Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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FXUS65 KFGZ 010429
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 PM MST FRI OCT 31 2014

.SYNOPSIS...ON SATURDAY...WINDY AND COLDER WEATHER WILL DEVELOP AS
A COLD FRONT MOVES THROUGH ARIZONA. THIS SYSTEM WILL BRING A FEW
RAIN SHOWERS TO HIGHER ELEVATIONS ON SATURDAY. BETTER CHANCES FOR
RAIN AND SNOW ARRIVE LATE SATURDAY NIGHT THROUGH SUNDAY EVENING.
SNOW LEVELS WILL FALL BELOW 7000 FEET BY SUNDAY AFTERNOON. DRY
WEATHER RETURNS BY TUESDAY...AS WELL AS A SLOW WARMING TREND.

&&

.DISCUSSION...A STRONG TROUGH OF LOW PRESSURE IS PUSHING ON THE WEST
COAST THIS EVENING. THIS WILL CONTINUE MOVING EASTWARD AND WILL
IMPACT NORTHERN ARIZONA INTO MONDAY. A BAND OF MID TO HIGH LEVEL
CLOUDS IS PUSHING ACROSS ARIZONA FROM THE WEST THIS EVENING. LOWER
LEVEL MOISTURE IS MOVING ACROSS EASTERN ARIZONA THIS EVENING WHERE A
FEW LIGHT SHOWERS ARE DEVELOPING OVER EASTERN GILA COUNTY AND
SOUTHERN  NAVAJO COUNTY. WILL SENT OUT AN UPDATE FOR TIMING OF CLOUDS
THIS EVENING. OTHERWISE...THE FORECAST IS IN GOOD SHAPE.

&&

.PREV DISCUSSION /410 PM MST/...A DEEP AND COLD TROUGH CENTERED
ALONG 132W WILL MOVE ONSHORE TONIGHT AND WILL AFFECT OUR AREA
THROUGH THE WEEKEND. SOME DEEPER SUB-TROPICAL MOISTURE AHEAD OF THE
TROUGH HAS MOVED INTO FAR EASTERN ARIZONA...WHERE A FEW SHOWERS AND
THUNDERSTORMS WILL PERSIST INTO THE EVENING.

ASIDE FROM THAT...THE MAIN EFFECTS FROM THIS SYSTEM WILL AT FIRST
BE WIND. SOUTHWEST FLOW CONTINUES STRENGTHENING TONIGHT AND THEN
STAYS STRONG THROUGH SATURDAY. FLOW WILL THEN DECREASE FROM WEST TO
EAST ON SUNDAY. SFC WINDS INTO THE EVENING WILL STAY BELOW WIND
ADVISORY CRITERIA...WITH THE EXCEPTION OF A SOME LEE SIDE LOCATIONS
LATER TONIGHT. MANY AREAS ON SATURDAY WILL HAVE GUSTS IN EXCESS OF
40MPH...AND A WIND ADVISORY HAS BEEN ISSUED.

IN ADDITION TO THE WIND...HIGHER PW VALUES TO OUR SOUTH FROM A
DECAYING TROPICAL SYSTEM WILL BE IMPORTED NORTHWARD AS THE TROUGH
APPROACHES. SOME MID-LEVEL CLOUD FORMATION IS LIKELY ON SATURDAY AND
A FEW SHOWERS MAY REACH THE SURFACE AT THE HIGHER ELEVATIONS. BY
LATER SATURDAY NIGHT AND SUNDAY...FRONTAL DYNAMICS AND COLDER AIR
MOVE INTO THE STATE AND SOME LIGHT TO MODERATE QPF WILL DEVELOP AS A
RESULT. THE BEST CHANCE SEEMS TO BE THROUGH THE I-17 CORRIDOR AND
WESTWARD. SNOW LEVELS WITH THIS FRONT WILL REACH BELOW 7000 FEET AND
THE FIRST SNOW OF THE SEASON IS PROBABLE FROM FLAGSTAFF WEST. THE
FRONT WILL PUSH EAST SUNDAY AFTERNOON...WITH DRYING FLOW AND RIDGING
DEVELOPING AS WE HEAD INTO NEXT WEEK.

&&

.AVIATION...FOR THE 12Z PACKAGE...A FEW -SHRA/-TSRA WILL CONTINUE TO
BE POSSIBLE EAST OF A KPAN-KE91 LINE TONIGHT. ISOLD TO WDLY SCT
-SHRA SATURDAY...MAINLY WEST OF A KPAN-KPGA LINE 14Z-06Z WITH GUSTY
SOUTHWEST WINDS. THERE MAY BE AREAS OF MVFR CEILINGS OVER THE HIGH
TERRAIN AS WELL. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

WIND ADVISORY FROM 11 AM TO 6 PM MST SATURDAY FOR AZ PUBLIC ZONES
004-006-007-009-011>017-039-040.

&&

$$

PUBLIC.....MAS/PETERSON
AVIATION...MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






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