418
FXUS65 KPSR 301921
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1221 PM MST WED SEP 30 2026
KEY MESSAGES
- ASIDE FROM A FEW SHOWERS POSSIBLE IN FAR EASTERN GILA COUNTY THIS
AFTERNOON, DRY CONDITIONS WITH NEAR ZERO RAIN CHANCES WILL
PERSIST THROUGH THE NEXT SEVERAL DAYS.
- AS HIGH PRESSURE GRADUALLY BUILDS OVER THE REGION, A GRADUAL
WARMING TREND IS EXPECTED WITH NEAR TO SLIGHTLY ABOVE NORMAL
TEMPERATURES RETURNING BY THE END OF THE WEEK AND INTO THE
WEEKEND.
SHORT TERM /TODAY THROUGH FRIDAY/
LATEST WATER VAPOR SATELLITE IMAGERY INDICATED THE UPPER LOW
RESPONSIBLE FOR THE ACTIVE WEATHER THE LAST COUPLE OF DAYS IS
CURRENTLY CENTERED OVER NM. MUCH OF THE AREA IS CURRENTLY ON THE
SUBSIDENT SIDE OF THE LOW WITH DRIER AIR BUILDING IN. A FEW
SHOWERS, HOWEVER, MAY STILL DEVELOP MAINLY ACROSS FAR EASTERN GILA
COUNTY THIS AFTERNOON ALONG THE DEFORMATION ZONE ON THE BACK SIDE
OF THE LOW. OTHERWISE, WITH THE DRIER AIR AND RIDGING ALOFT
GRADUALLY BUILDING IN FROM THE EASTERN PACIFIC, DRY CONDITIONS
WITH ZERO RAIN CHANCES WILL PREVAIL THROUGH THE REST OF THE WEEK
UNDER MOSTLY CLEAR SKIES.
DUE TO THE LINGERING INFLUENCES OF THE NEGATIVE 500 MB HEIGHT
ANOMALIES FROM THE DEPARTING UPPER LOW, AFTERNOON HIGH TEMPERATURES
TODAY ACROSS MUCH OF THE SOUTH-CENTRAL AZ LOWER DESERTS WILL ONLY
TOP OUT IN THE LOW 80S, WHICH IS A SOLID 10 DEGREES BELOW NORMAL FOR
THIS TIME OF THE YEAR, WHILE WARMER READINGS IN THE 90S CAN BE EXPECTED
ACROSS THE WESTERN DESERTS. AS THE RIDGING ALOFT GRADUALLY BUILDS
OVER THE REGION DURING THE NEXT COUPLE OF DAYS, TEMPERATURES
THROUGH THE END OF THE WEEK WILL GRADUALLY WARM UP WITH LOWER
DESERT HIGHS RETURNING TO THE MID 90S ACROSS SOUTH-CENTRAL AZ TO
AROUND 100 DEGREES ALONG AND WEST OF THE LOWER COLORADO RIVER
VALLEY BY FRIDAY.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
MODEL GUIDANCE SHOWS UPPER-LVL RIDGING MIGRATING OVER THE FOUR
CORNERS REGION BY THIS WEEKEND WITH 500 MB HGHT FIELDS INCREASING
TO AROUND 588-590 DAM. AS THIS OCCURS, GLOBAL MODELS SHOW A WEAK
UPPER- LOW DEVELOPING OVER N MX AND FAR W TX WHICH WILL INDUCE
EASTERLY FLOW ALOFT OVER OUR FORECAST AREA. THE INCREASED PRESSURE
GRADIENT BETWEEN BOTH FEATURES WILL BRING BREEZY CONDITIONS TO
SOUTHEASTERN AND SOUTHCENTRAL AZ FROM SATURDAY THROUGH MONDAY.
ELEVATED WINDS WILL LIKELY DEVELOP EACH MORNING AND PERSIST INTO
THE EARLY AFTERNOON WITH GUSTS REACHING 30-35 MPH OVER THE HIGH
TERRAIN AND 20- 25 MPH ACROSS THE LOWER DESERTS. THIS SFC EASTERLY
FLOW WILL HELP KEEP HIGH TEMPERATURES NEAR NORMAL ACROSS
SOUTHCENTRAL AZ, BUT OVERNIGHT LOWS WILL BE ELEVATED IN THE LOW TO
MID 70S. THE 500 MB RIDGE AXIS LOOKS TO SHIFT BACK TO THE OVER
SOCAL AND THE GREAT BASIN EARLY NEXT WEEK AS A WEAK TROUGH PASSES
THROUGH THE INTERMOUNTAIN WEST. THIS PATTERN SHOULD MAINTAIN
TEMPERATURES IN A NEAR NORMAL RANGE ACROSS CENTRAL AND EASTERN
PORTIONS OF THE REGION, BUT ALLOW HIGHS TO WARM AROUND 3-5 DEGREES
ABOVE NORMAL ACROSS THE WESTERN DESERTS WHERE HIGHS WILL LIKELY
REACH THE LOW 100S EACH AFTERNOON.
AVIATION
UPDATED AT 1710Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION CONCERNS ARE EXPECTED DURING THE TAF PERIOD.
WINDS WILL BE VERY LIGHT WITH EXTENDED PERIODS OF VRB CONDITIONS.
THE TYPICAL WESTERLY SHIFT IS NOT ANTICIPATED THIS AFTERNOON,
THOUGH SOME OCCASIONAL OBSERVATIONS ARE STILL LIKELY. CLOUD DECKS
AS LOW AS 6-8 KFT WILL LINGER THROUGH EARLY THIS AFTERNOON AHEAD
OF CLEAR SKIES THROUGH THE REMAINDER OF THE FORECAST.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION CONCERNS ARE EXPECTED DURING THE NEXT 24 HOURS UNDER
CLEAR SKIES. OUTSIDE OF EXTENDED PERIODS OF VRB CONDITIONS,
SOUTHERLY/SOUTHEASTERLY FLOW WILL BE COMMON AT BOTHER TERMINALS,
WITH SPEEDS GENERALLY AOB 10 KT.
FIRE WEATHER
ASIDE FROM A FEW AFTERNOON SHOWERS ACROSS THE FAR EASTERN
DISTRICTS TODAY, DRY CONDITIONS WILL PREVAIL DURING THE NEXT
SEVERAL DAYS. TEMPERATURES WILL REMAIN BELOW NORMAL ACROSS
SOUTH-CENTRAL AZ AND NEAR NORMAL FOR AREAS ALONG AND WEST OF THE
COLORADO RIVER VALLEY THROUGH THE REST OF THIS WEEK WITH GRADUAL
WARMING ANTICIPATED THROUGH THE WEEKEND. RELATIVE HUMIDITY WILL
BOTTOM OUT AROUND 15-30% ACROSS THE WESTERN DISTRICTS AND REMAIN
ABOVE 40% ACROSS THE EASTERN DISTRICTS THROUGH THE END OF THE WEEK
ALONG WITH GOOD TO EXCELLENT OVERNIGHT RECOVERIES. WINDS WILL
BE LIGHT AND DIURNAL WITH SPEEDS REMAINING PREDOMINANTLY 10 MPH
OR LESS OVER THE NEXT FEW DAYS BEFORE A STRONGER EASTERLY GRADIENT
WIND SETS IN BY THIS WEEKEND.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...LOJERO
LONG TERM...SALERNO
AVIATION...RW
FIRE WEATHER...LOJERO/SALERNO
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