Issued by NWS Flagstaff, AZ
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-- Discussion containing changed information from previous version are highlighted. --000 FXUS65 KFGZ 100913 AFDFGZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 210 AM MST WED FEB 10 2010 .SYNOPSIS...-- Changed Discussion --THE CENTER OF A PACIFIC STORM WILL MOVE ACROSS NORTHWEST SONORA MEXICO TODAY AND THEN TO THE EAST BY THURSDAY MORNING. THE NORTHERN FRINGES OF THIS STORM WILL BRUSH THE NORTHLAND. AS A RESULT...ALONG AND SOUTH OF THE MOGOLLON RIM THERE WILL BE A GOOD CHANCE OF MOUNTAIN SNOW AND LOWER ELEVATION RAIN SHOWERS. FURTHER NORTH...SHOWERS WILL REMAIN ISOLATED. STARTING THURSDAY...HIGH PRESSURE WILL BUILD ACROSS THE SOUTHWEST UNITED STATES WITH WARMER DAYTIME TEMPERATURES AND DRY CONDITIONS LASTING THROUGH THE UPCOMING HOLIDAY WEEKEND.-- End Changed Discussion --&& .DISCUSSION...-- Changed Discussion --THE CENTER OF A PACIFIC STORM SYSTEM WAS SPINNING JUST OFF THE SOUTHERN CALIFORNIA/AND NORTHERN BAJA COASTS EARLY THIS MORNING...WITH A SOUTHWARD HEADING. OVER THE NEXT 18 TO 24-HOURS THE STORM CENTER WILL TRACK SOUTHEASTWARD ACROSS NORTHERN BAJA AND THEN INTO NORTHWEST SONORA MEXICO BY 07Z THURSDAY. BY SUNRISE THURSDAY THE STORM WILL BE ACCELERATING EASTWARD AND WEAKENING AS IT HEADS OFF TO THE EAST ACROSS CHIHUAHUA MEXICO. THE PROJECTED STORM TRACK SUGGESTS THAT THE ACCUMULATION OF PRECIP. NORTH OF THE MOGOLLON RIM WILL BE LIGHT TO NO PRECIPITATION AT ALL. ALONG AND SOUTH OF THE MOGOLLON RIM THERE WILL BE A GOOD CHANCE OF SHOWERS WITH ACCUMULATING PRECIPITATION AND SNOW AMOUNTS WILL BE ON THE LIGHT SIDE. THE SNOW LEVEL WILL HOVER AROUND 5000 FEET WITH SNOW ACCUMULATIONS GENERALLY OF 1-2 INCHES OR LESS. THE ONLY EXCEPTION WILL BE IN THE WHITE MOUNTAINS WHERE 2-4 INCHES OF SNOW COULD ACCUMULATE WITH LOCALLY HIGHER AMOUNTS ABOVE 8000 FEET. FOR THURSDAY AND HEADING INTO EARLY NEXT WEEK...A LARGE-SCALE PATTERN SHIFT APPEARS TO BE TAKING SHAPE WITH A LONGWAVE RIDGE FORMING OVER THE WESTERN STATES AND THE MAIN JET STREAM HEADING TO THE NORTH. THERE WILL STILL BE A THREAT OF A WEAK STORM OR TWO DIVING SOUTHEAST ALONG THE EAST SIDE OF THE RIDGE AND ACROSS PORTIONS OF NORTHERN ARIZONA...BUT CURRENT MODEL TRENDS SUGGEST THAT MAINLY DRY CONDITIONS AND WARMER DAYTIME TEMPERATURES ARE IN STORE HEADING INTO THE WEEKEND.-- End Changed Discussion --&& .AVIATION...-- Changed Discussion --FOR THE 12Z PACKAGE...ANOTHER ROUND OF SHOWERS WILL BEGIN TO MOVE ACROSS ARIZONA FROM THE SOUTHWEST AFTER 14Z AS A LOW PRESSURE CENTER MOVES ACROSS NORTHWEST MEXICO. SHOWERS WILL BE MOST NUMEROUS SOUTH OF THE MOGOLLON RIM THROUGH 02Z THURSDAY. ONLY ISOLATED SHOWERS ARE EXPECTED NORTH OF THE RIM. EXPECT MVFR TO IFR CONDITIONS IN THE SHOWERS WITH SNOW LEVELS AROUND 4-5 KFT. PATCHY FOG WILL BE POSSIBLE AFTER 04Z THURSDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.-- End Changed Discussion --&& .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC.............TC AVIATION...........MCCOLLUM VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.
