104
FXUS65 KTWC 212015
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
115 PM MST FRI NOV 21 2025
SYNOPSIS
AN ACTIVE PATTERN CONTINUES THROUGH THIS WEEKEND AS A
SECOND SYSTEM IS EXPECTED TO ARRIVE LATE TODAY THROUGH SUNDAY.
CHANCES FOR PRECIPITATION HOLD OFF FOR MUCH OF SOUTHEASTERN
ARIZONA UNTIL SATURDAY AFTERNOON AND EVENING, THOUGH SHOWERS MAY
BEGIN TO MOVE INTO WESTERN PIMA WESTERN TO CENTRAL PORTIONS OF
ARIZONA TODAY.
DISCUSSION
AS THE CUT-OFF LOW SITS OFF THE SOUTHERN COAST OF
CALIFORNIA, MOISTURE IS BEING PULLED INTO SOUTHERN ARIZONA
VISUALIZED BY THE OVERCAST SKIES. THIS CUT-OFF LOW IS CURRENTLY
BRINGING A DECENT AMOUNT OF RAIN TO FAR SOUTHWESTERN ARIZONA AND
SOUTHERN CALIFORNIA AND WILL VERY SLOWLY MAKE ITS WAY EASTWARD TO
OUR AREA. PRECIPITATION CHANCES START IN WESTERN PIMA COUNTY THIS
AFTERNOON BUT THEN BACKS OFF OVERNIGHT AS THE LOW OSCILLATES
SLIGHTLY TO THE WEST. CHANCES FOR PRECIPITATION TOMORROW BEGIN IN
FAR WESTERN PIMA COUNTY STARTING IN THE EARLY AFTERNOON AROUND
1100 TO 1200 MST EXPANDING EASTWARD BECOMING SCATTERED TO
WIDESPREAD BY 1500 TO 1600 MST. ISOLATED EMBEDDED THUNDERSTORMS
WILL ALSO BE POSSIBLE SATURDAY AFTERNOON. INITIALLY THE AIR MASS
WILL BE RELATIVELY WARM WITH HIGH TEMPERATURES ONLY A DEGREE OR
TWO BELOW NORMAL. SNOW LEVELS WILL BE AT OR JUST ABOVE MOUNTAIN
PEAKS THROUGH SATURDAY EVENING, THEN DROP TO 7500 FEET SATURDAY
NIGHT AS COOLER AIR MOVES IN. INITIALLY PRECIP WILL BE ALL RAIN,
TURNING TO SNOW ABOVE 7500 FEET SATURDAY NIGHT. MOST OF THE
PRECIPITATION WILL FALL SATURDAY AFTERNOON INTO THE EVENING WITH
RAIN AMOUNTS BETWEEN 0.1" TO 0.5" IN THE VALLEYS AND SNOW 1" TO 2"
ON MOUNT LEMMON AND 4" TO 6" ON MOUNT GRAHAM AND THE WHITE
MOUNTAINS. PRECIPITATION CHANCES DIMINISH FROM THE WEST TO EAST AS
THE LOW MOVES OUT OF THE AREA INTO COLORADO MID-DAY SUNDAY.
TEMPERATURES WITH THIS SYSTEM WILL COOL TO 7-10 DEGREES BELOW
NORMAL CONTINUING THROUGH MONDAY. FREEZING TEMPERATURES ARE LIKELY
FOR AREAS EAST OF TUCSON IN THE LOWER VALLEYS SATURDAY MORNING,
RETURNING AGAIN EACH MORNING STARTING MONDAY. HIGH TEMPERATURES
HOWEVER WARM TO AROUND NORMAL OR JUST ABOVE NORMAL THROUGH
THANKSGIVING AS WEAK RIDGING BUILDS IN BEHIND THE LOW. CONDITIONS
THROUGH THE UPCOMING WORK WEEK WILL BE DRIER THAN WE HAVE OBSERVED
THESE LAST SEVERAL DAYS.
AVIATION
VALID THROUGH 23/00Z.
BKN TO OVC SKIES AOA 15-25K FT AGL ACROSS THE AREA. CLOUDS WILL
BECOME LESS COVERED OVER KDUG, KOLS, AND KSAD BECOMING SCT TO BKN
BY 22/11Z. CLOUDS WILL INCREASE TO BKN TO OVC AGAIN BY 22/22Z AOA
15-20K FT AGL. SFC WINDS WILL GENERALLY BE FROM THE SOUTHEAST AT
5-10 KTS THROUGH 22/16Z INCREASING TO 10-15 KTS GUSTING 20-25 KTS
AT KTUS, KSAD, AND KDUG AND UP TO 30 KTS AT KOLS. PRECIPITATION
CHANCES BEGIN AROUND 22/20Z STARTING IN KTUS EXPANDING EAST
THROUGHOUT THE AFTERNOON INTO THE EVENING. THERE IS A SLIGHT
CHANCE FOR EMBEDDED THUNDERSTORMS BETWEEN 22/21Z THROUGH THE
FORECAST PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
FIRE WEATHER
BELOW NORMAL TEMPERATURES CONTINUE THROUGH THE
WEEKEND WITH MINIMUM RELATIVE HUMIDITIES ABOVE 30 PERCENT. THE
SECOND SYSTEM ARRIVES LATE FRIDAY THROUGH SATURDAY BRINGING
ANOTHER ROUND OF SHOWERS AND HIGH ELEVATION MOUNTAIN SNOW. CHANCES
FOR SHOWERS REMAIN WEST OF TUCSON THROUGH SATURDAY MORNING, THEN
SPREAD EAST SATURDAY AFTERNOON AND EVENING LINGERING SUNDAY.
TEMPERATURES BELOW NORMAL SUNDAY AND MONDAY THEN RISE TO NEAR
NORMAL BY THE MIDDLE OF NEXT WEEK.
TWC WATCHES/WARNINGS/ADVISORIES
NONE.
MALARKEY
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