128
FXUS65 KPSR 190837
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
137 AM MST TUE MAY 19 2026
KEY MESSAGES
- A BROAD SCALE TROUGHING PATTERN WILL PERSIST OVER THE WESTERN
U.S. THROUGH THE END OF THE WEEK, WITH A SLOW WARMING TREND, BUT
OVERALL NEAR NORMAL TEMPERATURES.
- DRY CONDITIONS, WITH NO THREAT OF RAIN, AND SEASONAL AFTERNOON
BREEZES ARE EXPECTED THROUGH THE NEXT 7 DAYS.
SHORT TERM /TODAY THROUGH THURSDAY/
A BROAD TROUGH, WITH A FEW WEAK SHORTWAVES SWINGING THROUGH, WILL
PERSIST ACROSS THE SOUTHWEST THROUGH THURSDAY WITH RATHER BENIGN
SPRING-LIKE WEATHER CONDITIONS EXPECTED. THERE WILL BE A SLOW
RISE IN TEMPERATURES AS 500MB HEIGHTS SLOWLY RISE DESPITE THE
LINGERING TROUGH. HIGH TEMPERATURES THIS AFTERNOON WILL BE AROUND
5 DEGREES WARMER THAN YESTERDAY, WITH LOWER DESERTS FORECAST TO
REACH THE LOWER 90S. NORMAL HIGHS THIS TIME OF YEAR ARE IN THE
MIDDLE-90S, WHICH THE LOWER DESERTS WILL RETURN TO TOMORROW AND
THURSDAY AS WARMING STEADILY CONTINUES. MORNINGS WILL REMAIN
PLEASANTLY COOL, MOSTLY IN THE UPPER 50S AND 60S. SCATTERED HIGH
CLOUDS WILL BE PULLED NORTHEASTWARD ACROSS THE DESERT SOUTHWEST
TODAY THROUGH EARLY TOMORROW AND ANOTHER WEAK SHORTWAVE FROM THE
NORTHWEST WILL BRING SOME HIGH CLOUDS FOR THURSDAY. THE HIGH
CLOUDS WILL NOT BE TOO OPTICALLY THICK, SO THERE WILL STILL BE
PLENTY OF SUN TO GO AROUND. OTHERWISE, VERY DRY CONDITIONS CAN BE
EXPECTED OVER THE NEXT THREE DAYS, WITH AFTERNOON HUMIDITY LEVELS
FALLING BELOW 15% NEARLY EVERYWHERE, AND THERE IS NO SHOT AT ANY
RAIN. ASIDE FROM SOME BREEZY NORTHERLY WINDS ACROSS SOUTHEAST CA
AND THE LOWER COLORADO RIVER THIS MORNING (GUSTS UP TO 20-30 MPH),
DRIVEN BY STRONG PRESSURE RISES OVER NV, WINDS EACH DAY WILL
MOSTLY FOLLOW SEASONAL TRENDS; LIGHT WINDS DURING THE OVERNIGHT
AND MORNING HOURS AND MODEST UPSLOPE BREEZES IN THE AFTERNOONS
WITH GUSTS UP TO 15-25 MPH.
LONG TERM /FRIDAY THROUGH MONDAY/
THE SLOW WARMING TREND IS FORECAST TO CONTINUE THROUGH FRIDAY AND
THIS COMING WEEKEND. GLOBAL ENSEMBLE GUIDANCE SUPPORTS THE LARGE-
SCALE SYNOPTIC PATTERN ACROSS THE WEST FINALLY EVOLVING OUT OF
THE CURRENT STATE, WITH THE STRONG BLOCKING RIDGE NEAR B.C. CANADA
GIVING WAY/WEAKENING AS A STRONG LOW TRAVERSES ACROSS ALASKA.
THIS CHANGE WILL RESULT IN AT LEAST A TEMPORARY DE-AMPLIFICATION
OF THE PATTERN ACROSS THE WESTERN CONUS FOR THE WEEKEND AND A
TREND TOWARD POSITIVE 500MB HEIGHT ANOMALIES WITH BRIEF
ANTICYCLONIC FLOW DEVELOPING OVER THE DESERT SOUTHWEST. THIS
TREND WILL LEAD TO HIGH TEMPERATURES REACHING INTO THE UPPER 90S
BY FRIDAY AND PUSHING 100 DEGREES BY SUNDAY - MONDAY (30-60% ODDS
OF >=100).
THIS PATTERN SHIFT WILL ALSO ALLOW FOR SOME MOISTURE TO
SEEP INTO AZ, FROM THE SOUTHEAST AND WITH EVENING GULF SURGES, AS
GLOBAL GUIDANCE SHOWS A SLOW UPTREND IN PWATS FRIDAY THROUGH THE
WEEKEND. THIS MAY END UP LEADING TO SOME AZ HIGH TERRAIN AFTERNOON
CONVECTION, WHICH IS SUPPORTED BY SOME LOW-END NBM POPS THIS
WEEKEND (<25% OVER EASTERN AZ MOUNTAINS). THE ODDS ARE A LITTLE
HIGHER MONDAY WITH THE POTENTIAL FOR A WEAK PACIFIC LOW TO MOVE
INLAND FROM THE WEST, BUT THIS IS ABOUT ALL THAT CAN BE
ANTICIPATED THIS FAR OUT. THIS IS CLIMATOLOGICALLY THE DRIEST TIME
OF YEAR FOR THE AZ AND SOCAL LOWER DESERTS, SO IT IS HARD TO PUT
MUCH OPTIMISM INTO A LONG-RANGE PRECIP FORECAST FOR THE LOWER
DESERTS.
AVIATION
UPDATED AT 0520Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS EXPECTED THROUGHOUT THE TAF
PERIOD. WESTERLY WINDS WILL CONTINUE INTO THE OVERNIGHT HOURS.
WINDS WILL RESUME THEIR MORE TYPICAL DIURNAL PATTERN OVERNIGHT
TONIGHT THROUGH TUESDAY WITH EASTERLY WINDS EXPECTED BY 08-10Z AND
CONTINUING THROUGH THE EARLY MORNING HOURS. A BRIEF PERIOD OF
SOUTHERLY WINDS IS EXPECTED TO PRECEDE THE WESTERLY SHIFT BY THE
EARLY AFTERNOON. SKIES WILL REMAIN CLEAR OVERNIGHT WITH INCREASING
HIGH CLOUDS TOMORROW AFTERNOON AND EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER MOSTLY CLEAR SKIES CAN BE
EXPECTED THROUGHOUT THE TAF PERIOD. AT KIPL, WINDS WILL VARY
BETWEEN N-NW AND W'RLY THROUGH THE TAF PERIOD, WITH SPEEDS
REMAINING AOB 10 KT. AT KBLH, WINDS WILL MAINTAIN A N-NW
DIRECTION THROUGH THE TAF PERIOD. A PERIOD OF WIND GUSTS OF 20-25
KT IS EXPECTED FROM THE LATE MORNING THROUGH THE EARLY AFTERNOON,
OTHERWISE WINDS WILL BE AOB 10 KT. SKIES WILL REMAIN CLEAR
OVERNIGHT WITH INCREASING HIGH CLOUDS STARTING TOMORROW MORNING.
FIRE WEATHER
THERE WILL BE A SLOW DAY-TO-DAY WARMING OF TEMPERATURES, BUT
OVERALL HIGH TEMPERATURES WILL REMAIN NEAR SEASONAL NORMALS AS THE
NORMALS ALSO SLOWLY RISE. VERY DRY CONDITIONS WILL ALSO PERSIST
THROUGH THE END OF THE WEEK WITH MINIMUM RH VALUES AROUND 5-15%
EACH DAY. THERE WILL BE A SLIGHT BUMP UP IN MOISTURE THIS WEEKEND,
THAT MAY LEAD TO SOME DRY THUNDERSTORMS IN THE MOUNTAINS OF
EASTERN AZ, BUT MINIMUM RHS WILL STILL BE AROUND 10-15%. OVERNIGHT
RECOVERIES WILL BE POOR TO FAIR, MOSTLY AROUND 25-45%. SEASONAL
WIND PATTERNS ARE EXPECTED THROUGH THE REST OF THE WEEK, WITH
AFTERNOON UPSLOPE BREEZES UP TO 15-25 MPH. THERE WILL LIKELY BE A
SLIGHT UPTICK IN SOUTHERLY UP-RIVER WINDS ALONG THE COLORADO RIVER
VALLEY FRIDAY THROUGH THIS WEEKEND, WITH A SMALL PATTERN SHIFT,
BUT AFTERNOON AND EVENING GUSTS ARE CURRENTLY FORECAST TO TOP OUT
IN THE 20-30 MPH RANGE ALONG THE RIVER. THERE WILL ALSO LIKELY BE
A RETURN OF EVENING AND EARLY-OVERNIGHT GULF SURGE BOUNDARIES
MOVING UP FROM THE GULF OF CALIFORNIA THROUGH THE AZ DESERTS.
THESE BOUNDARIES WILL MOSTLY LEAD TO A BRIEF UPTICK IN WINDS AND
SUDDEN SOUTHWESTERLY WIND SHIFTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...BENEDICT
LONG TERM...BENEDICT
AVIATION...BERISLAVICH
FIRE WEATHER...BENEDICT
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