244
FXUS65 KPSR 040955
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 AM MST MON MAY 4 2026
KEY MESSAGES
- MUCH COOLER TEMPERATURES WITH BELOW NORMAL READINGS WILL PREVAIL
DURING THE NEXT COUPLE OF DAYS.
- BREEZY TO LOCALLY WINDY CONDITIONS WILL BE COMMON THROUGH TUESDAY
WITH MODEST RAIN CHANCES ACROSS THE ARIZONA HIGH TERRAIN AREAS.
- A RAPID WARMING TREND TO ABOVE NORMAL TEMPERATURES IS LIKELY BY
THE LATTER HALF OF THE WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
THE LATEST WATER VAPOR SATELLITE IMAGERY AS WELL AS STREAMLINE
ANALYSIS SHOW A RATHER POTENT CUT-OFF LOW SITUATED JUST OFF THE
CENTRAL CA COAST WITH A LARGE STREAM OF MID TO HIGH-LEVEL CLOUDINESS
MOVING THROUGH THE DESERT SOUTHWEST. THE CUT-OFF LOW WILL CONTINUE
TO SLOWLY MIGRATE INLAND LATER TODAY THROUGH CENTRAL CA BEFORE
MOVING SOUTHEASTWARD THROUGH SOUTHERN CA AND AZ DURING THE DAY
TUESDAY AS AN OPEN WAVE. AS THE LOW CONTINUES TO SLOWLY APPROACH
THE REGION, 500 MB HEIGHT FIELDS WILL CONTINUE TO DECREASE INTO
THE 568-574DM RANGE AND COMBINED WITH THICK MID TO UPPER-LEVEL
CLOUDINESS, LIMITING THE SOLAR RADIATION, AFTERNOON HIGH
TEMPERATURES WILL BE A GOOD 10-15 DEGREES COOLER COMPARED TO
YESTERDAY AS READINGS ACROSS MOST OF THE LOWER DESERT COMMUNITIES
ONLY TOP OUT IN THE LOW 80S. THESE TEMPERATURES WILL BE A GOOD
5-10F BELOW NORMAL FOR EARLY MAY. THE ADDITIONAL HEIGHT FALLS AND
ENHANCED JET ENERGY WILL CONTINUE TO ENHANCE THE LOWER
TROPOSPHERIC WINDS. HOWEVER, THE THICKER CLOUD COVER MAY TEMPER
THE OVERALL MIXING DEPTH AND THUS THE ABILITY FOR THE HIGHER
MOMENTUM AIR TO FULLY MIX DOWN TO THE SURFACE. THUS, EVEN THOUGH
SOME GUSTY WINDS ARE LIKELY TO MATERIALIZE THIS AFTERNOON/EVENING,
IT WILL LIKELY NOT BE AS STRONG AS YESTERDAY WITH MANY AREAS
LIKELY OBSERVING GUSTS BETWEEN 20-30 MPH. SOME LOCALLY HIGHER
GUSTS IN EXCESS OF 30-35 MPH WILL ONCE AGAIN BE POSSIBLE ACROSS
WESTERN PORTIONS OF IMPERIAL COUNTY DUE TO MOUNTAIN ROTOR ACTION.
CANNOT RULE OUT TEMPORARY GUSTS EXCEEDING 40 MPH ACROSS THE WIND
PRONE AREAS OF SOUTHWESTERN IMPERIAL COUNTY.
AS THE LOW CONTINUES TO SLOWLY MIGRATE EASTWARD FROM THE EASTERN
PACIFIC, A PLUME OF SUBTROPICAL MOISTURE OUT AHEAD OF THE FEATURE
WILL BE ADVECTED INTO SOUTHERN AND EASTERN AZ LATER TODAY. THE
LATEST MODEL GUIDANCE HAS CONTINUED THE UPTREND IN MOISTURE LEVELS
AS PWATS ARE NOW SHOWN TO PEAK TO BETWEEN 0.8-1.0". THIS MOISTURE
COMBINED WITH THE LARGE FORCING FOR ASCENT FROM THE LOW WILL
RESULT IN AN AREA OF LIGHT SHOWERS TO BREAK OUT THIS EVENING
THROUGH THE OVERNIGHT PERIOD ACROSS PORTIONS OF SOUTHEAST AZ
AS WELL AS ACROSS THE FOOTHILLS AND THE HIGHER TERRAIN AREAS TO
SOUTH AND EAST OF PHOENIX AS DEPICTED BY THE LATEST HI-RES
GUIDANCE. IT IS NOT INCONCEIVABLE TO EVEN SEE SOME RAIN DROPS
MAKING IT TO THE SURFACE ACROSS THE GREATER PHOENIX AREA. ACTIVITY
WILL CONTINUE TO AFFECT THE HIGHER TERRAIN AREAS TO THE NORTH AND
EAST OF PHOENIX INTO THE FIRST PART OF TUESDAY. OVERALL RAINFALL
AMOUNTS SHOULD REMAIN ON THE LIGHT SIDE, WITH MOST AREAS OBSERVING
LESS 0.10". OTHERWISE, AS THE COLD CORE MOVES DIRECTLY OVERHEAD
ON TUESDAY AFTERNOON, HIGH TEMPERATURES ACROSS MOST OF THE LOWER
DESERT COMMUNITIES WILL STRUGGLE TO REACH 80 DEGREES WITH MANY
AREAS TOPPING OUT IN THE UPPER 70S, WHICH WILL BE A SOLID 10-15F
BELOW NORMAL.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
THE PRIMARY ENERGY FROM THE LOW WILL EXIT TO THE NORTHEAST AND GET
ABSORBED BY ANOTHER BROAD TROUGH ENCOMPASSING MOST OF THE CENTRAL
AND EASTERN CONUS ON WEDNESDAY. MEANWHILE, A TRAILING PIECE OF
ENERGY WILL DEVELOP INTO A WEAK CUT-OFF LOW JUST SOUTH OF THE
INTERNATIONAL BORDER IN NORTHERN SONORA AS AN UPPER-LEVEL RIDGE OF
HIGH PRESSURE BUILDS ALONG THE WEST COAST. ALTHOUGH THERE
CONTINUES TO SOME UNCERTAINTY WITH RESPECT TO THE SPEED
PROGRESSIONOF THIS FEATURE AS IT CUTS OFF FROM THE MAIN JET
STREAM ENERGY, LATEST TRENDS HAS BEEN FOR A FASTER EASTWARD
PROGRESSION THROUGH THE LATTER HALF OF NEXT WEEK WITH NO SENSIBLE
WEATHER IMPACTS EXPECTED FOR OUR REGION.
OTHERWISE, THE MAIN WEATHER STORY HEADING TOWARDS THE END OF THE
WEEK AND BEYOND WILL BE THE RISING TEMPERATURES WITH AN EXTENDED
STRETCH OF TRIPLE DIGIT HIGHS. AS THE UPPER-LEVEL RIDGE GRADUALLY
BUILDS ACROSS THE WESTERN CONUS BY THE LATTER HALF OF THE WEEK,
TEMPERATURES WILL BE ON A RAPID WARMING TREND WITH HIGHS BACK UP
IN THE 90S ON THURSDAY AND INTO TRIPLE DIGITS AS EARLY AS FRIDAY
AND BEYOND. AS AFTERNOON HIGHS CLIMB INTO THE TRIPLE DIGITS, THE
OVERALL HEATRISK LEVEL ACROSS MOST OF THE AREA WILL INCREASE INTO
THE MODERATE CATEGORY.
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
SOME GUSTY WINDS WILL CONTINUE TO REMAIN THREAT THROUGH TUESDAY AS
AN AREA OF LOW PRESSURE APPROACHES AND MOVES THROUGH THE REGION,
WITH ONLY A LOCALLY ELEVATED FIRE DANGER THREAT EXPECTED AS HIGHER
HUMIDITIES WILL LIMIT A GREATER RISK. SOME MODEST RAIN CHANCES
WILL BE IN PLACE, MAINLY ACROSS THE FAR EASTERN DISTRICTS, LATE
TODAY THROUGH TUESDAY MORNING WITH THE CHANCES FOR WETTING RAINS
REMAINING ON THE LOW SIDE. AFTERNOON MINRHS BETWEEN 15-25% WILL BE
COMMON TODAY BEFORE INCREASING INTO A 20-35% RANGE TUESDAY ALONG
WITH GOOD OVERNIGHT RECOVERIES. 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 THIS MORNING FOR CAZ562.
WIND ADVISORY UNTIL 3 AM PDT EARLY THIS MORNING FOR CAZ566-567.
SHORT TERM...LOJERO
LONG TERM...LOJERO
AVIATION...RW
FIRE WEATHER...LOJERO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page