331
FXUS65 KTWC 231547
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
847 AM MST THU JUL 23 2026
SYNOPSIS
EXPECT LIMITED THUNDERSTORM ACTIVITY TODAY ACROSS
SOUTHEAST ARIZONA AS THE COMBINATION OF DRIER AIR AND A RIDGE
OF HIGH PRESSURE ALOFT MOVE INTO THE REGION FROM THE EAST.
ALTHOUGH WE WILL MAINTAIN A LOW-GRADE THUNDERSTORM PATTERN THE
NEXT FEW DAYS, WE WILL ALSO SEE AFTERNOON HIGH TEMPERATURES
RAPIDLY INCREASE WITH EXTREME HEAT EXPECTED ACROSS THE AREA
FRIDAY AND SATURDAY. OTHERWISE, THE UPPER PATTERN EVENTUALLY
MOVES INTO A MORE FAVORABLE LOCATION FOR AN INCREASED POTENTIAL
FOR STRONG AND ORGANIZED THUNDERSTORMS THIS WEEKEND.
UPDATE
THOUGH DECENT MOISTURE LINGERS TODAY, AS PREVIOUSLY DESCRIBED,
WARMING ALOFT WILL REDUCE INSTABILITY AND KEEP THUNDERSTORM
CHANCES ON THE ISOLATED (AROUND 10-15 PERCENT) SIDE TODAY. BRIEF
HEAVY RAINERS (0.25-0.5 INCHES WITH A VERY ISOLATED CHANCE OF AN
INCH DEPENDING ON STORM COVERAGE) AND WIND GUSTS TO AROUND 40
MPH ARE THE LIKELY HAZARDS WITH THESE THUNDERSTORMS THIS
AFTERNOON AND EVENING.
DISCUSSION
THE UPPER PATTERN THIS MORNING IS DEFINED BY
STRONG RIDGE OF HIGH PRESSURE CENTERED OVER WEST-CENTRAL TEXAS
EXTENDING AS FAR WEST AS ERN ARIZONA. THE LATEST GOES PRECIPITABLE
WATER IMAGERY INDICATED GENERALLY 1.40-1.60 INCHES OF PWAT
ACROSS SEAZ WITH DRIER VALUES AOA 1.25 INCHES IN THE EXTREME
CORNER OF THE STATE. THE IMAGERY ALSO INDICATED SUB 1 INCH PWATS
IN NEW MEXICO AND CHIHUAHUA MEXICO THAT WILL MOVE INTO THE CWA
THIS AFTERNOON. GIVEN THE COMBINATION OF WARMING TEMPS ALOFT
AND THE GENERAL DRYING, WE WILL STRUGGLE TO SEE ANYTHING MORE
THAN ISOLATED CONVECTION ACROSS OUR NECK OF THE WOODS TODAY. THE
BIG CHANGE WITH THE FORECAST WILL OCCUR THE NEXT FEW DAYS AS
THE STRONG UPPER-HIGH CENTER MOVES WSW INTO SRN NEW MEXICO BY
24/00Z THIS AFTERNOON THEN INTO ERN ARIZONA BY 25/00Z FRIDAY
AFTERNOON. WE WILL SEE AFTERNOON TEMPERATURES JUMP RAPIDLY TODAY
WITH ANOTHER INCREASE FRIDAY AND AN EVER SO SLIGHT INCREASE
SATURDAY AS THE UPPER HIGH CENTER GETS SETUP NEAR THE FOUR
CORNERS.
AS STATED FROM THE PREVIOUS FORECAST, THE HOTTEST DAYS EXPECTED
ARE FRIDAY AND SATURDAY. TEMPERATURES WILL RANGE FROM 105 TO
112 DEGREES IN THE TUCSON METRO, WESTERN DESERTS, AND UPPER GILA
RIVER VALLEY. ELSEWHERE TEMPERATURES WILL RANGE FROM 100 TO 105
DEGREES. THIS INCREASE IN TEMPERATURES IN COMBINATION WITH THE
WARM LOW TEMPERATURES OF 80 TO 85 DEGREES HAVE NECESSITATED AN
EXTREME HEAT WARNING FOR FRIDAY AND SATURDAY WHEN TEMPERATURES
WILL BE 6 TO 10 DEGREES ABOVE NORMAL. MAJOR HEATRISK IS EXPECTED
FOR THE VALLEYS, SO BE AWARE OF THE SIGNS FOR HEAT ILLNESS/STROKE,
STAY HYDRATED, STAY INDOORS WITH AIR CONDITIONING WHEN POSSIBLE,
AND CONSIDER MOVING PLANS INDOORS DURING THE HOTTEST TIME OF
DAY.
OTHERWISE, WITH THE UPPER-HIGH IN A MORE FAVORABLE LOCATION
NEAR THE FOUR CORNERS SATURDAY, THIS INCREASES THE LIKELIHOOD
OF THUNDERSTORMS MOVING OFF THE MOGOLLON RIM INTO TUCSON IN THE
LATE AFTERNOON. THE COMBINATION OF VERY STRONG SURFACE HEATING,
DRIER AIR ALOFT AND MODEST MID-LEVEL FLOW WILL INCREASE THE
POTENTIAL FOR STRONGER, MORE ORGANIZED CLUSTERING OF SHOWERS AND
THUNDERSTORMS SATURDAY. AN ADDITIONAL SURGE OF DEEP MOISTURE IS
THEN EXPECTED TO MOVE INTO SOUTHEAST ARIZONA LATE THIS WEEKEND
AS AN EASTERLY WAVE ASSOCIATED WITH THE REMAINS OF TROPICAL
STORM BERTHA MOVES WEST INTO THE SOUTHERN GULF OF CALIFORNIA
INITIATING A GULF SURGE.
AVIATION /15Z THURSDAY THROUGH 15Z FRIDAY/
VALID THROUGH 23/12Z. FEW-SCT 12-15K FT AGL AND BKN
CIRRUS AOA 20K FT AGL THROUGH 23/20Z THIS AFTERNOON, THEN SCT-
BKN 7-10K FT AGL WITH A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS
BETWEEN 23/20Z AND 24/02Z. CLEARING SKIES DURING THE EVENING.
SURFACE WINDS GENERALLY LESS THAN 12 KTS, EXCEPT FOR AROUND
STORMS WHERE VRB GUSTS TO 35 KTS WILL BE POSSIBLE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
EXPECT LIMITED THUNDERSTORM ACTIVITY TODAY ACROSS
SOUTHEAST ARIZONA AS THE COMBINATION OF DRIER AIR AND A RIDGE
OF HIGH PRESSURE ALOFT MOVE INTO THE REGION FROM THE EAST.
ALTHOUGH WE WILL MAINTAIN A LOW-GRADE THUNDERSTORM PATTERN THE
NEXT FEW DAYS, WE WILL ALSO SEE AFTERNOON HIGH TEMPERATURES
RAPIDLY INCREASE WITH EXTREME HEAT EXPECTED ACROSS THE AREA
FRIDAY AND SATURDAY. OTHERWISE, THE UPPER PATTERN EVENTUALLY
MOVES INTO A MORE FAVORABLE LOCATION FOR AN INCREASED POTENTIAL
FOR STRONG AND ORGANIZED THUNDERSTORMS THIS WEEKEND. MIN RHS
15-25% IN THE LOWER DESERT LOCATIONS AND 30-40% IN THE MOUNTAINS
THE NEXT FEW DAYS. DEEPER MOISTURE IS THEN EXPECTED TO MOVE
INTO THE AREA FROM THE SOUTH LATE THIS WEEKEND RESULTING IN A
NOTICEABLE INCREASE IN MIN RHS THE FIRST HALF OF NEXT WEEK.
WINDS THIS WEEK WILL REMAIN MAINLY LIGHT AND UNDER 15 MPH,
THOUGH STRONG AND ERRATIC WINDS WILL BE POSSIBLE WITH ANY
THUNDERSTORM.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING FROM 10 AM FRIDAY TO 8 PM MST SATURDAY
FOR AZZ501>509.
UPDATE...EDWARDS
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