY
ACTIVE DAY FOR SOUTHEAST AZ, WITH FAVORABLE SHEAR AND INSTABILITY
FOR SOME ORGANIZED STORM CLUSTERS. GIVEN HIGH DCAPE MAGNITUDES
(>1500 J/KG), THE STORMS IN SOUTHEAST AZ MONDAY WILL BE CAPABLE OF
SENDING OUTFLOWS, POTENTIALLY STRONG AND WITH DUST, WESTWARD AND
NORTHWARD THROUGH PINAL COUNTY. THESE OUTFLOWS AND A GULF SURGE
MONDAY NIGHT WILL BE THE DRIVER OF THE INCREASE IN MOISTURE
HEADING INTO TUESDAY. WHILE THIS SOUNDS PROMISING FOR STORM
CHANCES ACROSS THE LOWER DESERTS HEADING INTO TUESDAY, WITH MUCH
BETTER INSTABILITY, SUBSIDENCE, PERSISTENT VERY WARM TEMPERATURES
ALOFT, AND FAIRLY HIGH INHIBITION WILL CONTINUE TO COUNTER/HINDER
CONVECTIVE POTENTIAL. THUS, NBM POPS REMAIN LOW FOR OUR AREA, WITH
THE BEST CHANCES RESIDING ACROSS FAR SOUTHERN AND EASTERN GILA
COUNTY WHERE CHANCES CLIMB TO 20-30% BY TUESDAY.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AFTER WEAKENING SLIGHTLY TO START THE WEAK, GLOBAL ENSEMBLES
SUPPORT THE SUBTROPICAL HIGH RESTRENGTHENING DURING THE SECOND
HALF OF THE WEEK, BACK UP TO A 600DAM HIGH, BUT ALSO DRIFTING A
LITTLE FURTHER NORTH TOWARD/INTO UT. H5 HEIGHTS OVER THE LOCAL
AREA ARE FORECAST TO CLIMB BACK UP TO A PEAK OF AROUND 596-597DAM
BY FRIDAY. COOLEST TEMPERATURES OVER THE NEXT WEEK ARE FORECAST
FOR WEDNESDAY, BUT TEMPERATURES WILL STILL BE ABOVE NORMAL WITH
LOWER DESERT HIGHS IN THE 106-112 DEGREE RANGE. DESPITE THE
RESTRENGTHENING OF THE HIGH, HIGH TEMPERATURES ARE NOT FORECAST TO
SEE A SIGNIFICANT INCREASE AGAIN, ROUGHLY 1 DEGREE EACH DAY
THROUGH SATURDAY, LIKELY DUE TO THE THE INCREASED MOISTURE.
HOWEVER, THE FORECAST CALLS FOR JUST ENOUGH WARMING TO ONCE AGAIN
INCREASE THE COVERAGE OF MAJOR HEATRISK. MORNING LOW TEMPERATURES
WILL LIKELY REMAIN QUITE WARM - BARRING ANY COOLING FROM STORMS -
MOSTLY IN THE 80S TO RIGHT AROUND 90 DEGREES.
WITH THE SMALL MOVEMENTS OF THE SUBTROPICAL HIGH MIDWEEK AND SHIFT
NORTH LATE WEEK, THERE WILL BE A BETTER FETCH OF EASTERLY WINDS
ACROSS SOUTHERN NEW MEXICO, SOUTHERN ARIZONA, AND NORTHERN MEXICO.
ABOVE NORMAL MOISTURE IS ALSO SHOWN TO STICK AROUND THROUGH THE
END OF THE WEEK AND NEXT WEEKEND, WITH 60S DEW POINTS. THIS
PATTERN WILL AT LEAST SUPPORT DAILY ROBUST THUNDERSTORMS
DEVELOPING OVER THE AZ HIGH TERRAIN, BUT THERE IS STILL
UNCERTAINTY WHETHER STORMS CAN FIRE OFF OR SURVIVE INTO LOWER
DESERT AREAS LIKE PHOENIX AND POINTS FURTHER WEST. STILL, THIS
LOOKS LIKE THE BEST CHANCE OF THE SUMMER SO FAR FOR THUNDERSTORMS
IN PORTIONS OF SOUTHWEST AZ AND SOUTHEAST CA, WHO HAVE BEEN
LACKING FOR RAIN SO FAR THIS SUMMER. LATEST NBM/WPC FORECAST
CONTINUES TO SHOW 10-30% POPS ACROSS MUCH OF SOUTH-CENTRAL ARIZONA
BY THURSDAY AND CONTINUING THROUGH THE END OF THE WEEK. A PERIOD
OF STRONGER MID-LEVEL EASTERLIES AND PERHAPS AND EASTERLY WAVE/IT
WILL CERTAINLY IMPROVE THE ODDS OF STORM CHANCES ACROSS THE AREA
STRONG TO SEVERE WIND GUSTS WILL BE POSSIBLE WITH MOST STORMS AND
AN INCREASE IN MIXING RATIOS UP TO 11-12 G/KG LATE WEEK WILL
SUPPORT VERY HEAVY RAINFALL.
AVIATION
UPDATED AT 0623Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE PRIMARY AVIATION WEATHER CONCERN AND POTENTIAL IMPACT WILL BE
STRONG THUNDERSTORM OUTFLOW WINDS MOVING THROUGH THE PHOENIX AREA
LATE MONDAY EVENING FROM THE SOUTH. THERE IS MODERATE TO HIGH
CONFIDENCE THAT AN OUTFLOW WILL MOVE THROUGH AT SOME POINT IN THE
EVENING, CURRENTLY FAVORED BETWEEN 03-06Z, BUT THERE IS
UNCERTAINTY ON HOW STRONG WINDS WILL BE. THERE IS MODEL SUPPORT
FOR GUSTS AS HIGH AS 35-40 KTS AND WINDS OF THIS MAGNITUDE MAY
ALSO BRING A WALL OF DUST INTO THE AREA, ENOUGH TO REDUCE
VISIBILITY TO 5SM OR LESS. STORMS ARE EXPECTED TO STAY WELL EAST
AND SOUTH OF THE AREA, BUT THERE IS STILL A 5-10% SOMETHING POPS
UP OR DRIFTS INTO THE METRO.
AHEAD OF MONDAY EVENING'S OUTFLOW, WINDS WILL CONTINUE TO FOLLOW
TYPICAL DIURNAL TENDENCIES, WITH SOME GUSTY (20-25 KT) WESTERLY
WINDS IN THE AFTERNOON. THERE IS ALSO A LOW CHANCE FOR A FEW
SPOTTY HIGH BASED SHOWERS AROUND DAYBREAK. MID AND HIGH CLOUDS
WILL BE COMMON THROUGH THE TAF PERIOD, WITH BASES DROPPING DOWN TO
AROUND 10K FT AGL MONDAY EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY SOUTHERLY WINDS, PRIMARILY AT KBLH MONDAY AFTERNOON, WILL BE
THE MAIN AVIATION WEATHER ISSUE THROUGHOUT THE TAF PERIOD UNDER
MOSTLY CLEAR SKIES. AT KIPL, WINDS WILL GENERALLY BE OUT OF THE
SOUTHEAST FOLLOWING A PERIOD OF SOUTHWEST TONIGHT. AT KBLH, WINDS
WILL GENERALLY FLUCTUATE OUT OF THE SOUTH TO SOUTH-SOUTHWEST.
OVERALL WIND SPEEDS WILL FLUCTUATE BETWEEN 8-13 KTS, WITH GUSTS
NEAR 20-25 KTS IN THE AFTERNOON AT KBLH THAT INCREASE FURTHER IN
THE EVENING UPWARDS OF 25-30 KTS. LOCALIZED DUST STREAMERS AND
WIDESPREAD LOFTED DUST MAY BE GENERATED BY THE WINDS MONDAY NIGHT,
WHICH MAY IMPACT SLANTWISE VISIBILITY.
FIRE WEATHER
STRONG HIGH PRESSURE AND VERY HOT TEMPERATURES, WITH DRY
CONDITIONS, WILL PERSIST INTO THE START OF THE NEW WORKWEEK.
AFTERNOON HIGH TEMPERATURES WILL RANGE BETWEEN 110-115 DEGREES FOR
MANY LOWER ELEVATION LOCATIONS OVER THE NEXT COUPLE OF DAYS. MIN
RHS WILL GRADUALLY IMPROVE WITH VALUES RANGING BETWEEN 15-20%
MONDAY BEFORE CLIMBING TO AROUND 20-25% TUESDAY. OVERNIGHT MAX RHS
WILL ALSO IMPROVE, RISING FROM 35-50% OVERNIGHT TONIGHT TO 50-70%
TUESDAY MORNING. THE INCREASING MOISTURE WILL RESULT IN AN
INCREASE IN SHOWER AND STORM CHANCES. INITIALLY, STORM CHANCES
THIS WEEKEND THROUGH THE START OF THE WEEK WILL FOCUS IN FAR
EASTERN AND SOUTHEASTERN AZ, WITH POTENTIAL FOR STORM OUTFLOW
WINDS TO PROGRESS INTO SOUTH-CENTRAL AZ. SLIGHT CHANCES FOR STORMS
(15-30%) THEN SPREAD TO SOUTH-CENTRAL AZ BY THE MIDDLE AND SECOND
HALF OF THE WEEK. OUTSIDE OF STORM OUTFLOWS, WINDS WILL MOSTLY
FOLLOW DIURNAL PATTERNS, BUT WEST SOUTHWESTERLY WINDS WILL BE
DOMINANT MUCH OF THE TIME WITH AFTERNOON GUSTS OF 15-25 MPH AT
TIMES.
CLIMATE
RECORD HIGH TEMPERATURES:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
AUG 2 114 IN 2025 117 IN 1918 117 IN 1969
AUG 3 116 IN 2024 116 IN 1998 117 IN 2021
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST TUESDAY FOR AZZ530>544-546-
548>551-553>555-559.
EXTREME HEAT WARNING UNTIL 8 PM MST MONDAY FOR AZZ545-547-552-
556>558-560>563.
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT TUESDAY FOR CAZ562-563-
565>567-569-570.
EXTREME HEAT WARNING UNTIL 8 PM PDT MONDAY FOR CAZ560-561-564-
568.
SHORT TERM...SMITH/BENEDICT
LONG TERM...BENEDICT
AVIATION...BENEDICT
FIRE WEATHER...SMITH/BENEDICT
CLIMATE...18
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