978
FXUS65 KPSR 200501
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 PM MST SUN APR 19 2026
UPDATE
UPDATED AVIATION
KEY MESSAGES
- TEMPERATURES WILL REMAIN AROUND 5 TO 10 DEGREES ABOVE DAILY
NORMALS THROUGH TUESDAY.
- A PASSING WEATHER SYSTEM WILL RESULT IN PERIODS OF BREEZY TO
LOCALLY WINDY CONDITIONS AND COOLER TEMPERATURES DURING THE LATTER
HALF OF THIS WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
LATEST MID-LEVEL WATER VAPOR IMAGERY SHOWS UPPER LEVEL RIDGING
BUILDING OVER THE DESERT SW, SANDWICHED BETWEEN TWO LARGE UPPER
LEVEL TROUGHS. ONE TROUGH IS TO THE REGION'S EAST SPANNING ACROSS
MUCH OF THE CENTRAL PLAINS, AND THE SECOND IS TO THE REGION'S WEST,
CURRENTLY IN THE EASTERN PACIFIC OFF THE NW COAST. WITH THESE
SYSTEMS IN PLACE, TIGHTENING OF THE PRESSURE GRADIENT HAS RESULTED
IN STRONG EASTERLY WINDS ACROSS THE HIGH TERRAIN OF SOUTHCENTRAL AZ
THIS MORNING. THE STRONGER WIND GUSTS WILL RELAX TO SUB ADVISORY
LEVELS FOR THE AFTERNOON, HOWEVER WIND GUSTS BETWEEN 20-30MPH CAN
STILL BE POSSIBLE IN THE HIGHER TERRAIN AREAS. MODELS CONTINUE TO
HINT AT THE CHANCE OF VIRGA SHOWERS THIS EVENING IN SE AZ WITH THE
INCREASE IN CLOUD COVERAGE THROUGHOUT TODAY. DESPITE THE INCREASING
CLOUD COVER, UPPER-LVL RIDGING WILL CONTINUE TO BRING ABOVE NORMAL
TEMPERATURES TODAY WITH HIGHS IN THE LOW TO MID 90S ACROSS THE LOWER
DESERT REGION.
BY MONDAY THE RIDGE WILL BEGIN TO SHIFT EASTWARDS INTO THE PLAINS,
HOWEVER H5 HEIGHTS WILL CONTINUE TO BE BETWEEN 577-580 DAM OVER THE
DESERT SW. THIS WILL RESULT IN TEMPERATURES REMAINING IN THE LOW TO
MID 90S ACROSS THE LOWER DESERTS. MODELS ARE POINTING TOWARDS MONDAY
AFTERNOON HAVING 100-300 J/KG OF MU CAPE IN EASTERN AZ, AND ENOUGH
MID LEVEL MOISTURE FOR THE POTENTIAL OF A FEW CONVECTIVE SHOWERS
DEVELOPING, MAINLY ALONG THE MOGOLLON RIM AND IN THE WHITE
MOUNTAINS, WHILE THE LOWER DESERTS ARE EXPECTED TO REMAIN DRY.
TEMPERATURES START TO TREND A FEW DEGREES COOLER BY TUESDAY WITH
HIGHS MOSTLY IN THE LOWER 90S ACROSS THE LOWER DESERTS, WITH
LOCALIZED AREAS IN THE WESTERN PORTIONS OF THE CWA IN THE UPPER 80S.
THIS IS IN RESPONSE TO THE TROUGH WEST OF THE REGION BEGINNING TO
APPROACH NORTHERN CA, WHILE SIMULTANEOUSLY THE RIDGING FURTHER MOVES
EASTWARDS OUT OF THE REGION. OTHERWISE, AHEAD OF THE SYSTEM MOVING
OVER THE DESERT SW, WINDS WILL BEGIN TO INCREASE IN THE AFTERNOON,
ESPECIALLY IN SE CA WHERE GUSTS COULD REACH 20-30 MPH.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
BY THE MIDDLE OF THE WORKWEEK, TROUGHING OVER THE WEST COAST WILL
FINALLY PUSH INLAND OVER THE INTERMOUNTAIN WEST, ALBEIT IN A
WEAKENING PHASE. ENSEMBLES MEMBERS ARE IN GOOD AGREEMENT ON THE
EVOLUTION OF THE SHORTWAVE TROUGH WHICH IS EXPECTED TO REMAIN WELL
NORTH OF OUR FORECAST AREA. HOWEVER, THE DESERT SOUTHWEST WILL STILL
BE UNDER THE INFLUENCE OF NEGATIVE HEIGHT ANOMALIES WHICH WILL RESULT
IN COOLER TEMPERATURES (LIKELY CLOSER TO SEASONAL LEVELS, IN THE 80S
ACROSS THE LOWER DESERTS) BEGINNING ON WEDNESDAY. PERIODS OF BREEZY
TO LOCALLY WINDY CONDITIONS CAN ALSO BE ANTICIPATED ACROSS THE
ENTIRE FORECAST AREA DUE TO THE TIGHTENING OF THE 500-700 MB HEIGHT
GRADIENT. THE MOST WIDESPREAD BREEZY CONDITIONS LOOK TO BE ON
WEDNESDAY AND MAINLY ACROSS EASTERN AZ ON THURSDAY AS THE TROUGH
AXIS PASSES NORTH OF THE FORECAST AREA. QUASI-ZONAL FLOW ALOFT WILL
RETURN BY FRIDAY AND INTO NEXT WEEKEND AHEAD OF ANOTHER POTENTIAL
SHORTWAVE TROUGH. THIS WILL ALLOW FOR A SLIGHT BOOST IN TEMPERATURES
TO A FEW DEGREES ABOVE NORMAL.
AVIATION
UPDATED AT 0500Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
WINDS WILL BE THE PRIMARY FORECAST ISSUE THROUGH MONDAY NIGHT AS
THICKER MID/HIGH CIGS CLEAR BY MONDAY MORNING. FORECAST CONFIDENCE
INCREASES LATE TONIGHT AND MONDAY AS WIND DIRECTIONS EVENTUALLY
SWITCH TO EASTERLY, THEN OBTAIN THE TRADITIONAL AFTERNOON/EVENING
WEST COMPONENT. SOME ENHANCED GUSTS MAY ENTER THE METRO MONDAY
EVENING CAUSING THE NOCTURNAL SWITCH BACK TO EASTERLY TO BECOME
DELAYED MUCH LATER INTO MONDAY NIGHT/TUESDAY MORNING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO SIGNIFICANT WEATHER ISSUES WILL EXIST THROUGH MONDAY NIGHT UNDER
MOSTLY CLEAR SKIES. WINDS WILL GENERALLY OSCILLATE BETWEEN SE AND SW
AT KIPL WHILE FAVORING A SOUTHERLY DIRECTION AT KBLH. INCREASED
GUSTINESS OVER 20KT WILL BECOME MORE COMMON MONDAY LATE
AFTERNOON/EVENING, ESPECIALLY AT KBLH.
FIRE WEATHER
DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE OVER THE
NEXT FEW DAYS BEFORE COOLER AND BREEZY WEATHER ARRIVES MID-WEEK.
ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST ACROSS SOUTH-CENTRAL
AZ THROUGH THE AFTERNOON, IMPROVING BY THE EVENING HOURS. WINDS WILL
WEAKEN ON MONDAY BEFORE BREEZY TO LOCALLY WINDY CONDITIONS RETURN ON
TUESDAY WITH WIDESPREAD ELEVATED FIRE WEATHER CONDITIONS. AFTERNOON
HUMIDITY LEVELS ARE EXPECTED TO REMAIN BELOW 15% AND AT TIMES IN THE
SINGLE DIGITS OVER THE NEXT SEVERAL DAYS, WITH ONLY MINOR DAY TO DAY
VARIATIONS. OVERNIGHT RECOVERIES WILL ALSO VARY THROUGH THE WEEK,
BUT REMAIN MOSTLY IN THE 30-50% RANGE. DUE TO THE BREEZY AND DRY
CONDITIONS, PERIODS OF ELEVATED FIRE WEATHER CONDITIONS CAN BE
EXPECTED DURING THE MIDDLE TO LATTER HALF OF THIS WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM..RYAN
LONG TERM...SALERNO
AVIATION...18
FIRE WEATHER...RYAN/SALERNO
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