233  
FXUS65 KTWC 212033  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
133 PM MST THU AUG 21 2025  
   
SYNOPSIS
 
DAILY CHANCES FOR THUNDERSTORMS AND RAIN SHOWERS FOR  
SOUTHEAST ARIZONA WITH DAY TO DAY VARIABILITY ON COVERAGE AND  
INTENSITY. ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND AND THEN  
TRENDING DOWN TO NEAR NORMAL BY THE START OF THE NEW WEEK. AN EXTREME  
HEAT WARNING IN EFFECT TODAY THROUGH FRIDAY AND A BLOWING DUST  
ADVISORY IS IN EFFECT TODAY FROM 4 PM TO 9 PM THIS EVENING.  
 

 
   
DISCUSSION
 
A FIELD OF CUMULUS CLOUDS HAVE DEVELOPED ACROSS THE  
REGION SOME BEGINNING TO TOWER. DUE TO THE LOCATION OF HIGH  
PRESSURE, STORMS AND SHOWERS WILL INITIATE ALONG THE HIGHER  
TERRAIN AND MOVE WEST TO SOUTHWEST ACROSS THE REGION. COCHISE  
COUNTY WILL HAVE DRIER AIR, LEADING TO LOWER CHANCES FOR RAIN  
SHOWERS AND THUNDERSTORMS. THE 12Z HREF SHOWS THERE IS A 10%  
CHANCE FOR 50KT WINDS THIS AFTERNOON AND WITH THE 18Z SOUNDING  
LAUNCHED AT TUS SHOWING 1200 J/KG DCAPE, THE MAIN CONCERN WITH  
THUNDERSTORMS THIS AFTERNOON IS STRONG OUTFLOW WINDS AND BLOWING  
DUST. THERE IS A BLOWING DUST ADVISORY FOR THE AREA BETWEEN  
TUCSON AND PHOENIX ALONG I-10 FROM 4 PM TO 9 PM THIS EVENING.  
EXPECT VISIBILITIES TO DROP BETWEEN 1/4 TO 1 MILE IN BLOWING  
DUST. THE EXTREME HEAT WARNING IS STILL IN EFFECT TODAY THROUGH  
TOMORROW EVENING FOR THE LOWER ELEVATIONS OF MOST OF SOUTHERN  
ARIZONA. REMEMBER TO STAY HYDRATED AND SPEND TIME INDOORS WITH  
A/C. IF YOU NEED TO SPEND TIME OUTSIDE, WEAR LIGHT WEIGHT, LIGHT  
COLORED CLOTHING AND TAKE FREQUENT BREAKS. TAKE TIME TO LEARN THE  
SIGNS OF HEAT EXHAUSTION AND HEAT STROKE, KEEPING IN MIND THAT  
HEAT STROKE IS AN EMERGENCY.  
 
THE FOUR CORNERS HIGH WILL CONTINUE TO INFLUENCE THE REGION. THE  
HIGH NOW OVAL SHAPED, IS BRING NORTHEASTERLY FLOW ACROSS  
SOUTHEASTERN ARIZONA. HEAT IS STILL A CONCERN THROUGH TOMORROW AS  
LOW ELEVATIONS WILL BE ABOVE 100 DEGREES TO 110 DEGREES WITH  
LITTLE OVERNIGHT REPRIEVE. THOSE AREAS WILL EXPERIENCE MAJOR  
HEATRISK TO ISOLATED AREAS OF EXTREME HEATRISK THROUGH FRIDAY. WE  
WILL BE TRENDING DOWN SLIGHTLY IN TEMPERATURES THIS WEEKEND BUT  
AREAS WILL BE ON THE CUSP ON MAJOR HEATRISK PER CLIMATOLOGY.  
OVERNIGHT TEMPERATURES WILL CONTINUE TO BE HIGH WITH WIDESPREAD  
MAJOR HEATRISK OVERNIGHT.  
 
BY THE WEEKEND, DRYER AIR WILL PUSH MORE INTO THE REGION, BUT  
THERE WILL BE ENOUGH INSTABILITY AND MOISTURE TO GIVE DAILY  
CHANCES. HIGHER TERRAIN WILL NATURALLY BE THE BETTER AREAS FOR  
THOSE RAIN CHANCES. THE FOUR CORNERS HIGH WILL TRANSFORM ITSELF TO  
RIDGE THROUGH THE GREAT BASIN BY THE START OF THE NEW WEEK. PLUS,  
TROUGHINESS WILL DEVELOP NEAR THE PACIFIC COAST. THIS WILL OPEN  
UP SOUTHEASTERLY TO SOUTHERLY FLOW OF DEEP MONSOON MOISTURE BACK  
INTO THE REGION. ENSEMBLE MODELS SHOW OUR PAWTS SHOOTING UP TO  
1.4-1.6 INCHES AT TUCSON WITH HIGHER VALUES TOWARDS YUMA. THIS  
TONGUE OF MOISTURE WILL PROVIDE BETTER CHANCES AND COVERAGE FOR  
RAIN SHOWERS AND THUNDERSTORMS. AS OF THIS FORECAST, TUESDAY  
THROUGH WEDNESDAY APPEAR TO BE THE WETTEST DAYS IN THE FORECAST  
PERIOD. INCREASE MOISTURE WILL LOWER OUR TEMPERATURES AND LEANING  
BELOW NORMAL THROUGH THE NEW WEEK.  
 

 
   
AVIATION
 
VALID THROUGH 23/00Z.  
 
FEW TO SCT CLOUDS AOA 7K TO 10K FT AGL WITH ACROSS THE REGION. BY  
ISOLATED TO SCATTERED -SHRA/-TSRA FORMING ALONG THE HIGHER  
TERRAIN AND MOVING WESTWARD FROM 21/22 THROUGH 22/06Z. LINGERING  
-SHRA IS POSSIBLE THROUGH 22/10Z. SFC WINDS WILL GENERALLY BE  
EASTERLY- SOUTHEASTERLY LESS THAN 12 KTS THROUGH THE FORECAST  
PERIOD. EXPECT GUSTY AND ERRATIC WINDS WITH ANY -TSRA. AVIATION  
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.  
 

 
   
FIRE WEATHER
 
EXPECT DAILY CHANCES FOR RAIN SHOWERS AND  
THUNDERSTORMS INTO THE NEW WEEK. DRYER AIR WILL BE MOVING INTO THE  
REGION TO CREATE DAY TO DAY VARIABILITY OF INTENSITY AND  
COVERAGE. TEMPERATURES WILL BE RUNNING ABOVE NORMAL THROUGH THE  
WEEKEND WITH AN EXTREME HEAT WARNING IN EFFECT THROUGH FRIDAY IN  
THE LOWER ELEVATIONS. WINDS WILL GENERALLY REMAIN LESS THAN 15 MPH  
WITH THE AFTERNOON GUSTINESS INTO THE NEW WEEK. MIN RHS WILL BE  
15-20 PERCENT IN THE LOW ELEVATIONS AND 20-30 IN THE MOUNTAINS  
THROUGH THE WEEKEND. DEEP MONSOON MOISTURE WILL RETURN EARLY NEXT  
WEEK TO PROVIDE HIGHER WETTING RAIN CHANCES AND COVERAGE AS WELL  
AS BETTER MIN RHS AND BELOW NORMAL TEMPERATURES.  
 

 
 

 
   
TWC WATCHES/WARNINGS/ADVISORIES
 
 
EXTREME HEAT WARNING UNTIL 8 PM MST FRIDAY FOR AZZ501>507-509.  
 
BLOWING DUST ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM MST THIS  
EVENING FOR AZZ502-504>506.  
 

 
 

 
 
MALARKEY/ STRONGMAN  
 
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