Weather Service Report


674 
FXUS65 KPSR 280900
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
200 AM MST SAT MAR 28 2015

.SYNOPSIS... 
HIGH PRESSURE OVER THE REGION WILL LEAD TO AFTERNOON TEMPERATURES 
REACHING THE MIDDLE 90S THIS WEEKEND. AN AREA OF WEAK LOW PRESSURE 
WILL MOVE INTO THE SOUTHWEST EARLY NEXT WEEK...BRINGING INCREASED 
CLOUDINESS AND SLIGHTLY COOLER TEMPERATURES. HOWEVER...TEMPERATURES 
WILL REMAIN MUCH ABOVE NORMAL THROUGH NEXT WEEK.

&&

.DISCUSSION...
THE WELL ADVERTISED MID-TROPOSPHERIC ANTI-CYCLONE WAS CENTERED OVER 
FAR SRN ARIZONA EARLY THIS MORNING...WITH 00Z REGIONAL SOUNDING DATA 
MEASURING CENTRAL H5 HEIGHTS AT 585DM AND H8 TEMPERATURES AS WARM AS 
+24C. UNDER CLEAR SKIES AND UNUSUALLY HIGH MIXING DEPTHS...THICKNESS 
MEASURES WILL CONTINUE TO CLIMB THROUGH THE WEEKEND (1000-850MB 
VALUES EXCEEDING 143DM) YIELDING HIGHS IN THE MIDDLE AND UPPER 90S 
(SOME LOCATIONS AROUND YUMA LIKELY FLIRTING WITH THE 100 DEGREE 
THRESHOLD). OVERALL FORECAST CONFIDENCE IS HIGH THAT DAILY RECORDS 
WILL BE REACHED IN MANY LOCATIONS THIS WEEKEND...BEFORE SOME SUBTLE 
COOLING NEXT WEEK. 

A WEAK PV ANOMALY CURRENTLY NEAR 28N 132W IN CONJUNCTION WITH A 
LARGER WAVE BREAKING INTO THE APEX OF THE WRN CONUS RIDGE AXIS WILL 
DAMPEN/DISPLACE THE HIGHER AMPLITUDE FLOW PATTERN NEXT WEEK. MODEL 
OUTPUT REMAINS CONSISTENT IN PROGRESSING SOUTHERN STREAM SHORTWAVE 
ENERGY THROUGH SONORA MONDAY...AND ONLY MODEST FLUX OF MID/HIGH 
LEVEL MOISTURE NORTHWARD. IF ANYTHING...THE TREND HAS BEEN TOWARDS 
MORE MEAGER MOISTURE ENTRAINMENT SUCH THAT FORECAST BUFR SOUNDINGS 
NOW ONLY SUGGEST BARELY OVER 3 G/KG OF WELL MIXED MOISTURE 
PROFILES...AND SATURATION ALMOST EXCLUSIVELY LIMITED TO HEIGHTS 
ABOVE 15K FT. 

QUASI-ZONAL FLOW BEST TYPIFIED BY A NEAR PERSISTENCE FORECAST WILL 
CHARACTERIZE THE PATTERN MUCH OF NEXT WEEK. H5 HEIGHTS WILL 
FLUCTUATE BETWEEN 572DM AND 578DM THROUGH THE PERIOD ONLY MODULATED 
BY A SERIES OF FAST MOVING SHORTWAVES PROGRESSING THROUGH THE GREAT 
BASIN. THE PASSAGE OF EACH WAVE MAY FOSTER AN INCREASED SFC PRESSURE 
GRADIENT YIELDING PERIODS OF GUSTY WINDS...HOWEVER UNCERTAINTY IN 
TIMING AND MAGNITUDE ARE STILL SUBSTANTIAL (THE OPERATIONAL ECMWF 
REMAINING THE MORE ROBUST SOLUTION WITH WELL ORGANIZED FROPA THE END 
OF NEXT WEEK). REGARDLESS...DAILY TEMPERATURE ANOMALIES CLOSE TO 10F 
ABOVE NORMAL WILL BE COMMON FOR MUCH OF THE WEEK. 
 
&&

.CLIMATE...

RECORD HIGHS THIS WEEKEND...

CITY         MARCH 28      MARCH 29
----         --------      --------
PHOENIX     95 IN 1986     95 IN 1971
YUMA        97 IN 1893    100 IN 1879

&&

.AVIATION... 
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND 
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND 
KBLH... 

STRONG HIGH PRESSURE OVER THE REGION WILL RESULT IN CONTINUED CLEAR 
SKIES AND LIGHT WINDS. WIND DIRECTIONS WILL FOR THE MOST PART FOLLOW 
TYPICAL DIURNAL SWINGS...BUT QUITE A GOOD AMOUNT OF VARIABILITY IS 
LIKELY. NO AVIATION IMPACTS THROUGH AT LEAST SATURDAY.
 
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.   

&& 

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
ABNORMALLY WARM TEMPERATURES AND LOW HUMIDITIES WILL BE SEEN THROUGH 
THE PERIOD UNDER PERSISTENT HIGH PRESSURE ALOFT. HIGH TEMPERATURES 
ACROSS THE DESERTS SHOULD REACH INTO THE LOW TO MID 90S FOR SUNDAY 
THROUGH TUESDAY...BEFORE COOLING SLIGHTLY STARTING WEDNESDAY. 
MINIMUM HUMIDITIES ACROSS THE DESERTS WILL DIP TO BETWEEN 6-11 
PERCENT EACH AFTERNOON. WINDS WILL REMAIN FAIRLY LIGHT OVERALL...BUT 
AFTERNOON BREEZINESS IS POSSIBLE EACH DAY. HIGHER WIND SPEEDS ARE 
LIKELY ON TUESDAY AND AGAIN ON THURSDAY WITH AFTERNOON GUSTS 
APPROACHING 20-25 MPH. NO BIG CONCERNS AS FAR AS MEETING CRITICAL 
FIRE WEATHER THRESHOLDS ON ANY PARTICULAR DAY AS WINDS WILL REMAIN 
WELL BELOW THRESHOLDS. 

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.

&&

$$

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DISCUSSION...MO
CLIMATE...MO
AVIATION....KUHLMAN 
FIRE WEATHER...KUHLMAN

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