003
FXUS65 KPSR 150745
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 AM MST SUN MAR 15 2026
KEY MESSAGES
- STRONG HIGH PRESSURE WILL KEEP TEMPERATURES WELL ABOVE NORMAL
THROUGH THE END OF WEEKEND AND START OF THE UPCOMING WEEK
- 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/
EARLY MORNING ATMOSPHERIC ANALYSIS REVEALS HIGH AMPLITUDE RIDGING
LOCATED OVER THE EASTERN PACIFIC AS VIGOROUS SHORTWAVE TROUGH
DIVES THROUGH THE ROCKIES. THE DESERT SOUTHWEST FINDS ITSELF IN
THE MIDDLE OF THESE TWO WEATHER, WITH THE FORMER OF THESE FEATURES
HELPING TO KEEP TEMPERATURES ABOVE-NORMAL THROUGH THE END OF THE
WEEKEND AND INTO THE START OF NEXT WEEK, WHILE THE LATTER ACTUALLY
HELPS TO KEEP TEMPERATURES FROM RISING FURTHER THAN WHERE THEY
ALREADY HAVE BEEN AS IT DISPLACES HIGH PRESSURE FURTHER TO OUR
WEST. HIGH TEMPERATURES THE NEXT FEW AFTERNOON FOR THE LOWER
DESERTS WILL BE GENERALLY IN THE LOWER TO MIDDLE 90S, 10-15
DEGREES WARMER THAN TYPICAL FOR THIS POINT IN MARCH.
THE NORTHERLY DISTURBANCE WON'T SCRAPE BY WITHOUT DOING MORE THAN
JUST KEEPING TEMPERATURES AT BAY AS TIGHTENING OF THE REGIONAL
PRESSURE GRADIENT WILL LEAD TO BREEZY TO LOCALLY WINDY CONDITIONS.
THE STRONGEST GUSTS FOCUSED AROUND THE LOWER COLORADO RIVER VALLEY
WHERE READINGS 25-30 MPH APPEAR LIKELY. ISOLATED HIGHER GUSTS
GREATER THAN 35 MPH CANNOT BE RULED OUT BUT SHOULD BE CONFINED TO
HIGHER RIDGE TOP AREAS AND LOCATIONS WITHIN THE RIVER VALLEY WHERE
CHANNELING CAN OCCUR. RESIDUAL BREEZINESS WILL BE SEEN ON MONDAY
OVER THE SAME AREA, WITH THE ADDITION OF HIGHER TERRAIN AREAS OF
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 0500Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER CONCERNS WILL EXIST THROUGH SUNDAY NIGHT UNDER
OCCASIONAL HIGH CIRRUS DECKS. CONFIDENCE IS EXCELLENT THAT AN
EASTERLY WIND COMPONENT WILL PERSIST IN THE PHOENIX METRO THROUGH
EARLY AFTERNOON BEFORE ABRUPTLY BECOMING WESTERLY. SPEEDS MAY EXCEED
10KT WITH MODEST GUST PRIOR TO SUNSET AND DECOUPLING. IN SE
CALIFORNIA, A W/SW WIND COMPONENT THROUGH SUNRISE SHOULD BECOME MORE
NORTHERLY LATER SUNDAY MORNING WITH GUSTS 20-25KT COMMON AT KBLH IN
THE AFTERNOON.
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
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...18
FIRE WEATHER...RW
CLIMATE...18/KUHLMAN
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