852  
FXUS65 KTWC 012206  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
306 PM MST TUE JUL 1 2025  
   
SYNOPSIS  
MONSOON MOISTURE HAS ARRIVED IN SOUTHEAST ARIZONA. THE  
MAIN FOCUS AREA THIS AFTERNOON AND EVENING FOR THUNDERSTORM ACTIVITY  
WILL BE ACROSS EASTERN PIMA, SANTA CRUZ, SOUTHEAST PINAL AND THE  
TOHONO O'ODHAM NATION WHERE STRONG OUTFLOW WINDS AND BLOWING DUST  
EXPECTED WITH THUNDERSTORM ACTIVITY. MORE WIDESPREAD THUNDERSTORM  
ACTIVITY TO INCLUDE A HEAVY RAIN AND LOCALIZED FLASH FLOOD THREAT  
ALONG WITH GUSTY WINDS WEDNESDAY. A DRYING TREND IS EXPECTED FOR  
THE JULY 4TH HOLIDAY AND THIS WEEKEND WITH STORM COVERAGE MORE  
ISOLATED AND FOCUSED FROM TUCSON SOUTHWARD. TEMPERATURES WILL DROP  
TO NEAR NORMAL LEVELS BY WEDNESDAY, THEN BELOW NORMAL TO END THE  
WEEK BEFORE WARMING BACK UP TO NEAR TO SLIGHTLY ABOVE NORMAL THIS  
WEEKEND AND EARLY NEXT WEEK.  
 
 
   
DISCUSSION  
THE SUSPENDED DUST FROM THE STRONG AND GUSTY  
THUNDERSTORM OUTFLOWS YESTERDAY CONTINUE TO SLOWLY SETTLE OUT OF  
THE AIR THIS AFTERNOON...BUT A SIGNIFICANT HAZE RESIDES ACROSS ALL  
OF SOUTHEAST ARIZONA. UNFORTUNATELY, CONDITIONS ARE RIPE FOR  
ANOTHER ROUND OF ISOLATED TO SCATTERED THUNDERSTORMS TO PRODUCE  
OUTFLOW WIND GUSTS TO 40-50 MPH THIS AFTERNOON/EVENING...RESULTING  
IN ADDITIONAL BLOWING DUST ACROSS CENTRAL PIMA (TOHONO O'ODHAM  
NATION), EASTERN PIMA (TUCSON METRO AREA) AND SOUTHEAST PINAL  
COUNTIES. THERE IS A BLOWING DUST ADVISORY IN EFFECT UNTIL 8 PM  
MST.  
 
THE UPPER PATTERN THIS AFTERNOON IS DEFINED BY A 500 MB HIGH CENTERED  
OVER NORTHERN ARIZONA AND AN ESTABLISHED UPPER TROUGH ACROSS THE  
CALIFORNIA COASTLINE. THE LATEST GOES TOTAL PRECIPITABLE WATER  
IMAGERY INDICATED VALUES BETWEEN 0.95 AND 1.10 INCHES ACROSS ALL  
OF SOUTHEAST ARIZONA, WITH 1.50 INCHES NUDGING NORTHWARD INTO  
CENTRAL SONORA MEXICO.  
 
THUNDERSTORMS DEVELOPMENT TODAY WILL INITIALLY OCCUR ACROSS SOUTH  
CENTRAL ARIZONA (S TO SSW OF TUCSON) AND THE EAST CENTRAL  
MOUNTAINS OF ARIZONA. THE ARE TO THE SOUTH COINCIDES WITH THE  
BEST AREA OF DEEP-LAYER MOISTURE FLUX CONVERGENCE SEEN ON THE SPC  
MESOSCALE ANALYSIS. ALTHOUGH THIS IS WHERE THE DEEPER LOWER-TO-MID  
LEVEL MOISTURE IS MOVING INTO THE AREA, THE LOWER-LEVELS STILL  
REMAIN FAIRLY DRY WHICH WILL ENHANCE DOWNDRAFTS. EXPECT STRONG  
THUNDERSTORM OUTFLOW WINDS TO 40-50 MPH TO PRODUCE BLOWING DUST  
AGAIN THIS AFTERNOON. THE DEVELOPMENT THAT OCCURS IN THE WHITE  
MOUNTAINS WILL MOVE WSW TOWARD PINAL COUNTY AS THE AFTERNOON  
PROGRESSES. THE OUTFLOWS FROM THESE STORMS AND THE AFOREMENTIONED  
STORMS IN SOUTH-CENTRAL ARIZONA WILL FOCUS THE AREA OF BLOWING  
DUST ACROSS THE CENTRAL PORTIONS OF OUR CWA.  
 
THAT DEEPER MOISTURE SOUTH OF CENTRAL SONORA MEXICO WILL CONTINUE  
TO NUDGE ITS WAY INTO OUR NECK OF THE WOODS WEDNESDAY SHIFTING  
THE THREAT FROM THUNDERSTORMS WITH STRONG THUNDERSTORM OUTFLOWS  
TO MORE OF A HEAVY RAINFALL THREAT. THE UPPER TROUGH OVER  
CALIFORNIA BEGINS TO SHIFT EAST WEDNESDAY...AND AS IT DOES, IT  
PROVIDES AN NICE ENHANCEMENT TO THE LIFT DUE TO THE DIFFLUENCE  
ALOFT. THE 01/12Z HREF INDICATED THE HEAVIEST RAINFALL WILL OCCUR  
ALONG A LINE FROM SELLS TO NOGALES TOMORROW AFTERNOON, WITH A 70%  
CHANCE OF 3-HR RAINFALL IN EXCESS OF AN INCH, AND EVEN A 10%  
CHANCE OF RAINFALL IN EXCESS OF 3 INCHES ACROSS PORTIONS OF SANTA  
CRUZ COUNTY. GIVEN THE COMBINATION OF THE DEEPER ATMOSPHERIC  
MOISTURE IN PLACE, AND THE UPPER LIFT PROVIDED BY THE APPROACHING  
UPPER TROUGH, WE HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH  
WEDNESDAY BETWEEN 11 AM MST AND 11 PM MST. WE EXTENDED THE AREA OF  
THE FLASH FLOOD WATCH TO INCLUDE EASTERN PIMA COUNTY (TUCSON  
METRO AREA) AND WESTERN COCHISE COUNTY (SIERRA VISTA). IT HAS BEEN  
A LONG TIME SINCE WE HAVE SEEN A SOLID RAINFALL ACROSS THE  
FORECAST AREA. WE ARE HOPING THE FFA WILL ASSIST US IN MESSAGING  
THE IMPORTANCE OF STAYING SAFE WHEN ENCOUNTERING RUNNING WATER OF  
UNKNOWN DEPTH IN NORMALLY DRY WASHES, ROADWAY DIPS AND OTHER LOW-  
LYING AREAS...ESPECIALLY IN URBAN AREAS.  
 
WE WILL SEE A DRYING TREND FOR THE FOURTH OF JULY HOLIDAY, WITH  
ONLY ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED. DEEPER MOISTURE  
RETURNS EARLY NEXT WEEK, AND A MORE FAVORABLE FLOW PATTERN WILL  
INCREASE CHANCES OF THUNDERSTORMS AS WE MOVE TOWARD THE MIDDLE OF  
NEXT WEEK.  
 
 
   
AVIATION  
VALID THROUGH 03/00Z. SCT-BKN 7-12K FT AGL THRU  
02/06Z, BECOMING SCT-BKN 12-15K FT AGL OVERNIGHT, THEN SCT-BKN  
5-10K FT AGL AFT 02/18Z. SFC WINDS ELY/SELY AT 5-15 KTS WITH  
GUSTS 20-25 KTS. EXPECT SCATTERED -SHRA/-TSRA THRU 02/03Z WITH  
KTUS/KOLS MOST LIKELY TERMINALS TO BE IMPACTED (~40-50% CHANCE).  
SCATTERED TO NUMEROUS -SHRA/-TSRA WILL OCCUR AFTER 02/18Z  
WEDNESDAY WITH CIGS BKN 5-8K FT AGL. STORMS THAT DEVELOP THIS  
AFTERNOON AND EVENING WILL PRODUCE GUSTY OUTFLOW WINDS GREATER  
THAN 35 KTS WITH REDUCED VISIBILITY DUE TO LOCALIZED BLDU.  
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.  
 
 
   
FIRE WEATHER  
HOT THIS AFTERNOON COOLING TO AROUND CLIMATOLOGICAL  
NORMAL THROUGH SATURDAY AS DEEPER ATMOSPHERIC MOISTURE MOVES INTO  
SOUTHEAST ARIZONA, THEN WARMING BACK UP SUNDAY INTO EARLY NEXT  
WEEK. MIN RH'S 15 TO 30 PERCENT TODAY WITH SCATTERED SHOWERS AND  
THUNDERSTORMS FOR MOST OF SOUTHEAST ARIZONA. EVEN HIGHER MOISTURE  
LEVELS MOVE IN FOR WEDNESDAY AND THURSDAY WITH POTENTIAL THAT SOME  
OF THE THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. SOME  
DRYING WILL TEND TO LOWER THUNDERSTORM CHANCES TO AROUND 20 TO 30  
PERCENT FRIDAY INTO THE WEEKEND WITH THE HIGHEST CHANCES ALONG THE  
INT'L BORDER. GUSTY EAST TO SOUTHEAST WINDS TODAY WITH GUSTY AND  
ERRATIC WINDS TO 40-50 MPH NEAR ANY THUNDERSTORMS. OTHERWISE  
WINDS GENERALLY LIGHT AND UNDER 15 MPH.  
 
 
   
TWC WATCHES/WARNINGS/ADVISORIES  
 
BLOWING DUST ADVISORY UNTIL 8 PM MST THIS EVENING FOR AZZ502>506-  
515.  
 
FLOOD WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR  
AZZ502>504-507-513>515.  
 
 
 
 
 
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab AZ Page
Main Text Page