FXUS65 KFGZ 290401
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST SAT NOV 28 2009
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL IMPACT NORTHERN ARIZONA
THROUGH MONDAY WITH AREAS OF MOUNTAIN SNOW AND VALLEY RAIN...COLDER
TEMPERATURES...AND BREEZY WINDS. THIS STORM WILL MOVE SOUTHEAST OF
ARIZONA BY TUESDAY...WITH DRY AND SEASONAL TEMPERATURES EXPECTED FOR
THE REST OF THE WEEK.
&&
.DISCUSSION...THE SLOW MOVING LOW PRESSURE CURRENTLY CENTERED OVER
SOUTHERN CALIFORNIA WILL CONTINUE TO MOVE SOUTHEASTWARD ACROSS
SOUTHWESTERN ARIZONA INTO MEXICO THIS EVENING...BRINGING MOUNTAIN
SNOW AND VALLEY RAIN TO NORTHERN ARIZONA. AT 945 PM NATIONAL WEATHER
SERVICE DOPPLER RADAR SHOWED AND AREA OF RAIN AND SNOW SHOWERS
CENTERED OVER NORTH CENTRAL ARIZONA. PRECIPITATION IS EXPECTED TO
CONTINUE ACROSS NORTHERN ARIZONA THROUGH SUNDAY.
&&
.PREVIOUS DISCUSSION...315 PM...A SLOW MOVING STORM SYSTEM LOCATED
OVER SOUTHERN NEVADA WILL SWEEP ACROSS ARIZONA TONIGHT AND TOMORROW
FROM NORTHWEST THROUGH SOUTHEAST...PRODUCING MOUNTAIN SNOW AND
VALLEY RAIN. THE LATEST SATELLITE AND RADAR IMAGERY SHOWS SEVERAL
UNSTABLE SHOWER BANDS DEVELOPING ACROSS THE REGION. THESE SHOWER
BANDS ARE INCREASING IN BOTH COVERAGE AND INTENSITY. ISOLATED
THUNDERSTORM ACTIVITY IS ALSO OCCURRING NEAR PAGE AND WINDOW
ROCK...EXPECT ISOLATED THUNDERSTORM ACTIVITY TO CONTINUE ACROSS
NORTHERN ARIZONA UNTIL AROUND SUNSET.
THE WINTER STORM IN SOUTHERN NEVADA WILL SLOWLY MOVE SOUTH ACROSS
WESTERN ARIZONA THIS AFTERNOON AND EVENING WITH ENOUGH DYNAMICS AND
OROGRAPHIC LIFT TO PRODUCE WIDESPREAD RAIN AND SNOW SHOWERS ACROSS
THE NORTHLAND. THE SNOW LEVEL WILL GRADUALLY DECREASE FROM AROUND
7000 TO 8000 FEET THIS AFTERNOON TO 6000 TO 7000 FEET BY SUNDAY
MORNING. RAIN AND SNOW SHOWERS WILL CONTINUE TO SPREAD ACROSS THE
REGION OVERNIGHT PRODUCING 2 TO 8 INCHES OF SNOWFALL ACCUMULATION
ABOVE THE 6000 FOOT ELEVATION LEVEL BY NOON ON SUNDAY. A WINTER
WEATHER ADVISORY WAS ISSUED FOR SIGNIFICANT SNOWFALL ACCUMULATIONS
OF 4 TO 8 INCHES OVER THE KAIBAB PLATEAU...THE WHITE
MOUNTAINS...NORTHEAST PLATEAUS... BLACK MESA AND THE CHUSKA
MOUNTAINS...SEE PRODUCT WSWFGZ FOR DETAILS.
SUNDAY AFTERNOON THROUGH MONDAY...BY SUNDAY AFTERNOON THE STORM
SYSTEM WILL BE CUT OFF FROM THE POLAR FRONT JET AND WILL BE
POSITIONED OVER THE NORTHERN GULF OF CALIFORNIA. FORECAST MODELS
SHOW THE LOW PRESSURE SYSTEM WILL MOVE EASTWARD AWAY FROM ARIZONA.
WE EXPECT RAIN AND SNOW SHOWER ACTIVITY TO DIMINISH FROM SUNDAY
AFTERNOON THROUGH MONDAY. THE BEST CHANCES FOR PRECIPITATION DURING
THIS PERIOD WILL BE IN THE WHITE MOUNTAINS REGION WITH A 30 TO 50
PERCENT CHANCE FOR LIGHT SNOW SHOWERS LINGERING THROUGH MONDAY
AFTERNOON. COLD AND BREEZY NORTHEASTERLIES ARE FORECAST AS A HIGH
PRESSURE RIDGE BEGINS TO BUILD IN BEHIND THE EXITING STORM SYSTEM.
TUESDAY THROUGH FRIDAY...ANOTHER BREAK IN THE WEATHER PATTERN IS
FORECAST FOR THE WORK WEEK AS A WEAK HIGH PRESSURE RIDGE BUILDS
IN ACROSS THE WESTERN UNITED STATES. EXPECT A DRYING TREND THROUGH
THE MIDDLE OF NEXT WEEK WITH TEMPERATURES REMAINING SLIGHTLY BELOW
NORMAL THROUGH WEDNESDAY. WINDS WILL BE LIGHT THROUGH THURSDAY WITH
BREEZY SOUTHWESTERLIES POSSIBLE BY FRIDAY AFTERNOON. NO ADDITIONAL
PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
&&
.AVIATION...FOR THE 06Z PACKAGE...BKN-OVC CIGS FROM 3K-5K FT AGL
WITH SCT-NMRS SHRA/SHSN...WILL CONTINUE TO DEVELOP ALONG THE
MOGOLLON RIM AND WHITE MTS AND INCREASE IN COVERAGE THIS EVENING.
AREAS MVFR AND ISOLD IFR ARE POSSIBLE THROUGH SUNDAY AFTERNOON
SHOWER ACTIVITY SHOULD TAPER OFF 18Z. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.................CLARK/MCCOLLUM
AVIATION...............CLARK
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.
