795
FXUS65 KPSR 132022
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
120 PM MST TUE MAY 13 2025
SYNOPSIS
A WEATHER DISTURBANCE PUSHING THROUGH THE REGION WILL RESULT IN
GUSTY WINDS SLOWLY WEAKENING AND TEMPERATURES FALLING INTO A BELOW
NORMAL RANGE THE NEXT COUPLE DAYS. HOWEVER, WEAK HIGH PRESSURE WILL
BUILD BACK INTO THE AREA ALLOWING TEMPERATURES TO MODERATE BACK TO
NEAR NORMAL LATER THIS WEEK. ANOTHER DRY WEATHER SYSTEM WILL SWEEP
INTO THE SOUTHWEST EARLY NEXT WEEK YIELDING ANOTHER ROUND OF GUSTY
WINDS AND COOLER THAN NORMAL TEMPERATURES.
DISCUSSION
EARLY AFTERNOON WV IMAGERY AND OBJECTIVE ANALYSIS DEPICTS NEGATIVE
HEIGHT ANOMALIES MIGRATING INTO THE GREAT BASIN WITH THE TROUGH BASE
AND ENHANCED JET CORE PROPAGATING THROUGH THE FORECAST AREA. WHILE
THE MOST ROBUST HEIGHT FALLS WILL REMAIN WELL NORTH OF THE CWA, DEEP
MIXING DEPTHS AND SUFFICIENT PRESSURE GRADIENT HAS RESULTED IN VERY
GUSTY WINDS IMPACTING MUCH OF THE REGION. NOT SURPRISINGLY, THE MOST
PRONOUNCED GUSTS HAVE BEEN MEASURED NEAR TERRAIN FEATURES, AND
VARIOUS HEADLINE PRODUCTS REMAIN IN EFFECT THROUGH THIS EVENING. AS
THE CIRCULATION CENTER EJECTS INTO THE CENTRAL/NORTHERN PLAINS
WEDNESDAY, GRADIENT WILL RELAX FORCING WINDS BACK INTO A MORE
TRADITIONAL LATE SPRING PATTERN. HOWEVER, H5 HEIGHTS WILL REMAIN
DEPRESSED IN A 570-574DM RANGE YIELDING HIGH TEMPERATURES SOME 4F-8F
BELOW THE DAILY NORMALS.
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED TROUGH, BROAD
CYCLONIC/QUASI ZONAL FLOW WILL PREVAIL OVER THE SW CONUS THROUGH THE
REMAINDER OF THIS WEEK WITH H5 HEIGHTS ONLY GRADUALLY REBOUNDING
AROUND 576DM. AS THE LOWER/MIDDLE TROPOSPHERIC THERMAL PROFILES
MODERATE, MODEL GUIDANCE SPREAD REMAINS EXTREMELY NARROW
HIGHLIGHTING EXCELLENT FORECAST CONFIDENCE OF TEMPERATURES RETURNING
TO NEAR NORMAL LEVELS. FORECAST UNCERTAINTY INCREASES EARLY NEXT
WEEK AS OPERATIONAL AND ENSEMBLE GUIDANCE SHOW ANOTHER TROUGH WITH
DEEP NEGATIVE HEIGHT ANOMALIES PROPAGATING INTO THE GREAT BASIN.
ENSEMBLE MEMBERSHIP IS MOST DISPERSIVE WITH RESPECT TO THE DEPTH OF
THIS TROUGH AND EQUATORWARD EXTENT OF THE COLD CORE AND ASSOCIATED
VORTICITY CENTERS. OVERALL ENSEMBLE FORECAST TRENDS OF A DEEPER AND
SLOWER TROUGH EVOLUTION MATCHES A CONCEPTUAL PREFERRED FLOW PATTERN
UNDER THE CIRCUMSTANCES, AND WOULD STILL FAVOR THE SLOWER, DEEPER
MODEL FORECASTS. REGARDLESS, THERE IS SUFFICIENT MODEL AGREEMENT
SUGGESTING ANOTHER ROUND OF GUSTY WINDS AND COOLER TEMPERATURES
IMPACTING THE REGION DURING THE FIRST HALF OF NEXT WEEK.
AVIATION
UPDATED AT 1720Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
GUSTY WSW WINDS WILL BE THE PRIMARY AVIATION CONCERN DURING THE
TAF PERIOD UNDER FEW HIGH CLOUDS. GUSTS TO AROUND 25 KTS WILL PICK
UP OVER THE NEXT FEW HOURS AND PERSIST INTO EARLY THIS EVENING,
EVENTUALLY SUBSIDING BY 03-04Z. THOUGH W-SW WINDS ARE ANTICIPATED TO
PREVAIL THROUGH THE OVERNIGHT HOURS, DIRECTIONS MAY TRY TO SHIFT S-
SE OR BECOME VRB FOR A PERIOD EARLY WEDNESDAY MORNING. CONFIDENCE IS
TOO LOW TO INCLUDE S-SE WINDS EARLY WEDNESDAY MORNING AT ANY OF THE
TERMINALS EXCEPT FOR KIWA, SO HAVE OPTED FOR PREVAILING VRB GROUPS
AT THE OTHER SITES, WITH SPEEDS AOB 6 KTS DURING THAT TIMEFRAME.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY WINDS AND THE POTENTIAL FOR BRIEF VISIBILITY RESTRICTIONS FROM
BLOWING DUST WILL CONTINUE TO BE THE PRIMARY AVIATION CONCERNS AT
THE SE CALIFORNIA TERMINALS UNDER FEW OCCASIONAL HIGH CLOUDS. WINDS
WILL REMAIN WESTERLY AT KIPL AND SOUTHWESTERLY AT KBLH THROUGH MUCH
OF THE TAF PERIOD AND ARE EXPECTED TO SHIFT NW WEDNESDAY MORNING
AFTER SUNRISE. AT KIPL, GUSTS OF 25-30 KT WILL CONTINUE THROUGH THE
AFTERNOON AND WILL THEN PICK UP LATE THIS AFTERNOON WITH GUSTS OF 30-
35 KT EXPECTED THROUGH THE EVENING. GUSTS WILL FINALLY START TO
SUBSIDE DURING THE OVERNIGHT/EARLY MORNING HOURS WEDNESDAY. AT KBLH,
WINDS WILL PICK UP OVER THE NEXT FEW HOURS, WITH GUSTS TO AROUND 25
KTS BECOMING COMMON DURING THE AFTERNOON AND EARLY EVENING.
FIRE WEATHER
WEAKENING WIND SPEEDS AND COOLING TEMPERATURES WILL REDUCE THE FIRE
DANGER THE NEXT SEVERAL DAYS, HOWEVER ANOTHER INCOMING SYSTEM WILL
ALLOW WINDS TO STRENGTHEN AGAIN OVER THE WEEKEND. UNDER MORE TYPICAL
SPRINGTIME UPSLOPE GUSTINESS, MINIMUM HUMIDITY VALUES WILL FALL INTO
THE TEENS THE NEXT SEVERAL DAYS FOLLOWING POOR TO FAIR OVERNIGHT
RECOVERY OF 20-50%. GUSTY WINDS WILL MATERIALIZE AGAIN THIS WEEKEND
WITH THE NEXT WEATHER DISTURBANCE, HOWEVER COOLING TEMPERATURES AND
INCREASED HUMIDITY LEVELS MAY PRECLUDE WIDESPREAD CRITICAL
CONDITIONS. AT THIS TIME, SATURDAY AFTERNOON POSES THE GREATEST
THREAT OF AN ELEVATED FIRE DANGER.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...RED FLAG WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ133.
CA...WIND ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR CAZ562.
WIND ADVISORY UNTIL 2 AM PDT WEDNESDAY FOR CAZ563-566-567.
DISCUSSION...18/SMITH
AVIATION...WHITTOCK
FIRE WEATHER...18
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