FXUS65 KTWC 102101
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
215 PM MST THU DEC 10 2009

.SYNOPSIS...A SERIES OF WEAK DISTURBANCES IN THE WESTERLY FLOW ALOFT 
WILL BRING PERIODS OF HIGH CLOUDS TO SOUTHEAST ARIZONA WITH A FEW 
SPRINKLES POSSIBLE FRIDAY AND SATURDAY. THE LAST DISTURBANCE IN THIS 
SERIES WILL BRING A FEW SHOWERS MAINLY NEAR THE MOUNTAINS SUNDAY 
NIGHT. A RIDGE OF HIGH PRESSURE WILL BRING A WARMING TREND NEXT 
WEEK.

&&

.DISCUSSION...WESTERLY FLOW ALOFT WITH TROUGH STILL DOMINATING MOST 
OF COUNTRY DOWNSTREAM. EXPECT PATCHES OF MID AND HIGH CLOUD 
FILTERING IN FROM DIRTY WEST COAST RIDGE FROM TIME TO TIME. FIRST IN 
A SERIES OF IMPULSES COMING ONSHORE INTO SOUTHERN CALIFORNIA. COULD 
BRING A FEW SPRINKLES NEAR MOUNTAINS TOMORROW. ANOTHER WEAKNESS IN 
THE FLOW PUSHES QUICKLY THROUGH SATURDAY WITH THE MAIN SYSTEM COMING 
THROUGH THE AREA FROM THE WEST LATE SUNDAY INTO MONDAY. NOT MUCH 
MOISTURE OR DYNAMICS THIS FAR SOUTH...AND THIS SYSTEM IS NOT NEARLY 
AS COLD AS THE LAST STORM. SHOULD SEE A FEW SHOWERS AROUND BUT MOST 
OF THE WEATHER WILL BE NORTH OF OUR AREA. NOT REALLY MUCH COLD AIR 
INVOLVED AND WINDS WILL NOT BE A FACTOR.

BROAD LONG PERIOD RIDGE PHASING IN NEXT WEEK...BUT ACTUAL HEIGHT AND 
THICKNESS VALUES NOT THAT HIGH...TEMPERATURES RECOVERING TO 3 OR 5 
DEGREES ABOVE CLIMO. PROBABLY ON THE DIRTY SIDE WITH PATCHES OF MID 
AND HIGH CLOUD AT TIMES.

&&

.AVIATION...MOSTLY CLEAR THIS EVENING WITH INCREASING MID AND HIGH 
CLOUD LATE TONIGHT INTO SATURDAY AS A WEAK DISTURBANCE MOVES ACROSS 
THE AREA. WILL ALSO SEE A FEW CUMULUS CLOUDS AROUND 7-9KFT AGL. 
NORMAL DIURNAL WIND TRENDS DURING THE NEXT 24 HOURS. AVIATION 
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

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

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

$$

WEATHER.GOV/TUCSON