388
FXUS65 KPSR 121139
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
439 AM MST TUE MAY 12 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- AN EXTREME HEAT WARNING REMAINS IN EFFECT FOR THE PHOENIX METRO
AREA THROUGH EARLY THIS EVENING WITH TEMPERATURES TOPPING OUT
BETWEEN 105 TO 107 DEGREES.
- BREEZY CONDITIONS ARE ANTICIPATED ALONG THE LOWER COLORADO RIVER
VALLEY TODAY AND WEDNESDAY AND OVER THE AZ HIGH TERRAIN ON
WEDNESDAY.
- A MORE NOTICEABLE COOLING TREND STARTING WEDNESDAY WILL DROP
HIGH TEMPERATURES INTO THE UPPER 90S TO AROUND 100 DEGREES,
LASTING THROUGH THE UPCOMING WEEKEND.
SHORT TERM /TODAY THROUGH WEDNESDAY/
A STRONG UPPER LEVEL RIDGE WITH NEAR CLIMATOLOGICAL RECORD H5
HEIGHTS IS POSITIONED ACROSS THE DESERT SOUTHWEST. ADDITIONALLY, A
WEAK SHORTWAVE TROUGH IS ALSO LOCATED OVER CENTRAL BAJA.
SOUTHEASTERLY FLOW IN BETWEEN THE TWO SYSTEMS DID RESULT IN SOME
SCATTERED CONVECTION ACROSS NORTHERN MEXICO YESTERDAY ALONG WITH
SOME REMNANT MOISTURE FROM THE CONVECTION MAKING ITS WAY
NORTHWESTWARD INTO SOUTHERN ARIZONA. THIS MOISTURE MAY RESULT IN
SOME MORNING MID LEVEL CLOUDS, BUT OVERALL TODAY WILL AGAIN BE
SUNNY TO MOSTLY SUNNY FOR MOST LOCATIONS.
AS THE WEAK SHORTWAVE CONTINUES TO MOVE NORTHWARD INTO SOUTHERN
CALIFORNIA LATER TODAY, HEIGHT FALLS ACROSS THE WESTERN DESERTS
WILL BRING SOME SLIGHT RELIEF FROM YESTERDAY'S NEAR 110 DEGREE
HIGHS AS READINGS MOSTLY TOP OUT BETWEEN 102-106 DEGREES. THE
RIDGE WILL REMAIN MORE DOMINANT ACROSS ARIZONA RESULTING IN HIGHS
OF 105-107 DEGREES IN THE PHOENIX AREA WHERE AN EXTREME HEAT
WARNING REMAINS IN EFFECT. THE SOUTHEASTERLY FLOW CONTINUING
ACROSS THE AREA THROUGH THE REST OF TODAY MAY ALLOW FOR SOME
WIDELY ISOLATED CONVECTIVE SHOWERS ACROSS SOUTHEAST ARIZONA AND
LIKELY SOME CLOUDS INTO THE SOUTH-CENTRAL ARIZONA LOWER DESERTS BY
THIS EVENING. SOUTHERLY BREEZY TO LOCALLY WINDY CONDITIONS WILL
ALSO AFFECT PORTIONS OF SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA
THIS AFTERNOON WITH GUSTS AS HIGH AS 25-30 MPH IN SOME LOCATIONS.
BY WEDNESDAY MORNING THE WEAK SHORTWAVE IS FORECAST TO HAVE MOVED
INTO CENTRAL CALIFORNIA AND WESTERN NEVADA AS ANOTHER STRONGER
PACIFIC WAVE MOVES EASTWARD ACROSS THE PACIFIC NORTHWEST. BOTH
SYSTEMS WILL COMBINE INTO A LARGER TROUGH WITH A TRAILING TROUGH
AXIS EVENTUALLY MAKING ITS WAY INTO OUR REGION BY THURSDAY. AT
THE SAME TIME, IT WILL COMPLETELY DISPLACE THE RIDGE TO THE EAST
OF OUR REGION ALLOWING FOR MODEST HEIGHT FALLS AND COOLING
TEMPERATURES. FORECAST HIGHS FOR WEDNESDAY DROP INTO THE UPPER 90S
TO JUST OVER 100 DEGREES ACROSS THE LOWER DESERTS.
LONG TERM /THURSDAY THROUGH MONDAY/
THE WEATHER PATTERN LATER THIS WEEK IS EXPECTED SHIFT TO A MORE
ZONAL WESTERLY DRY FLOW PATTERN, BUT WITH SOME INFLUENCE FROM
PASSING TROUGHS TO OUR NORTH. THE DRYING FLOW WILL RESULT IN CLEAR
TO MOSTLY CLEAR SKIES FOR THURSDAY-SATURDAY WITH TEMPERATURES
REMAINING QUITE STABLE AVERAGING 5-7 DEGREES ABOVE NORMAL.
ENSEMBLES ARE CURRENTLY FAVORING A LARGER PACIFIC TROUGH MOVING
THROUGH THE PACIFIC NORTHWEST THIS WEEKEND BRINGING LOWER HEIGHTS
AS FAR SOUTH AS THE SOUTHWESTERN U.S. NBM/WPC TEMPERATURE
GUIDANCE SUGGESTS DAYTIME HIGHS FALLING BACK MORE INTO THE UPPER
90S BY AROUND SUNDAY.
AVIATION
UPDATED AT 1130Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
OCCASIONALLY GUSTY SSW-W WINDS THIS AFTERNOON/EVENING WILL BE
PRIMARY WEATHER ISSUE THROUGH THE TAF PERIOD UNDER FEW-SCT MID AND
HIGH CLOUD DECKS. WINDS THIS MORNING SHOULD GENERALLY FAVOR AN
EASTERLY COMPONENT, BUT A PERIOD OF VARIABILITY OR EARLIER THAN
USUAL SW SWITCH CANNOT BE RULED OUT. CONFIDENCE IS MODERATE TO
GOOD THAT SSW-SW WINDS WILL BECOME FAVORED ACROSS THE TERMINALS BY
18-20Z, WITH OCCASIONAL GUSTS TO AROUND 15 KTS DEVELOPING DURING
THE AFTERNOON. DURING THE EVENING, CONFIDENCE REMAINS HIGH ENOUGH
TO INCLUDE TEMPO STRONGER SW-W GUSTS TO AROUND 20 KTS, AS HI-RES
GUIDANCE CONTINUES TO SHOW A SIGNAL SIMILAR TO A GULF SURGE.
HOWEVER, VIRGA TO THE SOUTH/SOUTHEAST OF THE PHOENIX AIRSPACE
COULD CONCEIVABLY CAUSE SOME ERRATIC WIND BEHAVIOR AND GUSTS FROM
A MORE SOUTHERLY DIRECTION AROUND THE SAME TIME, WITH A HIGHER
LIKELIHOOD OF THAT IMPACT AT KIWA.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
PERIODS OF GUSTY WINDS WITH DIRECTIONS MOSTLY OUT OF THE SOUTH AT
KBLH AND VARYING BETWEEN SE AND W AT KIPL WILL BE THE PRIMARY
AVIATION CONCERN THROUGH THE NEXT 24 HOURS UNDER FEW MID TO HIGH
CLOUD DECKS. SOUTHEAST WINDS WILL BE FAVORED THROUGHOUT THE DAY AT
KIPL, SWITCHING SW-W BY 02-03Z THIS EVENING. SPEEDS WILL INCREASE
THROUGH THE MORNING HOURS, WITH GUSTS LIKELY DEVELOPING BY THE
AFTERNOON TO AROUND 20 KTS AT KIPL AND 25 KTS AT KBLH. AFTER THE
SW-W SWITCH AT KIPL IN THE EVENING, CONFIDENCE IS LOW ON WHETHER
GUSTS WILL DEVELOP AND EXACTLY WHEN THEY WILL SUBSIDE, BUT WINDS
SHOULD REMAIN OUT OF A PREVAILING WESTERLY DIRECTION OVERNIGHT.
GUSTS AT KBLH SHOULD SUBSIDE AROUND SUNSET.
FIRE WEATHER
HOT, DRY, AND LOCALLY BREEZY TO WINDY CONDITIONS WILL RESULT IN
ELEVATED FIRE WEATHER POTENTIAL THIS AFTERNOON ACROSS THE LOWER CO
RIVER VALLEY. WIND GUSTS OF 20-30 MPH ALONG WITH RHS 7-10% ARE
EXPECTED ACROSS THE LOWER CO RIVER VALLEY. ELSEWHERE TODAY, WINDS
WILL BE LIGHTER BUT WITH AFTERNOON GUSTS OF 15-20 MPH POSSIBLE.
WEDNESDAY WILL BRING ANOTHER ROUND OF BREEZY WINDS OVER SOUTHEAST
CALIFORNIA AND THE ARIZONA HIGH TERRAIN WITH ELEVATED FIRE WEATHER
CONDITIONS AGAIN A POSSIBILITY. TEMPERATURES TODAY WILL BE 10-15
DEGREES ABOVE NORMAL DROPPING TO 5-8 DEGREES ABOVE NORMAL STARTING
WEDNESDAY. WINDS WILL DIMINISH STARTING THURSDAY, BUT VERY DRY
CONDITIONS WILL CONTINUE TO PREVAIL.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ537-540-
542>544-546-548-550-551.
CA...NONE.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...WHITTOCK
FIRE WEATHER...KUHLMAN
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