000
FXUS65 KFGZ 181642
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
942 AM MST FRI APR 18 2014

.SYNOPSIS...
A PASSING WEATHER SYSTEM WILL BRING MOSTLY CLOUDY SKIES...A CHANCE
OF SHOWERS AND A DROP IN TEMPERATURES TO NEAR NORMAL TODAY AND
SATURDAY. BEGINNING SUNDAY...TEMPERATURES WILL WARM BEFORE ANOTHER
PASSING WEATHER SYSTEM CAUSES A PERIOD OF STRONG GUSTY WINDS TUESDAY
AND WEDNESDAY.

&&

.DISCUSSION...
THE CURRENT FORECAST APPEARS TO BE ON TRACK. SATELLITE IMAGERY
INDICATES THE PRESENCE OF A WEAK LOW CURRENTLY MAKING LANDFALL IN
EXTREME SOUTHERN CALIFORNIA. THICK MID AND HIGH CLOUD COVER IS
STREAMING NORTHWARD AHEAD OF THIS SYSTEM AND HAS CAUSED MOSTLY
CLOUDY TO CLOUDY SKIES ACROSS NORTHERN ARIZONA. IN ADDITION...DEW
POINTS ACROSS SOUTHERN ARIZONA HAVE RISEN CONSIDERABLY OVER THE
LAST 24 HOURS. HIGH RESOLUTION MODELS INDICATE THAT THIS MOISTURE
WILL SLOWLY CREEP NORTHWARD THROUGHOUT THE DAY TODAY MOISTENING
THE BOUNDARY LAYER AND INCREASING THE CHANCES FOR PRECIPITATION.

&&

.PREVIOUS DISCUSSION /300 AM MST/...
A WEAK LOW PRESSURE SYSTEM WAS CENTERED JUST OFF THE SOUTHERN
CALIFORNIA COAST DURING THE MORNING HOURS...HEADING EASTWARD. FOR
TODAY AND SATURDAY THIS LOW WILL GRADUALLY MOVE ACROSS THE SOUTHWEST
UNITED STATES. SOUTHWEST FLOW AHEAD OF THE LOW WILL DRAW SOME
MOISTURE NORTHWARD ACROSS ARIZONA. THE DYNAMICS FOR UPWARD MOTION
WITH THIS SYSTEM ARE EXTREMELY WEAK. THE MAIN FORCING FOR ANY
PRECIPITATION WILL BE MOISTURE AND COOLER MID LEVEL TEMPERATURES IN
COMBINATION WITH DAYTIME HEATING. AS A RESULT...LOOK FOR THE BEST
CHANCE FOR SHOWERS DURING THE AFTERNOON AND EARLY EVENING BOTH DAYS.
IT WILL BE UNSTABLE ENOUGH FOR ISOLATED THUNDERSTORMS...ESPECIALLY
ON SATURDAY AS THE COOLEST MID LEVEL TEMPERATURES MOVE OVERHEAD.
PRECIPITATION AMOUNTS LOOK TO BE ON THE LIGHT SIDE.
OTHERWISE...COOLER DAYTIME TEMPERATURES UNDER MOSTLY CLOUDY SKIES
ARE IN ORDER.

SUNDAY AND MONDAY...EXPECT FAIR WEATHER AND MOSTLY SUNNY SKIES AS
A BRIEF PERIOD OF HIGH PRESSURE SETTLES IN OVER THE STATE.
HOWEVER...SOME LINGERING MOISTURE COUPLED WITH DAYTIME HEATING
WILL CAUSE A SLIGHT CHANCE FOR SHOWERS OVER HIGHER TERRAIN SUNDAY
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10
DEGREES ABOVE NORMAL.

TUESDAY ONWARD...MODELS ARE IN FAIR AGREEMENT IN ANOTHER WEATHER
SYSTEM MOVING ACROSS ARIZONA FROM TUESDAY AFTERNOON THROUGH
THURSDAY. THE MAIN IMPACT FROM THIS SYSTEM LOOKS TO BE A ROUND OF
STRONG SOUTHWEST WINDS. OTHERWISE...CURRENT MODEL SOLUTIONS SHOW
JUST A SLIGHT CHANCE OF SHOWERS AND WITH A COOLER AIR MASS...A
DROP TO NEAR NORMAL TEMPERATURES.

&&

.AVIATION...
FOR THE 18Z PACKAGE...CEILINGS WILL LOWER THROUGH THE
AFTERNOON HOURS...WITH CEILINGS IN THE 5-10 KFT RANGE ANTICIPATED TO
DEVELOP FROM SOUTH TO NORTH BETWEEN 21-03Z. BRIEF MVFR CONDITIONS IN
-SHRA WILL BE POSSIBLE IN THIS WINDOW. ISOLATED -TSRA MAY OCCUR AS
WELL. VFR CONDITIONS EXPECTED FROM 06Z-18Z SATURDAY WITH SOME LOW
VFR CEILINGS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FIRE WEATHER...
A PACIFIC LOW PRESSURE SYSTEM WILL BRING COOLER AND
UNSETTLED WEATHER TO NORTHERN ARIZONA TODAY AND SATURDAY. EXPECT
INCREASING CLOUD COVER THROUGHOUT THE DAY TODAY WITH SCATTERED LIGHT
SHOWERS DEVELOPING THIS AFTERNOON. BREEZY SOUTHERLY WINDS WILL ALSO
DEVELOP THIS AFTERNOON. THE CHANCE FOR SHOWERS WILL CONTINUE TONIGHT
WITH AN UPTICK IN ACTIVITY EXPECTED AGAIN SATURDAY AFTERNOON.
DAYTIME TEMPERATURES WILL BE VERY CLOSE TO NORMAL BOTH DAYS.

SUNDAY THROUGH TUESDAY...A SLIGHT CHANCE FOR A SHOWER WILL CONTINUE
OVER THE HIGH TERRAIN SUNDAY WITH OTHERWISE DRY AND WARMER WEATHER
RETURNING UNDER HIGH PRESSURE. A LOW PRESSURE TROUGH FORECAST TO
MOVE INTO THE WESTERN STATES EARLY NEXT WEEK WILL BRING STRONG AND
GUSTY WINDS ON TUESDAY WITH BREEZY TO WINDY CONDITIONS CONTINUING
THROUGH MIDWEEK. NO PRECIPITATION IS FORECAST WITH THE TROUGH AT
THIS TIME.

&&

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

&&

$$

PUBLIC.........RR/MCCOLLUM
AVIATION.......AT
FIRE WEATHER...AT

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF