285
FXUS65 KPSR 031118
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
418 AM MST SUN MAY 3 2026
UPDATE
12Z AVIATION DISCUSSION.
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES WITH LOWER DESERT HIGHS IN THE MIDDLE NINETIES
WILL CONTINUE TODAY BEFORE MUCH COOLER TEMPERATURES INTO A
BELOW NORMAL CATEGORY BRIEFLY MATERIALIZES DURING THE FIRST PART
OF THE WEEK.
- BREEZY TO LOCALLY WINDY CONDITIONS WILL MATERIALIZE THROUGH THE FIRST
PART OF THE WEEK WITH SOME MODEST RAIN CHANCES ACROSS THE
ARIZONA HIGHER TERRAIN AREAS.
- A RAPID WARMING TREND TO ABOVE NORMAL TEMPERATURES IS LIKELY BY
THE LATTER HALF OF THE WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
EARLY MORNING WATER VAPOR SATELLITE IMAGERY DEPICTS A RIDGE OF HIGH
PRESSURE CENTERED OVER THE DESERT SOUTHWEST WHILE A ROBUST CUT-OFF
LOW SITS OFF THE CENTRAL CA COAST. UNDER THE INFLUENCE OF THE
RIDGE, AFTERNOON HIGH TEMPERATURES WILL CONTINUE TO RUN A GOOD 4-7
DEGREES ABOVE NORMAL AS READINGS TOP OUT IN THE MIDDLE 90S ACROSS
MOST OF THE LOWER DESERT LOCATIONS. AS THE CUTOFF CONTINUES TO
SLOWLY MARCH ITS WAY EASTWARD THROUGHOUT THE DAY, THE COMBINATION
OF GRADUAL HEIGHT FALLS AND INCREASING JET ENERGY WILL RESULT AN
ENHANCEMENT IN THE LOW-LEVEL WIND FIELD HEADING INTO THIS
AFTERNOON AND EVENING WITH WIDESPREAD BREEZY TO LOCALLY WINDY
CONDITIONS EXPECTED, ESPECIALLY ACROSS THE SOUTHWEST AZ AND
SOUTHEAST CA AS PEAK GUSTS TOP OUT IN THE 25-35MPH RANGE. ACROSS
THE WESTERN HALF OF IMPERIAL COUNTY, MOUNTAIN ROTOR ACTION
COMBINED WITH DOWNSLOPING FLOW WILL CAUSE WINDS TO BE EVEN
STRONGER WITH GUSTS IN EXCESS OF 40 MPH LIKELY TO MATERIALIZE AT
TIMES HEADING INTO THIS EVENING. GIVEN THIS SCENARIO, WIND
ADVISORIES HAVE BEEN HOISTED FOR MUCH OF THE WESTERN HALF OF
IMPERIAL COUNTY, INCLUDING THE IMPERIAL VALLEY, FOR THE EVENING
AND OVERNIGHT PERIOD. THE STRONG WIND GUSTS MAY ALSO RESULT IN
AREAS OF BLOWING DUST AFFECTING PORTIONS OF THE IMPERIAL VALLEY,
RESULTING IN TEMPORARY REDUCTIONS IN VISIBILITIES.
THE AFOREMENTIONED CUT-OFF LOW WILL SLOWLY MIGRATE INLAND INTO
CENTRAL CA ON MONDAY BEFORE MIGRATING SOUTHEASTWARD INTO SOUTHERN CA
AND AZ ON TUESDAY WHILE TRANSITIONING INTO AN OPEN WAVE. AS THE LOW
MIGRATES INLAND, THE COMBINATION OF 500 MB HEIGHT FIELDS DROPPING
INTO THE 568-574DM RANGE AND MORE ABUNDANT MID TO UPPER-LEVEL
CLOUDINESS WILL RESULT IN MUCH COOLER TEMPERATURES WITH AFTERNOON
HIGHS 10-13F COOLER THAN TODAY AS READINGS TOP OUT IN LOW TO MID 80S
ACROSS THE LOWER DESERTS. THESE TEMPERATURE READINGS WILL BE A GOOD
5-10F BELOW NORMAL FOR EARLY MAY. ENHANCED JET ENERGY WILL CONTINUE
TO SUPPORT ENHANCED FLOW THROUGHOUT THE LOW LEVELS AND THUS ANOTHER
DAY WITH AFTERNOON/EVENING PEAK GUSTS BETWEEN 25-35 MPH CAN BE
EXPECTED. IN ADDITION, THE SLOW MIGRATION OF THE LOW WILL ALSO ALLOW
FOR SOME SUBTROPICAL MOISTURE TO BE ADVECTED ACROSS THE SOUTHEASTERN
HALF OF AZ AS PWATS RISE TO 0.7-0.9" OR AROUND 200% OF NORMAL. THIS
MOISTURE ALONG WITH ROBUST SYNOPTIC FOCUSING WILL RESULT IN SOME
SCATTERED LIGHT SHOWER ACTIVITY TO BREAK OUT MOSTLY ACROSS THE
HIGHER TERRAIN AREAS EAST OF PHOENIX LATE MONDAY NIGHT INTO THE
FIRST PART OF TUESDAY WHILE ACROSS THE LOWER DESERTS OF SOUTH-
CENTRAL AZ, SOME LIGHT SPRINKLES/VIRGA WILL BE POSSIBLE AS THE LOW-
LEVELS WILL REMAIN TOO DRY TO SUPPORT ACCUMULATING RAINFALL.
AS THE COLD CORE MOVES DIRECTLY OVERHEAD ON TUESDAY, AFTERNOON HIGH
TEMPERATURES WILL BE EVEN COOLER WITH MOST LOWER DESERT LOCATIONS
STRUGGLING TO REACH 80 DEGREES. THIS WILL BE A SOLID 10 DEGREES
BELOW NORMAL AND WILL POSSIBLY BE THE COOLEST TEMPERATURES THE
REGION WILL OBSERVE UNTIL THE FALL. BREEZY CONDITIONS WILL CONTINUE
TO REMAIN IN PLACE FOR MUCH OF THE REGION, HOWEVER, WIND SPEEDS
WILL BE WEAKER AS PEAK GUSTS TOP OUT BETWEEN 15-30 MPH.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
THE MAIN ENERGY ASSOCIATED WITH THE UPPER LOW WILL EXIT TO THE
NORTHEAST ON WEDNESDAY WITH UPPER-LEVEL RIDGING BUILDING ALONG
THE WEST COAST. HOWEVER, MODEL GUIDANCE IS SHOWING A TRAILING
PIECE OF ENERGY LEFT BEHIND THAT WILL LIKELY DEVELOP INTO A CUT-OFF
LOW SOMEWHERE TO THE SOUTH OF THE REGION WITH DIFFERENCES NOTED
WITH RESPECT TO THE POSITIONING AND SPEED AS IT GRADUALLY
PROGRESSES EASTWARD THROUGH THE LATTER HALF OF THE WEEK.
NEVERTHELESS, GIVEN THAT THIS FEATURE WILL BE POSITIONED FAR
ENOUGH SOUTH, IT WILL LIKELY NOT HAVE MUCH IN THE WAY OF SENSIBLE
WEATHER IMPACTS FOR THE REGION. WITH UPPER-LEVEL HEIGHT FIELDS
STEADILY RISING FROM THE BUILDING RIDGE OVER THE WEST COAST,
TEMPERATURES DURING THE LATTER HALF OF THE WEEK WILL RAPIDLY WARM
FROM THE MIDDLE 80S ON WEDNESDAY TO MIDDLE 90S ON THURSDAY.
ADDITIONAL WARMING INTO THE TRIPLE DIGITS IS FORECAST AS EARLY AS
FRIDAY AND WILL LIKELY BE THE START OF AN EXTENDED STRETCH OF
TRIPLE DIGIT HIGHS AS THE UPPER-LEVEL RIDGE GRADUALLY BUILDS
ACROSS THE WESTERN CONUS.
AVIATION
UPDATED AT 1118Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
GUSTY WINDS WILL BE THE MAIN AVIATION CONCERN THROUGH THE TAF
PERIOD. MARGINAL BREEZINESS WILL BE COMMON THIS MORNING (15-18Z)
AND ONCE AGAIN IN THE EVENING (02-05Z) WHERE GUST WILL GENERALLY
BE BETWEEN 20-30 KTS. EASTERLY WINDS WILL PREVAIL THROUGH THIS
MORNING WITH A LATER THAN USUAL SHIFT TO THE W THIS AFTERNOON. A
PERIOD OF SOUTHERLY CROSSWINDS ARE EXPECTED PRIOR TO THE WESTERLY
SHIFT. SCT-BKN SKIES WILL PROGRESSIVELY BECOME OVC BY MIDNIGHT
TONIGHT.
A WILDCARD IN THE FORECAST IS THE POTENTIAL FOR SLANTWISE VIS
ISSUES FOR KPHX COME MORNING DUE TO A BRUSH FIRE TO THE WEST OF
THE TERMINAL. EASTERLY MORNING WINDS ARE EXPECTED TO TAKE SMOKE
MAINLY TO THE WEST OF THE AIRSPACE, THEREFORE LIKELY NOT IMPACTING
THE SITE DIRECTLY, BUT REDUCTIONS IN APPROACH VIS CANNOT BE
COMPLETELY RULED OUT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
THE MAIN AVIATION CONCERN DURING THE NEXT 24 HOURS WILL BE BREEZY
TO WINDY CONDITIONS THIS AFTERNOON AND EVENING. VRB WINDS AT KBLH
THIS MORNING WILL EVENTUALLY BECOME ESTABLISHED OUT OF THE S BY
MID MORNING. GUSTS 20-25 KT ENTER THE PICTURE BY THE EARLY
AFTERNOON HOURS AND ARE EXPECTED TO PREVAIL THROUGH THE REST OF
THE TAF PERIOD. AT KIPL, E'RLY WINDS WILL QUICKLY SWITCH TO THE W
BY THE AFTERNOON, WITH PEAK GUSTS POTENTIALLY EXCEEDING 35 KT BY
THE EVENING. THESE ENHANCED GUSTS WILL INCREASE THE POTENTIAL FOR
BLOWING DUST, WHICH MAY RESULT IN REDUCTIONS IN VIS. HOWEVER,
CONFIDENCE IS TOO LOW TO WARRANT ANY MENTION OF SUB- VFR
VISIBILITIES IN THE TAF AT THIS TIME. SCT-BKN MID TO HIGH CLOUDS
WILL BE COMMON THROUGH SUNDAY EVENING.
FIRE WEATHER
DRY CONDITIONS ALONG WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE
TODAY. AN APPROACHING LOW PRESSURE SYSTEM WILL RESULT IN
WIDESPREAD BREEZY TO LOCALLY WINDY CONDITIONS THROUGH THE FIRST
PART OF THE WEEK AND TEMPERATURES COOLING INTO A BELOW NORMAL
CATEGORY MONDAY-TUESDAY. GUSTY AFTERNOON WINDS COMBINED WITH LOW
HUMIDITIES WILL LIKELY PRODUCE ELEVATED FIRE WEATHER CONDITIONS
TODAY AND MONDAY. AS THE LOW PRESSURE SYSTEM MOVES THROUGH THE
DESERT SOUTHWEST, THE CHANCE OF SHOWERS WILL INCREASE LATE MONDAY
INTO THE FIRST PART OF TUESDAY ACROSS THE FAR EASTERN DISTRICTS,
HOWEVER, THE PROBABILITY OF WETTING RAINS WILL REMAIN ON THE LOW
SIDE. AFTERNOON MINRHS BETWEEN 10-20% WILL BE COMMON TODAY BEFORE
INCREASING INTO A 15-25% RANGE MONDAY AND INTO A 20-35% RANGE
TUESDAY. LIGHTER WINDS AS WELL AS MUCH WARMER TEMPERATURES AND
LOWER HUMIDITIES ARE THEN FORECAST FOR THE LATTER HALF OF THE
WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM PDT MONDAY FOR
CAZ562.
WIND ADVISORY FROM 7 PM THIS EVENING TO 3 AM PDT MONDAY FOR
CAZ566-567.
SHORT TERM...LOJERO
LONG TERM...LOJERO
AVIATION...RYAN/RW
FIRE WEATHER...LOJERO
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