Area Forecast Discussion
Issued by NWS Phoenix, AZ

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000
FXUS65 KPSR 090533 AAA
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1035 PM MST MON FEB 8 2016

.UPDATE... UPDATED AVIATION SECTION.

.SYNOPSIS...HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE
OVER THE SOUTHWESTERN UNITED STATES THIS WEEK. THIS WILL RESULT IN A
PROLONGED PERIOD OF SUNNY SKIES...ABOVE NORMAL TEMPERATURES...
RELATIVELY LIGHT WINDS...AND LOW HUMIDITY.

&&

.DISCUSSION... A VERY MILD EVENING (FOR EARLY FEB) IS BEING OBSERVED
ACROSS THE REGION...WITH MANY OF THE WARMER LOWER DESERT LOCATIONS
STILL IN THE 70S AT THIS HOUR. VERY STRONG RIDGING ALOFT...WITH
500MB HEIGHTS AOA 584DM...COMBINED WITH LOW-LEVEL DOWNSLOPE
NORTHEASTERLY FLOW HELPED TO PUSH TEMPERATURES THIS AFTERNOON WELL
UP INTO THE 80S AT MANY LOWER DESERT SPOTS ACROSS OUR CWA...WITH
PHOENIX SKY HARBOR REACHING 85F...JUST A DEGREE SHY OF THE RECORD
FOR THE DATE. THE LATEST NAM AND 18Z GFS CONTINUE TO INDICATE THAT
THIS VERY WARM WEATHER WILL LAST THROUGH AT LEAST THE REST OF THE
WEEK...WITH LITTLE DAY-TO-DAY CHANGE IN TEMPERATURES THROUGH THE
PERIOD...UNDER MOSTLY CLEAR SKIES. FOR THE REST OF TONIGHT...OTHER
THAN SOME VERY MINOR ADJUSTMENTS TO THE HOURLY GRIDS...CURRENT
FORECASTS ARE LOOKING QUITE GOOD...NO UPDATES ARE PLANNED.

&&

.PREVIOUS DISCUSSION...

THROUGH FRIDAY...

AN ANOMALOUSLY STRONG HIGH PRESSURE SYSTEM BUILT OVER THE REGION
LAST NIGHT AND WILL REMAIN STATIONARY THIS WEEK. TEMPERATURES ON THE
LOWER DESERTS WILL WARM INTO THE 80S.  HOWEVER...A DEVELOPING
SUBTROPICAL LIKE LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK WELL
SOUTH OF AZ...MOVING EAST ACROSS CENTRAL BAJA TODAY INTO NORTH
CENTRAL MEXICO SOUTH OF EL PASO ON TUE.  A RESULTING NORTH/SOUTH
PRESSURE GRADIENT WILL CONTINUE THE NORTH/NORTHEAST BREEZES ACROSS
THE REGION...PARTICULARLY DOWN THE COLORADO RIVER VALLEY THE
REMAINDER OF THE AFTERNOON AND EVENING. LIGHTER WINDS ARE FORECAST
ON TUESDAY.


THIS WEEKEND...

AGAIN...STEADY STATE UNSEASONABLY WARM AFTERNOONS...IN THE 80S OVER
THE LOWER DESERTS...WILL CONTINUE INTO THE WEEKEND. HOWEVER...THE
HIGH PRESSURE SYSTEM WILL BREAK DOWN SATURDAY AS A MUCH WEAKENED
PACIFIC DISTURBANCE IS FORECAST TO MOVE ACROSS NORTHERN AZ. OF MUCH
GREATER INTEREST...IS A SHEARED PORTION OF THIS PACIFIC SYSTEM
FORMING A CUTOFF LOW OFF THE SAN DIEGO COAST SUNDAY...DEEPENING
SOUTH TO OFFSHORE SOUTHERN BAJA MONDAY...NEAR THE NORTHERN EDGES OF
WARM EL NINO WATERS.  IN COMPARISON...WE REMEMBER DURING THE 1991-
1992 EL NINO EVENT...CUTOFF LOWS IN THIS EL NINO REGION SPUN UP
INCREDIBLY FAST DUE TO THE PHASING OF A SUBTROPICAL JETSTREAM. THIS
RESULTED IN APPRECIABLE RAINS ON THE SOUTHERN AZ DESERTS. PERHAPS
RAIN IS IN THE OFFING NEXT MONDAY AND TUESDAY WHICH IS A LITTLE
BEYOND THIS 7 DAY FORECAST.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

HIGH PRESSURE OVER THE 4-CORNERS REGION TO KEEP WINDS FROM AN
EASTERLY DIRECTION AT ALL OF THE PHX AREA TERMINALS THROUGH THE TAF
PERIOD. WIND SPEED WILL REMAIN MAINLY AOB 8 KTS...EXCEPT FOR A
PERIOD OF TIME DURING THE LATE MORNING-EARLY AFTERNOON HOURS ON
TUESDAY...WHEN STRONGER WINDS ALOFT MIXING DOWN TO THE SFC INCREASES
SPEEDS A BIT...UP INTO THE 10-12KT RANGE AT KPHX. SKIES TO REMAIN
BASICALLY CLEAR THROUGH THE TAF PERIOD.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NORTHERLY BREEZES AT KBLH TO GRADUALLY DIMINISH LATE TONIGHT AND
EARLY TUESDAY...AS SFC PRESSURE GRADIENTS WEAKEN OVER THE
REGION...WITH WINDS BECOMING LIGHT/VARIABLE BY TUESDAY AFTERNOON.
WINDS AT KIPL TO REMAIN ON THE LIGHT SIDE...MAINLY AOB 8
KTS...FOLLOWING TYPICAL DIURNAL TRENDS. SKIES TO REMAIN MAINLY CLEAR
THROUGH TONIGHT...WITH SOME PATCHY CIRRUS CLOUD LAYERS PASSING OVER
THE TERMINALS DURING THE DAY ON TUESDAY.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY THROUGH SUNDAY...AN UNSEASONABLY STRONG HIGH PRESSURE
RIDGE WILL BUILD OVER THE WESTERN STATES DURING THE WEEK. THIS WILL
LEAD TO A PERSISTENT PERIOD OF WELL ABOVE NORMALS HIGH TEMPERATURES
...WITH READINGS PEAKING 10 TO 15 DEGREES ABOVE SEASONAL NORMALS.
MANY LOWER ELEVATION AND DESERT SITES WILL SEE A STRETCH OF DAYS
WITH HIGH TEMPERATURES WARMING PAST THE 80 DEGREE MARK. RH`S WILL
ALSO REMAIN ON THE DRIER AND BELOW NORMAL SIDE DURING THE WEEK WITH
MIN VALUES TYPICALLY IN THE LOW TO MIDDLE TEENS.

LOCALLY BREEZY CONDITIONS ALONG THE CO RIVER VALLEY ARE EXPECTED
EACH AFTERNOON. MORE NOTICEABLE EASTERLY WINDS WILL FLOW INTO THE
SOUTH-CENTRAL AZ DESERTS...WITH ELEVATED WINDS OVER RIDGETOPS AND
GAPS TO THE NORTH/EAST OF PHOENIX. WINDS ELSEWHERE WILL GENERALLY
FOLLOW TYPICAL DRAINAGE/SLOPE DRIVEN HEADINGS WITH LIGHT SPEEDS. BY
WEEKS END THE UPPER RIDGE WILL BEGIN TO SHIFT TO OUR EAST AS
TROUGHING ALIGNS ITSELF OVER THE WEST COAST AGAIN. SOME VERY SLIGHT
TEMPERATURE COOLING AND INCREASING CLOUDINESS ARE LIKELY OVER THE
WEEKEND.

&&

.CLIMATE...
                   PHOENIX         |        YUMA
             FCST | RECORD (YEAR)  | FCST | RECORD (YEAR)

MON FEB 8      83 | 86 (1970)      |   81 | 88 (1996)
TUE FEB 9      83 | 84 (1987)      |   83 | 90 (2015)
WED FEB 10     83 | 87 (1951)      |   83 | 93 (1951)
THU FEB 11     83 | 83 (1951)      |   84 | 86 (1971)

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.

&&

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

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA/VASQUEZ
CLIMATE......NOLTE
AVIATION...PERCHA
FIRE WEATHER...NOLTE/CB


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