
AFDFLG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
325 PM MST WED NOV 05 2003
.SYNOPSIS...A TROUGH OF LOW PRESSURE WILL REMAIN OVER THE WESTERN
HALF OF THE UNITED STATES THROUGH THE WEEKEND. EXPECT OCCASIONAL
HIGH CLOUDS...LIGHT WINDS...AND SEASONABLE DAYTIME TEMPERATURES
THROUGH FRIDAY. A WEATHER DISTURBANCE WILL BRING INCREASING
CLOUDINESS ALONG WITH SHOWERS...AND BREEZY WINDS TO MUCH OF NORTHERN
ARIZONA ON SATURDAY AND SUNDAY.
&&
.DISCUSSION...HIGH CLOUDS ARE STREAMING ONTO THE CALIFORNIA COAST
THIS AFTERNOON...THIS MOISTURE WILL MOVE ACROSS NORTHERN ARIZONA
OVERNIGHT BRINGING INCREASING HIGH CLOUDS. CLOUDS THICKEN ON
THURSDAY AS MORE UPPER LEVEL MOISTURE INCREASES OVER THE AREA. A
WEAK WARM FRONT MOVES OVER THE AREA THURSDAY NIGHT INTO FRIDAY
MORNING...EXPECTING MAINLY VIRGA FROM THIS AS IT MOVES ACROSS THE
AREA...THAT IS THE REASON FOR THE 10 % CHCS OF PRECIP NORTHERN
ZONES. ANOTHER WEAK WARM FRONT FRIDAY NIGHT INTO SATURDAY
MORNING...WITH ADDITIONAL LIGHT VIRGA AND MOISTENING FROM THE TOP
DOWN. BECOMING WINDY ON SATURDAY AS THE PRESSURE GRADIENT INCREASES
IN RESPONSE TO THE LOW COMING ON SHORE AND MOVING INTO NORTHERN
NEVADA. MAY BE LOOKING AT WIND ADVISORY WINDS EAST OF THE MOGOLLON
RIM SATURDAY AFTERNOON. MAIN DYNAMIC LIFT MOVES ACROSS NORTHWEST
QUARTER OF THE STATE ALONG WITH A MODERATE COLD FRONT. OROGRAPHICS
WILL BE WEAK TO MODERATE FROM THE SOUTHWEST.
TEMPERATURE FORECAST WILL BE INTERESTING FOR THE LOWER VALLEY AREAS
IN NORTHERN ARIZONA. WITH CLOUD COVER THURSDAY AND FRIDAY ALONG WITH
LIGHT WINDS...THE LOWER VALLEY AREAS MAY NOT MIX OUT AND STAY
RELATIVELY COOL.
FOR SUNDAY...ZONAL FLOW FOLLOWS IN THE WAKE OF SATURDAY'S STORM
SYSTEM...WITH A LOT OF MID-LEVEL TO UPPER LEVEL CLOUD DEBRIS.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE AROUND THE MONDAY TIME
FRAME. THE 12Z GFS IS BEGINNING TO LOOK MORE LIKE THE ECMWF FROM A
DAY AGO WITH ANOTHER CLOSE LOW ACROSS NORTHERN SECTIONS OF
CALIFORNIA. LAST NIGHTS GFS-00Z HAS A MORE PROGRESSIVE WAVE MOVING
THROUGH ARIZONA ON MONDAY. WE WILL TAKE THE MIDDLE OF THE
ROAD...THINKING THAT A PIECE OF THIS SYSTEM WILL BREAK OFF AND MOVE
ACROSS THE AREA ON MONDAY. WE WILL USE CHCS POPS TO COVER THIS...AS
DYNAMICS WILL BE WEAKER THAN ADVERTISED BY THE GFS-00Z FROM LAST
NIGHT.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
TC
Dennis
