Heavy Snow in Arizona, March 11, 2006

AZZ020>028-CAZ030>033-110600-

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
430 PM MST FRI MAR 10 2006

SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION

.SYNOPSIS...
THE STRONGEST STORM SYSTEM THIS WINTER FROM THE NORTHWEST WILL SWING
EAST ACROSS THE AREA THIS WEEKEND. WIND WILL DECREASE SOMEWHAT
TONIGHT...BUT INCREASE AGAIN SATURDAY. COLDER WEATHER WITH
SIGNIFICANT DESERT RAIN AND MOUNTAIN SNOW WILL OCCUR LATE TONIGHT
THROUGH SATURDAY NIGHT WITH THE MOST ABUNDANT RAIN AND MOUNTAIN SNOW
IN SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA SATURDAY
AND SATURDAY NIGHT. DRY WEATHER WITH A WARMING TREND IS EXPECTED
NEXT WEEK...AS HIGH PRESSURE RETURNS TO THE AREA.

&&

.SHORT TERM...
TONIGHT THROUGH MONDAY...
ISOLATED SHOWERS WERE OCCURRING FROM WESTERN MARICOPA COUNTY WEST
ACROSS SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA THIS AFTERNOON.
OTHERWISE...IT WAS PARTLY SUNNY AND WINDY TODAY WITH SOME BLOWING
SAND AND DUST IN THE DESERT AREAS. TEMPERATURES WERE GENERALLY 2 TO
5 DEGREES COOLER AT MID AFTERNOON TODAY COMPARED WITH THE SAME TIME
YESTERDAY.

A WIND ADVISORY IS IN EFFECT FOR JOSHUA TREE NATIONAL PARK...
IMPERIAL...EASTERN RIVERSIDE...YUMA...AND LA PAZ COUNTIES THROUGH 8
PM MST/7 PM PST THIS EVENING...AND AGAIN FROM 12 NOON MST/11 AM PST
TO 8 PM MST/7 PM PST SATURDAY. A HEAVY SNOW WARNING IS IN EFFECT FOR
JOSHUA TREE NATIONAL PARK ABOVE 3 THOUSAND FEET FROM 1 AM TO 5 PM
PST SATURDAY...AND FOR SOUTHERN GILA COUNTY ABOVE 4 THOUSAND FEET
FOR SATURDAY AND SATURDAY NIGHT.

A MAJOR CHANGE IN THE WEATHER IS ON THE WAY. IT STILL LOOKS AS IF WE
WILL BRING AN END TO THE RECORD DRY SPELL. SIGNIFICANT DESERT RAIN
AND MOUNTAIN SNOW IS LIKELY THIS WEEKEND.

IT LOOKS AS IF THE MOST SIGNIFICANT COLD PACIFIC STORM SYSTEM OF THE
SERIES FROM THE NORTHWEST WILL BRING AN INCREASING CHANCE OF SHOWERS
AND MOUNTAIN SNOW FROM THE WEST TONIGHT WITH SHOWERS LIKELY SATURDAY
AND MAINLY IN SOUTH-CENTRAL ARIZONA SATURDAY NIGHT. SNOW LEVELS ARE
EXPECTED TO BE LOWEST IN JOSHUA TREE NATIONAL PARK...AS LOW AS 25
HUNDRED FEET...AND AT LEAST DOWN TO 4 THOUSAND FEET IN SOUTHERN GILA
COUNTY WITH MORE THAN HALF A FOOT OF SNOW ABOVE 4 THOUSAND FEET AND
POSSIBLY OVER A FOOT OF SNOW ABOVE 5 THOUSAND FEET. THUS...HAVE
ISSUED A HEAVY SNOW WARNING FOR BOTH JOSHUA TREE NATIONAL PARK AND
SOUTHERN GILA COUNTY AS PREVIOUSLY MENTIONED.

THE MOST ABUNDANT AMOUNT OF RAIN AND SNOW WITH THIS STORM SYSTEM IS
EXPECTED TO OCCUR IN SOUTH-CENTRAL ARIZONA SATURDAY AND SATURDAY
NIGHT.

WE HAVE RAISED THE RAIN AND SNOW AMOUNTS AND PROBABILITY OF
OCCURRENCE TONIGHT THROUGH SATURDAY NIGHT. OVER THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED IN THE SOME SOUTH-CENTRAL DESERT AREAS
INCLUDING PHOENIX...AND OVER ONE INCH OF RAIN IS POSSIBLE EAST OF
THE GREATER PHOENIX AREA WITH AT LEAST HALF A FOOT TO A FOOT OF SNOW
ABOVE 4 THOUSAND FEET WITH A MIXTURE OF RAIN AND SNOW BETWEEN ABOUT
3 THOUSAND AND 4 THOUSAND FEET...ESPECIALLY SATURDAY NIGHT.

WIND IS EXPECTED TO DECREASE SOMEWHAT TONIGHT...BUT REMAIN AT LEAST
BREEZY THROUGH THE NIGHT TONIGHT...THEN IT WILL BECOME WINDY AGAIN
SATURDAY. THE WIND IS EXPECTED TO BECOME STRONG ENOUGH AGAIN FOR
A WIND ADVISORY IN SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA BY
SATURDAY AFTERNOON INTO SATURDAY EVENING AS PREVIOUSLY MENTIONED.

HAVE A DECREASE IN SHOWERS FROM THE WEST OVER MOST OF THE AREA BY
SUNDAY AS THE MAIN PART OF THE STORM SYSTEM MOVES NORTHEAST OF THE
AREA. HOWEVER...HAVE KEPT SHOWERS AND MOUNTAIN SNOW IN THE CHANCE
CATEGORY FOR SOUTHERN GILA COUNTY SUNDAY.

HIGHER PRESSURE ALOFT FROM THE PACIFIC IS EXPECTED TO BRING MOSTLY
SUNNY SKIES AND A RECOVERY OF TEMPERATURES MONDAY.

&&

.LONG TERM...
MONDAY NIGHT THROUGH FRIDAY...
NOT MUCH CHANGE TO ADD TO THE EXTENDED FORECAST DISCUSSION. NO
PRECIPITATION EXPECTED IN THE EXTENDED...AS MODELS CONTINUE TO
INDICATE RIDGING BUILDING OVER THE WRN CONUS TUESDAY THROUGH
FRIDAY...WITH HIGHS BUILDING BACK INTO THE UPPER 70S AND LOWER 80S
ACROSS THE LOWER DESERTS OF OUR CWA. LATE THURSDAY-FRIDAY TIME
FRAME...EURO/GFSLR BOTH ADVERTISE ANOTHER ERN PAC UPPER LEVEL
TROF...WITH THE AXIS TAKING SHAPE JUST OFF THE NRN CA COAST
...INCREASING HIGH LEVEL CLOUDINESS OVER THE DESERT SOUTHWEST AND
MODERATING TEMPS BY THE END OF THE WEEK.

&&

.CLIMATE...
THE RECORD DRY SPELL IS FORECAST TO COME TO AN END THIS WEEKEND...
POSSIBLY AS EARLY AS TONIGHT. THERE HAS BEEN A TOTAL OF 142
CONSECUTIVE DAYS WITH NO RAIN AT PHOENIX SKY HARBOR...NOT EVEN A
TRACE...THROUGH THURSDAY THE 9TH OF MARCH. IF IT DOES NOT RAIN
BEFORE MIDNIGHT TONIGHT (FRIDAY NIGHT)...IT WOULD BE A TOTAL OF 143
CONSECUTIVE DAYS WITH NO RAIN...BUT THAT WOULD BE THE MAXIMUM...
SINCE THERE IS AT LEAST AN 80 PERCENT CHANCE OF RAIN AT PHOENIX SKY
HARBOR SATURDAY.

RECORD-KEEPING IN PHOENIX BEGAN 6 AUGUST 1895.

&&

.AVIATION...
00Z TAFS...TAFS ADEQUATELY DEPICT EXPECTED WEATHER. SEE TAFS
PHXTAFPHX...PHXTAFIWA...PHXTAFYUM...LAXTAFBLH AND LAXTAFIPL FOR
MORE DETAILED INFORMATION.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...WIND ADVISORY FOR YUMA AND LA PAZ COUNTIES INCLUDING ZONES
     20...21...25...AND 26 UNTIL 8 PM MST THIS EVENING...AND AGAIN
     FROM 12 NOON TO 8 PM MST SATURDAY.

     HEAVY SNOW WARNING SATURDAY AND SATURDAY NIGHT FOR
     SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS...ZONE
     24...ABOVE 4 THOUSAND FEET.

CA...WIND ADVISORY FOR JOSHUA TREE NATIONAL PARK...IMPERIAL COUNTY...
     AND EASTERN RIVERSIDE COUNTY...ZONES 30...31...32...AND 33
     THROUGH 7 PM PST THIS EVENING...AND AGAIN FROM 11 AM TO
     7 PM PST SATURDAY.

     HEAVY SNOW WARNING LATE TONIGHT AND SATURDAY FROM 1 AM TO
     5 PM PST FOR JOSHUA TREE NATIONAL PARK...ZONE 30...ABOVE
     3 THOUSAND FEET.

&&

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

ELLIS/MEYERS