401
FXUS65 KPSR 231700
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1100 AM MST WED APR 23 2025
UPDATE
UPDATED AVIATION
SYNOPSIS
DRY AND GENERALLY TRANQUIL CONDITIONS WILL PERSIST OVER THE NEXT FEW
DAYS WITH TEMPERATURES RUNNING NEAR TO SLIGHTLY ABOVE SEASONAL
VALUES. A DRY WEATHER SYSTEM WILL MOVE OFF THE EASTERN PACIFIC LATER
THIS WEEK, BRINGING BREEZY TO LOCALLY WINDY CONDITIONS ALONG WITH A
COOLDOWN WITH TEMPERATURES FALLING BELOW SEASONAL NORMALS DURING THE
WEEKEND.
DISCUSSION
CURRENT MID-LEVEL WV IMAGERY SHOWS SOUTHWEST FLOW ALOFT OVER THE
DESERT SOUTHWEST, WITH A WEAK SHORTWAVE DISTURBANCE MAKING ITS WAY
ONSHORE ALONG THE OREGON/NORCAL COAST. THIS SHORTWAVE DISTURBANCE
WILL DO LITTLE TO IMPACT SENSIBLE WEATHER FOR OUR AREA TODAY, OTHER
THAN PERHAPS SOME STRONGER SUNDOWNER WINDS IN THE TYPICALLY PRONE
AREAS OF WESTERN IMPERIAL COUNTY THIS EVENING AND A SLIGHT INCREASE
IN AFTERNOON BREEZINESS ELSEWHERE COMPARED TO YESTERDAY. GLOBAL
GUIDANCE SHOWS THE SAME, MOSTLY BENIGN SOUTHWEST FLOW/HIGH PRESSURE
ALOFT REGIME BEING MAINTAINED THROUGH THE END OF THE WORKWEEK,
RESULTING IN CONTINUED WARM AND DRY CONDITIONS. AS SUCH, EXPECT
FAIRLY STABLE TEMPERATURES DAY-TO-DAY, WITH AFTERNOON HIGHS IN THE
UPPER 80S TO LOWER 90S ACROSS THE LOWER DESERTS (AND PERHAPS
SLIGHTLY COOLER OUT WEST BY FRIDAY, IN THE MIDDLE 80S.)
THE MAIN STORY DURING THE FORECAST PERIOD REMAINS BREEZY TO LOCALLY
WINDY CONDITIONS AND ELEVATED FIRE WEATHER CONCERNS THIS WEEKEND
ASSOCIATED WITH AN APPROACHING UPPER LEVEL LOW. ENSEMBLES HAVE COME
INTO MUCH BETTER AGREEMENT AS TO THE EVOLUTION OF AN EAST PACIFIC
TROUGH THAT WILL SLOWLY MOVE ONSHORE FRIDAY AND CONTINUE GRADUALLY
SHIFTING EASTWARD OVER THE GREAT BASIN THIS WEEKEND. HOWEVER, SOME
NOTABLE DISCREPANCIES IN TIMING AND EXACT POSITIONING OF THE LOW
STILL EXIST. REGARDLESS, ESSENTIALLY ALL SOLUTIONS KEEP THE FORECAST
AREA COMPLETELY DRY. LATEST ENS/NAEFS OUTPUT SUGGEST THAT HEIGHT
PACKING OVER THE AREA, AHEAD OF THE APPROACHING UPPER LOW, WILL BE
MAXIMIZED SOMETIME SATURDAY. THUS, EXPECT THE STRONGEST WINDS
AREAWIDE TO OCCUR SATURDAY AFTERNOON/EARLY EVENING DURING PEAK
MIXING. THE MAGNITUDE OF THE WINDS WILL BE LARGELY DEPENDENT ON THE
TRACK OF THE SYSTEM, BUT EARLY INDICATION ARE THAT GUSTS UPWARDS OF
25-35 MPH MAY BE COMMON, WITH ADVISORY LEVEL GUSTS TO 40+ MPH
POSSIBLE FOR THE USUALLY WINDY SPOTS OF SOUTHEAST CALIFORNIA AND THE
AZ HIGH TERRAIN. WE ARE SEVERAL DAYS FROM THIS LOW MOVING ONSHORE SO
FORECAST DETAILS COULD CERTAINLY CHANGE, BUT IF TRENDS CONTINUE IN
THE DIRECTION THEY ARE, WIND PRODUCTS MAY BE NEEDED LATER THIS WEEK.
THE OTHER IMPACT OF THE UPPER LOW ON OUR AREA WILL BE COOLER
TEMPERATURES THIS WEEKEND. LATEST NBM HIGHS SHOW TEMPERATURES
COOLING TO BETWEEN 5-10 DEGREES BELOW SEASONAL NORMALS FOR A DAY OR
TWO, IN THE UPPER 70S TO AROUND 80F BY SATURDAY FOR THE WESTERN
DESERTS AND BY SUNDAY FOR THE SOUTH-CENTRAL AZ LOWER DESERTS. A
WARMING TREND WILL COMMENCE EARLY NEXT WEEK AS THE UPPER LOW WEAKENS
AND GRADUALLY PASSES THE REGION TO THE NORTH. AFTERNOON HIGHS ARE
LIKELY TO REACH SEASONAL VALUES ONCE AGAIN BY TUESDAY.
AVIATION
UPDATED AT 1700Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT; AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER ISSUES WILL EXIST THROUGH THURSDAY AFTERNOON UNDER
CLEAR SKIES. TRENDS IN WINDS WILL BE SIMILAR TO THE PAST 24 HOURS
WITH PERIODS OF VARIABILITY AND/OR NEARLY CALM CONDITIONS,
ESPECIALLY DURING THE DIURNAL TRANSITION. WHILE SOME MODEST WIND
GUSTS UP TO 20KT WILL BE POSSIBLE AROUND THE PHOENIX METRO THIS
AFTERNOON, WHILE MORE PERSISTENT GUSTS AROUND 25KT WILL BE LIKELY AT
SE CALIFORNIA TERMINALS DURING THE LATE AFTERNOON/EVENING.
FIRE WEATHER
DRY CONDITIONS WILL PERSIST THROUGH THE NEXT 7 DAYS, WITH SEASONABLY
WARM TEMPERATURES THROUGH THE END OF THE WORKWEEK. A WEAK WEATHER
DISTURBANCE WILL SLIGHTLY INCREASE AFTERNOON BREEZES AREAWIDE TODAY
COMPARED TO YESTERDAY, BUT OTHER THAN THAT, EXPECT TYPICAL DIURNALLY
DRIVEN AND GENERALLY LIGHT WINDS THROUGH THURSDAY. AN APPROACHING,
MORE POTENT LOW PRESSURE SYSTEM LATE WEEK INTO THIS WEEKEND WILL
INCREASE WINDS FRIDAY FOR THE WESTERN DISTRICTS AND AREAWIDE BY
SATURDAY, LEADING TO LOCALLY ELEVATED TO NEAR CRITICAL FIRE WEATHER
CONDITIONS FOR THE TYPICALLY PRONE AREAS, SUCH AS THE ARIZONA HIGH
TERRAIN EAST OF PHOENIX. TEMPERATURES WILL ALSO COOL BELOW NORMAL
THIS WEEKEND AS A RESULT OF THE LOW PRESSURE SYSTEM. AFTERNOON
MINRHS WILL GENERALLY FALL INTO THE LOWER TEENS THROUGH THE END OF
THE WORKWEEK AND SLIGHTLY HIGHER THIS WEEKEND, IN THE MIDDLE TO
UPPER TEENS, THANKS TO THE COOLER TEMPERATURES. OVERNIGHT RECOVERIES
WILL BE POOR TO FAIR, GENERALLY BETWEEN 25-45% THROUGH THE END OF
THE WORKWEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
DISCUSSION...WHITTOCK
AVIATION...18
FIRE WEATHER...WHITTOCK
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