Area Forecast Discussion
Issued by NWS Phoenix, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KPSR 040227
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
727 PM MST SUN MAY 3 2015

.SYNOPSIS...A SERIES OF PACIFIC WEATHER DISTURBANCES IS FORECAST TO
MOVE INTO THE REGION...RESULTING IN A COOLING TREND. A LARGE AND
COLDER DISTURBANCE IS FORECAST TO MOVE INTO THE REGION EARLY MONDAY
MORNING THROUGH TUESDAY...FOR AN INCREASING CHANCE OF SHOWERS AND
THUNDERSTORMS...MAINLY ACROSS ARIZONA. CLEARING IS EXPECTED LATE
TUESDAY THROUGH THE REMAINDER OF THE WEEK AND NEXT WEEKEND...HOWEVER
WITH SEVERAL PACIFIC WEATHER SYSTEMS FORECAST TO MOVE INTO THE
WESTERN STATES NORTH OF ARIZONA THIS WEEK...BELOW NORMAL TEMPERATURES
ARE EXPECTED THE NEXT SEVEN DAYS.

&&

.DISCUSSION...
ISOLATED SHOWERS CONTINUE TO PERCOLATE ACROSS PORTIONS OF WESTERN
MARICOPA COUNTY AND CENTRAL PINAL COUNTY. UNLIKE YESTERDAY...DUST
PROBLEMS HAVE BEEN FEW AND FAR BETWEEN THIS EVENING AS STORMS HAVE
STRUGGLED TO MAINTAIN CORES ABOVE 20-25KFT. NONETHELESS A FEW SPOTS
SOUTHWEST OF THE METRO MANAGED TO SQUEEZE OUT A FEW HUNDREDTHS OF AN
INCH OF RAINFALL SINCE 00Z.

TAKING A LOOK AT INCOMING 00Z NAM...21Z SREF...AND THE LAST 5-6 RUNS
OF THE HRRR...ALL GUIDANCE IS POINTING TOWARD THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS AFTER MIDNIGHT WITH
MEASURABLE PRECIP ACROSS THE PHOENIX AREA BEFORE DAYBREAK.
APPROXIMATELY HALF OF THE 21Z SREF MEMBERS INDICATE MEASURABLE PRECIP
AT KPHX AROUND 09Z AND I FELT IT PRUDENT TO ADJUST THE FORECAST IN
THAT DIRECTION. MAKING SOME UPWARD ADJUSTMENTS TO THE POPS AFTER 06Z
AND ACCELERATING THE ONSET OF RAIN ACROSS THE AREA. WHILE AMOUNTS
WILL BE LIGHT /FEW HUNDREDTHS/...IT SHOULD NONETHELESS MAKE FOR A
DAMP MONDAY MORNING COMMUTE.

THE REMAINDER OF THE INHERITED FORECAST GRIDS ARE IN GOOD
SHAPE...WILL MAKE MINOR ADJUSTMENTS TO TEMPS/DEWPOINTS/WINDS BASED ON
OBSERVATIONAL TRENDS BUT NOTHING SIGNIFICANT.

&&

.PREVIOUS DISCUSSION...
MONDAY THROUGH TUESDAY...
FOR MONDAY AND TUESDAY A MAJOR COOL PACIFIC TROF IS STILL ON TRACK
TO MOVE FORECAST TO MOVE INTO SOUTHERN CA TONIGHT THEN INTO AZ MONDAY
MORNING THROUGH TUESDAY MORNING. THIS IS A MUCH COLDER TROF WITH WITH
SOMEWHAT STRONG UPPER LEVEL DYNAMICS...AND...WITH INCREASED BOUNDARY
LAYER MOISTURE WILL LEAD TO A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS AREA-WIDE. SINCE IT WILL BE A SLOW EASTWARD MOVING
TROF...THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO
EARLY TUESDAY.

WEDNESDAY...PARTLY CLOUDY SKIES ARE EXPECTED WITH NO PRECIP AS A
MINOR SHORTWAVE RIDGE MOVES QUICKLY THROUGH THE REGION.

THURSDAY THROUGH SATURDAY...ANOTHER COOL TROF IS FORECAST TO MOVE
INTO THE WESTERN REGION MAINLY NORTH OF OUR FORECAST AREA. PRECIP
CHANCES SHOULD MOSTLY BE CONFINED TO OUR SOUTHEAST CA JOSHUA TREE
ZONE 30. HOWEVER...STRONG 500-300 MB HEIGHT FALLS OVER THE MOHAVE
DESERT OF CA FRIDAY SUGGESTS VERY STRONG GUSTY WEST WINDS ACROSS
MUCH OF SOUTHEAST CA AND THE COLORADO RIVER VALLEY.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWERS HAVE AVOIDED THE PHOENIX TERMINALS SO FAR THIS EVENING...BUT
WILL BECOME MORE SCATTERED IN NATURE AROUND 09Z WITH SEVERAL HOURS OF
-SHRA EXPECTED AT ALL 3 PHOENIX TAF SITES. EXPECTING CIGS TO LOWER TO
AROUND 4-6KFT /WILL VARY BASED ON INTENSITY OF PASSING SHOWERS/
THROUGH APPROX 15Z...THEN IMPROVE FOR A BIT INTO THE EARLY AFTERNOON
HOURS. EXPECTING ANOTHER ROUND OF ISOLATED/SCATTERED LATE-DAY -SHRA
AFTER 22Z BUT AT THIS POINT WILL ONLY MENTION VCSH AS CONFIDENCE IN
AREAL COVERAGE IS LOW. AS FOR WINDS...SHOULD SEE A PERSISTENT
WESTERLY DIRECTION AT KPHX OVERNIGHT ALTHOUGH KIWA MAY TRY AND TAKE
ITS USUAL TURN OUT OF THE SOUTHEAST AFTER MIDNIGHT.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NOT EXPECTING ANY SHOWERS TO IMPACT EITHER KIPL OR KBLH. MOST LIKELY
IMPACT FROM THE APPROACHING TROUGH WILL BE IN THE FORM OF BLOWOFF
CIRRUS AND BREEZY AFTERNOON WINDS. OTHERWISE...WEATHER IMPACTS SHOULD
BE CONFINED TO AREAS EAST OF THE CO RIVER.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRY WEATHER...AND SLIGHTLY WARMER TEMPERATURES TO RETURN WEDNESDAY
AS WEAK HIGH PRESSURE PASSES OVER THE REGION. GUSTY WINDS AND COOLER
TEMPERATURES TO PREVAIL ACROSS THE REGION FROM THURSDAY ONWARD INTO
SATURDAY AS ANOTHER PACIFIC STORM SYSTEM MOVES ACROSS THE GREAT
BASIN. FIRE DANGER LEVELS WILL LIKELY BE ELEVATED DURING THIS PERIOD
AS AFTERNOON HUMIDITIES FALL INTO THE TEENS. SLIGHTLY WARMER
TEMPERATURES AND LESS WIND CAN BE EXPECTED ON SATURDAY AS THE
AFOREMENTIONED PACIFIC STORM SYSTEM BEGINS TO MOVE OFF TO THE EAST.

&&

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

$$

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

DISCUSSION...LEINS/VASQUEZ
AVIATION...LEINS
FIRE WEATHER...NOLTE/PERCHA


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.