727
FXUS65 KTWC 282206
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
306 PM MST TUE JUL 28 2026
SYNOPSIS
EXPECT DAILY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
THIS WEEK WITH DAY TO DAY VARIABILITY IN COVERAGE AND STRENGTH.
HIGH TEMPERATURES WILL WARM TO 7-12 DEGREES ABOVE NORMAL
THURSDAY INTO THE WEEKEND WITH AN EXTREME HEAT WARNING THROUGH
SUNDAY.
DISCUSSION
ACTIVITY THUS FAR HAS BEEN CONFINED TO NORTHERN
GRAHAM/GREENLEE, WITH A COUPLE TRANSIENT SUPERCELLS ALREADY
NOTED. THESE INITIAL CELLS SHOULD CONTINUE TO PUSH NW AND OUT
OF THE CWA WITHIN THE NEXT HOUR OR SO.
FOR THE REST OF THE DAY...LOOKING AT THE CURRENT MESOANALYSIS
SHOWS MLCAPE 1000-2000 J/KG WITH POCKETS SLIGHTLY OVER 2000 J/KG
IN SOUTHERN COCHISE COUNTY. EFFECTIVE SHEAR IS MODEST AROUND
20-35 KTS, WHICH SUPPORTS ANOTHER FAVORABLE ENVIRONMENT FOR
STRONG TO SEVERE MULTICELLS AND ONE OR TWO TRANSIENT SUPERCELLS.
CAMS ALSO SHOW THIS SCENARIO, BUT COVERAGE WOULD BE ISOLATED AT
BEST. MAIN THREATS WILL BE WIND GUSTS TO 60 MPH AND MARGINALLY
SEVERE HAIL TO AROUND 1" IN DIAMETER. WHILE HEAVY RAIN IS
POSSIBLE, FLASH FLOODING WOULD BE VERY LOCALIZED GIVEN THE
PROGRESSIVE MOTION OF ANY STORMS.
TOMORROW IS TRICKY FORECAST, AS THERE ARE HINTS OF ANOTHER
LARGE SONORAN MCS WHICH COULD SKIRT OR SNEAK INTO EXTREME
SOUTHERN AZ. WHILE CONFIDENCE IS LOW AT THIS TIME, ITS WORTH
MENTIONING THE POSSIBILITY. THIS WOULD INCREASE A LOCALIZED
SEVERE/FLASH FLOOD RISK ALONG THE INTERNATIONAL BORDER. THE
FLASH FLOODING RISK WOULD BE GREATEST FOR AREAS SATURATED IN
THE SAN PEDRO WATERSHED.
NO CHANGES TO THE EXTREME HEAT WARNING AS HEAT WILL BUILD THE
REST OF WEEK, PEAKING THIS WEEKEND. NAEFS MEAN 500 MB HEIGHTS AT
THE 99.5 PERCENTILE OR MAX COMPARED TO THE CFSR CLIMATOLOGY
THURSDAY INTO THE WEEKEND. TEMPERATURES WARM 7-12 DEGREES ABOVE
NORMAL DURING THIS TIME FRAME LEADING TO WIDESPREAD AREAS OF
MAJOR TO EXTREME HEATRISK. BECAUSE OF THIS AN EXTREME HEAT
WARNING REMAINS IS IN PLACE THURSDAY THROUGH SUNDAY. THE TWO
WARMEST DAYS LOOK TO BE FRIDAY AND SATURDAY WITH TUCSON POSSIBLY
SEEING 110 DEGREES BOTH DAYS. NBM PROBABILITIES FOR TUCSON
INTERNATIONAL TO HIT 110 DEGREES HAVE DROPPED INTO THE 20-35%
RANGE BOTH DAYS, BUT STILL QUITE SIGNFCIANT.
STORM CHANCES DROP TO THEIR LOWEST OF THE WEEK THURSDAY, BEFORE
SLOWLY RAMPING BACK UP BY THE WEEKEND. GREATEST COVERAGE
REMAINS SOUTH AND EAST OF TUCSON THROUGH THE REST OF THE WEEK,
WITH SOME DAY TO DAY VARIABILITY BASED ON THE PREVIOUS DAYS
CONVECTION.
AVIATION /20Z TUESDAY THROUGH 20Z WEDNESDAY/
VFR THROUGH THE FORECAST PERIOD. FEW TO SCT CLOUD DECKS THIS
AFTERNOON AND EVENING AOA 7-9K FT AGL. VCTS IN KDUG THIS
AFTN/EVENING WITH ISO/SCT COVERAGE OF TS/SHRA SOUTH AND EAST OF
KTUS. SFC WINDS LESS THAN 12KTS, WITH THE EXCEPTION OF ANY TS
OUTFLOW WINDS.
FIRE WEATHER
HIGH TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEK WITH AN
EXTREME HEAT WARNING IN PLACE THURSDAY THROUGH SATURDAY. EXPECT
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WITH DAY-TO-DAY VARIABILITY ON COVERAGE OF STORMS INTO THE
WEEKEND. ANY THUNDERSTORM WILL BRING A THREAT OF SEVERE, ERRATIC
WIND GUSTS AS WELL AS BRIEF HEAVY RAINFALL AND AN ISOLATED THREAT
OF FLASH FLOODING. MIN RH VALUES WILL BE 20-40 PERCENT IN THE
LOWER DESERTS THROUGH AT LEAST MID-WEEK. BY MID TO LATE WEEK, MIN
RH COULD DIP INTO THE TEENS IN THE LOWER DESERTS. WINDS THIS
WEEKEND WILL MAINLY BE LIGHT AND UNDER 12 MPH OUTSIDE OF
THUNDERSTORMS.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING FROM 10 AM THURSDAY TO 8 PM MST SUNDAY
FOR AZZ501>509.
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