527
FXUS65 KTWC 131910
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1210 PM MST MON JUL 13 2026
SYNOPSIS
THERE WILL BE THUNDERSTORM CHANCES EACH AFTERNOON AND
EVENING THROUGH THE COMING WEEK WITH DAY TO DAY VARIABILITY IN
LOCATION AND SEVERITY. SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON OVER AREAS OF SOUTHEAST ARIZONA GENERALLY
ALONG A LINE FROM DOUGLAS TO TUCSON. ANY THUNDERSTORM TODAY MAY
PRODUCE HEAVY RAINFALL AND STRONG WIND GUSTS. HIGH TEMPERATURES
WILL BE NEAR NORMAL TO JUST BELOW NORMAL THROUGH MID WEEK WITH
SOME FURTHER COOLING POSSIBLE BY THE END OF THE WEEK.
KEY MESSAGES
- SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND
EVENING, WITH THE BULK OF THE ACTIVITY EXTENDING ALONG A LINE
FROM DOUGLAS TO TUCSON.
- THE PRIMARY CONCERN WITH THE STORMS TODAY WILL BE THE
POTENTIAL FOR HEAVY RAINFALL. THE SECONDARY CONCERN WILL BE
STRONG THUNDERSTORM OUTFLOW WINDS TO 45 MPH WITH AREAS OF
BLOWING DUST ACROSS SE PINAL AND THE NORTHERN PORTIONS OF THE
TOHONO O'ODHAM NATION.
- THUNDERSTORM CHANCES WILL CONTINUE DAILY THROUGH THE WEEK WITH
DAY TO DAY VARIABILITY IN LOCATION AND SEVERITY.
- HIGH TEMPERATURES ARE FORECAST TO BE NEAR NORMAL TO JUST BELOW
NORMAL THROUGH MID-WEEK, WITH THE POTENTIAL FOR FURTHER
COOLING BY THE END OF THE WORK WEEK.
DISCUSSION
THE UPPER PATTERN IS DEFINED BY A STRONG RIDGE OF
HIGH PRESSURE EXTENDING FROM THE FOUR CORNERS/ ROCKIES REGION
UP INTO THE NORTHERN PLAINS. THE SOUTHERN PERIPHERY OF THIS
FEATURE WILL SLIGHTLY RE-ORIENT ITSELF TODAY, RESULTING IN A
WEAK DEFORMATION AXIS ALOFT EXTENDING FROM DOUGLAS TO TUCSON.
THIS IS WHERE WE CAN EXPECT TO SEE THE BEST COVERAGE OF STORMS
THIS AFTERNOON AS THE MID-LEVEL STORM MOTIONS WILL BE TOWARD THE
NORTHWEST ALONG THE DEFORMATION AXIS ALOFT. THE GOES
PRECIPITABLE WATER IMAGERY INDICATED DEEP MOISTURE ACROSS OUR
NECK OF THE WOODS, WITH VALUES BETWEEN 1.30-1.50 EAST OF A LINE
FROM NOGALES TO SAFFORD, AROUND 1.50 INCHES NEAR THE TUCSON
METRO AND 1.75 TO 2.00 ACROSS WESTERN PIMA COUNTY. GIVEN THIS
MOISTURE AND THE POTENTIAL FOR TRAINING STORMS MOVING ALONG THE
SAME AXIS, THE PRIMARY CONCERN FOR THE STORMS TODAY WILL BE THE
POTENTIAL FOR HEAVY RAINFALL. THE 13/12Z HREF AGREES WITH THIS
ASSESSMENT, WITH A 30-50% PROBABILITY THIS AFTERNOON FOR MORE
THAN AN INCH OF RAINFALL (3-HOUR WITHIN 40 KM OF A GIVEN
LOCATION) EXTENDING FROM DOUGLAS TO THE TUCSON METRO AREA.
ALTHOUGH WE MAY SEE SOME MID-LEVEL DRY AIR TO OUR EAST GET
ENTRAINED INTO SOME OF THE STORMS INCREASING THE POTENTIAL FOR
STRONG OUTFLOWS, GIVEN THE LACK OF MODEST MID-LEVEL SHEAR LIKE
WE HAVE SEEN THE PAST FEW DAYS, I DON'T THINK WE WILL SEE
CLUSTERING OF STORMS AND THE POTENTIAL FOR ORGANIZED OUTFLOWS
IS GENERALLY LOWER. DONT GET ME WRONG, I DO THINK WE WILL SEE
STRONG OUTFLOWS TO 40-45 MPH TODAY RESULTING IN AREAS OF BLOWING
DUST NW OF TUCSON IN SOUTHEAST PINAL AND THE NORTHERN TOHONO
O'ODHAM NATION). THIS TOO IS SUPPORTED BY THE 13/12Z HREF WITH A
70-90% PROBABILITY OF WIND GUSTS FROM STORMS OF 30+ KTS.
OTHERWISE, AN UPPER TROUGH OVER THE SOUTHEASTERN STATES TODAY
WILL MAKE ITS WAY WEST AROUND THE SOUTHERN PERIPHERY OF THE
MASSIVE UPPER RIDGE EXPANDING ACROSS THE UPPER MIDWEST INTO THE
MID ATLANTIC STATES. THIS WILL BRING THIS FEATURE INTO OUR NECK
OF THE WOODS AS INVERTED TROUGH/EASTERLY WAVE AS EARLY AS
WEDNESDAY BUT MORE LIKELY THURSDAY AND FRIDAY. THIS 'RIM-SHOT'
PATTERN WILL RESULT IN DECENT DYNAMICS/DEFORMATION ALOFT THUS
INCREASING THE SEVERE AND FLASH FLOOD POTENTIAL. SO, THIS IS
LIKE THAT ROADWAY SIGN YOU SEE ON A WINDING MOUNTAIN ROAD
INFORMING YOU OF 'DANGEROUS CURVES AHEAD'. IN THIS CASE, IT
SHOULD READ, 'ACTIVE AND STRONG STORMS AHEAD'.
AVIATION
VALID THROUGH 15/00Z. FEW-SCT 8-10K FT THRU 13/20Z,
THEN SCT-BKN 7-10K FT AGL BKN 12-15K FT AGL WITH SCATTERED -TSRA
/-SHRA THROUGH 14/03Z...THEN SCT-BKN 12-15K FT AGL OVERNIGHT.
CLOUD AND STORM RE-DEVELOPMENT AFTER 14/20Z TUESDAY AFTERNOON
HEAVY RAINFALL, MOUNTAIN OBSCURATIONS, AND ERRATIC STRONG WIND
GUSTS 35-40 KTS POSSIBLE WITH ANY THUNDERSTORM. OUTSIDE OF
THUNDERSTORMS WINDS MAINLY LIGHT AND TERRAIN DRIVEN, EXPECT FOR
THE GILA RIVER VALLEY WHERE 10-14 KT SOUTHEAST WINDS AND GUSTS
TO 22 KTS ARE EXPECTED THRU 14/02Z THIS EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
DAILY CHANCES FOR THUNDERSTORMS WILL CONTINUE
EACH AFTERNOON AND EVENING THROUGH THE COMING WEEK WITH DAY TO
DAY VARIABILITY. MINIMUM RELATIVE HUMIDITY 25-30 PERCENT IN THE
LOWER DESERT LOCATIONS AND ABOVE 40 PERCENT IN THE MOUNTAINS
THIS WEEK. WIND TODAY MAINLY LIGHT AND TERRAIN DRIVEN, WITH THE
EXCEPTION OF THE GILA RIVER VALLEY WITH SOUTHEAST WINDS 12-16
MPH WITH GUSTS TO 25 MPH. GUSTY AND ERRATIC WIND GUSTS TO 45 MPH
WILL BE POSSIBLE NEAR THUNDERSTORMS, ESPECIALLY FROM TUCSON TO
THE NORTHWEST ACROSS SOUTHEAST PINAL AND NORTH-CENTRAL AND
NORTHEAST PIMA COUNTY. WINDS THIS WEEK WILL REMAIN MAINLY UNDER
15 MPH, THOUGH STRONG AND ERRATIC WINDS WILL BE POSSIBLE WITH
ANY THUNDERSTORM.
TWC WATCHES/WARNINGS/ADVISORIES
NONE.
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