High Wind in Arizona, September 30, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST WED SEP 30 2009

COR ELEVATION OF 48 KT OBSERVED WIND IN DISCUSSION.

.SYNOPSIS...EXPECT STRONG WINDS ACROSS MUCH OF NORTHERN ARIZONA
TODAY AS A COLD FRONT MOVES ACROSS THE STATE. DAYTIME TEMPERATURES
WILL BE 10 TO 15 DEGREES COOLER THROUGH THURSDAY. A HARD FREEZE WILL
BE POSSIBLE ABOVE 6000 FEET FRIDAY MORNING. ANOTHER LOW PRESSURE
SYSTEM WILL BRING WINDY CONDITIONS AND COOL TEMPERATURES THIS
WEEKEND.

&&

.DISCUSSION...
AT 9 AM...SURFACE OBSERVATIONS FROM MANY SITES IN NORTHERN ARIZONA
INDICATE SOUTHWEST WIND GUSTS FROM 35 TO 50 MPH. THIS MORNINGS
SOUNDINGS SHOWED 48 KNOTS OF WIND AT 9000 FT MSL AND 57 KNOTS AT
12000 FT MSL. TODAYS HIGH WIND WARNING AND WIND ADVISORIES LOOK GOOD
AS DO THE RED FLAG WARNINGS. NO UPDATES NEEDED AT THIS TIME.

PREV DISCUSSION...330 AM MST...A STORM SYSTEM WILL MOVE THROUGH THE
GREAT BASIN TODAY...PUSHING A COLD FRONT INTO NORTHERN ARIZONA.
STRONG WINDS WILL CONTINUE ALONG AND AHEAD OF THE FRONT...WITH THE
STRONGEST WINDS THIS MORNING FOR CENTRAL AND WESTERN
ARIZONA...SPREADING INTO EASTERN ARIZONA LATER IN THE DAY. A HIGH
WIND WARNING HAS BEEN ISSUED FOR EASTERN ARIZONA WHERE GUSTS MAY
REACH 60 MPH. BLOWING DUST IS EXPECTED OVER THE VALLEYS OF NORTHEAST
ARIZONA...INCLUDING THE WINSLOW AND KAYENTA AREAS. THE SYSTEM HAS
ALSO TAPPED ENOUGH MOISTURE FOR SCATTERED SHOWERS AND A FEW
THUNDERSTORMS ACROSS CENTRAL ARIZONA AND THESE WILL SPREAD EASTWARD
DURING THE DAY. MUCH DRIER AIR WILL MOVE IN BY AFTERNOON WITH MANY
AREAS SEEING CRITICAL FIRE WEATHER CONDITIONS.

THE OTHER MAIN WEATHER STORY WILL BE MUCH COOLER AIRMASS MOVING INTO
THE AREA BEHIND THE TROUGH. HIGHS TODAY WILL BE ABOUT 10 DEGREES
COOLER THAN TUESDAY...AND EVEN COOLER YET ON THURSDAY WITH HIGHS UP
TO 15 DEGREES COOLER THAN TUESDAY. LOW TEMPERATURES THURSDAY MORNING
WILL APPROACH FREEZING FOR MOST LOCATIONS ABOVE 7000 FEET...AND A
HARD FREEZE APPEARS LIKELY FRIDAY MORNING DOWN TO THE 6000 FOOT
LEVEL. A FREEZE WARNING MAY BE REQUIRED FOR SOME OF OUR HIGHER
ELEVATION ZONES.

AFTER ANOTHER COLD START SATURDAY MORNING...TEMPS WILL MODERATE
CLOSE TO NORMAL FOR HIGHS SATURDAY AFTERNOON. ANOTHER TROUGH IS
FORECAST TO DROP ACROSS THE GREAT BASIN THIS WEEKEND...RESULTING
IN BREEZY CONDITIONS AND A CHANCE OF RAIN SATURDAY INTO EARLY NEXT
WEEK.

&&

.AVIATION...FOR THE 18Z PACKAGE...EXPECT STRONG SOUTHWEST WINDS 20
TO 30 KTS WITH GUSTS TO 40 KTS ACROSS THE FORECAST AREA...AND
UP TO 50 KTS FROM THE LITTLE COLORADO RIVER VALLEY
NORTHEASTWARD WHERE BLOWING DUST MAY LOCALLY LIMIT VISIBILITIES.
ISOLATED SHOWERS AND CIGS...BKN070-090...WILL PERSIST ALONG AND
SOUTH OF THE EASTERN MOGOLLON RIM AND WHITE MOUNTAINS THROUGH THE
AFTERNOON...OTHERWISE MOSTLY CLEAR SKIES AND VFR CONDITIONS
EXPECTED. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 5 PM MST
TODAY FOR AZ ZONES 010-011-013-014-039-040.

WIND ADVISORY IN EFFECT UNTIL 5 PM MST WEDNESDAY FOR AZ ZONES
004>007-009-012-015>017.

RED FLAG WARNING WEDNESDAY FROM 11 AM UNTIL 6 PM MST FOR FIRE
WEATHER ZONES 105>108-137-138.

RED FLAG WARNING WEDNESDAY FROM 11 AM UNTIL 8 PM MST FOR FIRE
WEATHER ZONES 109>114-139-140.

&&

PUBLIC.....DL
AVIATION...BAK

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
519 AM MST WED SEP 30 2009

AZZ004>018-037>040-010000-
KAIBAB PLATEAU-MARBLE AND GLEN CANYONS-GRAND CANYON COUNTRY-
COCONINO PLATEAU-YAVAPAI COUNTY MOUNTAINS-
NORTHEAST PLATEAUS AND MESAS HWY 264 NORTHWARD-CHINLE VALLEY-
CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY-
LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY-
WESTERN MOGOLLON RIM-EASTERN MOGOLLON RIM-WHITE MOUNTAINS-
NORTHERN GILA COUNTY-YAVAPAI COUNTY VALLEYS AND BASINS-
OAK CREEK AND SYCAMORE CANYONS-BLACK MESA AREA-
NORTHEAST PLATEAUS AND MESAS SOUTH OF HWY 264-
519 AM MST WED SEP 30 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
ARIZONA...NORTH CENTRAL ARIZONA...NORTHEAST ARIZONA AND WEST
CENTRAL ARIZONA.

.DAY ONE...TODAY AND TONIGHT

AN APPROACHING STORM SYSTEM WILL BRING STRONG SOUTHWEST WINDS TO
PORTIONS OF NORTHERN ARIZONA TODAY. A HIGH WIND WARNING IS IN
EFFECT FOR EAST CENTRAL AND NORTHEAST ARIZONA WHERE GUSTS NEAR
60 MPH ARE EXPECTED. AREAS OF BLOWING DUST MAY ALSO AFFECT TRAVEL
IN THESE AREAS. A WIND ADVISORY IS IN EFFECT FOR MUCH OF THE
REMAINDER OF CENTRAL AND NORTHERN ARIZONA. MUCH DRIER AIR WILL
MOVE IN LATER TODAY AND A RED FLAG WARNING HAS ALSO BEEN ISSUED
FOR MUCH OF THE AREA...SEE THE RED FLAG WARNING FOR DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE FIRST HARD FREEZE OF THE SEASON WILL BE POSSIBLE FOR MANY
LOCATIONS ABOVE 5500 FEET THURSDAY NIGHT INTO FRIDAY MORNING.