FXUS65 KTWC 090352
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
852 PM MST TUE DEC 8 2009

.SYNOPSIS...DRIER WESTERLY FLOW ALOFT WILL MOVE IN FOR THE NEXT DAY 
OR SO WITH DRY CONDITIONS. BY LATE THIS WEEK...A SOMEWHAT MOIST 
PACIFIC FLOW WILL RETURN TO THE AREA WITH A CHANCE OF VALLEY RAIN 
AND MOUNTAIN SNOW SHOWERS AS EARLY AS THURSDAY BUT MORE LIKELY 
FRIDAY INTO THIS WEEKEND. 

&&

.DISCUSSION...WATER VAPOR IMAGERY SHOWS THE UPPER LOW THAT BROUGHT 
THE WIND...RAIN AND MOUNTAIN SNOW TO OUR AREA YESTERDAY EVENING AS 
WELL AS THIS MORNING...IS NOW OVER THE CENTRAL PLAINS/UPPER MIDWEST. 

THE WINDS HAVE DIMINISHED ACROSS MOST OF MY FORECAST AREA WITH THE 
EXCEPTION OF THE DOUGLAS AREA WHERE WINDS ARE STILL SUSTAINED AT 17 
MPH WITH GUSTS TO 24 MPH VIA THE LATEST BISBEE-DOUGLAS AIRPORT 
SURFACE OBSERVATION. EVEN SO...THE WINDS SHOULD GRADUALLY DIMINISH 
THERE AS WELL AS THE LOW CONTINUES TO MOVE AWAY AND WEAK RIDGING 
BUILDS IN FROM THE WEST. 

TEMPERATURES SEEM TO BE ON TRACK FOR A CHILLY NIGHT ACROSS SOUTHEAST 
ARIZONA WITH THE PASSAGE OF THE SYSTEM AND LACK OF CLOUDS...WITH THE 
EXCEPTION OF A FEW HIGH CIRRUS CLOUDS FROM TIME TO TIME. 

&&

.AVIATION...SCT HIGH LEVEL CLOUDS MAINLY ABOVE 15K FT AGL WILL MOVE 
INTO THE REGION OVERNIGHT AND DURING THE DAY WEDNESDAY. WINDS 
GENERALLY LIGHT AND DIURNAL IN NATURE TONIGHT...THEN BECOMING WEST 
TO SOUTHWEST AT 10 TO 15 KTS DURING THE AFTERNOON HOURS ON 
WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

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

&&

.PREV DISCUSSION...BRIEF FLAT RIDGING MOVES IN FOR A TRANQUIL 
WEDNESDAY WITH SOME MID AND HIGH LEVEL CIRRUS CLOUDS DRIFTING 
THROUGH THE AREA. DAYTIME TEMPERATURES WILL BE ABOUT 5 DEGREES BELOW 
NORMAL. THEN THE PACIFIC JET BECOMES MORE ACTIVE AS A WELL 
ESTABLISHED ZONAL AND MOIST WESTERLY FLOW ESTABLISHES ITSELF ACROSS 
THE DESERT SOUTHWEST. LATEST MODEL GUIDANCE FIELDS INDICATE SLIGHT 
CHANCES OF PRECIPITATION THURSDAY MAINLY ACROSS THE HIGHER TERRAIN 
WITH THE FIRST DISTURBANCE FOLLOWED BY A SOMEWHAT BETTER CHANCE OF 
PRECIPITATION FRIDAY AS DEEPER MOISTURE ESTABLISHES ITSELF AND 
ANOTHER DISTURBANCE MOVES THROUGH. THE ACTIVE PATTERN CONTINUES THIS 
WEEKEND WITH THE GFS/ECMWF A BIT MORE AMPLIFIED BY SUNDAY INTO 
MONDAY WITH PERHAPS ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW THEN. 
BEST COURSE OF ACTION IS TO MORE OR LESS MAINTAIN SLIGHT CHANCE TO 
LOWER END CHANCE POPS THROUGH THE WEEKEND UNTIL WE GET A BETTER 
HANDLE ON TIMING ISSUES ETC.  

&&

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

$$

MOLLERE

WEATHER.GOV/TUCSON