Wind Advisory 9999, NWS Flagstaff, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
345 AM MST FRI JAN 11 2007

.SYNOPSIS...EXPECT GUSTY WINDS TO CONTINUE OVER MUCH OF THE AREA
TODAY AHEAD OF A STRONG AND COLD PACIFIC STORM SYSTEM. THIS SYSTEM
WILL BRING MUCH COLDER TEMPERATURES TODAY INTO THE WEEKEND ALONG
WITH SNOW AND LOW ELEVATION RAIN TO NORTHERN ARIZONA. EXPECT THE
COLDEST TEMPERATURES OF THE SEASON BY MONDAY MORNING.

&&

.DISCUSSION...VERY STRONG COLD FRONT IS MOVING THOUGH NEVADA AND
UTAH THIS MORNING. SNOW HAS BEEN FALLING AT THE RATE OF ABOUT 1/2
INCH AN HOUR IN CEDAR CITY JUST BEHIND THE FRONT. THE FRONT MOVED
THROUGH ST GEORGE AT ABOUT 930Z THIS MORNING. THERE IS WIND ADVISORY
FOR THE WESTERN MOGOLLON RIM AND THE KAIBAB PLATEAU THROUGH NOON
...MAINLY FOR THE DOWNSLOPE REGIONS WHERE GUSTS NEAR 55 MPH WILL BE
POSSIBLE. AS THE FRONT MOVES THROUGH...THE WIND ADVISORY WILL CHANGE
TO A SNOW AND BLOWING SNOW ADVISORY FOR MUCH OF THE AREA ABOVE 5500
FEET. ALSO A WIND ADVISORY IN EFFECT TODAY FOR MUCH OF THE LOWER
ELEVATION AREAS NORTH OF THE MOGOLLON RIM NOT ALREADY COVERED BY THE
SNOW AND BLOWING SNOW ADVISORY.

PREVIOUS DISCUSSION...
EXPECT SIGNIFICANT HGHT FALLS WITH THIS SYSTEM AND LARGE SCALE
ADIABATIC COOLING ALOFT. DIVQ FIELDS SHOW AN EXTENDED PERIOD OF
UPWARD FORCING ACROSS NRN AZ FROM THIS AFTERNOON UNTIL MID DAY
SATURDAY. OROGRAPHIC COMPONENT WILL ALSO BE VERY STRONG WITH 40-50
KNOTS OF WIND IN THE 850-500 MB LAYER. LAPSE RATES WILL BE FAIRLY
STABLE IN THE EARLY STAGES BUT WILL BECOME UNSTABLE LATER. MODELS
HAVE BEEN FAIRLY CONSISTENT DEPICTING A SHALLOW MOIST LAYER WITH
THIS SYSTEM. THIS WILL RESULT IN SATURATED LAYERS INITIALLY NOT
REACHING INTO THE -10 TO -20C REGION WHERE THE ICE AND SNOW GROWTH
PROCESS CAN BE ENHANCED. BY SATURDAY MORNING...A DEEP COLD POOL AND
SOME ENHANCEMENT OF THE BNDY LAYER MOISTURE WILL ALLOW THE SATURATED
LAYER TO EXTEND UPWARD INTO THIS FAVORED SNOW PRODUCTION REGION. THE
COMBINATION OF STRONG SYNOPTIC UPWARD MOTION...STRONG OROGRAPHICS...
AND FAVORABLE LAPSE RATES AND MOISTURE WILL RESULT IN MODERATE
SNOWFALL ACCUMULATIONS OVER THE HIGHER TERRAIN. THE LATEST GFS
FORECAST INDICATES A SIGNIFICANT FRONTOGENETICAL PRECIP BAND LOCATED
OVER WESTERN COCONINO AND NW YAVAPAI COUNTIES FOR MUCH OF THE DAY
FRIDAY. THIS WILL HAVE TO BE WATCHED AS A FOCUS FOR HEAVIER SNOW.
EARLIER SHIFT ISSUED A SNOW AND BLOWING SNOW ADVISORY FOR THE HIGHER
TERRAIN AREAS OF NORTHERN AZ FROM NOON FRIDAY THROUGH NOON SATURDAY.
NOT PLANNING ANY CHANGES TO THIS FOR NOW.

LONG TERM...VERY COLD AND DRY AIR WILL MOVE OVER THE STATE ON SUNDAY
LEADING TO THE COLDEST LOW TEMPERATURES OF THE SEASON BY MONDAY
MORNING. A DRY SHORT WAVE CLIPS THE NORTHERN PART OF THE STATE ON
MONDAY AND WILL REINFORCE THE COLD AIR. HIGH TEMPERATURES ABOVE 6000
FEET WILL LIKELY REMAIN IN THE 30S FOR MOST OF NEXT WEEK.

&&
.AVIATION...FOR THE 12Z PACKAGE...AN APPROACHING STORM SYSTEM WILL
BRING PROGRESSIVELY LOWER CEILINGS TO THE AREA THROUGH
18Z...ESPECIALLY OVER HIGHER TERRAIN AREAS. BY 18Z...AREAS OF IFR
AND MVFR CEILINGS WILL BE COMMON AT ELEVATIONS OVER 6 KFT MSL...WITH
HIGHER CEILINGS IN THE LOWER VALLEYS. AS LOW CEILINGS
DEVELOP...SCATTERED RAIN AND SNOW SHOWERS WILL ALSO DEVELOP...WITH
SNOW LEVELS INITIALLY NEAR 5500 FEET FALLING TO MOST VALLEY FLOOR
LOCATIONS BY 00Z SATURDAY. SOUTHWESTERLY WINDS WILL GENERALLY RANGE
FROM 15 TO 25 KTS FOR THE NEXT 24 HOURS...WITH AREAS OF MUCH
STRONGER WINDS NORTHEAST OF HIGHER PEAKS...AND IN THE LITTLE
COLORADO RIVER VALLEY AFTER 17Z TODAY. EXPECT WIDESPREAD MVFR TO IFR
CONDITIONS TO CONTINUE EARLY INTO SATURDAY MORNING EAST OF TWEB RTE
390. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL NOON MST FRIDAY FOR ZONES AZZ004-005-015.

SNOW AND BLOWING SNOW ADVISORY NOON FRIDAY THROUGH NOON SATURDAY FOR
ZONES AZZ004-006-008-011-015>017-039.

A WIND ADVISORY 1000 AM TO 600 PM ZONES 012>014-040

&&

MAS/TC

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
400 PM MST WED JAN 10 2007

AZZ004>018-037>040-110700-
WESTERN MOGOLLON RIM-GRAND CANYON COUNTRY-YAVAPAI COUNTY MOUNTAINS-
YAVAPAI COUNTY VALLEYS AND BASINS-OAK CREEK AND SYCAMORE CANYONS-
MARBLE AND GLEN CANYONS-KAIBAB PLATEAU-COCONINO PLATEAU-
NORTHEAST PLATEAU AND MESAS HWY 264 NORTHWARD-
NORTHEAST PLATEAU AND MESAS SOUTH OF HWY 264-
CHINLE VALLEY-CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
BLACK MESA AREA-LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY-
LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY-
EASTERN MOGOLLON RIM-WHITE MOUNTAINS-NORTHERN GILA COUNTY-
400 PM MST WED JAN 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO...NORTHERN
GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA.

.DAY ONE...TODAY

A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHEASTWARD ACROSS ARIZONA
OVERNIGHT. THE BEST CHANCES FOR PRECIPITATION WILL BE OVER THE
EASTERN MOGOLLON RIM AND WHITE MOUNTAINS TONIGHT AND EARLY THURSDAY.
ELSEWHERE...LITTLE OR NO PRECIPITATION IS EXPECTED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A DEEP LOW PRESSURE SYSTEM WILL BRING STRONG AND GUSTY SOUTHWEST
WINDS TO NORTHERN ARIZONA ON THURSDAY AND FRIDAY. SUSTAINED
SOUTHWESTERLY WINDS OF 15 TO 25 MPH WITH GUSTS UP TO 40 MPH ARE
POSSIBLE WITH THIS STORM SYSTEM.

IN ADDITION TO THE STRONG WINDS...THIS SYSTEM HAS THE POTENTIAL OF
PRODUCING MODERATE SNOWFALL ACCUMULATIONS. THE MOST FAVORABLE PERIOD
FOR ACCUMULATING SNOWFALL APPEARS TO BE FROM LATE FRIDAY THROUGH
EARLY SATURDAY. A SNOW ADVISORY OR WINTER STORM WATCH FOR PORTIONS
OF NORTHERN ARIZONA MAY BE REQUIRED.

MONITOR YOUR FAVORITE MEDIA SOURCE FOR UPDATES ON THIS DEVELOPING
WINTER WEATHER SITUATION. UPDATES ARE ALSO AVAILABLE ON THE WEB AT
WWW.WEATHER.GOV/FLAGSTAFF

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.