582
FXUS65 KPSR 040520
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 PM MST SUN MAY 3 2026
UPDATE
UPDATED AVIATION DISCUSSION
KEY MESSAGES
- MUCH COOLER TEMPERATURES WILL MATERIALIZE OVER THE REGION THE
NEXT COUPLE DAYS.
- BREEZY TO LOCALLY WINDY CONDITIONS WILL BE COMMON THE FIRST PART
OF THE WEEK WITH MODEST RAIN CHANCES ACROSS ARIZONA HIGH TERRAIN
AREAS.
- A RAPID WARMING TREND WITH TEMPERATURES INTO AN ABOVE NORMAL
TERRITORY WILL ARRIVE THE LATTER HALF OF THE WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
SHORTWAVE RIDGING OVER THE AREA WAS QUICKLY BECOMING DAMPENED AS
TROUGHING WITH INTENSIFYING JET ENERGY AND HEIGHT FALLS SLOWLY
ADVANCE INTO THE SW CONUS. THE INCREASED MOMENTUM IMPARTED BY THIS
SYSTEM COMBINED WITH SEASONALLY DEEP MIXING DEPTH WILL PROMOTE
REGIONALLY GUSTY AFTERNOON WINDS THE NEXT COUPLE DAYS, ALTHOUGH THE
STRONGEST IMPACTFUL WINDS WILL OCCUR IN THE TYPICAL LOCATIONS OF THE
FAR WESTERN CWA. WITH A FRONT MOVING ONSHORE THIS AFTERNOON
DEEPENING THE WINDWARD MARINE LAYER AND OPTIMALLY TIMED ROBUST
HEIGHT FALLS EDGING INLAND, MOUNTAIN ROTORS AND HYDRAULIC JUMPS WILL
BE FAVORED THIS EVENING OVER THE WESTERN HALF OF IMPERIAL COUNTY
WHERE SOLID ADVISORY LEVEL WIND GUSTS 40-50 MPH APPEAR LIKELY.
LOCALIZED BLOWING DUST AND DOWNSTREAM LOFTED DUST WILL BE POSSIBLE
OVERNIGHT BEFORE SURFACE GUSTS WEAKEN SLIGHTLY.
TROUGHING IN THE FORM OF A CLOSED LOW WILL SLOWLY MIGRATE INLAND
MONDAY WITH A CONTINUATION OF MODEST HEIGHT FALLS SPREADING INTO THE
FORECAST AREA. WITH H5 HEIGHTS RETREATING INTO A 568-574DM RANGE,
MIDLEVEL TEMPERATURES WILL FALL ABRUPTLY WHILE THICKER HIGH CLOUDS
RESTRICT BETTER INSOLATION SUCH THAT AFTERNOON HIGHS SHOULD BE 10F-
15F COOLER THAN TODAY (OR 5F-10F BELOW NORMAL FOR EARLY MAY). WHILE
STRONGER WINDS ALOFT AND CONTINUED HEIGHT FALLS WILL SUPPORT ANOTHER
ROUND OF GUSTY WINDS MONDAY AFTERNOON/EVENING, THICK CLOUDS MAY
RETARD MIXING DEPTHS AND THE ABILITY TO TAP HIGHER MOMENTUM AIR,
LIMITING LOWER ELEVATIONS WINDS WITH MORE PRONOUNCED GUSTS RELEGATED
TO MOUNTAIN PEAKS. EVEN THE WINDIEST FAR SW IMPERIAL COUNTY
LOCATIONS MAY ONLY FLIRT WITH ADVISORY CRITERIA AS HEIGHT FALLS WILL
HAVE ALREADY MOVED EAST AND WINDS THROUGH THE TROPOSPHERIC DEPTH
WEAKENING QUICKLY.
THE GREATEST FORECAST CHALLENGE AND UNCERTAINTY IS THE POTENTIAL FOR
SHOWERS IN THE EASTERN CWA MONDAY NIGHT AND TUESDAY. MODELS CONTINUE
TO ADVERTISE A PLUME OF BETTER SUBTROPICAL MOISTURE ABSORBED INTO
THE STRONGER SW FLOW ADVECTING INTO SOUTHERN AND EASTERN ARIZONA.
WHILE A LARGE COMPONENT OF THE MOISTURE WILL BE ABOVE 600MB, TRENDS
IN MODELING SUGGEST BETTER AVAILABILITY OF 6-7 G/KG MIXING RATIOS IN
THE H8-H7 LAYER RESULTING IN TOTAL COLUMN PWATS NEAR 1.00" (OR
BETTER THAN 200% OF NORMAL) BY TUESDAY MORNING. THERE ARE
INDICATIONS OF A SUBTLE SHORTWAVE COMBINED WITH A MIDLEVEL FRONT
ALONG THE COLD CORE ALLOWING FAVORABLE SATURATED ASCENT EARLY
TUESDAY MORNING. THIS IS A TIME OF REDUCED LOW LEVEL T/TD SPREADS,
SO THE INFLUENCE OF SUB-CLOUD EVAPORATION SHOULD BE REDUCED.
ENSEMBLE OUTPUT IS WIDELY VARYING THOUGH DOES ARGUE FOR BETTER
RAINFALL CHANCES IN FOOTHILL AND MOUNTAIN OROGRAPHIC UPSLOPE REGIONS
SOUTH AND EAST OF PHOENIX, THOUGH A FEW SHOWERS IN THE EASTERN PARTS
OF THE METRO CANNOT BE DISCOUNTED. OTHERWISE, AS THE COLD CORE MOVES
DIRECTLY OVERHEAD ON TUESDAY AFTERNOON, HIGH TEMPERATURES WILL BE
10F-15F BELOW NORMAL WITH LOWER DESERT COMMUNITIES STRUGGLING TO
EVEN REACH 80F RESULTING IN POSSIBLY THE COOLEST DAY IN THE FORECAST
AREA FOR THE NEXT 6 MONTHS.
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 0520Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION CONCERNS ARE EXPECTED DURING THE TAF PERIOD.
WINDS WILL FOLLOW FAMILIAR DIURNAL TRENDS, THOUGH THE TYPICAL
TURNING OF THE WINDS DURING THE LATE MORNING WILL COMMENCE EARLY
THAN NORMAL, AROUND 14Z OR SO. THE TURN WILL MORE GRADUAL AS WELL,
WHICH SHOULD RESULT IN AT LEAST A FEW HOURS OF S'RLY CROSS-RUNWAY
WINDS AT KPHX AND KDVT. THOUGH NO PREVAILING INCLUDE GUSTS AT THIS
TIME, OCCASIONAL GUSTS IN THE MID-TEENS TO AROUND 20 KT ARE LIKELY
TO BE OBSERVED FROM MID-MORNING INTO THE EVENING HOURS. CLOUD
LEVELS WILL SLOWLY DROP OVER THE NEXT 24 HOURS, WITH LOWER BASES
AROUND 5-6 KT ENTERING THE PICTURE TOWARD THE END OF THE FOREAST
WINDOW. A FEW SHOWERS WILL ACCOMPANY THESE LOWER CLOUDS, BUT
SHOULD REMAIN MOSTLY TO THE EAST OF THE AIRSPACE. THE MOST LIKELY
TERMINAL TO ANY RAINFALL WILL BE KIWA SO MENTION OF VCSH HAS BEEN
ADDED TO THE TAF. IT IS NOT OUT OF THE QUESTION THE OTHER
TERMINALS MAY SEE SOME WEAK ECHOES/VIRGA, BUT CHANCES ARE TOO LOW
TO INCLUDE MENTION OF ANY VCSH/SHRA AT THESE SITES AT THIS TIME.
SLANTWISE VIS/HAZY CONDITIONS WILL CONTINUE TO BE A POTENTIAL
CONCERN DUE TO A BRUSH FIRE IN BUCKEYE. THE NIGHTLY E'RLY WIND
SHIFT WILL KEEP ANY SMOKE AWAY FROM THE TERMINALS. HOWEVER, THE
USUAL AFTERNOON SWITCH TO THE W/SW, LOFTED SMOKE WILL SHIFT MORE
TOWARD THE METRO, SO OPERATIONAL IMPACTS, MAINLY AT KSDL AND KDVT
CANNOT BE RULED OUT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
BREEZY TO WINDY CONDITIONS WILL CONTINUE BE THE MAIN AVIATION
CONCERN DURING THE NEXT 24 HOURS. AT KIPL, GUSTS 35-40 KT WILL BE
POSSIBLE THROUGH ABOUT 09Z BEFORE WINDS RELAX, THOUGH GUSTS 20-25
KT SHOULD CONTINUE OVERNIGHT. ANOTHER WINDOW OF GUSTS 30-35 KT
WILL BE POSSIBLE MONDAY EVENING, BUT CONFIDENCE SURROUNDING GUSTS
REACHING THAT LEVEL IS MEDIUM AT BEST. AREAS OF BLOWING/LOFTED
DUST GENERATED BY THESE ENHANCED WINDS SHOULD REMAIN CLEAR OF THE
TERMINAL, BUT ISOLATED INSTANCES OF REDUCED SURFACE AND SLANTWISE
VIS CANNOT BE RULED OUT. AT BLH, GUSTS SHOULD ABATE OVERNIGHT, BUT
REEMERGE LATE MONDAY MORNING, REACHING NEAR 25 KT ONCE AGAIN.
BKN-0VC SKIES WILL BE COMMON THROUGH MOST OF THE PERIOD.
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 UNTIL 8 AM PDT MONDAY FOR CAZ562.
WIND ADVISORY UNTIL 3 AM PDT MONDAY FOR CAZ566-567.
SHORT TERM...18/LOJERO
LONG TERM...LOJERO
AVIATION...RW
FIRE WEATHER...LOJERO
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