653  
FXUS65 KTWC 102104  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
204 PM MST FRI MAY 10 2024  
   
SYNOPSIS
 
 
WARM, DRY, AND BREEZY CONDITIONS CONTINUE THROUGH THE WEEKEND. DAILY  
HIGH TEMPERATURES WILL BE NEAR NORMAL THROUGH THE WEEKEND, THEN  
SEVERAL DEGREES ABOVE NORMAL NEXT WEEK.  
 

 
   
DISCUSSION
 
 
AN UPPER LOW WILL SLOWLY SHIFT FROM THE GREAT BASIN EASTWARD PAST  
THE CENTRAL-SOUTHERN ROCKIES THROUGH THIS WEEKEND. THIS PATTERN  
PUTS SOUTHERN ARIZONA UNDER PERSISTENT TIGHTENED AND INCREASED  
FLOW ALOFT, WHICH CONTINUES NEXT WEEK AS A SUBTROPICAL JET LOOKS  
TO REMAIN IN THE VICINITY. THIS WILL LIKELY LEAD TO AFTERNOON  
BREEZINESS THROUGH MUCH OF THE FORECAST PERIOD THROUGH NEXT WEEK.  
WITHOUT ANY MAJOR FLUCTUATIONS IN FLOW OVER THE NEXT SEVERAL  
DAYS, NO CHANGES FROM THE CURRENT DRY WEATHER IS EXPECTED.  
AFTERNOON MINIMUM RELATIVE HUMIDITIES REMAIN DRY WITH VALUES DOWN  
TO THE SINGLE DIGITS IN THE VALLEYS, BUT FOR THE MOST PART WINDS  
LOOK TO STAY LIGHT ENOUGH TO PREVENT MORE CONCERNING FIRE WEATHER  
CONDITIONS. THE EXCEPTION WILL BE TOMORROW AS THE UPPER LOW IS  
CROSSING THE AREA TO THE NORTH, WHICH SHOULD PRODUCE SUSTAINED  
WINDS OF 15 TO 20 MPH. THIS MAY PRODUCE NEAR CRITICAL FIRE WEATHER  
CONDITIONS TOMORROW AFTERNOON, ESPECIALLY IN AREAS CLOSER TO THE  
NEW MEXICO BORDER.  
 
THE PATTERN REMAINS DRY THROUGH EARLY NEXT WEEK WHILE A SHORTWAVE  
RIDGE IS EXPECTED TO CROSS THE REGION. THEN A SOUTHERN STREAM  
TROUGH SHOULD CROSS SOUTHERN ARIZONA THROUGH THE MIDDLE OF THE  
WEEK. THE LACK OF ANY NOTABLE MOISTURE WITH THIS PASSAGE KEEPS THE  
FORECAST MOSTLY DRY, THOUGH WITH A SLIGHT CHANCE OF SHOWERS OR  
THUNDERSTORMS IN THE WHITES WHICH WILL BE ON THE EDGE OF BETTER  
INSTABILITY TO THE NORTH.  
 
TOWARDS THE END OF NEXT WEEK ENSEMBLE TEMPERATURE PROBABILITIES  
FAVOR A RISE IN TEMPERATURES WHERE HIGHS INTO THE UPPER 90S WOULD  
BE POSSIBLE. THE 500MB SOLUTIONS HOWEVER SHOW A FAR AMOUNT OF  
DISAGREEMENT IN THE UPPER LEVEL PATTERN DURING THIS PERIOD,  
LEADING TO A LESS CERTAIN FORECAST FOR THIS TREND. EC/GEFS/CMC  
MEAN 500MB HEIGHTS STILL FAVOR SOME SORT OF UPPER LEVEL HEIGHT  
GROWTH, SO THE QUESTION IS LIKELY AT WHAT POINT DO TEMPERATURES  
WARM FURTHER AND IF A FEW DEGREES ABOVE NORMAL OR WELL ABOVE  
NORMAL IS MORE LIKELY.  
 

 
   
AVIATION
 
VALID THROUGH 12/00Z.  
SKIES SKC THRU THE VALID FORECAST PERIOD. SFC WINDS WESTERLY TO  
NORTHWESTERLY AT 10-15 KTS WITH GUSTS OF 20-25 KTS. AFTER 11/04Z,  
SFC WINDS RETURN TO TYPICAL DIURNAL .AVIATION...WIND SHIFTS AND  
LESS THAN 10 KTS THROUGH 11/18Z. TOMORROW SFC WINDS WESTERLY TO  
NORTHWESTERLY WITH SPEEDS OF 10-15 KTS AND OCCASIONAL GUSTS TO  
AROUND 25 KTS THROUGH END OF PERIOD. AVIATION DISCUSSION NOT  
UPDATED FOR TAF AMENDMENTS.  
 

 
   
FIRE WEATHER
 
 
AFTERNOON TEMPERATURES NEAR TO SLIGHTLY ABOVE NORMAL WILL PERSIST  
INTO NEXT WEEK. MIN RH VALUES WILL REMAIN IN THE SINGLE DIGITS TO  
LOWER TEENS IN THE VALLEYS, WITH VALUES GENERALLY IN THE TEENS  
FOR THE MOUNTAINS. TOMORROW AND SUNDAY, BREEZY WEST TO NORTHWEST  
WINDS 15-20 MPH COMBINED WITH ALREADY LOW RELATIVE HUMIDITY IN  
PLACE MAY RESULT IN NEAR CRITICAL FIRE WEATHER CONDITIONS.  
OTHERWISE, TYPICAL AFTERNOON BREEZINESS WILL PERSIST INTO NEXT  
WEEK EACH AFTERNOON DUE TO DAYTIME HEATING. WINDS BECOME LIGHT AND  
VARIABLE OVERNIGHT.  
 

 
   
TWC WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
PUBLIC...EDWARDS  
AVIATION...STRONGMAN  
FIRE WEATHER....EDWARDS  
 
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON  
 
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