027
FXUS65 KPSR 082005
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
105 PM MST SUN JUN 8 2025
DISCUSSION
KEY MESSAGES:
- DRY CONDITIONS THROUGH THE PERIOD WITH TEMPERATURES PEAKING
UPWARDS OF 10 DEGREES ABOVE NORMAL EARLY THIS WEEK
- WIDESPREAD MODERATE HEATRISK THROUGH THE FIRST HALF OF THIS WEEK
RELAXING SLIGHTLY BY THE END OF THE WEEK
VERY LITTLE HAS CHANGED RECENTLY IN THE WESTERN HEMISPHERE SYNOPTIC
PATTERN WITH REX BLOCKING DOMINATING THE WESTERN CONUS AND DEEP
NEGATIVE HEIGHT ANOMALIES SPINNING INTO THE UPPER MIDWEST/GREAT
LAKES. STRONG SUBTROPICAL RIDGING CONTINUES TO HOVER SOUTH OF THE
INTERNATIONAL BORDER, BUT WILL REMAIN DAMPENED AS A RESULT OF THE
ZONAL, BASAL JET STREAK COMPRISING THE BLOCKING STRUCTURE LIMITING
ANY POLEWARD EXPANSION. AS SUCH, H5 HEIGHTS WILL HOVER IN A 586-
590DM RANGE THE NEXT SEVERAL DAYS WITH THE THERMAL RESPONSE
MAXIMIZED OVER THE NEXT 48 HOURS. NUMERICAL GUIDANCE SPREAD REMAINS
RELATIVELY NARROW ADVERTISING TEMPERATURES SOME 5F-10F ABOVE NORMAL
THROUGH AT LEAST THE MIDDLE OF THE WEEK BEFORE THE CONUS FLOW
PATTERN MODIFIES. NBM OUTPUT CONTINUES TO SHOW LOWER ELEVATIONS OF
SE CALIFORNIA WITH THE BEST ODDS (70-90%) OF HITTING 110F WITH
PROBABILITIES DECREASING TO A 50-70% RANGE ACROSS THE SW ARIZONA,
AND GENERALLY LESS THAN 50% IN THE PHOENIX METRO. REGARDLESS,
WIDESPREAD MODERATE HEATRISK WILL EXIST ACROSS THE LOWER DESERT
COMMUNITIES THROUGH MIDWEEK.
ENSEMBLE MEMBERS REMAIN CONSISTENT IN DEPICTING A BREAKDOWN IN
HEMISPHERIC BLOCKING DURING THE LATTER HALF OF THE WEEK DUE TO
PROGRESSIVE PACIFIC JET ENERGY INTRODUCING A SERIES OF SHORTWAVES
INTO THE NW CONUS. HOWEVER, TRENDS IN ENSEMBLE MEMBERSHIP CONTINUE
TO ADVERTISE LESS AGGRESSIVE MIDLEVEL HEIGHT FALLS INTO THE WESTERN
CONUS KEEPING THE PRIMARY NEGATIVE HEIGHT ANOMALIES WELL OFFSHORE.
AS A RESULT, HEIGHT FALLS ACROSS THE SW CONUS WILL BE EXTREMELY
SUBTLE AND FORECAST MODELS ARE NOW ADVERTISING ALMOST NO REDUCTION
IN TEMPERATURES INTO THE END OF THE WEEK. INSTEAD, A GROWING
PREPONDERANCE OF ENSEMBLE MEMBERS SUGGEST SUBTROPICAL RIDGING
FINALLY BUILDING INTO THE FORECAST AREA AHEAD OF THE EAST PACIFIC
TROUGHING WITH H5 HEIGHTS IN EXCESS OF 590DM SPREADING NORTH AND
WEST. IN FACT, ALMOST ALL GEFS MEMBERS DEPICT A 595DM ANTI-CYCLONE
SETTLING NEAR THE AZ-NM BORDER BY THE END OF THE WEEKEND WITH AN
INCREASING PERCENTAGE OF CMC MEMBERSHIP QUICKLY FOLLOWING SUIT.
THUS, ITS BECOMING MORE LIKELY WIDESPREAD LOWER ELEVATIONS 110F+
READINGS WILL MATERIALIZE BY THE END OF THIS FORECAST PERIOD WITH
GROWING ODDS OF NOTABLE MAJOR HEATRISK AND EXTREME HEAT HEADLINES.
AVIATION
UPDATED AT 1700Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
NO AVIATION WEATHER CONCERNS UNDER CLEAR SKIES ARE EXPECTED
THROUGHOUT THE TAF PERIOD. THE OVERALL WIND PATTERN WILL CONTINUE TO
EXHIBIT THE TYPICAL DIURNAL TENDENCY WITH SPEEDS AOB 10 KTS. A FEW
AFTERNOON GUSTS UPWARDS OF 15-20 KTS WILL BE POSSIBLE THIS AFTERNOON
BEFORE TAPERING OFF THIS EVENING. PERIODS OF LIGHT AND VARIABLE
WINDS ARE LIKELY AS WELL, ESPECIALLY DURING THE TRANSITION PERIODS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION WEATHER CONCERNS UNDER CLEAR SKIES ARE EXPECTED
THROUGHOUT THE TAF PERIOD. WINDS AT KIPL WILL GENERALLY REMAIN LIGHT
AND VARIABLE THROUGH THIS AFTERNOON BEFORE A WESTERLY COMPONENT SETS
IN THIS EVENING. AT KBLH, WINDS WILL FLUCTUATE BETWEEN THE SOUTHEAST
AND SOUTHWEST. OVERALL WIND SPEEDS WILL REMAIN AOB 10 KTS, ALTHOUGH
THERE WILL BE A PERIOD THIS EVENING WHERE SOME GUSTS UPWARDS OF 20
KTS WILL BE POSSIBLE AT KIPL. PERIODS OF LIGHT AND VARIABLE WINDS
ARE LIKELY TO CONTINUE AT BOTH TERMINALS THROUGHOUT THE TAF PERIOD.
FIRE WEATHER
TEMPERATURE WILL REMAIN ABOVE NORMAL THROUGH THE WEEK WITH THE
WARMEST READINGS OCCURRING THE NEXT COUPLE DAYS. MINRHS WILL FALL
INTO THE SINGLE DIGITS MONDAY, THEN JUST ABOVE 10% THE REMAINDER OF
THE WEEK. POOR TO FAIR OVERNIGHT RECOVERY OF 20-40% WILL BE COMMON.
WINDS WILL TEND TO FOLLOW THEIR TYPICAL DIURNAL TENDENCIES WITH
PERIODS OF AFTERNOON UPSLOPE GUSTINESS. SOME ENHANCED GUSTINESS MAY
AFFECT SOME DISTRICTS DURING THE END OF THE WEEK RESULTING IN A
SLIGHTLY ELEVATED FIRE DANGER.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
DISCUSSION...18/BERISLAVICH
AVIATION...SMITH/YOUNG
FIRE WEATHER...18/BERISLAVICH
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