297
FXUS65 KPSR 120013
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
513 PM MST SUN MAY 11 2025
UPDATE
00Z AVIATION DISCUSSION.
SYNOPSIS
TEMPERATURES WILL COOL THROUGH THE MIDDLE OF THE WEEK AS A DRY
WEATHER SYSTEM MOVES INTO THE REGION. ASSOCIATED WITH THIS WEATHER
DISTURBANCE, GUSTY WINDS WILL BE COMMON THE NEXT SEVERAL DAYS.
TEMPERATURES SHOULD SLOWLY REBOUND DURING THE LATTER HALF OF THE
WEEK EVENTUALLY HOVERING AROUND THE SEASONAL NORMALS.
DISCUSSION
A BLOCKING PATTERN WHICH HAS PREDOMINATED THE CONUS WILL SLOWLY OPEN
OVER THE NEXT SEVERAL DAYS AS A SERIES OF PROGRESSIVE PACIFIC
DISTURBANCES AND STRONG JET ENERGY DISLODGE CUTOFF NEGATIVE HEIGHT
ANOMALIES ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. H5 HEIGHTS NEAR
585DM OVER THE SW CONUS WHICH HAVE SUPPORTED TEMPERATURES SOME 10F
ABOVE NORMAL WILL GRADUALLY ERODE CLOSER TO 572DM OVER THE NEXT 72
HOURS AS MODEST HEIGHT FALLS ENTER THE REGION. WHILE THE PRIMARY
COLD CORE/CIRCULATION CENTER AND STRONGEST FORCING WILL REMAIN NORTH
OF THE FORECAST AREA, SUFFICIENT JET ENERGY AND HIGHER MOMENTUM
WITHIN A SEASONALLY DEEP MIXING DEPTH WILL RESULT IN PERIODICALLY
GUSTY WINDS EARLY IN THE WEEK. WITH MODELS DEPICTING 25-35KT WINDS
DEVELOPING IN A H8-H7 LAYER CORRESPONDING TO THE INCOMING HEIGHT
FALLS AND WEAKENING FRONTAL BOUNDARY, CONFIDENCE IS VERY GOOD THAT
ENHANCED GUSTS WILL IMPACTS MUCH OF THE REGION BEGINNING IN SE
CALIFORNIA MONDAY, THEN MIGRATING EASTWARD TUESDAY. AN ENHANCED FIRE
DANGER AND LOCALIZED BLOWING DUST MAY BE THE MOST SIGNIFICANT
HAZARDS WITH THIS WEATHER SYSTEM PASSAGE.
ALTHOUGH THE CONUS PATTERN WILL REMAIN SLOWLY PROGRESSIVE DURING THE
LATTER HALF OF THE WEEK, SOME MEASURE OF BROAD CYCLONIC, OR QUASI-
ZONAL FLOW WILL SETTLE OVER THE SOUTHWEST. AS SUCH, FORECAST
CONFIDENCE IS GOOD THAT H5 HEIGHTS SHOULD HOVER IN A 576-579DM RANGE
WITH THE PATTERN CONFIGURATION PROHIBITING SIGNIFICANT HEIGHT RISES
OR RAPID WARMING. INSTEAD, NARROW GUIDANCE SPREAD SUGGESTS READINGS
RETURNING TO A NEAR NORMAL MID-MAY LEVEL PERSISTING INTO THE
WEEKEND. ENSEMBLE SPREAD STARTS GROWING NOTABLY TOWARDS THE END OF
THE PERIOD AS MEMBERSHIP IS SPLIT BETWEEN MAINTAINING NEGATIVE
HEIGHT ANOMALIES OVER THE SW CONUS, OR SHIFTING MEAN TROUGHING INTO
THE EASTERN CONUS AND ALLOWING BROAD RIDGING TO MATERIALIZE OVER THE
FORECAST AREA. CMC MEMBERS REMAIN THE MOST AMPLIFIED WITH NEGATIVE
ANOMALIES CENTERED OVER THE FORECAST AREA WITH TRENDS IN GEFS
MEMBERSHIP POINTING TOWARDS HIGHER PROBABILITIES OF AMPLIFIED
HEIGHTS AND/OR FLAT RIDGING. AT THIS TIME, THESE DISPARATE SOLUTIONS
FORM AN ENSEMBLE MEAN NOT FAR FROM A TYPICAL, DRY QUASI-ZONAL MAY
PATTERN.
AVIATION
UPDATED AT 0000Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
NO AVIATION CONCERNS ARE ANTICIPATED THROUGH THE FORECAST PERIOD.
WINDS WILL REMAIN LIGHT, AOB 8 KTS OUT OF THE WSW OVER THE NEXT
SEVERAL HOURS BEFORE BECOMING EASTERLY AT KPHX AND KIWA BY 07-09Z.
WINDS WILL INCREASE OUT OF THE S-SE AFTER SUNRISE TOMORROW
MORNING, RESULTING IN A SOUTHERLY CROSS-RUNWAY COMPONENT AT KPHX
FOR APPROX 3-4 HOURS BEFORE ULTIMATELY SHIFTING OUT OF THE SW BY
THE EARLY AFTERNOON. GUSTS BETWEEN 20-25 KTS WILL BE COMMON FROM
THE LATE AFTERNOON THROUGH THE EARLY EVENING AT ALL TERMINALS.
HIGH CLOUDS WILL CONTINUE TO OVERSPREAD THE REGION TONIGHT AND
INTO TOMORROW WITH BASES REMAINING AOA 15 KFT AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY WINDS WILL BE THE PRIMARY AVIATION CONCERN AT THE SOUTHEAST
CA TERMINALS, ESPECIALLY BY TOMORROW AFTERNOON AND EVENING. WINDS
WILL CONTINUE TO REMAIN WESTERLY AT KIPL AND SOUTHERLY TO
SOUTHWESTERLY AT KBLH THROUGH THE PERIOD. INTERMITTENT GUSTS TO
AROUND 20 KTS WILL BE POSSIBLE AT BOTH TERMINALS THROUGH THIS
EVENING BEFORE DIMINISHING OVERNIGHT. BY TOMORROW MORNING THROUGH
THE AFTERNOON, STRONGER GUSTS WILL MATERIALIZE AT BOTH TERMINALS,
REACHING 25-30 KTS AT TIMES. THERE IS A MEDIUM PROBABILITY 30-50%
OF GUSTS EXCEEDING 35 KTS AT KIPL BY TOMORROW EVENING. HIGH CLOUDS
WILL CONTINUE TO OVERSPREAD THE REGION THROUGH TOMORROW WITH BASES
REMAINING AOA 20 KFT AGL.
FIRE WEATHER
AN ELEVATED FIRE DANGER WILL EXIST MONDAY AND TUESDAY AS WARM
TEMPERATURES, LOW HUMIDITY LEVELS, AND GUSTY WINDS BECOME JUXTAPOSED
WITH RECEPTIVE, DRY FINE FUELS. AFTERNOON HUMIDITY LEVELS IN THE
TEENS WILL BE COMMON THROUGHOUT THE WEEK FOLLOWING POOR TO FAIR
OVERNIGHT RECOVERY OF 20-50%. WIND SHOULD BE STRONGEST MONDAY AND
TUESDAY WITH GUSTS 25-35 MPH DURING THE AFTERNOON AND EARLY EVENING.
GUSTS WILL LIKELY BE MOST PRONOUNCED ACROSS RIDGE TOPS AND IN THE
TYPICAL DOWNSLOPING AREAS. SPEEDS SHOULD WEAKEN DURING THE LATTER
HALF OF THE WEEK, THOUGH STILL WILL RETAIN THE USUAL UPSLOPE
GUSTINESS. TEMPERATURES WILL ALSO COOL DURING THE MIDDLE OF THE WEEK
AS THE WEATHER SYSTEM MOVES INTO THE REGION, HOWEVER SHOULD REBOUND
CLOSER TO THE SEASONAL NORMAL BY THE END OF THE WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY FROM 5 AM MONDAY TO 5 AM PDT WEDNESDAY FOR CAZ562.
DISCUSSION...18
AVIATION...SALERNO
FIRE WEATHER...18
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