000
FXUS65 KFGZ 101904
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1000 AM MST FRI OCT 10 2008
.SYNOPSIS...A STRONG STORM SYSTEM DEVELOPING OVER THE WESTERN GREAT
BASIN WILL BRING CONTINUED VERY WINDY CONDITIONS TO MUCH OF THE
REGION THROUGH SATURDAY. THE WINDIEST PERIOD WILL BE LATE THIS
EVENING INTO SATURDAY AFTERNOON...WHEN HIGH WINDS IN EXCESS OF 60
MILES PER HOUR ARE POSSIBLE. THIS STORM WILL ALSO BRING SHARPLY
COLDER TEMPERATURES...WITH A CHANCE OF RAIN AND SNOW ESPECIALLY EAST
OF FLAGSTAFF. COLD TEMPERATURES WILL REMAIN SUNDAY AND MONDAY...
BEFORE GRADUAL IMPROVEMENT FOR THE REMAINDER OF NEXT WEEK.
&&
.DISCUSSION...A STRONG AND COLD STORM SYSTEM WAS DIVING SOUTHWARD OVER
NEVADA AND CALIFORNIA THIS MORNING. THIS SYSTEM IS FORECAST TO CONTINUE
MOVING SOUTHWARD INTO SOUTHERN NEVADA TONIGHT...THEN NORTHEAST INTO
UTAH AND NORTHERN ARIZONA SATURDAY...BRINGING A MAJOR WIND EVENT TO
MANY AREAS. SOME FORECAST UPDATES HAVE BEEN SENT FOR TONIGHT...
MAINLY TO INCREASE WIND GUSTS. RAIN CHANCES WERE ALSO INCREASED FOR
THE AREA SE OF PAYSON TO ST JOHNS...AS MOISTURE IS PULLED NORTHWARD
AHEAD OF THE LOW. OTHERWISE...CURRENT FORECASTS ARE IN GOOD
SHAPE...AND DISCUSSED IN DETAIL BELOW.
.PREV DISCUSSION...(300 AM MST FRI OCT 10)...THE WINDIEST TIMES
APPEAR TO BE LATE TONIGHT INTO SATURDAY AFTERNOON. MODELS HAVE BEEN
VERY CONSISTENT WITH STRONG 700MB WINDS OF 50 TO 70 KNOTS ACROSS THE
NORTHLAND DURING THIS TIME FRAME. THIS WILL MORE THAN LIKELY LEAD TO
A MAJOR WIND EVENT ACROSS MUCH OF THE REGION AND A HIGH WIND WATCH
HAS BEEN ISSUED FOR ALL AREAS EXCEPT FOR YAVAPAI AND NORTHERN GILA
COUNTY. SUSTAINED WINDS OF 35 TO 45 MPH WITH GUSTS GREATER THAN 60
MPH IS ENTIRELY POSSIBLE LATE SATURDAY MORNING AND AFTERNOON. PEOPLE
LIVING IN THE HIGH WIND WATCH AREA SHOULD TAKE NECESSARY PRECAUTIONS
NOW BEFORE THE ONSET OF THIS MAJOR WIND EVENT.
AS FAR AS POPS GO...THERE IS STILL A POSSIBILITY THAT SIGNIFICANT
MOISTURE AHEAD OF HURRICANE NORBERT COULD BE TAPPED BY THIS TROUGH.
THE FARTHER EAST OF FLAGSTAFF...THE MORE LIKELY A SCENARIO THIS IS.
OUR CURRENT GRIDS HAVE THE HIGHEST POPS OVER THE WHITES...WITH SOME
COLD-POOL POPS NORTHWEST OF FLAGSTAFF SATURDAY AFTERNOON. THIS LOOKS
GOOD. THE EUROPEAN HAS BEEN THE MOST AGGRESSIVE WITH ITS QPF FIELD
HIGHER AND MORE WEST THAN THE OTHER SOLUTIONS...ALTHOUGH THE NAM IS
NOW SHOWING SIGNIFICANT AMOUNTS OVER THE WHITES AND EASTERN RIM.
HAVE THEREFORE ADJUSTED QPF AMOUNTS HIGHER OVER THE AFOREMENTIONED
AREAS. IT LOOKS AS IF THE SNOW LEVELS WILL REMAIN HIGH OVER THIS
AREA...AROUND 9000 FEET AND HIGHER...BUT WOULD NOT BE SURPRISED TO
SEE THE SNOW LEVELS LOWERED ANOTHER 500 FEET OR SO DUE TO
EVAPORATIVE COOLING.
THE SYSTEM WILL MOVE NORTH AND EAST OF THE FORECAST AREA DURING THE
DAY ON SUNDAY. THIS WILL HELP TO BRING THE WINDS DOWN TO A MORE
TOLERABLE LEVEL. A RETURN TO DRIER WEATHER IS EXPECTED TO RETURN FOR
THE BEGINNING OF NEXT WEEK WITH TEMPERATURES AROUND NORMAL.
&&
.AVIATION...FOR THE 18Z PACKAGE...A STRONG LOW PRESSURE SYSTEM WILL
BRING STRONG WINDS TODAY AND SATURDAY. EXPECT SOUTHWEST WINDS OF 25
TO 35 KTS WITH GUSTS REACHING 45 KTS DURING THE AFTERNOON. SOME
MOISTURE WILL MOVE NORTHWARD OVER FAR EASTERN ARIZONA WITH AN
INCREASING CHANCE OF SHOWERS WITH CEILINGS OF 1-3 KFT AGL BY
SATURDAY MORNING. ELSEWHERE VFR CONDITIONS ARE ANTICIPATED. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 11 PM MST TODAY FOR AZZ004>007-
009>017-039-040.
HIGH WIND WATCH FROM 11 PM THIS EVENING THROUGH SATURDAY EVENING FOR
AZZ004>007-009>017-039-040.
WIND ADVISORY FROM 7 AM TODAY TO 9 PM MST SATURDAY FOR
AZZ008-018-037-038.
&&
$$
PUBLIC.........JJ
AVIATION.......MAS
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.
