682
FXUS65 KTWC 131654
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
954 AM MST SAT SEP 13 2025
SYNOPSIS
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
AGAIN BE POSSIBLE TODAY SOUTH AND EAST OF TUCSON. AN ISOLATED
RISK OF STRONG WINDS, LARGE HAIL, HEAVY RAIN, AND BLOWING DUST
WILL ACCOMPANY THESE THUNDERSTORMS. DRY AIR MOVES IN SUNDAY
LEADING TO NO THUNDERSTORMS. TEMPERATURES TRANSITION FROM BELOW
NORMAL THIS WEEKEND TO ABOVE NORMAL NEXT WEEK WITH A MODEST RETURN
OF THUNDERSTORM CHANCES TUESDAY AND THE END OF THE WORK WEEK.
UPDATE
AT THE TIME OF THIS WRITING A FEW THUNDERSTORMS CONTINUE
TO BE OBSERVED ON RADAR ACROSS EASTERN GRAHAM, GREENLEE, AND COCHISE
COUNTIES WITH THINNING LOW TO MID-LEVEL CLOUD COVER STRETCHING BACK
ACROSS THE TUCSON METRO. LATEST GOES SATELLITE IMAGERY DEPICTED AN
ESTIMATED 0.8-1.1 INCHES OF PRECIPITABLE WATER WITH THE HIGHER
AMOUNTS FOCUSED EAST OF TUCSON. DEW POINTS WERE IN THE MID 60S FROM
TUCSON AND NOGALES EASTWARD.
NOT MUCH CHANGE IN THE FORECAST THINKING FOR TODAY WITH ISOLATED TO
SCATTERED THUNDERSTORMS EXPECTED MAINLY TO THE EAST AND SOUTH OF
TUCSON SUPPORTED BY BROAD SYNOPTIC SCALE LIFT FROM A TROUGH AXIS
MOVING OVER ARIZONA. PRECIPITABLE WATER CONTENT OF 1.0 TO 1.3 INCHES
COMBINED WITH 35-55 KNOTS OF EFFECTIVE BULK SHEAR AND A 40 KNOT 500
MB FLOW FAVORS MORE SUSTAINED BUT QUICK MOVING STORMS TODAY MOVING
FROM SOUTHWEST TO NORTHEAST. THE MAIN FORECAST CONCERN WITH THESE
STORMS WILL BE GUSTY OUTFLOW WINDS RESULTING IN BLOWING DUST.
HOWEVER, SIMILAR TO YESTERDAY, WE COULD SEE ISOLATED INSTANCES OF
LARGE HAIL AND HEAVY RAINFALL WITH ANY STRONGER AND MORE SUSTAINED
THUNDERSTORM UPDRAFT. THUS, THE SECONDARY THREAT BECOMES LARGE HAIL
AND LOCALIZED FLASH FLOODING, ESPECIALLY WHERE STORMS TRACK OVER THE
SAME WATERSHED IN A SHORT PERIOD OF TIME.
TOMORROW INTO NEXT WEEK TEMPERATURES WILL BEGIN TO REBOUND WITH THE
TROUGH PASSAGE WITH HIGHS IN THE MID TO UPPER 80S TO THE SOUTH AND
EAST OF TUCSON AND IN THE MID TO UPPER 90S FROM TUCSON WEST.
PRECIPITATION CHANCES WILL BE MINIMAL (10-20%) MAINLY CONFINED TO
THE HUACHUCA AND CHIRICAHUA MOUNTAINS AND ALONG THE INTERNATIONAL
BORDER BEFORE SIGNS OF MODEST PUSH OF MOISTURE BY THE LATTER HALF OF
THE WEEK.
PREV DISCUSSION
/ISSUED 216 AM MST SAT SEP 13 2025/
CURRENT RADAR SHOWS ISOLATED SHOWERS AND THUNDERSTORMS EAST OF
TUCSON. THIS OVERNIGHT ACTIVITY IS THE RESULT OF A TROUGH MOVING
INTO NORTHERN ARIZONA PROVIDING ENOUGH SYNOPTIC SCALE LIFT FOR
SOME WEAK CONVECTION. THIS ACTIVITY WILL CONTINUE THROUGH THE
EARLY MORNING. EXPECT ANOTHER ROUND OF STRONG TO SEVERE STORMS
THIS AFTERNOON AND EVENING. THE SAME ENVIRONMENTAL INGREDIENTS AS
YESTERDAY ARE IN PLACE WITH PLENTY OF MOISTURE AND INSTABILITY AS
WELL AS 0-6KM WIND SHEAR OF 20-35 KTS. THE ONLY DIFFERENCE IS DRY
AIR WILL INTRUDE A LITTLE FURTHER EAST THAN YESTERDAY WHICH WILL
KEEP MOST THUNDERSTORMS ACTIVITY EAST OF TUCSON. BEST CHANCES WILL
BE IN COCHISE COUNTY AND SOUTHERN GRAHAM/GREENLEE COUNTIES.
EASTERN SANTA CRUZ COUNTY COULD SEE SOME ACTIVITY AS WELL. STORMS
WILL AGAIN BE CAPABLE OF ROTATION, WHICH WILL LEAD TO LONGER LIVED
UPDRAFTS WITH THE MAIN HAZARDS BEING HAIL AND STRONG TO SEVERE
WIND GUSTS. HEAVY RAINFALL WILL ALSO BE POSSIBLE BUT FAST MOVING
STORMS WILL LESSEN THE FLASH FLOOD THREAT.
SUNDAY THE TROUGH WILL BE EAST OF ARIZONA AND WILL TAKE THE
MOISTURE WITH IT LEADING TO DRY CONDITIONS. TEMPERATURES WILL ALSO
BEGIN TO REBOUND. HIGHS TODAY WILL BE A FEW DEGREES BELOW NORMAL,
WARM TO AROUND NORMAL SUNDAY, THEN ABOVE NORMAL MONDAY INTO THE
MIDDLE OF NEXT WEEK. HIGH PRESSURE BUILDS OVER NORTHERN MEXICO
NEXT WEEK WHICH ALLOWS MOISTURE TO SLOWLY MOVE IN FROM THE SOUTH.
MONDAY WILL SEE LOW POPS (GENERALLY 15 PERCENT) ALONG THE
INTERNATIONAL BORDER INCREASING TUESDAY SOUTH AND EAST OF TUCSON
TO 20-40 PERCENT. LATER IN THE WEEK MODELS ARE HINTING AT A BETTER
PUSH OF MOISTURE ESPECIALLY WEST OF TUCSON.
AVIATION
VALID THROUGH 14/12Z.
ISOLATED THUNDERSTORMS POSSIBLE THROUGH THE MORNING MAINLY OVER
COCHISE AND GRAHAM COUNTIES. BY LATE MORNING INTO THE AFTERNOON
SCATTERED STRONG THUNDERSTORMS WILL BE POSSIBLE EAST OF TUCSON
WITH KSAD AND KDUG SEEING THE BEST CHANCES TO BE IMPACTED BY A
THUNDERSTORM. THE INGREDIENTS WILL BE IN PLACE FOR WIND GUSTS TO
50 KTS AND LARGE HAIL. HEAVY RAINFALL AND MOUNTAIN OBSCURATIONS
WILL ALSO BE POSSIBLE. STORMS WILL BEGIN TO DISSIPATE AFTER 14/03Z
AS DRY AIR BEGINS TO MOVE IN. OTHERWISE, SFC WIND SLY/SWLY AT
8-12 KTS WITH GUSTS TO 20 KTS THIS AFTERNOON AND EVENING. SFC WIND
LESS THAN 10 KTS AND VARIABLE IN DIRECTION AT OTHER TIMES.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
MINIMUM RH VALUES WILL BE IN THE 20-35 PERCENT
RANGE TODAY, LOWERING INTO THE 15-30 PERCENT RANGE SUNDAY AND
MONDAY, THEN BACK INTO THE 20-35 PERCENT RANGE. SCATTERED SHOWERS
AND THUNDERSTORMS ARE EXPECTED MAINLY FOR COCHISE COUNTY AND EAST
SANTA CRUZ COUNTY TODAY. THUNDERSTORMS TODAY WILL HAVE A RISK OF
VERY STRONG GUSTY WINDS, HAIL, AND HEAVY RAINFALL. DRY AREA-WIDE
SUNDAY, THEN A SLIGHT CHANCE OF THUNDERSTORMS SOUTH AND EAST OF
TUCSON RETURN AGAIN NEXT WEEK. OUTSIDE OF THUNDERSTORM OUTFLOWS,
EXPECT 20-FOOT WINDS TO BE 15 MPH OR LESS, WITH SOME
AFTERNOON/EARLY EVENING GUSTS TO AROUND 25 MPH.
TWC WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...DVS
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