FXUS65 KTWC 092050
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST WED DEC 9 2009

.SYNOPSIS...WESTERLY FLOW ALOFT WILL BRING QUIET WEATHER TO 
SOUTHEAST ARIZONA. EXPECT PATCHES OF HIGH CLOUDS FROM TIME TO 
TIME...WITH A SERIES OF WEAK DISTURBANCES BRINGING A SLIGHT CHANCE 
OF SHOWERS NEAR THE MOUNTAINS THURSDAY EVENING THROUGH SATURDAY. A 
STRONGER WEATHER SYSTEM WILL BRING A BETTER CHANCE OF VALLEY RAIN 
AND MOUNTAIN SNOW SHOWERS LATE SUNDAY AND SUNDAY NIGHT.

&&

.DISCUSSION...DRYING CONTINUES IN MID AND UPPER LEVELS WITH A PATCH 
OF CLOUD NOW EAST OF US. BRISK WESTERLY FLOW UNDER EXITING LARGE 
SCALE MEAN BROAD BASED TROUGH ACROSS MUCH OF THE UNITED STATES. MAIN 
ENERGY AND MOISTURE NOW PUSHING THROUGH THE MID WEST AND EASTERN 
STATES. SOME HEIGHT AND THICKNESS RECOVERY IN A LITTLE DRIER 
NORTHWESTERLY FLOW ON THE FRONT SIDE OF A WEAK DIRTY RIDGE NEAR THE 
COAST OVER THE NEXT COUPLE OF DAYS. SOME COLD NIGHTS...BUT 
TEMPERATURES CLIMBING BACK TO NEAR CLIMO. WEAKNESSES EMBEDDED IN THE 
FLOW COULD BRING SOME VIRGA AND LIGHT MOUNTAIN SHOWERS LATER IN THE 
WEEK.

A SYSTEM PUSHING IN FROM THE PACIFIC IS EXPECTED TO BRING A CHANCE 
OF VALLEY RAIN AND MOUNTAIN SNOW LATE SATURDAY INTO EARLY MONDAY. AS 
IT STANDS NOW THIS ONE DOESN'T LOOK LIKE IT WILL HAVE NEARLY ENERGY 
OR COLD PUNCH OF OUR MOST RECENT SYSTEM.

&&

.AVIATION...SCATTERED CLOUDS UNDER FLAT ZONAL FLOW ALOFT. NORMAL 
DIURNAL WIND TRENDS...10 TO 15 KTS THIS AFTERNOON DIMINISHING 
OVERNIGHT. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...NO FIRE WEATHER CONCERNS AT THIS TIME.
 
&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE. 

$$

WEATHER.GOV/TUCSON