851
FXUS65 KTWC 161036
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
336 AM MST SUN NOV 16 2025
SYNOPSIS
AN ACTIVE WEATHER PATTERN IS IN STORE FOR SOUTHEAST
ARIZONA OVER THE NEXT WEEK AS A SERIES OF LOW PRESSURE SYSTEMS
MOVE ACROSS THE REGION. THESE SYSTEMS WILL BRING COOLER TEMPERATURES,
A CHANCE OF PRECIPITATION AND BREEZY WINDS AT TIMES. AFTERNOON
TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL TODAY, WITH ANOTHER
PUSH OF COLD AIR RESULTING IN AFTERNOON TEMPERATURES 10 TO 13
DEGREES BELOW NORMAL BY THE MIDDLE OF NEXT WEEK.
DISCUSSION
THE UPPER PATTERN THIS MORNING IS DEFINED BY A STRONG
CUTOFF-LOW BEGINING TO EJECT NNE THROUGH THE SOUTHERN CALIFORNIA
BIGHT AND ITS KICKER TROUGH, CURRENTLY OFF THE COAST OF BRITISH
COLUMBIA, MOVING SE. THE LATEST GOES PRECIPITABLE WATER IMAGERY
INDICATED A SHRINKING SUBTROPICAL MOISTURE PLUME (BETWEEN 1.15-1.25
INCHES PWAT) ALONG THE SOUTHEAST PERIPHERY OF THE CUTOFF-LOW, EXTENDING
UP THE GULF OF CALIFORNIA AND INTO CENTRAL ARIZONA, WHERE A MAXIMA
OF PWAT NEAR 1.50 INCHES RESIDES.
THE BULK OF THE LIFT/FORCING ASSOCIATED WITH THIS EJECTING FEATURE
WILL CONTINUE TO REMAIN ACROSS SOUTHERN CALIFORNIA AND THE NW
HALF OF ARIZONA. THE UPPER TROUGH AXIS AND ASSOCIATED LOWER-LEVEL
COLD FRONT WILL TRACK ACROSS SW ARIZONA INTO CENTRAL ARIZONA
DURING THE DAY TODAY. MARGINAL MOISTURE CONVERGENCE ALONG THE
FRONTAL BOUNDARY THIS MORNING, WITH THE LATEST SATELLITE IMAGERY
INDICATING SOME ENHANCEMENT OF CLOUDS ACROSS WESTERN PIMA COUNTY
EARLY THIS MORNING, WITH A BAND OF SHOWERS EXTENDING NORTHWARD ACROSS
WESTERN MARICOPA COUNTY. THE MOST RECENT HRRR RUN SUGGESTS THAT
THIS BAND OF SHOWERS WILL EXPAND ALONG THE COLD FRONT OVER
CENTRAL PIMA COUNTY BEFORE DAYBREAK, SLOWLY MAKE ITS WAY ENE TO
THE TUCSON METRO AREA BY 9-11 AM, AND TO SAFFORD BY 1-3 PM.
RAINFALL AMOUNTS WILL GENERALLY BE LIGHT, WITH THE VALLEYS
EXPECTED TO RECEIVE BETWEEN A FEW HUNDREDTHS OF AN INCH UP TO A
TENTH INCH, AND 0.15-0.40 INCHES IN THE HIGHER TERRAIN/MOUNTAINS.
PRECIPITATION WILL FALL AS RAIN AS SNOW LEVELS WILL BE AROUND 10K
FEET DURING THE DAY, BUT A MIX OF RAIN/SNOW MAY BE POSSIBLE ON
THE MOUNTAIN TOPS AS THE COLDER AIR FILTERS INTO THE AREA BEHIND
THE FRONT AND SNOW LEVELS DROP TO NEAR 9000 FEET THIS AFTERNOON.
THIS SYSTEM WILL DEPART SOUTHEAST ARIZONA THIS EVENING, LEAVING
CHILLY TEMPERATURES IN ITS WAKE MONDAY MORNING. THE COMBINATION OF
THE COOLER AIRMASS, LIGHT WINDS AND CLEARING SKIES WILL RESULT IN
SOME POCKETS OF FOG IN THE EASTERN VALLEYS OF COCHISE COUNTY
MONDAY MORNING, ESPECIALLY THE SULPHUR SPRINGS VALLEY AND SOUTHERN
PORTIONS OF THE SAN PEDRO RIVER VALLEY.
OTHERWISE, THE UPSTREAM TROUGH RESPONSIBLE FOR EJECTING THE CUTOFF-
LOW WILL EVENTUALLY TAKE UP RESIDENCE IN THE WAKE OF ITS PREDECESSOR
IN THE MEAN TROUGH TO OUR WEST. THERE IS SOME VARIANCE WITH THE
ENSEMBLE MEMBERS ON THE LOCATION OF THE UPPER LOW TUESDAY
AFTERNOON NEAR SOUTHERN CALIFORNIA. THE LOCATION OF THIS FEATURE
MAY NOT BE THAT IMPORTANT AS THE UPPER LOW IS PROGGED TO PIVOT
WITH A MORE NEUTRAL ORIENTATION, WHICH IS MORE SUSCEPTIBLE TO
SWING EAST THROUGH OUR NECK OF THE WOODS WEDNESDAY. THE ONLY
CONCERN I HAVE IS IF THIS FEATURE CONTINUES TO MOVE FARTHER SOUTH
DURING THE PIVOT, THIS WOULD PUSH THE BEST DYNAMICS ACROSS
NORTHERN SONORA MEXICO. IN ANY EVENT, THIS SYSTEM WILL BE COLDER,
WITH A BETTER CHANCE FOR VALLEY RAIN AND MOUNTAIN SNOW ABOVE 7000
FEET. AS MENTIONED IN THE PREVIOUS FORECAST DISCUSSION, HIGH
TEMPERATURES WILL LOWER TO 10-13 DEGREES BELOW NORMAL ON
WEDNESDAY, WITH HIGHS IN THE LOWER TO MID 60S FROM TUCSON WESTWARD
AND IN THE MID 50S TO AROUND 60 DEGREES IN THE LOWER ELEVATIONS
OF SANTA CRUZ, COCHISE, GRAHAM AND GREENLEE COUNTIES. BREEZY WINDS
ARE ALSO EXPECTED TUESDAY AND WEDNESDAY, ESPECIALLY TO THE
EAST/SOUTHEAST OF TUCSON, WITH SOUTH-SOUTHWEST WINDS OF 15-20 MPH
AND GUSTS TO AROUND 30 MPH. COLDER MORNING LOW TEMPERATURES ARE
FORECASTED BEHIND THE SYSTEM THURSDAY AND FRIDAY MORNINGS AND MORE
WIDESPREAD FREEZING LOW TEMPERATURES ARE LIKELY OVER PORTIONS OF
EASTERN SANTA CRUZ, SOUTHWEST GRAHAM AND PORTIONS OF COCHISE
COUNTIES. OVERALL, MINOR TO MODERATE IMPACTS ARE EXPECTED WITH
THIS NEXT SYSTEM.
AVIATION
VALID THROUGH 17/12Z. SCT-BKN CLOUDS AT 7K-10K FT AGL
AREAWIDE WITH ISOLD-SCT -SHRA AND A SLIGHT CHANCE OF -TSRA THRU
17/00Z, THEN CLOUD COVER TAPERING OFF OVERNIGHT. SFC WIND LESS
THAN 10 KTS AND VARIABLE IN DIRECTION THROUGH 16/16Z, INCREASING
TO SLY/SWLY SFC WIND WITH SPEEDS OF 15-20 KTS AND GUSTS TO 25-30
KTS BY 16/19Z, PERSISTING THRU 17/03Z, THEN SFC WIND LESS THAN 10
KTS AND VARIABLE IN DIRECTION OVERNIGHT. PATCHY FOG MAY DEVELOP
ACROSS THE SULPHUR SPRINGS VALLEY AND SOUTHERN SAN PEDRO RIVER
VALLEY MONDAY MORNING RESULTING IN LOCALIZED VSBY 1-3SM BR,
POTENTIALLY IMPACTING KDUG, KFHU AND KALK. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
A STORM SYSTEM WILL MOVE ACROSS THE AREA TODAY,
WITH SHOWERS SPREADING FROM WEST TO EAST ACROSS SOUTHEAST ARIZONA
DURING THE DAY. THIS SYSTEM WILL ALSO BRING A SLIGHT CHANCE OF
THUNDERSTORMS AND COOLER TEMPERATURES. BREEZY SOUTHWEST WINDS OF
15-25 MPH WITH GUSTS TO 30-35 MPH ARE EXPECTED. ANOTHER SYSTEM IS
THEN EXPECTED TO MOVE INTO THE AREA TUESDAY AND ESPECIALLY WEDNESDAY
OF NEXT WEEK. THIS SYSTEM WILL BRING ANOTHER ROUND OF PRECIPITATION
ACROSS SOUTHEAST ARIZONA, WELL BELOW NORMAL TEMPERATURES AND BREEZY
SOUTH TO SOUTHWEST WINDS. RH VALUES WILL BE ON THE INCREASE, WITH
MIN RH VALUES WELL ABOVE CRITICAL LEVELS OVER THE NEXT WEEK (30-40
PERCENT IN THE VALLEYS AND 50-60+ PERCENT IN THE MOUNTAINS).
TWC WATCHES/WARNINGS/ADVISORIES
NONE.
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