FXUS65 KPSR 050958
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
300 AM MST SUN FEB 5 2012

.SYNOPSIS...
DRY CONDITIONS AND NEAR-NORMAL TEMPERATURES WILL CONTINUE THROUGH
TUESDAY. AN APPROACHING PACIFIC DISTURBANCE...MOVING TOWARD THE
SOUTHERN CALIFORNIA COAST TUESDAY...WILL SPREAD A SLIGHT CHANCE OF
SHOWERS OVER THE REGION LATE TUESDAY NIGHT AND WEDNESDAY. DRY AND
MUCH WARMER WEATHER WILL RETURN TO THE REGION NEXT THURSDAY THROUGH
SATURDAY.

&&

.DISCUSSION...
TODAY THROUGH TUESDAY...
DRY WEST TO NORTHWEST FLOW ALOFT WILL CONTINUE OVER THE FORECAST
AREA...SOUTHEAST CA TO SOUTH CENTRAL AZ...WITH TEMPERATURES NEAR
NORMAL. VARIABLE HIGH CLOUDS WILL ALSO BE PRESENT...HOWEVER THICKER
CLOUDS ARE FORECAST ON TUESDAY AHEAD OF AN APPROACHING PACIFIC
DISTURBANCE.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
A SIGNIFICANT PACIFIC LOW PRESSURE SYSTEM IS FORECAST TO MOVE TOWARD
THE SOUTHERN CA COAST TUESDAY...THEN DEEPEN SOUTH INTO CENTRAL BAJA
BY THURSDAY MORNING. NUMERICAL MODEL SOLUTIONS OF THE TRACK OF THIS
SYSTEM STILL DIVERGE. THE EUROPEAN MODEL BASICALLY KEEPS THIS SYSTEM
OFFSHORE FROM SOUTHERN CA AND BAJA ON WEDNESDAY...WITH LITTLE OR NO
PRECIP OVER OUR FORECAST AREA. ON THE OTHER HAND...THE GFS MODEL
MOVES THIS SYSTEM A BIT INLAND OVER SOUTHERN CA AND BAJA...WITH
CONSIDERABLE MOISTURE AND A THREAT OF SHOWERS FORECAST OVER MUCH OF
THE AREA ON WEDNESDAY.

THIS IS A DIFFICULT FORECAST DUE TO THE FACT THAT ALL MODELS HAVE
BEEN FAIRLY CONSISTENT IN THEIR SOLUTIONS THE PAST SEVERAL DAYS.
DUE TO THE UNCERTAINTY...WE WILL CONTINUE WITH THE FORECAST OF A
SLIGHT CHANCE OF SHOWERS AREA-WIDE WEDNESDAY.

THURSDAY AND FRIDAY...
AS THE LOW PRESSURE SYSTEM DEEPENS OVER NORTHWEST MEXICO...DRY
NORTHERLY FLOW ALOFT IS EXPECTED OVER OUR FORECAST AREA. HOWEVER
THIS PERIOD IS STILL SOMEWHAT UNCERTAIN DUE TO NUMERICAL MODEL
DIFFERENCES ON THE MOVEMENT OF MEXICAN LOW PRESSURE SYSTEM.

&&

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

MOSTLY CLEAR SKIES...GOOD VISIBILITIES AND LIGHT DIURNAL WINDS ARE
EXPECTED IN MOST AREAS THROUGH SUNDAY EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
BREEZY CONDITIONS SHOULD BEGIN TO AFFECT SOUTHEAST CALIFORNIA ON
WEDNESDAY AS A LOW PRESSURE SYSTEM BRINGS A SLIGHT CHANCE OF RAIN TO
MOST AREAS. MINIMUM HUMIDITY VALUES SHOULD START OUT IN THE MID 20S
TO LOW 30S IN MOST AREAS...HOWEVER EXPECT THEM TO INCREASE BY LATE
WEDNESDAY...ESPECIALLY IN SOUTHERN GILA AND PINAL COUNTIES.
OVERNIGHT RECOVERIES WILL REMAIN GOOD TO EXCELLENT. HIGH
TEMPERATURES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL THROUGHOUT THE
PERIOD EXCEPT WEDNESDAY WHEN THEY WILL BE NEAR NORMAL.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

DISCUSSION...VASQUEZ
AVIATION...MEYERS
FIRE WEATHER...SAWTELLE/KUHLMAN





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