586
FXUS65 KPSR 181713
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1013 AM MST MON MAY 18 2026
UPDATE
UPDATED 18Z AVIATION DISCUSSION.
KEY MESSAGES
- A WIND ADVISORY REMAINS IN EFFECT THROUGH 11 AM FOR PORTIONS OF
SOUTHEAST CALIFORNIA FOR STRONG NORTHERLY POST-FRONTAL WINDS.
- COOLEST TEMPERATURES OVER THE NEXT WEEK AND BEYOND ARE EXPECTED
TODAY, WITH HIGH TEMPERATURES 4 TO 7 DEGREES BELOW NORMAL,
BEFORE SLOWLY WARMING BACK UP AND NEARING 100 DEGREE HIGHS
AGAIN THIS WEEKEND.
- DAILY DRY CONDITIONS, WITH NO THREAT OF RAIN, AND SEASONAL
AFTERNOON BREEZINESS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
SHORT TERM /TODAY THROUGH TUESDAY/
A POTENT SHORTWAVE TROUGH WAS SEEN MOVING EASTWARD THROUGH UT
EARLY THIS MORNING WITH A SOUTHWARD AND SOUTHEASTWARD MOVING COLD
FRONT THROUGH AZ AND SOCAL. STRONG NORTHERLY WINDS AND WIDESPREAD
LOFTED DUST WERE OBSERVED POST-FRONT IN SAN BERNARDINO COUNTY.
THE COLD FRONT WILL CONTINUE DROPPING SOUTH THROUGH SOUTHEAST CA
AND SOUTHWEST AZ EARLY THIS MORNING, WITH STRONG NORTHERLY POST-
FRONTAL WINDS EXPECTED THROUGH MID-MORNING. A WIND ADVISORY IS IN
EFFECT FOR EASTERN RIVERSIDE AND NORTHEAST IMPERIAL COUNTIES
THROUGH 11 AM PDT/MST THIS MORNING WITH NORTHERLY GUSTS UP TO
35-50 MPH EXPECTED. LATEST HREF SHOWS STRONGEST 850MB WINDS (>40
MPH) OCCURRING THROUGH AROUND 3-5 AM PDT/MST THIS MORNING. DURING
THIS TIME IS WHEN THE GREATEST IMPACTS - PRIMARILY NORTHERLY
CROSSWINDS ACROSS I-10 AND LOCALIZED BLOWING DUST - ARE
ANTICIPATED. WHILE THE GRADIENT WIND IS EXPECTED TO WEAKEN AROUND
THE SUNRISE HOURS, SOME AREAS MAY SEE NORTHERLY WIND GUSTS PICK
BACK UP FOR A FEW HOURS AFTER SUNRISE DUE TO MIXING. OTHERWISE,
WINDS SHOULD GRADUALLY SUBSIDE ACROSS SOUTHEAST CA AND SOUTHWEST
AZ HEADING INTO LATE-MORNING AND THE AFTERNOON. HAZY SKIES SHOULD
BECOME EVIDENT AFTER SUNRISE THIS MORNING, WITH ALL THE LOFTED
DUST ACROSS CA AND NV, ESPECIALLY ACROSS SOUTHEAST CA AND
SOUTHWEST AZ.
HI-RES MODELS DEPICT THE COLD FRONT STALLING OUT ACROSS SOUTH-
CENTRAL AZ TOWARD SUNRISE AND MID-MORNING. SO, SOUTH-CENTRAL AZ IS
NOT EXPECTED TO EXPERIENCE ANY OF THE STRONG NORTHERLY AND
NORTHWESTERLY POST-FRONTAL WINDS. THERE WILL STILL BE SOME BREEZY
SOUTHWEST WINDS THOUGH LATE MORNING AND THIS AFTERNOON, MOSTLY
GUSTING UP TO 15-30 MPH. A NARROW BAND OF LOW LEVEL MOISTURE AND
FORCING ALONG AND AHEAD OF THE FRONT WILL LEAD TO SOME LOWER
CLOUDS THIS MORNING ACROSS SOUTH-CENTRAL AZ, INCLUDING THE PHOENIX
AREA, AND A FEW HI-RES MODELS STILL SUPPORT A BRIEF SPRINKLE
SHOWER. SO, A FEW DROPS FALLING IN THE MORNING, AFTER SUNRISE
CANNOT BE RULED OUT, BUT DO NOT EXPECT ANY MEASURABLE RAIN.
THE DIP IN 500MB HEIGHTS OVER THE AREA AND PUSH OF COOLER AIR FROM
THE NORTH WILL RESULT IN COOLER SURFACE TEMPERATURES TODAY, WITH
BELOW NORMAL HIGH TEMPERATURES EXPECTED ACROSS THE REGION. HIGHS
THIS AFTERNOON ARE FORECAST TO MOSTLY BE IN THE 80S ACROSS THE
LOWER DESERTS, WITH ONLY 10-20% CHANCES OF REACHING 90F IN PLACES
LIKE PHOENIX AND YUMA.
HEADING INTO TOMORROW, THE POTENT TROUGH WILL HAVE LEFT THE
REGION, EJECTING THROUGH THE PLAINS, BUT ANOTHER TRAILING WEAK
SHORTWAVE WILL FOLLOW AND KEEP A LARGE-SCALE TROUGH PATTERN IN
PLACE ACROSS THE DESERT SOUTHWEST. THIS WILL KEEP TEMPERATURES
FROM RAPIDLY WARMING BACK UP AND WHILE THEY WILL WARM UP FROM
TODAY, HIGHS TOMORROW ARE STILL FORECAST TO COME UP SHY OF DAILY
NORMALS. MOST LOWER DESERTS WILL TOP OUT WITH HIGHS IN THE LOWER
90S. WINDS TOMORROW WILL BE EVEN LIGHTER THAN TODAY FOR MOST
AREAS. ALTHOUGH, WITH THE TRAILING SHORTWAVE THERE WILL BE ANOTHER
ENHANCEMENT TO NORTHERLY WINDS DOWN THE COLORADO RIVER AND
SOUTHEAST CA, WITH PEAK WIND GUSTS AS HIGH AS 20-30 MPH IN THE
MORNING THROUGH MIDDAY. THE LAGGING SHORTWAVE WILL ALSO HELP DRAW
SCATTERED HIGH CLOUDS INTO THE DESERT SOUTHWEST THROUGH THE DAY.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
THROUGH THE REST OF THE WEEK, GLOBAL ENSEMBLES DEPICT A LASTING
WEAK LONGWAVE TROUGH PATTERN ACROSS THE DESERT SOUTH, WITH NEUTRAL
HEIGHT ANOMALIES AND NO SIGNIFICANT SHORTWAVES ROLLING THROUGH
THE REGION. THIS WILL TRANSLATE TO RATHER SEASONAL WEATHER
CONDITIONS, BUT WITH A SLOW DAY-TO-DAY WARMING TREND. HIGH
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH THE END OF THE
WORK WEEK - HIGHS IN THE MIDDLE TO UPPER 90S. MEANWHILE MORNING
LOWS ARE EXPECTED TO BE NEAR TO SLIGHTLY BELOW NORMAL, LARGELY DUE
TO DRY AIR/LOW HUMIDITY AND LIMITED CLOUD COVER. IT IS NOT UNTIL
THE WEEKEND WHEN ODDS OF HIGH TEMPERATURES REACHING THE 100 DEGREE
MARK SPIKES BACK UP TO AROUND 30-60%, AS THE LONGWAVE TROUGH
ACROSS THE DESERT SOUTHWEST BREAKS DOWN. CONDITIONS WILL REMAIN
DRY THROUGH THIS WEEKEND, WITH NO THREAT OF RAIN, AND SEASONAL
WIND PATTERNS ARE EXPECTED, WITH LIGHT WINDS THROUGH THE OVERNIGHT
AND MORNING HOURS AND AFTERNOON UPSLOPE BREEZES UP TO 15-25 MPH.
AVIATION
UPDATED AT 1710Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS EXPECTED THROUGHOUT THE TAF
PERIOD. WESTERLY WINDS WILL PREVAIL THROUGH THIS EVENING WITH SOME
OCCASIONAL AFTERNOON GUSTS INTO THE UPPER TEENS. WINDS WILL RESUME
THEIR MORE TYPICAL DIURNAL PATTERN TONIGHT THROUGH TUESDAY WITH
EASTERLY WINDS EXPECTED DURING THE OVERNIGHT AND EARLY MORNING
HOURS FOLLOWED BY A WESTERLY SHIFT BY THE LATE MORNING/EARLY
AFTERNOON. A FEW-SCT CLOUDS BETWEEN 6-8 KFT WILL PREVAIL INTO
EARLY THIS AFTERNOON BEFORE A FEW HIGH CLOUD DECKS MOVE IN DURING
THE LATE AFTERNOON FOLLOWED BY CLEAR SKIES DURING THE LATE
EVENING/OVERNIGHT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER MOSTLY CLEAR SKIES CAN BE
EXPECTED THROUGHOUT THE TAF PERIOD. NORTHERLY WINDS WILL PREVAIL
THROUGH THIS AFTERNOON BEFORE BACKING MORE OUT OF THE WEST TO
NORTHWEST THIS EVENING. WIND GUSTS UPWARDS OF 20-25 KTS WILL
CONTINUE ACROSS KBLH THROUGH THIS AFTERNOON BEFORE GUSTS SUBSIDE
EARLY THIS EVENING. AT KIPL, WINDS WILL GENERALLY REMAIN AOB 10
KTS THROUGHOUT THE PERIOD.
FIRE WEATHER
ELEVATED AND MARGINALLY CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED EARLY THIS MORNING ACROSS PORTIONS OF SOUTHEAST CA AS A
RESULT OF STRONG NORTHERLY WINDS AND DRY AIR FOLLOWING A FRONTAL
PASSAGE. CONDITIONS WILL IMPROVE BY LATE-MORNING/EARLY-AFTERNOON
AS NORTHERLY WINDS SUBSIDE. ELSEWHERE TODAY, WINDS WILL BE
LIGHTER, BUT STILL WITH PEAK SOUTHWESTERLY GUSTS UP TO 15-30 MPH
ACROSS SOUTH-CENTRAL AZ. MINIMUM RH VALUES TODAY WILL BE AROUND
5-10% ACROSS WESTERN DISTRICTS TO 15-25% ACROSS EASTERN DISTRICTS.
TEMPERATURES WILL BE COOLEST, AND BELOW NORMAL, TODAY, WHICH WILL
RESULT LOWER MAX MIXING HEIGHTS (UP TO 6-8K FT ABOVE GROUND
LEVEL). TEMPERATURES WILL SLOWLY WARM THROUGH THE END OF THE WEEK,
BUT REMAIN NEAR SEASONAL LEVEL, AND CONDITIONS WILL REMAIN DRY.
DAILY MINIMUM RH VALUES WILL BE AROUND 5-15% EACH DAY AFTER TODAY
WITH POOR TO FAIR OVERNIGHT RECOVERIES AT 25-50%. AFTER TODAY SEASONAL
WIND PATTERNS ARE EXPECTED THROUGH THE REST OF THE WEEK, WITH
AFTERNOON UPSLOPE BREEZES UP TO 15-25 MPH AND THE ONLY EXCEPTION
BEING ANOTHER BRIEF ENHANCED NORTHERLY WIND DOWN THE COLORADO
RIVER TOMORROW MORNING. THERE IS NO RAIN IN THE FORECAST THROUGH
THIS WEEKEND.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...BENEDICT
LONG TERM...BENEDICT
AVIATION...LOJERO
FIRE WEATHER...BENEDICT
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