132
FXUS65 KTWC 010331 AAA
AFDTWC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
831 PM MST FRI JUL 31 2026
UPDATE
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS
EVENING GREENLEE, GRAHAM AND COCHISE COUNTIES. RAINFALL AMOUNTS
FROM A COUPLE STORMS RANGED FROM 0.25" TO 0.35". AS OF 8 PM,
ISOLATED STORMS WERE ACROSS CENTRAL COCHISE COUNTY AND ACROSS
THE STATE LINE IN NM ACROSS SOUTHERN HIDALGO COUNTY. RATHER
QUITE THRU MIDNIGHT TO 3 AM TIME PERIOD, THEN A FEW ISOLATED
ELEVATED SHOWERS & STORMS DEVELOP EAST OF TUCSON AND SLOWLY PUSH
W-SW BEING DRIVEN BY UPPER LEVEL DIVERGENCE WILL BE MOVING OVER
THE AREA FROM THE EAST AS THE 300 MB RIDGE AXIS ORIENTATION
TURNS FROM NW-SE TO N-S. RAINFALL WILL BE LIGHT AND NOT EXPECTED
MUCH IN WINDS OUT OF ANY STORMS THAT DEVELOP. THESE SHOWERS MAY
LINGER THROUGH AROUND 8-9 AM TOMORROW. THIS OVERALL OVERNIGHT
PATTERN CHANGE MAY SHAVE OFF A COUPLE OF DEGREES IN FORECAST
HIGH TEMPERATURES TOMORROW, ESPECIALLY FROM TUCSON EAST. WILL
RUN OUT AN UPDATE ON THE OVERNIGHT INCREASE IN POPS VERSUS WHAT
THE NBM IS CURRENTLY SHOWING. WILL LEAVE TOMORROWS HIGHS TO THE
MIDSHIFT IF THEY THINK THEY NEED ANY MINOR CHANGES. OVERALL IT
WILL STILL BE A HOT DAY SATURDAY WITH EXTREME HEAT WARNING IN
EFFECT WITH MAJOR TO EXTREME HEATRISK ACROSS THE AREA. UPDATE
DUE OUT SHORTLY.
SYNOPSIS
LIMITED THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING
WITH ONLY LOCALES ALONG THE NM BORDER AND SE COCHISE COUNTY SEEING
ISOLATED THUNDERSTORMS. STORM COVERAGE AND CHANCES INCREASING
SATURDAY EAST OF TUCSON, BUT ESPECIALLY RAMP UP NEXT WEEK WITH A
MORE ACTIVE PATTERN. HIGH TEMPERATURES WILL BE 8-15 DEGREES ABOVE
NORMAL THROUGH MONDAY WITH GRADUAL MODEST COOLING THEREAFTER. THE
EXTREME HEAT WARNING IS IN EFFECT THROUGH MONDAY.
DISCUSSION
MOSTLY SUNNY SKIES ACROSS THE FORECAST AREA EARLY THIS
AFTERNOON AS THE MID/UPPER LEVEL HIGH PRESSURE RESULTING IN EXTREME
HEAT ACROSS THE REGION IS NOW LOCATED ACROSS EAST-CENTRAL ARIZONA.
THERE IS ENOUGH MOISTURE UNDER THE HIGH FOR SOME SHOWER AND
THUNDERSTORM ACTIVITY ACROSS THE WHITE MOUNTAINS AND THESE HAVE BEEN
DEVELOPING IN THE PAST HOUR OR TWO. GIVEN LACK OF STEERING FLOW UP
THERE, THE BULK OF THE ACTIVITY WILL REMAIN OVER THE HIGHER TERRAIN
BUT SOME OUTFLOWS PUSHING SOUTHWARD WILL HELP RESULT IN SOME
ISOLATED STORMS LATER THIS AFTERNOON AND EVENING ACROSS GRAHAM AND
COCHISE COUNTIES. MAIN CONCERN IS GUSTY WINDS, THOUGH THE STRONGEST
CORES WILL HAVE SOME LOCALLY HEAVY DOWNPOURS. WE ALSO CAN'T RULE OUT
A STRAY STORM OR TWO ALONG THE INT'L BORDER IN SANTA CRUZ COUNTY
LATER THIS EVENING AS THE STEERING FLOW IS A BIT BETTER ALONG THE
INT'L BORDER AND CAN RESULT IN A FEW STORMS PUSHING IN FROM ADJACENT
COCHISE COUNTY.
THE EXTREME HEAT WILL CONTINUE TO BE THE MAIN WEATHER STORY THIS
WEEKEND AND WITH MONDAY HIGH TEMPERATURES NOW NUDGING SLIGHTLY
HIGHER, THERE IS ENOUGH OF OUR FORECAST AREA UNDER MAJOR HEATRISK TO
JUSTIFY AN EXTENSION OF THE WARNING THROUGH MONDAY.
ISOLATED TO SCATTERED THUNDERSTORM COVERAGE ON SATURDAY
AFTERNOON/EVENING IS EXPECTED EAST OF TUCSON WITH THE BEST CHANCES
CLOSER TO THE AZ/NM BORDER. SPC CONTINUES TO HIGHLIGHT THIS AREA FOR
A MARGINAL RISK OF SEVERE THUNDERSTORMS DUE TO THE WIND THREAT AS
THE 12Z HREF HAS GREATER THAN 10% 40-KM NEIGHBORHOOD PROBABILITIES
OF WIND GUSTS OF 50 KTS OR GREATER.
A GENERALLY MORE ACTIVE PERIOD FOR SOUTHEAST ARIZONA MAY START AS
EARLY AS SUNDAY, BUT MUCH MORE LIKELY BY MONDAY AND CONTINUING
THROUGH THE REST OF NEXT WEEK AS A FAVORABLE EASTERLY TO
NORTHEASTERLY PATTERN SETS UP WITH THE STRONG HIGH PRESSURE
GRADUALLY SHIFTING INTO NORTHERN ARIZONA. WITH ADEQUATE MOISTURE IN
OUR AREA AND SOME EMBEDDED DISTURBANCES IN THE EASTERLY FLOW (STILL
A BIT HARD TO TIME THIS FAR OUT), SOME OF THESE DAYS LOOK TO BE
QUITE ACTIVE. THE GENERAL FLAVOR WILL BE MORE OF A SEVERE
THUNDERSTORM THREAT EARLY IN THE WEEK, TRANSITIONING TO A HYBRID
SEVERE THUNDERSTORM AND FLASH FLOODING THREAT AS THE WEEK
PROGRESSES.
TEMPERATURES FROM TUESDAY ONWARD LOWER TO ABOUT 3 TO 6 DEGREES ABOVE
NORMAL.
AVIATION /03Z SATURDAY THROUGH 03Z SUNDAY/
VALID THROUGH 02/00Z.
FEW-SCT 8K-12K FT AGL FOR MUCH OF THE PERIOD. ISOLATED TSRA
WILL BE POSSIBLE 31/21Z-01/06Z WITH KDUG TERMINAL HAVING THE BEST
CHANCE TO BE IMPACTED BY TSRA, KOLS COULD SEE TSRA AS WELL THIS
EVENING, BUT CONFIDENCE TOO LOW TON INCLUDE IN TAF. GUSTY SFC WINDS
NEAR TSRA WITH WIND GUSTS UP TO 35 KTS WILL BE POSSIBLE. SFC WINDS
NWLY 8-12 KTS THRU 01/03Z WITH OCCASIONAL GUSTS UP TO 25 KTS.
OTHERWISE, SFC WINDS LIGHT AND VARIABLE UNDER 10 KTS THEREAFTER THRU
01/18Z. WLY/NWLY WINDS 8-12 KTS THEN RESUME THRU THE END OF THE
VALID PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
HIGH TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH MONDAY WITH
WITH AN EXTREME HEAT WARNING IN EFFECT. EXPECT DAILY CHANCES OF
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS MAINLY SOUTH AND
EAST OF TUCSON THROUGH THE WEEKEND WITH SOME DAY TO DAY VARIABILITY.
STORM COVERAGE AND CHANCES ARE EXPECTED TO INCREASE IN COVERAGE NEXT
WEEK WITH AN ACTIVE PERIOD IN STORE. 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 10-
20 PERCENT THROUGH SATURDAY THEN 15-30 PERCENT SUNDAY INTO NEXT
WEEK. WINDS WILL BE TERRAIN DRIVEN AT 5 TO 10 MPH WITH OCCASIONAL
GUSTS UP TO 25 MPH.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING UNTIL 8 PM MST MONDAY FOR AZZ501>509.
UPDATE...
SYNOPSIS...
DISCUSSION...
AVIATION...
FIRE WEATHER...
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