000 
FXUS65 KFGZ 152151 CCA
AFDFLG

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST TUE JAN 15 2002

.SYNOPSIS...CLOUDS WILL CONTINUE TO THICKEN AND LOWER ACROSS 
NORTHERN ARIZONA TONIGHT...AS MID TO HIGH LEVEL MOISTURE MOVES INTO
THE SOUTHWESTERN UNITED STATES FROM THE EASTERN PACIFIC AHEAD OF AN
APPROACHING TROUGH OF LOW PRESSURE. IN ADDITION...EXPECT SCATTERED
SHOWERS TO DEVELOP TONIGHT...ESPECIALLY OVER THE HIGHER TERRAIN. THE
TROUGH WILL SWING ACROSS ARIZONA WEDNESDAY AFTERNOON AND EVENING 
...BRINGING AREAS OF VALLEY RAIN AND SNOW SHOWERS WITH COLDER
DAYTIME HIGH TEMPERATURES FOR WEDNESDAY AND THURSDAY. THE TROUGH
WILL LINGER OVER THE SOUTHWESTERN UNITED STATES THROUGH THE
WEEKEND...BRINGING COOLER TEMPERATURES AND A CONTINUATION THE
UNSETTLED WEATHER CONDITIONS.

.DISCUSSION...SAT IR IMAGERY INDICATED A BREAK IN CLOUDS OVER THE
LCR VALLEY IN AN AREA OF DOWNSLOPE FLOW LEE OF THE MOGOLLON RIM.
THIS ALLOWED BOUNDARY LAYER TO MIX OUT OVER THE LCR VALLEY WITH
DECENT SW FLOW REPORTED AT THE SFC. WINDS REPORTS FROM THE LCR
VALLEY HAVE  REMAINED BELOW ADV CRITERIA THOUGH. MAIN FCST FOCUS FOR
THE SHORT TERM WILL BE APPROACHING WEATHER SYSTEM AND ASSOCIATED MID
AND UPPER LEVEL SUB-TROPICAL MOISTURE TO AFFECT THE CWA OVER THE
NEXT 24 TO 36 HOURS. HAVE NOT SEEN TOO MUCH CHANGE IN CLOUD DECKS OR
LOW LEVEL MOISTURE TODAY...BUT AS MID AND UPPER LEVEL DYNAMICS OF
APPROACHING TROUGH BEGINS TO AFFECT THE AREA...WE SHOULD START TO
SEE A CHANGE TAKE PLACE TONIGHT AND WEDNESDAY. EXPECT PRECIP
DEVELOPMENT TO BE A FAIRLY SLOW PROCESS...WITH A GRADUAL MOISTENING
OF THE MID AND LOW LEVELS OF THE ATMOSPHERE...WITH LITTLE LOW LEVEL
CONVECTIVE SUPPORT. THUS...PRECIP AMOUNTS WILL BE ON THE RELATIVELY
LIGHT SIDE. CURRENT AVN QPF LOOK PRETTY REASONABLE...MAYBE SLIGHTLY
ON THE LOW SIDE. WILL FINE TUNE SNOW ACCUMULATIONS WITH THE AFT
PACKAGE...WITH SLIGHTLY HIGHER AMOUNTS IN PLACE FOR THE WHITES AND
EASTERN RIM...AND LIGHTER AMOUNTS IN THE DONWSLOPE VALLEY LOCATIONS.
FOR THE EXTENDED PD...MEAN LONG-WAVE TROUGH TO SET UP OVER THE SW US.
SEVERAL WAVES WERE NOTED IN EXTENDED PROGS TO PASS OVER THE SW US...
BUT THESE FOLLOWING A FAIRLY DRY TRAJECTORY OVER THE INTERMOUNTAIN
REGION...AND MAY BE WRUNG OUT BEFORE THEY REACH THE AREA. WILL KEEP
GENERALLY P/C THROUGH THE EXTENDED PD. 

.FGZ...NONE

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES LO/HI           PROBABILITY OF PRECIP
                 TON WED   THU     FRI        TON WED   THU     FRI
FLAGSTAFF        025/036 016/038 015/035      030 060 020 000 000 000
WINSLOW          031/047 024/045 023/042      030 040 020 000 000 000
PRESCOTT         031/044 025/044 024/041      020 050 030 000 000 000
PAGE             033/041 026/039 025/036      030 050 030 000 000 000
WINDOW ROCK      024/034 024/047 023/044      000 050 030 020 000 000
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                  TEMPERATURES LO/HI
                  TON WED     THU       FRI
CANYON DE CHELLY  031/036   031/049   030/046
COTTONWOOD        037/052   031/052   030/049
GRAND CANYON      027/038   018/040   017/037
GREER             024/037   015/039   014/036
HEBER             026/043   017/045   016/042
JACOB LAKE        026/034   017/036   016/033
NAVAJO N.M.       031/041   031/044   030/041
PAYSON            033/046   027/046   026/043
SEDONA            038/049   032/049   031/046
SELIGMAN          025/044   019/044   018/041
SHOW LOW          030/042   021/044   020/041
ST. JOHNS         030/048   023/046   022/043
WUPATKI N.M.      036/049   029/047   028/044