666
FXUS65 KPSR 260520
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 PM MST THU JUN 25 2026
UPDATE
06Z AVIATION DISCUSSION
KEY MESSAGES
- TEMPERATURES WILL BEGIN A COOLING TREND REACHING BELOW NORMAL
LEVELS OVER THE WEEKEND.
- UNUSUALLY STRONG WINDS WILL IMPACT THE REGION FRIDAY THROUGH
SUNDAY RESULTING IN AREAS OF BLOWING DUST AND CRITICAL FIRE WEATHER
CONDITIONS.
- MORE TRANQUIL WEATHER CONDITIONS AND A SLOW WARMING TREND WILL
ARRIVE DURING THE MIDDLE OF NEXT WEEK.
SHORT TERM /TODAY THROUGH SATURDAY/
SUBTROPICAL HIGH PRESSURE CONTINUES TO BE DAMPENED AND DISPLACED
INTO NORTHERN MEXICO IN RESPONSE TO INCREASING WESTERLY FLOW IN THE
NORTHERN STREAM AND HEIGHT FALLS APPROACHING THE WESTERN CONUS. WV
IMAGERY DEPICTS A SUBTLE SHORTWAVE LIFTING TOWARDS NORTHEAST ARIZONA
THIS AFTERNOON COINCIDENT WITH LINGERING MIDLEVEL MOISTURE. HOWEVER,
THE STRENGTHENING WESTERLY FLOW WILL ALLOW MIXING RATIOS TO DECREASE
CLOSER TO 7-8 G/KG ACROSS SOUTH-CENTRAL ARIZONA (AND MARKEDLY LOWER
IN THE WESTERN CWA), BUT STILL SUFFICIENT FOR MUCAPE VALUES AROUND
500 J/KG ACROSS ARIZONA HIGHER TERRAIN LOCATIONS. HREF OUTPUT
CONTINUES TO HIGHLIGHT SCATTERED STORMS OVER THESE HIGHER TERRAIN
AREAS, HOWEVER ONLY CLIPPING THE EASTERN PARTS OF GILA COUNTY. OVER
THE NEXT 48 HOURS, INCREASED TROUGHING WITH MORE ROBUST HEIGHT FALLS
WITH SURGE INTO THE SW CONUS LEADING TO MORE PRONOUNCED DRY AIR AND
A GRADUAL COOLING TREND, SUCH THAT CURRENT EXTREME HEAT WARNINGS
WILL BE ALLOWED TO EXPIRE AS SCHEDULED.
THE RARITY OF THE UPCOMING SYNOPTIC SETUP CANNOT BE UNDERSTATED WITH
EXTREMELY ANOMALOUS NEGATIVE HEIGHT ANOMALIES NEAR 4 NORMALIZED
STANDARD DEVIATIONS BELOW NORMAL SETTLING OVER THE GREAT BASIN
THROUGH THE WEEKEND. THIS SCENARIO RESEMBLES ONE MORE COMMON FOR
EARLY MAY VERSUS LATE JUNE WITH INTENSE ZONAL FLOW AND A TIGHTENING
PRESSURE GRADIENT DESCENDING INTO THE SOUTHWEST. NAEFS U-WIND
COMPONENT FORECASTS THROUGH THE ENTIRE SFC-H7 LAYER FRIDAY-SATURDAY
ESSENTIALLY IS AT THE SEASONAL MAXIMUM WITH RAW VALUES EASILY 30-
40KT. GIVEN THE MIXING DEPTHS THIS TIME OF YEAR, THIS HIGHER
MOMENTUM AIRMASS WILL BE TAPPED WITH FULL INSOLATION, AND FURTHER
EXACERBATED DOWNSTREAM OF TERRAIN FEATURES GIVEN THE LIKELIHOOD OF
COMPRESSION AND MOUNTAIN ROTORS. WIND ADVISORIES HAVE BEEN ISSUED
FOR THESE PREFERRED DOWNSTREAM LOCATIONS WHERE HIGH PROFILE VEHICLE
TRAVEL MAY BECOME DIFFICULT, AND LOCALIZED DENSE BLOWING DUST MAY BE
COMMON. IN ADDITION, RED FLAG WARNINGS CONTINUE THROUGH THE LOWER
COLORADO RIVER VALLEY AND EASTERN PARTS OF THE CWA WHERE COMBINED
WIND GUSTS, LOW HUMIDITY LEVELS, AND VERY DRY FUELS RECEPTIVE TO
FIRE COULD RESULT IN EXTREME FIRE BEHAVIOR AND UNCONTROLLED WILDFIRE
GROWTH. EVEN IN AREAS NOT COVERED BY THE WARNING, AN ELEVATED FIRE
DANGER WILL EXIST - ESPECIALLY SATURDAY WHEN THE MOST ANOMALOUS
WEATHER CONDITIONS WILL MATERIALIZE.
LONG TERM /SUNDAY THROUGH THURSDAY/
A LARGE PACIFIC TROUGH WILL BE THE DOMINANT WEATHER FEATURE ACROSS
THE WESTERN U.S. THROUGH THE FIRST HALF OF NEXT WEEK. THE DEEP LOW
WITH H5 HEIGHTS BRIEFLY REACHING NEAR RECORD LOWS BY LATE JUNE
STANDARDS OVER THE GREAT BASIN SUNDAY WILL KEEP THE PRESSURE
GRADIENT ABNORMALLY TIGHT. STRONG GRADIENT WINDS WILL BECOME MORE
FOCUSED ACROSS THE EASTERN HALF OF ARIZONA ON SUNDAY POSING A MAJOR
FIRE WEATHER THREAT. GUSTS OF 25-40 MPH ARE EXPECTED TO IMPACT A
GOOD PORTION OF THE AREA AS HUMIDITIES HOVER INTO A 5-15% RANGE. RED
FLAG CONDITIONS WILL CONTINUE OVER EASTERN ARIZONA SUNDAY WHERE
RAPID SPREAD AND GROWTH OF ANY NEW OR EXISTING FIRES IS POSSIBLE.
GUIDANCE EVENTUALLY SHOWS THE DEEP LOW GRADUALLY FILLING EARLY NEXT
WEEK, BUT REMAINING IN PLACE AT LEAST THROUGH THE MIDDLE OF THE
WEEK. WINDS WILL ALSO DIMINISH SOMEWHAT EARLY NEXT WEEK, BUT BREEZY
CONDITIONS ARE LIKELY TO PERSIST.
THE PRESENCE OF THE LARGE TROUGH WILL BRING SOME RELIEF FROM THE
HEAT THIS WEEKEND WITH NBM FORECAST HIGHS DROPPING BELOW NORMAL
AREAWIDE BY SUNDAY. DAYTIME HIGHS ANYWHERE FROM THE UPPER 90S TO
JUST OVER 100 DEGREES ARE EXPECTED ON SUNDAY AND MONDAY BEFORE
TEMPERATURES BEGIN TO SLOWLY RISE BACK CLOSER TO NORMAL AT SOME
POINT DURING THE LATTER HALF OF NEXT WEEK. OVERNIGHT LOWS WILL ALSO
BECOME QUITE PLEASANT WITH READINGS AS LOW AS THE MID 60S ACROSS THE
WESTERN DESERTS TO THE LOW TO MID 70S OVER THE REST OF THE LOWER
DESERTS.
AVIATION
UPDATED AT 0520Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE MAIN AVIATION CONCERNS WILL BE BREEZY CONDITIONS DURING THE
AFTERNOON HOURS FRIDAY, WITH GUSTS AROUND 20-25 KT. FAMILIAR
DIRECTIONAL PATTERNS CAN BE EXPECTED, WITH WINDS LIKELY TAKING A
LITTLE LONGER THAN USUAL TO FULLY TURN OUT OF THE W/SW, CREATING
A FEW HOURS WINDOW OF S'RLY CROSS WINDS AT KPHX AND KDVT. SCT MID-
LEVEL CLOUDS WILL STICK AROUND THROUGH THE MORNING HOURS BEFORE
SKIES BECOME MOSTLY CLEAR LATER IN THE FORECAST WINDOW.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
BREEZY TO WINDY CONDITIONS FRIDAY AFTERNOON AND EVENING WILL BE
THE MAIN AVIATION CONCERN. GUSTS OUT OF THE W AND SSW/SW AT KIPL
AND KBLH RESPECTIVELY WILL REACH UPWARDS OF 25-30 KT, WITH KIPL
LIKELY SEEING A WINDOW DURING THE EVENING HOURS WHEN READINGS
COULD REACH UPWARDS OF 35 KT AT TIMES. ALTHOUGH NOT INCLUDED IN
THE TAF AT THIS TIME DUE TO LOW CONFIDENCE, IT IS NOT OUT OF THE
QUESTION THAT THESE ENHANCED WINDS MAY RESULT IN REDUCED VIS DUE
TO BLDU. GUIDANCE DOES HINT AT SOME VIRGA AND LIGHT SHOWER
ACTIVITY FRIDAY MORNING AROUND KBLH, BUT ANY RADAR ECHOES THAT ARE
OBSERVED ARE NOT EXPECTED TO RESULT IN ANY OPERATIONAL IMPACTS.
MID-LEVEL CLOUDS TONIGHT WILL GIVE WAY TO MOSTLY CLEAR SKIES
DURING THE BACK HALF OF THE FORECAST.
FIRE WEATHER
ELEVATED FIRE DANGER WILL CONTINUE TODAY DUE TO LOW HUMIDITY, VERY
WARM TEMPERATURES, AND AFTERNOON UPSLOPE/UPVALLEY BREEZY CONDITIONS
WITH CRITICAL CONDITIONS DEVELOPING FRIDAY. RED FLAG WARNINGS HAVE
BEEN ISSUED FOR FRIDAY THROUGH SUNDAY FOR MUCH OF THE AREA. EXPECT
MINRHS TODAY INTO THE SINGLE DIGITS ACROSS THE WESTERN DISTRICTS,
BUT CLOSER TO 20% IN THE EAST. THESE VALUES WILL FALL CLOSER TO 5-
15% STARTING FRIDAY AND STAY IN THIS RANGE FOR SEVERAL DAYS. WINDS
WILL GENERALLY REMAIN TERRAIN DRIVEN TODAY WITH UPSLOPE GUSTS DURING
THE LATTER HALF OF THE AFTERNOON PEAKING AROUND 25 MPH. WINDS WILL
INCREASE STARTING FRIDAY WITH GUSTS INTO A 20-35 MPH RANGE AND
LOCALLY HIGHER OVER HIGHER TERRAIN AREAS. WINDS ARE LIKELY TO PEAK
ON SATURDAY WITH GUSTS COMMONLY REACHING 25-40 MPH. THESE WINDY AND
DRY CONDITIONS WILL COMBINE WITH THE VERY DRY FUELS TO CREATE A RISK
OF EXTREME FIRE BEHAVIOR. TEMPERATURES WILL COOL OFF THIS WEEKEND
REACHING TO SLIGHTLY BELOW NORMAL STARTING SUNDAY. WINDS ARE
EXPECTED TO GRADUALLY DIMINISH NEXT MONDAY INTO TUESDAY.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM MST SATURDAY FOR
AZZ131.
WIND ADVISORY FROM 11 AM TO 11 PM MST SATURDAY FOR AZZ530-533.
RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM MST SUNDAY FOR AZZ133.
CA...RED FLAG WARNING FROM 11 AM FRIDAY TO 8 PM PDT SATURDAY FOR
CAZ231.
WIND ADVISORY FROM 11 AM TO 11 PM PDT SATURDAY FOR CAZ564>567-
569-570.
WIND ADVISORY FROM 5 PM FRIDAY TO 11 AM PDT SUNDAY FOR CAZ562.
SHORT TERM...18
LONG TERM...18/KUHLMAN
AVIATION...RW
FIRE WEATHER...KUHLMAN
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