958
FXUS65 KPSR 152034
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
134 PM MST SUN MAR 15 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- STRONG HIGH PRESSURE WILL KEEP TEMPERATURES WELL ABOVE NORMAL
TODAY AND INTO THE START OF THE UPCOMING WORKWEEK
- FURTHER STRENGTHENING OF THE HIGH WILL RESULT IN AN
UNPRECEDENTED HEAT WAVE FOR MARCH WITH WIDESPREAD TRIPLE DIGITS
EXPECTED BY WEDNESDAY, AND READINGS NEAR 105 DEGREES BY
THURSDAY, SHATTERING DAILY RECORDS BY AS MUCH AS 10 DEGREES.
- AN EXTREME HEAT WATCH IS IN EFFECT FOR SOUTHEAST CALIFORNIA
STARTING WEDNESDAY, THEN EXPANDING EAST INTO SOUTHERN ARIZONA
THURSDAY
SHORT TERM /TODAY THROUGH MONDAY/
ATMOSPHERIC ANALYSIS SHOWCASES AN IMPRESSIVE RIDGE BUILDING IN
THE EASTERN PACIFIC ALONG SIDE A DEEP TROUGH THAT IS DIGGING DOWN
INTO THE PLAINS. THE DESERT SW CONTINUES TO EXPERIENCE POSITIVE
HEIGHT ANOMALIES EVEN THOUGH THE CORE OF THE RIDGE IS STILL WELL
TO THE REGION'S WEST. THESE H5 HEIGHTS WILL DRIVE TEMPERATURES
WELL ABOVE NORMAL FOR TODAY AND EARLY INTO THE NEXT WORKWEEK,
BEFORE TEMPERATURES RAMP UP EVEN FURTHER FOR THE LATTER HALF OF
THE WEEK AS THE RIDGE WILL SET UP OVER THE DESERT SW. HOWEVER,
FOR NOW, AFTERNOON HIGHS TODAY AND MONDAY ARE EXPECTED TO BE
MOSTLY IN THE LOWER 90S ACROSS THE LOWER DESERTS WITH AREAS, SUCH
AS YUMA AND THE IMPERIAL VALLEY PEAKING TO AT, OR NEAR 95 DEGREES.
A REMINDER THAT THE NORMAL HIGH TEMPERATURE FOR THIS TIME OF YEAR
GENERALLY SIT BETWEEN 77-81 DEGREES IN THE LOWER DESERT AREAS.
AS THE REGION SITS IN BETWEEN THESE TWO IMPRESSIVE SYSTEMS PRESSURE
GRADIENTS HAVE BEEN TIGHTENING, AND A SHORTWAVE TROUGH WILL SWEEP
THROUGH LEADING TO BREEZY TO LOCALLY WINDY CONDITIONS, MOST NOTABLY
ALONG THE COLORADO RIVER VALLEY STARTING THIS EVENING. THE STRONGEST
GUSTS ARE EXPECTED TO BE BETWEEN 25-30 MPH WITH ISOLATED HIGHER
GUSTS (35+ MPH) NEAR THE RIDGE TOPS AREAS. RESIDUAL BREEZINESS
WILL BE SEEN ON MONDAY OVER THE SAME AREA, WITH THE ADDITION OF
HIGHER TERRAIN AREAS OF EASTERN ARIZONA, WITH SIMILAR GUSTS
EXPECTED EVEN AS THE SHORTWAVE MOVES FURTHER EAST.
LONG TERM /TUESDAY THROUGH NEXT SUNDAY/
THE FORECAST FOR THE MIDDLE PORTION OF THE UPCOMING WEEK HAS NOT
CHANGED MUCH DURING THE PAST 24 HOURS. SUMMER-LIKE TEMPERATURES
APPEAR CERTAIN STARTING AS EARLY AS TUESDAY, WITH TEMPERATURES
PEAKING POTENTIALLY NEAR 110 DEGREES BY THE END OF THE WEEK. SEE
THE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS.
PREVIOUS DISCUSSION
THE AREA OF HIGH PRESSURE SUPPRESSED AND SHOVED WESTWARD BY THE
TRANSIENT DISTURBANCE WILL REBOUND AND EVENTUALLY MIGRATE OFF THE
EASTERN PACIFIC BY TUESDAY. AS IT MOVES, REGIONAL H5 HEIGHTS WILL
RISE MARKEDLY, REACHING NEAR 588-590DM BY TUESDAY. HOWEVER, GLOBAL
DETERMINISTIC GUIDANCE TAKES THINGS FURTHER SHOWING HEIGHTS ALOFT
PEAKING NEAR 594-596DM BY THURSDAY. FOR REFERENCE, SOUNDING
CLIMATOLOGY DATA FOR LAS VEGAS, FLAGSTAFF, AND TUCSON ALL SHOW
RECORD H5 HEIGHTS FOR MARCH ARE AROUND 590DM AND APRIL 591DM,
593DM, AND 592DM RESPECTIVELY. WITH THAT BEING SAID, THIS HIGH
WILL BE NEAR TO SLIGHTLY STRONGER THAN ANY RIDGE THIS REGION HAS
SEEN IN RECORDED HISTORY, NOT ONLY FOR MARCH, BUT FOR APRIL AS
WELL.
THIS ANOMALOUSLY STRONG HIGH WILL TRANSLATE TO RECORD TEMPERATURES,
NOT ONLY AT THE SURFACE, BUT THROUGHOUT MUCH OF THE ATMOSPHERE AS
WELL. H7-H5 TEMPERATURES WILL REACH ALL-TIME RECORDS BY TUESDAY,
WITH H8 READINGS JOINING THE FRAY BY WEDNESDAY. THESE CLIMATOLOGICAL
RECORDS WILL NOT BE JUST LAST ONE DAY EITHER AS FORECASTS SHOW THESE
ABNORMAL VALUES EXTENDING THROUGH THE END OF THE WORK WEEK AND EVEN
INTO THE WEEKEND. PUTTING THINGS QUANTITATIVELY, LOWER DESERT HIGHS
BY TUESDAY WILL BE IN THE UPPER 90S TO NEAR 100 DEGREES WITH VALUES
CLIMBING TO AROUND 105 DEGREES FOR MUCH OF THE LOWER DESERTS BY
THURSDAY. IF THESE TEMPERATURES ARE REALIZED, THOSE READINGS WOULD
BE 25 TO ALMOST 30 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
IT SHOULD NOT COME AS MUCH OF A SURPRISE THAT NUMEROUS RECORDS ARE
LIKELY TO BE BROKEN AT SOME POINT NEXT WEEK WITH TUESDAY LIKELY
BEING THE FIRST DAY WHEN ALL-TIME DAILY MAXTS BEGIN TO FALL.
HOWEVER, WITH THE LACK OF MOVEMENT FROM THE RIDGE OVERHEAD,
CONSECUTIVE DAYS WITH NEW RECORD TEMPERATURES APPEAR LIKELY. WHAT IS
ALSO VERY UNUSUAL ABOUT HOW STRONG THIS PATTERN WILL BE IS HOW MUCH
HIGH TEMPERATURES COULD POTENTIALLY BEST PREVIOUS RECORDS. FOR
INSTANCE, THE CURRENT FORECASTED HIGH TEMPERATURE FOR PHOENIX FOR
FRIDAY IS 106 DEGREES. WHILE IT IS TYPICAL TO SEE RECORDS BEATEN BY
A FEW DEGREES AT MOST, THIS FORECAST HIGH MAY BEAT FRIDAYS RECORD OF
96 BY 10 DEGREES.MONTHLY RECORDS ARE ALSO AT RISK OF FALLING DURING
THIS UPCOMING HEAT WAVE. THE ALL-TIME MARCH RECORDS FOR PHOENIX,
YUMA, AND EL CENTRO ARE 100, 102, AND 101 DEGREES RESPECTIVELY. ALL
OF THOSE VALUES COULD BE TIED OR ECLIPSED AS EARLY AS WEDNESDAY.
THE RECORD SETTING POTENTIAL DOESN'T END THERE. THE EARLIEST 100
DEGREE DAY RECORDED IN PHOENIX IS MARCH 26, WHICH WAS OBSERVED BACK
IN 1988, AND IS ACTUALLY THE ONLY OTHER TIME SINCE RECORDS BEGAN
WHEN TRIPLE DIGITS WERE ACHIEVED IN THE MONTH OF MARCH FOR THE CITY.
IT APPEARS THAT A NEW EARLIEST INSTANCE OF 100 DEGREE WILL BE SET AS
IT IS A MATTER OF WHEN, NOT IF, IT WILL HAPPEN. CURRENT FORECASTS
SUGGEST THAT WILL OCCUR ON WEDNESDAY THE 18TH, 8 DAYS AHEAD OF THE
PREVIOUS RECORD. FORTUNATELY, THE EARLIEST TRIPLE DIGIT READINGS FOR
YUMA AND EL CENTRO ARE MARCH 12TH AND 15TH RESPECTIVELY, SO THOSE
RECORDS ARE VERY MUCH SAFE FOR AT LEAST ANOTHER YEAR (AND HOPEFULLY
MUCH LONGER). NONETHELESS, THE AVERAGE FIRST 100 DEGREE READINGS FOR
THESE LOCATIONS IS LATE APRIL, SO WE WILL BE ALMOST A MONTH AND HALF
AHEAD OF SCHEDULE.
MODERATE HEATRISK WILL DEVELOP IN RESPONSE TO THE UPCOMING ABNORMAL
HEAT, WITH EVEN SOME LOCALIZED AREAS OF MAJOR HEATRISK NOT OUT OF
THE QUESTION. THEREFORE, AN EXTREME HEAT WATCH HAS BEEN ISSUED FOR
THE LOWER COLORADO RIVER VALLEY AND WESTWARD STARTING WEDNESDAY,
WHICH WILL EXPAND TO INCLUDE MUCH OF SOUTHERN ARIZONA BY THURSDAY.
AVIATION
UPDATED AT 1814Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT AVIATION WEATHER IMPACTS EXPECTED THROUGH MONDAY
UNDER PERSISTENT THIN CIRRUS. WINDS WILL SHIFT W BY 19-20Z WITH
SPEEDS INCREASING TO AROUND 10 KTS AND GUSTS UP TO 15-20 KTS THIS
AFTERNOON. WINDS SUBSIDE THIS EVENING AND SHIFT E-NE. WITH A NE
WIND ALOFT OVERNIGHT, A PERIOD OF LIGHT SW OR VARIABILITY MONDAY
MORNING. WINDS SHIFT W AROUND MIDDAY AGAIN MONDAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO SIGNIFICANT AVIATION WEATHER IMPACTS EXPECTED THROUGH MONDAY
UNDER PERSISTENT THIN CIRRUS. A NORTHERLY WIND WILL PREVAIL
THROUGH THE TAF PERIOD AT KBLH WITH GUSTS 20-25 KTS COMMON THIS
AFTERNOON. KIPL WILL ALSO SEE NORTHERLY WINDS THROUGH THIS
EVENING BEFORE SHIFTING BACK WESTERLY TONIGHT, WITH LIGHTER
SPEEDS.
FIRE WEATHER
HIGH PRESSURE WILL RESULT IN TEMPERATURES 10-15 DEGREES ABOVE NORMAL
TODAY THROUGH MONDAY BEFORE INCREASING TO 25-30 DEGREES ABOVE NORMAL
BY THE MIDDLE PORTION OF NEXT WEEK. ABNORMALLY HOT AND VERY DRY
CONDITIONS WILL TRANSLATE TO MINRH NEAR OR JUST BELOW 10% WITH
POOR OVERNIGHT RECOVERY AS MAXRHS WILL ONLY BE EXPECTED TO RUN
NEAR 20-40%. BREEZY TO LOCALLY WINDY CONDITIONS WILL BE OBSERVED
THIS EVENING THROUGH MONDAY, MAINLY OVER THE ARIZONA HIGH TERRAIN
AND THE LOWER COLORADO RIVER VALLEY, WITH THE STRONGEST GUSTS
(25-35 MPH) FOCUSED OVER THE LATTER AREA. THE BREEZY CONDITIONS,
COMBINED WITH LOW RH VALUES WILL RESULT IN ELEVATED TO ISOLATED
AREAS OF CRITICAL FIRE WEATHER CONDITIONS. HOWEVER, WITH THE
LIMITED SCOPE OF ENHANCED WINDS, NO FIRE WEATHER PRODUCTS ARE
NEEDED AT THIS TIME.
CLIMATE...
DAILY RECORD HIGHS THROUGH NEXT WEEKEND:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
3/15 92 IN 2013 98 IN 1934 100 IN 1934
3/16 99 IN 2007 99 IN 2007 100 IN 2007
3/17 99 IN 2007 101 IN 2007 101 IN 2007
3/18 95 IN 2017 96 IN 2017 95 IN 2007
3/19 96 IN 2017 98 IN 2017 96 IN 2017
3/20 96 IN 2017 99 IN 2004 98 IN 2004
3/21 97 IN 2004 102 IN 2004 100 IN 2004
3/22 94 IN 1990 98 IN 2004 96 IN 2004
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH SUNDAY EVENING
FOR AZZ530.
EXTREME HEAT WATCH FROM THURSDAY MORNING THROUGH SUNDAY EVENING
FOR AZZ531>544-546-548>551-553>555-559.
CA...EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH SUNDAY EVENING
FOR CAZ561>570.
SHORT TERM...RYAN
LONG TERM...RW
PREVIOUS DISCUSSION...RW
AVIATION...BENEDICT
FIRE WEATHER...RW/RYAN
CLIMATE...18/KUHLMAN
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