150
FXUS65 KPSR 290500
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 PM MST THU MAY 28 2026
UPDATE
UPDATED 06Z AVIATION DISCUSSION.
KEY MESSAGES
- BREEZY TO LOCALLY WINDY CONDITIONS CONTINUE THROUGH THE END OF
THE WORK WEEK, WITH THE STRONGEST GUSTS FOCUSED IN SOUTHEAST
CALIFORNIA TONIGHT AND EASTERN ARIZONA HIGH TERRAIN FRIDAY.
- ELEVATED FIRE WEATHER CONDITIONS WILL EXIST TODAY AND FRIDAY,
PARTICULARLY OVER EASTERN ARIZONA HIGHER TERRAIN AREAS.
- BELOW NORMAL TEMPERATURES INTO THE WEEKEND WILL WARM INTO AN
ABOVE NORMAL CATEGORY EARLY NEXT WEEK, WITH LOWER DESERT HIGHS
REACHING THE TRIPLE DIGITS AS EARLY AS SUNDAY.
SHORT TERM /TODAY THROUGH SATURDAY/
LOCAL SENSIBLE WEATHER CONDITIONS THROUGH THE END OF THE WORK
WEEK AND EVEN INTO THE WEEKEND WILL BE HEAVILY INFLUENCED BY A
CLOSED UPPER LOW CENTERED OVER CENTRAL CA/WEST-CENTRAL NV EARLY
THIS AFTERNOON. IN MIDLEVEL WATER VAPOR SATELLITE IMAGERY, THE
OBLONG APPEARANCE OF THIS LOW IS QUITE APPARENT, WITH A SHORTWAVE
ON EITHER SIDE, ONE ALONG ITS NORTHEASTERN PERIPHERY SWINGING
WESTWARD INTO THE PACIFIC NORTHWEST, WITH EXCELLENT UPPER LEVEL
DIVERGENCE, EFFECTIVE BULK SHEAR VALUES, AND LOCALLY HIGH
INSTABILITY LEADING TO A SEVERE WEATHER THREAT EAST OF THE
CASCADES OF WASHINGTON AND OREGON THIS AFTERNOON INTO THE EVENING.
THE OTHER SHORTWAVE WILL ROUND THE BASE OF THE UPPER LOW TONIGHT
AND HELP TO FINALLY DISLODGE IT AS IT EJECTS NORTHEASTWARD FRIDAY.
ENSEMBLES ARE IN EXCELLENT AGREEMENT ON THIS EVOLUTION, WITH NEGATIVE
H5 HEIGHT ANOMALIES REMAINING OVERHEAD THROUGH FRIDAY AND DIPPING
BRIEFLY AS LOW AS THE 6TH-15TH PERCENTILE OF CLIMATOLOGY, BETWEEN
568-575 DAM. THESE HEIGHTS ALOFT WILL SUPPORT LOWER DESERT HIGHS
10F-14F BELOW DAILY NORMALS ON FRIDAY, FOLLOWING MORNING LOWS THAT
ARE CLOSER TO 5F-10F BELOW NORMAL, WHICH TRANSLATES TO HIGHS IN
THE 80S AND LOWS FROM THE MIDDLE 50S TO MIDDLE 60S.
THE OTHER IMPACT FROM THE PROXIMITY OF THIS LOW WILL BE GUSTY
WINDS, LEADING TO AREAS OF ELEVATED FIRE DANGER DURING THE
AFTERNOON, PRIMARILY FOR THE HIGH TERRAIN EAST OF PHOENIX ON
FRIDAY. THE STRONGEST GUSTS WILL BE RELEGATED TO THE SOUTHWEST
CORNER OF IMPERIAL COUNTY TONIGHT, WHERE A WIND ADVISORY IS IN
EFFECT FROM 7 PM PDT THIS EVENING THROUGH 5 AM PDT FRIDAY MORNING.
HOWEVER, THERE COULD BE ADVISORY-LEVEL (35-45 MPH) GUSTS
EXTENDING AS FAR EAST AS THE SALTON SEA/IMPERIAL VALLEY LATER THIS
EVENING FOR A FEW HOURS. HEIGHTS ALOFT WILL REBOUND SATURDAY IN
THE WAKE OF THE DEPARTING UPPER LOW, AS A BRIEF PERIOD OF QUAZI-
ZONAL FLOW ESTABLISHES OVER THE SOUTHWEST US. THERMAL PROFILES
WILL QUICKLY RESPOND, WITH LOWER DESERT HIGHS RISING TO AROUND 5F
BELOW NORMALS, IN THE LOWER TO MIDDLE 90S BY SATURDAY, AND FURTHER
WARMING THROUGH THE REST OF THE WEEKEND AND EARLY NEXT WEEK.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
BY THIS WEEKEND TEMPERATURES WILL BEGIN TO WARM TOWARDS NORMAL
WITH SUNDAY EXPECTED TO BE BACK IN THE TRIPPLE DIGITS ACROSS THE
LOWER DESERTS AS H5 HEIGHTS BEGIN TO INCREASE. MODEL GUIDANCE
FAVORS A RIDGE SHIFTING WESTWARDS EARLY NEXT WEEK WITH THE AXIS
CENTERED THROUGH NEW MEXICO BY LATE MONDAY AFTERNOON. WHILE NOT
CENTERED OVER ARIZONA H5 HEIGHTS WILL INCREASE TO 585-588 DAM
RESULTING IN TEMPERATURES BETWEEN 103F-108F STARTING AS EARLY AS
MONDAY AND LASTING THROUGH AT LEAST WEDNESDAY BEFORE POTENTIALLY
COOLING 1-2 DEGREES LATE NEXT WEEK. THESE TEMPERATURES WILL EASILY
PUSH OUR HEATRISK INTO THE MODERATE CATEGORY, BUT RELATIVELY MILD
OVERNIGHT LOWS IN THE UPPER 60S TO MID 70S WILL HELP TO LIMIT THE
CHANCE OF REACHING NEAR THE MAJOR CATEGORY. OTHERWISE, DRY CONDITIONS
WITH MOSTLY CLEAR SKIES THROUGH EARLY NEXT WEEK.
AVIATION
UPDATED AT 0500Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE MAIN AVIATION FORECAST CONCERN WILL BE TIMING OF THE TYPICAL
E'RLY SHIFT TONIGHT/FRIDAY MORNING. FOR KPHX, UNCERTAINTY
REGARDING THIS SHIFT HAS INCREASED AND SOME GUIDANCE SHOWS IT MAY
NOT OCCUR AT ALL. SUBSEQUENT AMENDMENTS AND FORECAST PACKAGES
SHOULD PROJECT A HIGHER CONFIDENCE LEVEL ON IF SOME DEGREE OF
E'RLY WINDS WILL BECOME ESTABLISHED. HIGHER CONFIDENCE EXISTS AT
KIWA, WHERE SE/SSE WINDS ARE LIKELY TO OCCUR. REGARDLESS, W'RLY
WINDS WILL BECOME ESTABLISHED MUCH EARLIER THAN NORMAL, WITH GUSTS
IN THE UPPER TEENS TO AROUND 20 KT DEVELOPING BY THE LATE
MORNING. CLEAR SKIES WILL BE COMMON ACROSS THE REGION THROUGH
FRIDAY EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTS WILL DIMINISH AT KIPL TONIGHT, BUT SUSTAINED SPEEDS SHOULD
REMAIN RELATIVELY ELEVATED OVER THE NEXT SEVERAL HOURS. ANOTHER
ROUND OF BREEZY CONDITIONS IS SHOWN DEVELOPING FRIDAY EVENING, BUT
SHOULD BE MUCH MORE TAME WITH GUSTS AROUND 20-25 KT. AT BLH, SW
WINDS WILL BE COMMON THROUGH THE PERIOD, OUTSIDE OF A FEW HOURS OF
WNW'RLY FLOW FRIDAY MORNING. SKIES WILL BE CLEAR THROUGH FRIDAY
EVENING.
FIRE WEATHER
A LARGE WEATHER SYSTEM SITUATED OVER CALIFORNIA AND PORTIONS OF
THE DESERT SOUTHWEST WILL CONTINUE TO BRING BREEZY TO LOCALLY
WINDY CONDITIONS THROUGH THE END OF THE WORK WEEK. THE STRONGEST
GUSTS OF OVER 30-35 MPH WILL AFFECT PORTIONS OF SOUTHEAST
CALIFORNIA TONIGHT. THE STRONGEST GUSTS WILL THEN MIGRATE TO THE
EASTERN ARIZONA HIGH TERRAIN FRIDAY, LEADING TO ELEVATED FIRE
DANGER FOR THE EASTERN DISTRICT, DESPITE AN INCREASE IN AFTERNOON
MINRHS TO A 15-20% RANGE AREAWIDE ON FRIDAY. LIGHTER, MORE TYPICAL
WINDS FOR LATE MAY WILL RETURN SATURDAY ONWARD. BELOW NORMAL
TEMPERATURES THROUGH SATURDAY WILL WARM OVER THE WEEKEND, REACHING
AN ABOVE NORMAL CATEGORY EARLY NEXT WEEK. AS THE TEMPERATURES
HEAT UP, HUMIDITIES WILL DROP TO SEASONALLY LOW LEVELS LATE THIS
WEEKEND INTO EARLY NEXT WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY UNTIL 5 AM PDT FRIDAY FOR CAZ562.
SHORT TERM...WHITTOCK
LONG TERM...RYAN/KUHLMAN
AVIATION...RW
FIRE WEATHER...WHITTOCK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page