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000
FXUS65 KFGZ 230350
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 PM MST WED MAY 22 2013

.SYNOPSIS...
A BROAD LOW PRESSURE SYSTEM WILL SETTLE OVER THE PACIFIC NORTHWEST
THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY SOUTHWEST
WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA.

&&

.DISCUSSION...
RED FLAG WARNINGS FOR WEDNESDAY VERIFIED WELL WITH SURFACE OBSERVATIONS.
WIND SPEEDS HAVE FALLEN BELOW THE CRITICAL FIRE WEATHER THRESHOLDS
THIS EVENING AND THE WARNINGS FOR TONIGHT HAVE EXPIRED. STRONGER
WINDS AND CRITICAL FIRE WEATHER CONDITIONS WILL RETURN TOMORROW BY
MID MORNING AS A SHORT WAVE TROUGH MOVES THROUGH THE GREAT BASIN. A
RED FLAG WARNING AND WIND ADVISORY ARE IN EFFECT FOR THURSDAY OVER
MUCH OF NORTHERN ARIZONA.

LOOKING AT THE LARGER SCALE PRESSURE PATTERN THROUGH MEMORIAL
DAY...A BROAD LOW PRESSURE SYSTEM WILL REMAIN IN PLACE OVER THE
PACIFIC NORTHWEST AND A HIGH PRESSURE RIDGE WILL PERSIST OVER THE
GREAT PLAINS REGION. THIS WEATHER PATTERN WILL PRODUCE A WARM AND
DRY WEATHER CONDITIONS OVER NORTHERN ARIZONA WITH PERIODS OF GUSTY
WINDS. THE LATEST MODEL PROJECTIONS ARE IN GOOD AGREEMENT THAT THE
PACIFIC NORTHWEST LOW WILL WEAKEN SLIGHTLY FROM THURSDAY TO FRIDAY.
THIS PRESSURE CHANGE WILL WEAKEN THE SURFACE PRESSURE GRADIENTS IN
ARIZONA AND REDUCE OUR WIND SPEEDS. THESE LOWER WIND SPEEDS MAY BE
ENOUGH TO KEEP MOST AREAS JUST BELOW RED FLAG CONDITIONS FROM FRIDAY
ONWARD. HOWEVER...WE WILL NEED TO CLOSELY MONITOR THE WEATHER
SITUATION THROUGH THE WEEKEND AS SUBTLE CHANGES IN THE UPPER LEVEL
PATTERN COULD INCREASE OUR WIND SPEEDS ABOVE RED FLAG THRESHOLDS.

&&

.AVIATION...
FOR THE 06Z PACKAGE...VFR FOR MOST FOR THE NEXT 24 HOURS. AFT 16Z
THU...WINDS SOUTHWEST 15-30 KTS GUSTS TO 40 KTS...AREAS OF BLDU
POSSIBLE ACROSS NAVAJO AND APACHE COUNTIES. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

.FIRE WEATHER...
A BROAD TROUGH OF LOW PRESSURE WILL SETTLE OVER THE WESTERN STATES
THROUGH SUNDAY...BRINGING WARM AND DRY SOUTHWEST FLOW ACROSS
ARIZONA.

THE RED FLAG WARNING REMAINS IN EFFECT FOR THURSDAY FOR MUCH OF
NORTHERN ARIZONA. CONDITIONS SHOULD IMPROVE TONIGHT AS RELATIVE
HUMIDITY INCREASES AND WINDS DECREASE. SOME LOCATIONS DOWNWIND OF
HIGHER TERRAIN MAY EXPERIENCE BREEZY OVERNIGHT WINDS. ON THURSDAY
...VERY LOW RELATIVE HUMIDITY AND STRONG WINDS WILL GET AN EARLIER
START ACROSS MUCH OF NORTHERN ARIZONA AND THURSDAY RED FLAG
WARNING START TIME WAS ADVANCED TO 10 AM MST.

FRIDAY THROUGH SUNDAY...SOUTHWEST FLOW WILL CONTINUE BUT SLOW WITH
TIME. THE LATEST FORECAST DATA INDICATE A CHANCE FOR CRITICAL FIRE
WEATHER CONDITIONS ON FRIDAY FOR MAINLY NAVAJO AND APACHE COUNTIES.
BORDERLINE CONDITIONS ARE EXPECTED ACROSS THE NORTHLAND SATURDAY
AND SUNDAY AFTERNOONS.


&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

RED FLAG WARNING FROM 10 AM TO 8 PM MST
THURSDAY FOR AZZ104>117-137>140.

WIND ADVISORY FROM 10 AM TO 8 PM MST THURSDAY FOR
AZZ004>007-009>017-039-040.

&&

$$

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

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF