000
FXUS65 KFGZ 250312
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
812 PM MST THU APR 24 2014

.SYNOPSIS...EXPECT FAIR WEATHER TONIGHT. ON FRIDAY...WINDY
CONDITIONS WILL DEVELOP AS A STRONG LATE SEASON STORM SYSTEM
APPROACHES THE STATE. THE BULK OF THE STORM WILL MOVE THROUGH
NORTHERN ARIZONA ON SATURDAY WITH STRONG WINDS AND WIDESPREAD RAIN
AND SNOW. EXPECT CLEARING ON SUNDAY WITH FAIR AND WARMER WEATHER
THROUGH AT LEAST NEXT WEDNESDAY.

&&

.DISCUSSION...RELATIVELY WEAK PRESSURE GRADIENTS AND LIGHT
SOUTHWESTERLY FLOW WILL ALLOW FOR LIGHT AND VARIABLE WINDS AND
SEASONABLY COOL TEMPERATURES OVERNIGHT WHILE A PACIFIC STORM SYSTEM
APPROACHES FROM THE PACIFIC NORTHWEST. THIS WILL BRING STRONG
SOUTHWEST WINDS FRIDAY AND WIDESPREAD RAIN AND SNOW SATURDAY. THE
CURRENT FORECAST IS ON TRACK AND NO SHORT TERM UPDATES ARE NEEDED
THIS EVENING.

&&

.PREV DISCUSSION/338 PM MST/...FAIR AND WARM WEATHER IS AFFECTING
THE NORTHLAND THIS AFTERNOON AS A FLAT RIDGE OF HIGH PRESSURE MOVES
ACROSS THE REGION. A BROAD UPPER LEVEL LOW CAN BE SEEN MOVING INTO
THE PACIFIC NORTHWEST THIS AFTERNOON AND THIS WILL BE THE NEXT
WEATHER MAKER ACROSS NORTHERN ARIZONA. MODELS ARE IN GOOD AGREEMENT
THAT THIS TROUGH WILL DROP SOUTHWARD THROUGH CA ON FRIDAY AND THEN
HEAD EAST ACROSS NORTHERN AZ ON SATURDAY.

THE FIRST IMPACTS FROM THIS STORM WILL BE ON FRIDAY WHEN GUSTY
SOUTHWEST WINDS DEVELOP AS THE TROUGH APPROACHES. THE STRONGEST
WINDS ARE EXPECTED FROM THE WESTERN MOGOLLON RIM NORTH TO THE UT
BORDER WHERE A WIND ADVISORY IS IN EFFECT WITH WIND GUSTS REACHING 40
TO 45 MPH. SOME AREAS OF BLOWING DUST MAY DEVELOP ACROSS
NORTHEASTERN ARIZONA. ADDITIONALLY...DRY CONDITIONS WITH LOW
HUMIDITY WILL COMBINE WITH THE GUSTY WINDS TO PRODUCE CRITICAL
FIRE WEATHER CONDITIONS ACROSS NORTHEAST AZ AND A RED FLAG WARNING
IS IN EFFECT.

THE BULK OF THE PRECIPITATION WITH THIS EVENT WILL OCCUR WITH A
STRONG COLD FRONT PASSAGE ON SATURDAY. STRONG DYNAMIC LIFT WILL
COMBINE WITH A MODERATE PACIFIC MOISTURE TAP TO PRODUCE WIDESPREAD
RAIN AND HIGH ELEVATION SNOWFALL FOR A PERIOD SURROUNDING THE
FRONTAL PASSAGE. THE FRONT SHOULD MOVE INTO WESTERN AZ BY SUNRISE
SATURDAY...CENTRAL AZ BY 11 AM MST...AND WILL CLEAR THE NM BORDER BY
6 PM MST. TOTAL PRECIPITATION AMOUNTS LOOK TO BE IN THE 0.25 TO 0.50
INCH RANGE WITH LOCALLY HIGHER AMOUNTS. WEAK INSTABILITY MAY LEAD TO
A FEW THUNDERSTORMS AS WELL...AND WITH A STRONG VERTICAL SHEAR
PROFILE A SEVERE STORM CANNOT BE RULED OUT. SNOW LEVELS WILL FALL
RAPIDLY ALONG AND BEHIND THE FRONT. THE AREAS MOST LIKELY TO BE
AFFECTED BY ACCUMULATING SNOWFALL WILL BE THE MOGOLLON RIM...GRAND
CANYON RIM AND KAIBAB PLATEAU WHERE 2 TO 5 INCHES ARE POSSIBLE ABOVE
6000 FEET. THE COLD AIR BOTTOMS OUT OVER YAVAPAI COUNTY WHERE
ELEVATIONS DOWN TO 5500 FEET COULD SEE SOME SNOW MIXING IN WITH
RAIN. GIVEN THE FACT THAT SNOW BEGINS BEFORE DAYTIME HEATING...WE`RE
CONFIDENT IN ACCUMULATING SNOW FOR THE ABOVE MENTIONED AREAS BUT ARE
LESS CONFIDENT ACROSS THE HIGHER ELEVATIONS OF EASTERN AZ. DAYTIME
TEMPERATURES SHOULD RISE ENOUGH DURING THE DAY SATURDAY FOR SOME
MELTING TO OCCUR.

THIS IS A QUICK MOVING SYSTEM WITH SHOWERS DECREASING SATURDAY
EVENING AND COMING TO AN END OVERNIGHT. A DRIER MODERATE NORTHWEST
FLOW WILL DEVELOP THROUGH EARLY NEXT WEEK WITH TEMPERATURES
GRADUALLY RISING SUNDAY THROUGH TUESDAY. ANOTHER WEAK TROUGH MAY
SAG SOUTH INTO THE STATE MID TO LATE NEXT WEEK POTENTIALLY KEEPING
TEMPERATURES SLIGHTLY COOLER.

&&

.AVIATION...FOR THE 06Z PACKAGE...UNTIL 19Z...VFR CONDITIONS ARE
EXPECTED WITH OCCASIONAL UPPER LEVEL CLOUDINESS. WINDS LIGHT AND
VARIABLE. AFTER 19Z...ISOLD MVFR VISIBILITY IN BLOWING DUST IN THE
VALLEYS OF NORTHEAST AZ...OTHERWISE VFR CONDITIONS. WINDS SW
20-30G40KTS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FIRE WEATHER...
FRIDAY...AN APPROACHING PACIFIC LOW PRESSURE SYSTEM
WILL RESULT IN STRONG WINDS AND LOW RELATIVE HUMIDITY WITH PORTIONS
OF NORTHEAST ARIZONA REACHING CRITICAL FIRE WEATHER THRESHOLDS. A
RED FLAG WARNING IS IN EFFECT FOR NORTHEASTERN ARIZONA FOR FRIDAY.

SATURDAY...A LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE ACROSS
ARIZONA ON SATURDAY BRINGING WIDESPREAD RAIN...MOUNTAIN SNOW...AND
ISOLATED THUNDERSTORMS.

BREEZY NORTHERLY WINDS AND COOLER TEMPERATURES CAN BE EXPECTED ON
SUNDAY. MUCH WARMER TEMPERATURES CAN BE EXPECTED ON MONDAY AND
TUESDAY AS A RIDGE DEVELOPS OVER THE WEST.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

RED FLAG WARNING FROM NOON TO 8 PM MST FRIDAY FOR AZZ105-
109>114-139-140.

WIND ADVISORY FROM NOON TO 9 PM MST FRIDAY FOR AZZ004>007-
009>015-039-040.

&&

$$

PUBLIC.........DJO/MCS
AVIATION.......DJO
FIRE WEATHER...DB

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF