FXUS65 KPSR 131034
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
335 AM MST SAT MAR 13 2010

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY AND WARM WEATHER TO OUR
AREA SATURDAY. HOWEVER...A PACIFIC LOW PRESSURE SYSTEM WILL BRING
BREEZY TO WINDY CONDITIONS...ESPECIALLY ACROSS SOUTHEAST CALIFORNIA
AND SOUTHWEST ARIZONA LATE SATURDAY INTO SUNDAY...ALONG WITH A
SLIGHT CHANCE OF SHOWERS NORTH AND EAST OF THE PHOENIX AREA SUNDAY.
AFTER THE SYSTEM DEPARTS...DAYTIME TEMPERATURES ARE EXPECTED TO WARM
WELL INTO THE 80S ACROSS THE DESERT ELEVATIONS EARLY NEXT WEEK.

&&

.DISCUSSION...
UPSTREAM TROUGH HAS MOVED INTO THE GREAT BASIN WITH A 30 UNIT VORT
BEGINNING TO TAKE ON A NEGATIVE TILT IN NORTHERN NV. LATEST
GUIDANCE SUGGESTS TEMPS WILL WARM 4 TO 5 DEGREES FROM
YESTERDAY...BUT THIS SEEMS A BIT TOO MUCH CONSIDERING THE DECREASING
THICKNESSES AND MINIMAL WARMING BELOW 800 MB. MEANWHILE...MIXING
THROUGH ABOUT 5K FT IN SE CA WILL YIELD GUSTS TO AROUND 25 KT THIS
AFTERNOON AND CONFIDENCE IS HIGH THAT A WIND ADVISORY WILL NOT BE
NEEDED.

GFS/ECMWF ARE IN GOOD AGREEMENT THROUGH SUN...DEEPENING THE TROUGH
INTO A CLOSED LOW ACROSS THE MOGOLLON RIM. THIS PLACES THE
STRONGEST ASCENT ASSOCIATED WITH THE FRONTAL BAND GENERALLY NORTH
AND EAST OF THE FORECAST AREA. POPS WERE DROPPED ACROSS MARICOPA
COUNTY BUT STILL PEAK NEAR 30 PERCENT ACROSS EASTERN GILA COUNTY SUN
MORNING. POST-FRONTAL TEMPS FOR SUN ARE ALSO ON THE LOW END OF
GUIDANCE AS THE MEAN LAYER CIRCULATION CENTER DROPS INTO
WEST-CENTRAL NM.

RAPID WARMING TREND IS IN STORE FOR NEXT WEEK AS A STRONG RIDGE
DEVELOPS IN THE EASTERN PACIFIC. THE 80 DEGREE MARK SEEMS LIKE A
GOOD BET FOR TUE OR AT THE VERY LATEST WED IN PHOENIX. TEMPERATURES
WILL ALSO CLIMB INTO THE UPPER 80S ACROSS THE SOUTHWEST DESERTS.
NEXT CHANCE FOR PRECIP WOULD BE ON THU OR FRI AS A WEAK TROUGH MOVES
TOWARDS THE FOUR CORNERS. HIGHEST POPS REMAIN CONFINED TO THE HIGHER
TERRAIN EAST OF PHOENIX...BUT ONLY TOP OUT AROUND 10 PERCENT.

&&

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

MOSTLY CLEAR SKIES AND LIGHT WINDS...GENERALLY LESS THAN 10 KTS...
AT ALL TAF SITES THROUGH AT LEAST 15Z SATURDAY. LOW-MID LEVEL
GRADIENTS TIGHTEN AHEAD OF AN UPPER LEVEL LOW...AND SW-W SFC WINDS
BEGIN TO INCREASE...MAINLY OVER SOUTHEAST CA NEAR KIPL/KBLH AFTER
18Z SATURDAY...WITH GUSTS UP TO 25KTS POSSIBLE DURING THE AFTERNOON
HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH TUESDAY...
LATE SATURDAY AND SUNDAY ANOTHER PACIFIC LOW PRESSURE SYSTEM WILL
MOVE QUICKLY ACROSS THE REGION...CENTERED OVER NORTHERN ARIZONA BY
SUNDAY AFTERNOON. THIS WILL RESULT IN BREEZY TO WINDY CONDITIONS
AND COOLER TEMPERATURES. THERE IS A SLIGHT CHANCE OF SHOWERS SUNDAY
OVER SOUTHERN GILA COUNTY.

LATE MONDAY THROUGH WEDNESDAY...A STRONG HIGH PRESSURE SYSTEM WILL
DEVELOP OVER THE AREA. MOSTLY CLEAR SKIES AND MUCH WARMER
TEMPERATURES ARE EXPECTED THIS PERIOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...VASQUEZ


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