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000
FXUS65 KFGZ 180436
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 PM MST FRI MAY 17 2013

.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL CONTINUE TO MOVE ACROSS
ARIZONA THROUGH SATURDAY EVENING. THIS WILL KEEP US IN BREEZY TO
LOCALLY WINDY CONDITIONS WITH A SLIGHT CHANCE FOR SHOWERS OR
THUNDERSTORMS THROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR
SEASONAL NORMALS THROUGH THE WEEKEND BEFORE WARMING UP AGAIN NEXT
WEEK.

&&
.DISCUSSION...
THE MAIN LOW PRESSURE TROUGH IS CURRENTLY MOVING THROUGH EASTERN
ARIZONA THIS EVENING. PRESSURE GRADIENTS BEHIND THE TROUGH WILL
LESSEN...RESULTING IN LOWER WIND SPEEDS ON SATURDAY. A SECOND WEAKER
TROUGH CAN BE SEEN ON INFRARED SATELLITE IMAGERY JUST WEST OF THE
KAIBAB PLATEAU. THIS SECOND TROUGH WILL MOVE THROUGH THE UTAH BORDER
REGION THIS EVENING...ENHANCING CLOUD COVER AND BRINGING THE
SLIGHTEST CHANCES FOR A LIGHT SHOWER OR TWO ALONG AND NORTH OF A
LINE FROM THE GRAND CANYON TO WINDOW ROCK.

ON SUNDAY...MODELS SHOW A THIRD TROUGH MOVING THROUGH THE FOUR
CORNERS REGION. BREEZY SOUTHWEST TO WESTERLY WINDS ARE FORECAST WITH
A DRIER TREND STARTING ON SUNDAY.

MONDAY AND TUESDAY...THE TROUGH AXIS WILL MOVE INTO NEW MEXICO ON
MONDAY AND A WEAK HIGH PRESSURE RIDGE WILL SET UP OVER ARIZONA
THROUGH MID WEEK. EXPECT LIGHT TO BREEZY WINDS WITH CONTINUED DRY
CONDITIONS.

WEDNESDAY THROUGH FRIDAY...ANOTHER LARGE PACIFIC LOW WILL MOVE INTO
THE PACIFIC NORTHWEST ON WEDNESDAY. WIND SPEEDS WILL TREND UPWARD
APPROACHING CRITICAL FIRE WEATHER THRESHOLDS FOR THE SECOND HALF OF
NEXT WEEK.  MUCH WILL DEPEND ON THE MOVEMENT OF THIS NEXT LOW
PRESSURE SYSTEM. THE LATEST FORECAST SHOWS DRY HUMIDITY LEVELS WITH
WIND SPEEDS JUST BELOW OUR CRITICAL THRESHOLDS. WATCH FOR UPDATES IN
THE EXTENDED FORECAST PERIOD FROM WEDNESDAY ONWARD.

&&

.AVIATION...FOR THE 06Z PACKAGE...VFR CONDITIONS FOR THE NEXT 24
HOURS. BKN-OVC CLOUDS WILL INCREASE ACROSS EASTERN AZ THROUGH
MIDNIGHT WHILE CLEARING ACROSS WESTERN AZ. BASES OCCASIONALLY AS LOW
AS 12KFT MSL NORTH OF I-40. AFT 18Z SAT...SCT-BKN CUMULUS WITH BASES
AOA 14 KFT MSL ACROSS THE HIGHER TERRAIN AND ISOLATED HIGH BASED
THUNDERSTORMS NORTH OF I-40. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.

&&

.FIRE WEATHER...
COLD AIR ALOFT WILL MOVE INTO NORTHERN ARIZONA ON SATURDAY. EXPECT A
SLIGHT CHANCE OF HIGH BASED THUNDERSTORMS NORTH OF A LINE FROM SUPAI
TO FLAGSTAFF TO LUPTON. PORTIONS OF SOUTHERN APACHE COUNTY MAY
APPROACH CRITICAL FIRE WEATHER CRITERIA ON SATURDAY AFTERNOON...
ELSEWHERE WIND SPEEDS WILL BE LOWER THAN FRIDAY.

MONDAY THROUGH WEDNESDAY...EXPECT A GRADUAL WARMING TREND WITH LOW
AFTERNOON HUMIDITIES. CRITICAL FIRE WEATHER CONDITIONS ARE NOT
EXPECTED THROUGH TUESDAY....BUT MAY APPROACH CRITERIA ON WEDNESDAY
IN THE LITTLE COLORADO RIVER VALLEY.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........BOHLIN
AVIATION.......DL
FIRE WEATHER...BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF