FXUS65 KTWC 080416
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
910 PM PM MST MON DEC 7 2009

.SYNOPSIS...A STRONG WINTER STORM WILL BRING HIGH WINDS AND 
WIDESPREAD VALLEY RAIN AND SIGNIFICANT MOUNTAIN SNOW TO SOUTHEAST 
ARIZONA TONIGHT INTO MIDDAY TUESDAY. DRIER CONDITIONS WEDNESDAY 
FOLLOWED BY ANOTHER CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW THURSDAY 
INTO FRIDAY.

&&

.DISCUSSION...RADAR AND SATELLITE IMAGERY WERE INDICATING THAT THE 
FIRST ROUND OF VALLEY SHOWERS WAS ENDING ACROSS MOST OF SOUTHEAST 
ARIZONA. THE STRONG UPSLOPE FLOW ON THE OTHER HAND WILL CONTINUE TO 
PRODUCE PERIODS OF MOUNTAIN RAIN AND SNOW MOST OF THE NIGHT. THE 
SNOW LEVEL LATE THIS EVENING WAS STILL ABOVE 6000 FEET. SNOTEL DATA 
AT HANNAGAN MEADOW INDICATED THAT UP TO 9 INCHES HAD ALREADY FALLEN 
TODAY...AND NEARBY BEAVER HEAD WAS REPORTING 7 INCHES SO FAR. BASED 
ON THIS INFORMATION...HAVE UPDATED THE GRIDDED SNOW AMOUNT PRODUCT 
TO INDICATE HIGHER STORM TOTAL AMOUNTS FOR MAINLY MOUNT GRAHAM AND 
THE WHITE MOUNTAINS. PLEASE REFER TO THE NDFD GRIDS ON THE WEBSITE 
OR THE WEATHER STORY GRAPHICS LINKED ON THE MAIN PAGE OF 
WEATHER.GOV/TUCSON. 

OTHERWISE...THE MAIN STORY THIS EVENING HAS BEEN THE STRONG WIND. 
SOUTH TO SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS TO 40 MPH HAVE 
BEEN COMMON ACROSS THE AREA. WINDS WERE EVEN STRONGER ACROSS FAR 
WESTERN ARIZONA WHERE YUMA WAS REPORTING GUSTS TO 50 MPH. LATEST GFS 
MODEL SHOWED A SPEED MAX OF 60 KNOTS AT 850 MPH MOVING INTO THE 
SOUTHWEST DESERTS OF ARIZONA LATE THIS EVENING. THE GFS SHIFTS THIS 
SPEED MAX EASTWARD OVER SOUTHEAST ARIZONA AROUND MIDNIGHT TONIGHT. 
THE CURRENT WIND ADVISORY WILL COVER THESE STRONG WINDS...BUT PARTS 
OF COCHISE COUNTY ESPECIALLY AREAS ON THE EASTERN SLOPES OF NORTH TO 
SOUTH ORIENTED MOUNTAIN RANGES LIKE SIERRA VISTA COULD SEE GUSTS 
APPROACHING 60 MPH. FOR NOW...WILL MONITOR THINGS FOR A POSSIBLE 
HIGH WIND WARNING FOR THAT AREA. 

THE NEXT ROUND OF VALLEY SHOWERS SHOULD ARRIVE ACROSS WESTERN PIMA 
COUNTY BY 11 PM MST...THEN SPREAD EASTWARD WITH THE REST OF THE CWA 
SEEING VALLEY RAIN AFTER 1 AM MST THROUGH DAYLIGHT TUESDAY MORNING. 
THE CURRENT WINTER STORM WARNING AND BLIZZARD WARNING STILL LOOKED 
ON TRACK. 

PLEASE REFER TO THE ADDITIONAL SECTIONS BELOW AND THE VARIOUS WINTER 
WEATHER BULLETINS FOR MORE INFORMATION ON THIS WINTER STORM.  

&&

.AVIATION...CLOUD DECKS GENERALLY AROUND 4-7K FT AGL THROUGH 18Z 
TUESDAY. SCT -SHRA MAINLY NW KTUS THRU 00Z...THEN WIDESPREAD MVFR 
CONDITIONS DUE TO SHRA/HIGHER TERRAIN SHSN DURING THE 00Z-18Z PERIOD 
TUESDAY. SURFACE WINDS SWLY/WLY 15-30 KTS WITH GUSTS OF 30-45 KTS. 
CONDITIONS IMPROVING WITH DECREASING CLOUDS/PRECIP AND LESS WIND 
DURING THE 18Z-23Z PERIOD TUESDAY. AVIATION DISCUSSION NOT UPDATED 
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STRONG STORM SYSTEM WILL BRING WIDESPREAD VALLEY 
RAIN AND MOUNTAIN SNOW ESPECIALLY TONIGHT THROUGH MIDDAY TUESDAY. 
WINDY CONDITIONS WILL ALSO ACCOMPANY THIS SYSTEM. DRIER CONDITIONS 
WILL OCCUR WEDNESDAY. ENOUGH MOISTURE FOR A CHANCE OF RAIN AND 
MOUNTAIN SNOW THURSDAY INTO SATURDAY AS A SERIES OF DISTURBANCES 
MOVE ACROSS THE AREA. BREEZY TO OCCASIONALLY WINDY CONDITIONS MAY 
ALSO ACCOMPANY THESE SYSTEMS.

&&

.PREV DISCUSSION...SHORTWAVE RIDGE ALONG THE CALIFORNIA COAST WED 
WILL FLATTEN AND MOVE EWD ACROSS THE AREA WED NIGHT. DRY CONDITIONS 
WED AND WED NIGHT THOUGH RIDGE TO BE FAIRLY DIRTY WITH MID AND 
HIGH-LEVEL MOISTURE TO MOVE ACROSS THE AREA. THEREAFTER...A SERIES 
OF DISTURBANCES PROGGED TO MOVE MAINLY ACROSS THE GREAT BASIN REGION 
THUR INTO THE WEEKEND. ENOUGH MOISTURE TO SUPPORT A SLIGHT CHANCE OF 
VALLEY RAIN AND MOUNTAIN SNOW SHOWERS NE OF TUCSON THRU THIS 
PERIOD...WITH A SLIGHT CHANCE OF RAIN/MOUNTAIN SNOW SHOWERS TUCSON 
METRO AREA THUR-FRI.

DAYTIME HIGH TEMPS TUE ABOUT 10 DEGS OR SO BELOW NORMAL. WARMER WED 
WITH HIGH TEMPS THUR-MON TRENDING EITHER CLOSE TO NORMAL OR A FEW 
DEGS BELOW NORMAL.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
  BLIZZARD WARNING IN EFFECT THIS EVENING TO NOON MST TUESDAY 
   ABOVE 8000 FEET FOR AZZ019-030.

  WINTER STORM WARNING IN EFFECT THIS EVENING TO NOON MST TUESDAY    
   BETWEEN 6000 AND 8000 FEET FOR AZZ019-030.

  WINTER STORM WARNING IN EFFECT THIS EVENING TO NOON MST TUESDAY    
   ABOVE 6000 FEET FOR AZZ033>035.
  
  WIND ADVISORY IN EFFECT TIL NOON MST TUESDAY FOR ZONES             
   019-030-033>035.

  WIND ADVISORY IN EFFECT TIL 5 AM MST TUESDAY FOR ZONES 
   029-031-032.

$$

WEATHER.GOV/TUCSON