FXUS65 KFGZ 272204
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
300 PM MST FRI NOV 27 2009

.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM WILL IMPACT NORTHERN 
ARIZONA SATURDAY AND SUNDAY WITH COLDER TEMPERATURES...BREEZY 
CONDITIONS...MOUNTAIN SNOW AND VALLEY RAIN. THIS STORM WILL MOVE 
SOUTHEAST OF ARIZONA BY TUESDAY WITH DRY AND SEASONAL TEMPERATURES 
FOR THE REST OF THE WEEK. 

&&

.DISCUSSION...A LARGE BAND OF MID TO UPPER LEVEL CLOUDS IS MOVING 
EASTWARD ACROSS CALIFORNIA AND INTO ARIZONA THIS AFTERNOON. SURFACE 
AND LOW LEVEL MOISTURE IS ALSO MOVING NORTHEAST ACROSS SOUTHERN 
ARIZONA AND INTO NORTHERN ARIZONA. A CUMULUS FIELD HAS DEVELOPED 
OVER SOUTHERN ARIZONA BETWEEN NOGALES AND TUCSON. SURFACE 
DEWPOINTS HAVE ALSO JUMPED 15 TO 20 DEGREES OVER NORTHERN ARIZONA IN 
THE LAST 24 HOURS. 

MODELS ARE FINALLY IN CLOSE AGREEMENT WITH THE TRACK OF THE LOW 
DEVELOPING OFF THE CALIFORNIA COAST THIS AFTERNOON. THE LOW SHOULD 
BE OVER THE SAN DIEGO AREA SATURDAY AFTERNOON...OVER THE NORTHERN 
SEA OF CORTEZ SUNDAY AFTERNOON...NEAR GUAYMAS MONDAY AFTERNOON...AND 
OVER WEST TEXAS BY TUESDAY AFTERNOON.  

MOISTURE AND INSTABILITY ARE EXPECTED TO INCREASE OVER NORTHERN 
ARIZONA THROUGH THE DAY SATURDAY WITH THE CHANCE OF PRECIPITATION 
INCREASING. BY SATURDAY AFTERNOON THERE COULD BE A FEW THUNDERSTORMS 
AS WELL. THE BEST CHANCES OF PRECIPITATION FOR NORTHERN ARIZONA IS 
EXPECTED LATE SATURDAY INTO EARLY SUNDAY MORNING. BY SUNDAY 
NIGHT...THE LOW LEVEL FLOW ON THE NORTH SIDE OF THE LOW WILL BEGIN 
TO ADVECT DRY LOW TO MID-LEVEL AIR INTO AREAS NORTH OF THE MOGOLLON 
RIM FOR A DECREASE IN PRECIPITATION THERE. THE SNOW LEVEL WILL START 
OUT ABOVE 7000 FEET ON SATURDAY MORNING LOWERING TO AS LOW AS 4300 
FEET AS THE COLD FRONT MOVES ACROSS THE STATE SATURDAY NIGHT. MOST 
OF THE ACCUMULATING SNOW IS EXPECTED ABOVE 6500 FEET IN ADVANCE OF 
THE COLD FRONT. 

BY MONDAY MORNING...THE BEST MOISTURE AND LIFT SHOULD BE CONFINED TO 
THE EASTERN RIM INTO NORTHERN GILA AND THE WHITE MOUNTAINS. THE LOW 
EXITS OFF TO THE SOUTHEAST LATE MONDAY WITH A HIGH PRESSURE RIDGE 
BUILDING OVER THE SOUTHERN CALIFORNIA COAST BY TUESDAY MORNING. 

FOR THE REMAINDER OF THE WEEK NORTHERN ARIZONA WILL RESIDE IN 
NORTHERLY FLOW WITH THE HIGH PRESSURE RIDGE TO OUR WEST AND THE LOW 
PRESSURE TROUGH OVER THE CENTRAL U.S. THIS WILL BRING DRY CONDITIONS 
WITH NEAR SEASONABLE HIGH TEMPERATURES FOR THIS TIME OF THE YEAR. 

&&

.AVIATION...FOR THE 00Z PACKAGE...EXPECT VFR CONDITIONS TO CONTINUE 
UNTIL 06Z SATURDAY. FROM 28/06Z TO 28/12Z...INCREASING LOW LEVEL 
CLOUD COVER WILL PRODUCE LOCAL MVFR CIGS ALONG THE MOGOLLON RIM. 
FROM 28/12Z THROUGH 29/00Z...SKIES WILL BECOME CLOUDY WITH CHANCES 
FOR MVFR CIGS AND VSBY IN SCATTERED RAIN AND SNOW SHOWERS. SHOWER 
ACTIVITY WILL RAMP UP AFTER THE 28/18Z TIME PERIOD WITH SCATTERED 
MVFR AND LOCAL IFR CONDITIONS EXPECTED FOR ELEVATIONS ABOVE 6000 FT. 
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE. 

&&

$$

PUBLIC.................MAS
AVIATION...............RB

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER 
INFORMATION.