FXUS65 KFGZ 102308 CCA
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
405 PM MST THU DEC 10 2009

.SYNOPSIS...AFTER ANOTHER CLEAR AND COLD NIGHT TONIGHT...YET ANOTHER 
FAST-MOVING PACIFIC STORM SYSTEM WILL MOVE ACROSS THE STATE FRIDAY. 
THIS STORM HAS SOME MOISTURE WITH IT...AND IT WILL BRING SOME LIGHT
RAIN AND SNOW TO AREAS ALONG AND NORTH OF I-40. A FEW INCHES MAY 
FALL AT ELEVATIONS ABOVE 6000 FEET. A SERIES OF STORM SYSTEMS WILL 
BRING TWO MORE ROUNDS OF GENERALLY LIGHT RAIN AND SNOW TO THE 
REGION SATURDAY AND SUNDAY.

&&

.DISCUSSION...EXPECT ANOTHER COLD NIGHT TONIGHT AS SKIES CLEAR THIS 
EVENING BEHIND AN EXITING S/WV. THE NEXT IN A LINE OF PACIFIC S/WVS 
WILL MOVE INTO WESTERN ARIZONA FRIDAY MORNING...NEARING THE EASTERN 
BORDER BY FRIDAY EVENING. THIS WAVE HAS MORE MOISTURE ASSOCIATED 
WITH IT...AND WE DO EXPECTED MEASURABLE PRECIPITATION DURING THE DAY 
FRIDAY. MODELS AGREE ON DEEP SATURATION AROUND MIDDAY...BUT DISAGREE 
ON HOW LONG THIS SATURATION PERSISTS. THIS MAKES A BIG DIFFERENCE ON 
HOW MUCH QPF WILL REACH THE GROUND. THE BEST SCENARIO IS A ROUGH 
COMPROMISE FOR NOW...WHICH MEANS AROUND A TENTH INCH OF LIQUID ALONG 
AND NORTH OF THE I-40 CORRIDOR. A FEW LOCATIONS MAY SEE NEAR TWO 
TENTHS OF LIQUID...BUT THIS WILL BE LOCALIZED. THIS TRANSLATES TO AN 
INCH OR TWO OF NEW SNOW ABOVE 6000 FEET.

ANOTHER SIMILAR DISTURBANCE WILL BRING A BRIEF PERIOD OF RAIN AND 
SNOW TO THE SAME AREAS SATURDAY MORNING...AGAIN...NOT A WHOLE LOT OF 
QPF IS EXPECTED. 

FINALLY...BY LATER SUNDAY THROUGH SUNDAY NIGHT...THE LAST...AND 
POSSIBLY THE STRONGEST WAVE WILL MOVE THROUGH THE STATE. THIS SYSTEM 
IS STILL IN SOMEWHAT OF A DISARRAY AS MODELS FLIP-FLOP WITH REGARD 
TO THE EXTENT OF CYCLOGENESIS OFF THE CALIFORNIA COAST SATURDAY 
AFTERNOON. IT IS STILL A GOOD BET THAT WE WILL SEE MEASURABLE 
PRECIPITATION...ESPECIALLY SUNDAY AFTERNOON AND SUNDAY NIGHT...BUT 
THE AMOUNT IS STILL VERY MUCH IN QUESTION. STAY TUNED FOR UPDATES.

&&

.AVIATION...FOR THE 00Z PACKAGE...VFR CONDITIONS ARE EXPECTED UNDER 
SCT MID AND HIGH LEVEL CLOUDS THROUGH EARLY FRIDAY. SCT MVFR 
CONDITIONS INCREASING WEST TO EAST ACROSS NORTHERN ARIZONA ON FRIDAY 
WITH SCT -SN/-RA MOSTLY OVER HIGHER TERRAIN. AVIATION DISCUSSION NOT 
UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC......................PETERSON
AVIATION/FIRE WEATHER.......KLIMOWSKI

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