530
FXUS65 KPSR 050940
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
240 AM MST TUE MAY 5 2026
KEY MESSAGES
- WELL BELOW NORMAL TEMPERATURES EXPECTED TODAY AS AFTERNOON HIGHS
STRUGGLE TO REACH EIGHTY DEGREES ACROSS THE LOWER DESERTS.
- SHOWER ACTIVITY WILL PERSIST THROUGH THIS MORNING, PARTICULARLY ACROSS
THE FOOTHILLS AND HIGHER TERRAIN AREAS EAST OF PHOENIX.
- AS HIGH PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES THROUGH
THE END OF THE WEEK, A RAPID WARMING TREND TO ABOVE NORMAL
TEMPERATURES IS EXPECTED WITH TRIPLE DIGIT HIGHS MATERIALIZING
AS EARLY AS FRIDAY ACROSS THE LOWER DESERTS.
SHORT TERM /TODAY THROUGH THURSDAY/
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS AN UPPER-LEVEL LOW
CENTERED ACROSS CENTRAL CA. THIS UPPER-LEVEL LOW WILL CONTINUE TO
SLOWLY TREK EAST-SOUTHEASTWARD THROUGHOUT THE DAY, REACHING AZ
EARLY THIS EVENING. OUT AHEAD OF THE LOW, A LARGE MOISTURE PLUME
WITH SUBTROPICAL CONNECTION IS CURRENTLY ENVELOPING THE EASTERN
HALF OF AZ WITH THE LATEST SPC MESOANALYSIS SHOWING PWAT VALUES
RANGING BETWEEN 0.7-1.0 ACROSS CENTRAL AND SOUTHERN AZ. THE
COMBINATION OF THE MOISTURE IN PLACE AND THE LARGE SCALE FORCING
FOR ASCENT ASSOCIATED WITH THE LOW HAS LED TO AN AREA OF LIGHT
SHOWERS TO BREAK OUT ACROSS PORTIONS OF SOUTHEAST AZ, WITH
ACTIVITY EXTENDING NORTHWARD TO INCLUDE THE FOOTHILLS AND HIGHER
TERRAIN AREAS JUST EAST OF PHOENIX. THIS ACTIVITY IS EXPECTED TO
PERSIST THROUGHOUT THE MORNING HOURS ACROSS THESE AREAS. A FEW
SCATTERED SHOWERS MAY ALSO DEVELOP ACROSS THE PHOENIX METRO
THROUGHOUT THE MORNING HOURS AS WELL. FOR THE MOST PART, RAINFALL
AMOUNTS SHOULD REMAIN ON THE LIGHT SIDE, WITH MOST OF THE PHOENIX
AREA SEEING LITTLE TO NO ACCUMULATIONS WHILE AMOUNTS OF UPWARDS
OF 0.25", LOCALLY HIGHER IN THE MOST PERSISTENT BANDS, ARE LIKELY
ACROSS THE HIGHER TERRAIN AREAS EAST OF PHOENIX. ACTIVITY WILL
COME TO AN END ACROSS MOST OF THE REGION BY THIS AFTERNOON AS
DRIER AIR GRADUALLY FILTERS IN.
WITH COLD CORE OF THE LOW APPROACHING THE AREA HEADING INTO THIS
AFTERNOON, HIGH TEMPERATURES TODAY WILL BE WELL-BELOW NORMAL AS
READINGS STRUGGLE TO REACH 80 DEGREES, IN WHAT WILL LIKELY BE THE
COOLEST DAY FOR THE NEXT 6 MONTHS. WITH SOME JET ENERGY LINGERING
OVERHEAD, BREEZY CONDITIONS WILL ALSO CONTINUE TODAY WITH
AFTERNOON/EARLY EVENING GUSTS RANGING BETWEEN 15-30 MPH, WITH THE
STRONGEST GUSTS EXPECTED ACROSS IMPERIAL COUNTY.
THE MAIN ENERGY FROM THE LOW WILL EXIT TO THE NORTHEAST ON WEDNESDAY
AND WILL BE ABSORBED BY ANOTHER LARGER SCALE TROUGH THAT WILL
ENCOMPASS MOST OF THE CENTRAL AND EASTERN CONUS. MEANWHILE, A
TRAILING PIECE OF ENERGY IS EXPECTED TO BECOME CUTOFF FROM THE MAIN
JET STREAM AND FORM A NEW UPPER-LEVEL LOW ACROSS NORTHERN SONORA AS
A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST COAST. THIS FEATURE
WILL CONTINUE TO GRADUALLY PROGRESS EASTWARD THROUGH NORTHERN SONORA
THROUGH THURSDAY WITH NO SENSIBLE WEATHER IMPACTS EXPECTED FOR OUR
REGION. AS 500 MB HEIGHT FIELDS STEADILY RISE WITH THE BUILDING
RIDGE OVER THE WEST COAST, TEMPERATURES WILL BE ON A RAPID WARMING
TREND, WARMING INTO THE MIDDLE 80S ON WEDNESDAY TO MIDDLE 90S ON
THURSDAY ACROSS THE LOWER DESERTS.
LONG TERM /FRIDAY THROUGH MONDAY/
THE MAIN STORY HEADING INTO THE LONG TERM PERIOD WILL BE A
PROLONGED HEAT EPISODE THAT WILL MATERIALIZE AS TRIPLE DIGIT
HIGHS WILL BE IN PLACE FOR SEVERAL DAYS. AS THE AFOREMENTIONED
RIDGE CONTINUES TO GRADUALLY BUILD ACROSS THE WESTERN CONUS,
TEMPERATURES WILL CONTINUE TO GRADUALLY WARM WITH LOWER DESERT
HIGHS REACHING THE LOW 100S AS EARLY AS FRIDAY WITH WIDESPREAD
HIGHS IN THE LOW TO MID 100S CONTINUING THROUGH THE WEEKEND.
HEADING INTO EARLY NEXT WEEK, ENSEMBLES SHOW THE RIDGE INTENSIFYING
A BIT MORE AS 500 MB HEIGHT FIELDS NEAR 590DM. THIS WILL RESULT
IN ADDITIONAL WARMING, WITH THE LATEST NBM SHOWING WIDESPREAD
LOWER DESERT HIGHS IN THE MID TO UPPER 100S. WITH TEMPERATURES
HEATING UP INTO THE TRIPLE DIGITS BY THE END OF THE WEEK AND
BEYOND, WIDESPREAD MODERATE HEATRISK WILL BE IN PLACE ACROSS MOST
OF THE AREA. THUS, ANY VULNERABLE COMMUNITIES AND THOSE
PARTICIPATING IN OUTDOOR ACTIVITIES WILL NEED TO TAKE THE
NECESSARY HEAT PRECAUTIONS TO AVOID ANY HEAT-RELATED ILLNESSES.
AVIATION
UPDATED AT 0525Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
ISOLATED SHOWER ACTIVITY AND LOW VFR CIGS WILL BE THE MAIN
AVIATION CONCERN DURING THE FRONT HALF OF THE TAF PERIOD. SHOWERS
OVER SE AZ SHOULD REMAIN MOSTLY EAST OF THE AIRSPACE TONIGHT,
THOUGH A FEW VCSH, MAINLY NEAR KIWA, CANNOT BE RULED OUT.
CONFIDENCE REGARDING TIMING OF FURTHER SHRA ACTIVITY IS LOW, BUT
THE BEST WINDOW FOR MORE WIDESPREAD ACTIVITY LOOKS TO BE CLOSER TO
12-13Z, THOUGH IT IS NOT OUT OF THE QUESTION SOME ISOLATED CELLS
COULD POP A COUPLE HOURS EARLIER. SHRA WILL BE ACCOMPANIED BY
LOWER CLOUD DECKS, WITH FEW-SCT 4-5 KFT BASES AND BKN 5-6 KFT
CIGS. SUB-VFR CONDITIONS ARE NOT EXPECTED (CHANCES REMAIN
GENERALLY 20% OR LESS) BUT EVEN THESE VFR CIGS ARE LIKELY TO
RESULT IN SOME OPERATIONAL IMPACTS AT KPHX. BASES WILL BEGIN TO
GRADUALLY LIFT BY THE AFTERNOON. WINDS SHOULD CONTAIN A SW'RLY
COMPONENT THROUGH MOST OF THE PERIOD, THOUGH A BRIEF WINDOW OF SSE
AND EVEN VRB CONDITIONS CANNOT BE RULED OUT FOR KPHX AND KIWA
AROUND 10-13Z. IT SHOULD ALSO BE MENTIONED THAT POTENTIAL SHRA MAY
LEAD TO SHORT WINDOWS OF ERRATIC WINDS AT TIMES.
SLANTWISE VIS/HAZY CONDITIONS WILL LIKELY CONTINUE TO BE A
CONCERN DUE TO THE BRUSH FIRE IN BUCKEYE. WITH THE NOCTURNAL
INVERSION AND W'RLY WINDS, SOME SURFACE VIS REDUCTIONS ARE
POSSIBLE AT KSDL AND KDVT DURING THE MORNING HOURS. WINDS WILL
BEGIN TO TILT MORE TO THE W AND WNW LATER IN THE PERIOD, SO KPHX
MAY START TO EXPERIENCE OPERATIONAL IMPACTS DUE TO SMOKE AS WELL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
BREEZY TO WINDY CONDITIONS WILL CONTINUE TO BE THE MAIN AVIATION
CONCERN OVER THE NEXT 24 HOURS. STRONGEST WINDS WILL BE FOCUSED AT
KIPL WHERE W'RLY GUSTS AROUND 25 KT WILL BE COMMON, OUTSIDE OF A
BRIEF REPRIEVE OVERNIGHT. AT KBLH, BREEZINESS WILL MAKE A RETURN
TUESDAY AFTERNOON WITH MORE MARGINAL GUSTS AROUND 20 KT OUT OF THE
SW. CLEAR SKIES TONIGHT WILL GIVE WAY TO FEW-SCT LOWER BASES
AROUND 7-9 KFT BY MID TO LATE TUESDAY MORNING.
FIRE WEATHER
BELOW NORMAL TEMPERATURES WILL PREVAIL TODAY AND WEDNESDAY ACROSS
THE REGION AS READINGS ACROSS THE LOWER DESERTS WILL TOP OUT IN
THE UPPER 70S TODAY AND MIDDLE 80S WEDNESDAY. SCATTERED SHOWER
ACTIVITY WILL CONTINUE THROUGH THIS MORNING, PARTICULARLY ACROSS
THE HIGHER TERRAIN AREAS EAST OF PHOENIX. TOTAL RAINFALL AMOUNTS
WILL GENERALLY AVERAGE UNDER 0.25" ACROSS MOST AREAS, WITH
LOCALLY HIGHER AMOUNTS IN THE MORE PERSISTENT RAIN BANDS. BREEZY
CONDITIONS WILL CONTINUE FOR TODAY WITH AFTERNOON/EARLY EVENING
GUSTS PEAKING AT 15-30 MPH. MINRHS FOR THIS AFTERNOON WILL REMAIN
ELEVATED WITH VALUES BOTTOMING OUT BETWEEN 20-40%. LIGHTER WINDS
AS WELL AS MUCH WARMER TEMPERATURES AND LOWER HUMIDITIES ARE THEN
FORECAST FOR THE LATTER HALF OF THE WEEK AND BEYOND AS HIGH
PRESSURE BUILDS BACK INTO OUR REGION.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...LOJERO
LONG TERM...LOJERO
AVIATION...RW
FIRE WEATHER...LOJERO
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