735
FXUS65 KTWC 071944
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1244 PM MST TUE JUL 7 2026
SYNOPSIS
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED EACH DAY THIS WEEK, WITH THE POTENTIAL FOR AN INCREASE IN
STORM COVERAGE OVER THE WEEKEND. HOT TEMPERATURES FOR MUCH OF THE
WEEK BEFORE COOLING OFF THIS WEEKEND.
DISCUSSION
HIGH PRESSURE ALOFT EXTENDS FROM WEST OF THE BAJA
PENINSULA NORTHEASTWARD INTO THE EASTERN COLORADO. BY THURSDAY AND
FRIDAY THE UPPER WILL SHIFT WESTWARD WHEN IT WILL BE CENTERED OVER
THE EASTERN PACIFIC THROUGH THE NORTHERN BAJA AND INTO WESTERN
ARIZONA. OVER THE WEEKEND, THE MONSOON HIGH SHIFTS NORTHWARD TO
NORTH OF THE FOUR CORNERS INTO THE CENTRAL PLAINS.
WITH THE UPPER HIGH NEARLY OVERHEAD OR VERY CLOSE BY, HEAT WILL BE A
CONCERN THROUGH THURSDAY. HIGH TEMPERATURES WILL TOP OUT 4-7 DEGREES
ABOVE NORMAL AND AN EXTREME HEAT WARNING IS IN EFFECT THROUGH 8 PM
MST WEDNESDAY. THE EXTREME HEAT WARNING IS IN EFFECT FOR THE MUCH OF
PIMA COUNTY, SOUTH-CENTRAL AND SOUTHEAST PINAL COUNTY AND THE GILA
RIVER VALLEY OF GRAHAM COUNTY. MODERATE HEATRISK COVERS MUCH OF
SOUTHEAST ARIZONA THROUGH THURSDAY, WITH POCKETS OF MAJOR HEATRISK
IN THE WARNING AREA. THE EXTREME HEAT WARNING MAY NEED TO BE PUSHED
OUT THROUGH THURSDAY AND SUBSEQUENT SHIFTS WILL TAKE A CLOSER LOOK
AT THAT. FOR MORE INFORMATION ON THIS PRODUCT, PLEASE REFER TO
PHXNPWTWC.
PRECIPITABLE WATER VALUES HOLD NEARLY STEADY THROUGH WEDNESDAY, WITH
VALUES RANGING FROM 0.80" IN THE WHITE MOUNTAINS TO 1.25" ALONG THE
INTERNATIONAL BORDER. PW VALUES ARE THEN FORECASTED TO DROP AROUND
0.25" THURSDAY INTO FRIDAY AS THE UPPER HIGH LIFTS NORTHEAST ACROSS
THE STATE. BY SATURDAY AND SUNDAY, PW VALUES INCREASE FROM NEAR 1"
IN THE WHITE MOUNTAINS TO AROUND 1.5" ALONG THE INTERNATIONAL
BORDER. ISOLATED TO SCATTERED THUNDERSTORM CHANCES WILL EXIST
THROUGH WEDNESDAY, ROUGHLY EAST OF A LINE FROM HANNAGAN MEADOW TO
TUCSON TO NOGALES. THE STEERING FLOW REMAINS NORTHEAST TO SOUTHWEST
OVER THIS PERIOD. THE MAIN THREATS WILL BE GUSTY OUTFLOW WINDS TO 40-
45 MPH, BLOWING DUST ALONG INTERSTATE 10 AND LOCALIZED HEAVY
RAINFALL WITH THE STRONGEST STORMS. THURSDAY AND FRIDAY THUNDERSTORM
COVERAGE SHOULD DECREASE A LITTLE AND SHIFT SLIGHTLY EASTWARD WITH
LOWERING PW VALUES AND THE UPPER HIGH NEARLY OVERHEAD.
BY THIS WEEKEND, THE STEERING FLOW SHIFTS TO AN EAST TO WEST
DIRECTION AS THE UPPER HIGH BECOMES CENTERED NORTH/NORTHEAST OF THE
FOUR CORNERS. GIVEN THE FORECASTED INCREASE IN PW'S, FLASH FLOODING
WILL BECOME MORE OF A CONCERN. IN ADDITION, THUNDERSTORM COVERAGE
INCREASES TO INCLUDE ALL OF SOUTHEAST ARIZONA, INCLUDING CENTRAL AND
WESTERN PIMA COUNTY. HIGH TEMPERATURES OVER THE WEEKEND WILL LOWER
TO RIGHT AROUND NORMAL, WHICH IS THE LOWER 100S IN THE LOWER DESERTS
FROM TUCSON WESTWARD AND IN THE GILA RIVER VALLEY, WITH MID TO UPPER
90S IN THE LOWER ELEVATION LOCATIONS OF SANTA CRUZ AND COCHISE
COUNTIES.
AVIATION
VALID THROUGH 09/00Z.
FEW-SCT (LOCALLY BKN) CLOUDS AT 7K-10K AND ISOLD-SCT -SHRA/-TSRA AND
THE POTENTIAL FOR OUTFLOW WINDS UP TO 45 KTS THRU 08/04Z. CLOUDS AND
STORMS DIMINISHING BETWEEN 08/04Z AND 08/17Z. 08/17Z THROUGH THE END
OF THE FORECAST PERIOD, SCT-BKN CLOUDS AT 7K-10K AND ISOLD-SCT
-SHRA/-TSRA. OUTSIDE OF THUNDERSTORM OUTFLOWS, SFC WIND LESS THAN 12
KTS, FAVORING A WLY/NWLY DIRECTION DURING THE AFTERNOON/EARLY
EVENING HOURS AND VARIABLE IN DIRECTION AT OTHER TIMES. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
ABOVE NORMAL HIGH TEMPERATURES (4-7 DEGREES) THROUGH
THURSDAY, WITH HIGHS LOWERING TO AROUND NORMAL OVER THE UPCOMING
WEEKEND. MIN RH VALUES IN THE LOWER ELEVATIONS IN THE 13-17 PERCENT
RANGE THROUGH FRIDAY, INCREASING 5-10 PERCENT BY LATE IN THE WEEKEND
INTO EARLY NEXT WEEK. OUTSIDE OF ANY THUNDERSTORM OUTFLOW WINDS, 20-
FOOT WINDS WILL GENERALLY BE LESS THAN 15 MPH INTO EARLY NEXT WEEK.
THERE WILL BE A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY
DURING THE AFTERNOON/EVENING HOURS THIS WORK WEEK. THERE IS THE
POTENTIAL FOR INCREASING THUNDERSTORM CHANCES AND COVERAGE THIS
WEEKEND.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING UNTIL 8 PM MST WEDNESDAY FOR
AZZ501-502-504>506-509.
ZELL
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