000
FXUS65 KPSR 120304
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST THU MAR 11 2010

.SYNOPSIS...
HIGH PRESSURE ALOFT FROM THE PACIFIC WILL CONTINUE DRY WEATHER AND
THE WARMING TREND THROUGH SATURDAY...AND AGAIN MONDAY THROUGH
WEDNESDAY. A PACIFIC LOW PRESSURE SYSTEM FROM THE NORTHWEST WILL
TEMPORARILY RESULT IN COOLER WEATHER SUNDAY. IT WILL ALSO BE BREEZY
TO WINDY ACROSS THE ENTIRE AREA LATE SATURDAY AND SUNDAY INTO SUNDAY
NIGHT...WITH A SLIGHT CHANCE OF SHOWERS NORTH AND EAST OF THE PHOENIX
AREA. THE FIRST 80 DEGREE TEMPERATURE OF THE YEAR IN PHOENIX IS
EXPECTED TUESDAY OR WEDNESDAY NEXT WEEK.

&&

.DISCUSSION...
STRONG HIGH PRESSURE ALOFT BUILDING INTO ARIZONA FROM THE WEST AS
DRY SUBSIDENT NWLY FLOW OVERSPREADS THE AREA. IR IMAGERY AT 8 PM
SHOWED CLEAR SKIES ACROSS THE CWA. SURFACE DEWPOINTS OVER THE LOWER
DESERTS THIS EVENING RANGED MOSTLY FROM MID 20S TO MID 30S...IN
GENERAL DOWN FROM YESTERDAY...ESPECIALLY ACROSS OUR WESTERN CWA
WHERE DEWPOINTS WERE DOWN NEARLY 15 DEGREES IN PLACES SUCH AS YUMA
AND IMPERIAL. STRONG H5 HEIGHT RISES SHOWED UP ON THE EVENING PLOT
DATA...150M AT TUCSON AND 140M AT FLAGSTAFF. OF COURSE...FOR TODAY
THIS WARMING WAS INDEED ALOFT AS THE HIGH AT PHOENIX CAME IN AT A
VERY COOL 62 DEGREES...13 DEGREES BELOW NORMAL. FOR THE REST OF
TONIGHT CLEAR SKIES AND LIGHT WINDS WILL PREVAIL UNDER HIGH PRESSURE
ALOFT. NO UPDATES NEEDED TO THE CURRENT FORECAST. REST OF DISCUSSION
IS FROM THE PREVIOUS DAY SHIFT.

.PREVIOUS DISCUSSION...
THERE WAS SOME CLOUDINESS OVER THE HIGHEST MOUNTAINS OF FAR NORTHEAST
MARICOPA COUNTY...SOUTHERN GILA COUNTY...AND FAR NORTHEAST PINAL
COUNTY...OTHERWISE IT WAS SUNNY AT MID AFTERNOON TODAY. TEMPERATURES
WERE GENERALLY 1 TO 3 DEGREES WARMER...EXCEPT 5 TO 10 DEGREES WARMER
IN SOUTHERN GILA COUNTY...AND IT WAS DRIER WITH DEW POINT
TEMPERATURES GENERALLY 2 TO 7 DEGREES LOWER IN MOST OF SOUTH-CENTRAL
ARIZONA INCLUDING THE GREATER PHOENIX AREA...AND 10 TO 16 DEGREES
LOWER IN SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING THE
YUMA AND EL CENTRO/IMPERIAL AREAS COMPARED WITH THE SAME TIME
YESTERDAY.

BREEZY WEATHER FROM THE NORTH IN SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA TODAY WAS DUE TO THE DIFFERENCE IN PRESSURE BETWEEN SURFACE
HIGH PRESSURE BUILDING INTO NEVADA BEHIND THE LOW PRESSURE SYSTEM
THAT MOVED SOUTHEAST ACROSS ARIZONA LAST NIGHT.

HIGH PRESSURE ALOFT FROM THE PACIFIC WILL MOVE EAST ACROSS OUR AREA
TONIGHT AND FRIDAY RESULTING IN A CONTINUATION OF THE WARMING TREND
FRIDAY AND SATURDAY. TEMPERATURES ARE EXPECTED TO RISE INTO THE 70S
IN THE DESERT AREAS INCLUDING PHOENIX...YUMA...AND THE EL CENTRO/
IMPERIAL AREA WHICH IS NEAR OR SLIGHTLY BELOW AVERAGE FOR MID MARCH.
IT WILL BE MOSTLY CLEAR TONIGHT WITH SUNNY SKIES AGAIN FRIDAY. HIGH
CLOUDINESS FROM THE WEST IS EXPECTED FRIDAY NIGHT AND SATURDAY AHEAD
OF THE NEXT LOW PRESSURE SYSTEM FROM THE NORTHWEST...BUT PLENTY OF
SUNSHINE IS EXPECTED TO BE MIXED WITH THE HIGH CLOUDINESS SATURDAY.

A PACIFIC LOW PRESSURE SYSTEM WAS LOCATED WEST OF THE PACIFIC
NORTHWEST NEAR 140 DEGREES LONGITUDE THIS AFTERNOON. THIS NEXT
PACIFIC LOW PRESSURE SYSTEM FROM THE NORTHWEST IS EXPECTED TO MOVE
SOUTHEAST OVER EASTERN ARIZONA SUNDAY AND SUNDAY NIGHT. IT WILL
TEMPORARILY RESULT IN BREEZY TO WINDY WEATHER LATE SATURDAY AND
SUNDAY INTO SUNDAY NIGHT...AND COOLER WEATHER SUNDAY. THERE IS ALSO
A SLIGHT CHANCE OF SHOWERS IN SOUTH-CENTRAL ARIZONA NORTH AND EAST
OF THE PHOENIX AREA SUNDAY AND SUNDAY NIGHT.

STRONG HIGH PRESSURE ALOFT FROM THE PACIFIC WILL BRING MOSTLY CLEAR
NIGHTS AND SUNNY DAYS WITH A SIGNIFICANT WARMING TREND MONDAY THROUGH
WEDNESDAY NEXT WEEK. HIGHS ARE EXPECTED TO RISE INTO THE LOWER 80S
IN THE SOUTH-CENTRAL DESERT AREAS INCLUDING THE GREATER PHOENIX
AREA...AND MID 80S IN SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA
INCLUDING YUMA...EL CENTRO...AND IMPERIAL BY WEDNESDAY AND THURSDAY.
THESE TEMPERATURES ARE ABOVE AVERAGE FOR MID MARCH...BUT HAVE
COMMONLY OCCURRED AT SOME TIME DURING THE MONTH OF MARCH IN MANY
PREVIOUS YEARS.

THE FIRST 80 DEGREE TEMPERATURE OF THE YEAR IN PHOENIX IS EXPECTED
TUESDAY OR WEDNESDAY NEXT WEEK. HAVE BE ADJUSTED THE TEMPERATURES TO
SHOW THIS IN THE LATEST FORECAST PACKAGE.

&&

.AVIATION...
SOUTHEAST CALIFORNIA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
HIGH PRESSURE BUILDING IN FROM THE WEST WILL LEAD TO GENERALLY
CLEAR SKIES ALONG WITH LIGHT AND MOSTLY DIURNAL WINDS TONIGHT
THROUGH FRIDAY EVENING. WINDS AT KIWA TO FAVOR THE EAST FROM 06-18Z
FRIDAY OTHERWISE LIGHT VARIABLE OR LIGHT WEST.

SOUTH CENTRAL AZ INCLUDING KPHX AND KIWA...
HIGH PRESSURE WILL BUILD IN FROM THE WEST FOR GENERALLY CLEAR SKIES
AND RATHER LIGHT WINDS THROUGH FRIDAY EVENING. WINDS TO FAVOR THE
WEST/NORTHWEST AT KIPL AND THE NORTH AT BLH...ALTHOUGH WINDS SHOULD
BE QUITE VARIABLE AT KBLH AFTER 12Z FRIDAY.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SATURDAY THROUGH MONDAY...
A HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION FRIDAY NIGHT AND
SATURDAY...RESULTING IN WARMER TEMPERATURES. HUMIDITY LEVELS WILL
ALSO REMAIN LOW UNDER DRY NORTHERLY WINDS FROM NEVADA AND UTAH.
HOWEVER...LATE SATURDAY AND SUNDAY ANOTHER PACIFIC LOW PRESSURE
SYSTEM WILL MOVE QUICKLY ACROSS THE REGION RESULTING IN BREEZY TO
WINDY CONDITIONS AND COOLER TEMPERATURES. THERE IS A SLIGHT CHANCE
OF SHOWERS SUNDAY OVER SOUTHERN GILA COUNTY.  A STRONG HIGH PRESSURE
SYSTEM WITH MUCH WARMER TEMPERATURES SHOULD RETURN MONDAY.


&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

DISCUSSION...CB/ELLIS
AVIATION...CB
FIRE WEATHER...VASQUEZ

NWS PSR Office Area Forecast Discussion