FXUS65 KFGZ 251646
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
945 AM MST FRI DEC 25 2009

.SYNOPSIS...A DRY AND COLD PATTERN WITH BELOW NORMAL TEMPERATURES 
WILL CONTINUE THROUGH SATURDAY. UNSETTLED WEATHER IS POSSIBLE BY 
MONDAY EVENING...THROUGH WEDNESDAY.

&&

DISCUSSION...NORTHERLY FLOW BEHIND THE LARGE LOW PRESSURE SYSTEM... 
WHICH COVERS THE EASTERN TWO THIRDS OF THE COUNTRY...WILL CONTINUE 
TO ADVECT COLD AND DRY AIR ACROSS NORTHERN ARIZONA THROUGH SATURDAY 
NIGHT. BY SUNDAY...CLOUD COVER WILL INCREASE AS A WEAK DISTURBANCE 
CROSSES THE STATE. BY MONDAY...MODELS ARE INDICATING A BROAD 
TROUGH...WITH NORTHERN AND SOUTHERN LOW PRESSURE FEATURES...NEARING 
THE SOUTHWEST. THERE IS DISAGREEMENT AT THIS POINT AS TO THE 
STRENGTH AND LOCATION OF THESE TWO FEATURES WHICH RESULTS IN CLEARLY 
DIFFERENT PRECIPITATION SCENARIOS. WE WILL CONTINUE TO WAIT FOR 
BETTER MODEL AGREEMENT FOR THIS MONDAY THROUGH WEDNESDAY PERIOD 
BEFORE MAKING ANY SIGNIFICANT ADJUSTMENTS TO THE FORECAST.

BEYOND WEDNESDAY...ANOTHER WEAK DISTURBANCE IS FORECAST TO MOVE 
ACROSS THE SOUTHWEST THAT CURRENTLY APPEARS TO BE DRY. TEMPERATURES 
SHOULD RETURN TO NEAR NORMAL BY THE END OF THE PERIOD.

&&

.AVIATION...FOR THE 18Z PACKAGE...VFR CONDITIONS WITH OCCASIONAL 
NORTH-NORTHEASTERLY BREEZES FOR THE 24 HR TAF PERIOD. AVIATION 
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC.........LATTO
AVIATION.......DL

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