299  
FXUS65 KPSR 252310  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
410 PM MST SAT JAN 25 2020  
   
UPDATE
 
UPDATED AVIATION DISCUSSION.  
 

 
   
SYNOPSIS
 
 
SLIGHTLY ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE  
WEEKEND AS HIGH PRESSURE PREDOMINATES ACROSS THE WESTERN STATES. A  
SERIES OF WEAK LOW PRESSURE SYSTEMS WILL MOVE THROUGH THE FOUR  
CORNERS NEXT WEEK. HOWEVER, ONLY LIGHT PRECIPITATION IS EXPECTED  
ACROSS THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX.  
 

 
   
DISCUSSION
 
 
MESOANALYSIS THIS AFTERNOON WAS SHOWING AN UPPER RIDGE BUILDING INTO  
THE WESTERN CONUS AS DRY NORTHWESTERLY FLOW ALOFT PROMOTED MOSTLY  
CLEAR SKIES ACROSS THE REGION. SUNDAY WILL BE SIMILAR TO TODAY AS  
MOSTLY CLEAR SKIES PERSIST AND TEMPERATURES WARM UP INTO THE 70S  
DURING THE AFTERNOON ACROSS THE LOWER DESERTS. PHOENIX IS FORECAST  
TO HIT A HIGH OF 73 DEGREES TOMORROW AFTERNOON, WHICH IS SEVERAL  
DEGREES ABOVE SEASONAL NORMALS.  
 
NOT MUCH HAS CHANGED IN REGARDS TO NEXT WEEK'S FORECAST NARRATIVE. A  
COUPLE OF DISTURBANCES ARE STILL SET TO MOVE THROUGH THE DESERT  
SOUTHWEST WITH RAIN CHANCES REMAINING MINIMAL ACROSS SOUTH-CENTRAL  
ARIZONA. THE FIRST SHORTWAVE WILL PROPAGATE SOUTHEASTWARD INTO THE  
STATE SUNDAY NIGHT INTO MONDAY. VIRTUALLY ALL ECMWF EPS AND GEFS  
PLUME MEMBERS KEEP ANY MEASURABLE RAIN TO THE NORTHEAST OF OUR AREA.  
CURRENT POPS ACROSS SOUTH-CENTRAL ARIZONA REMAIN IN THE SINGLE  
DIGITS WHILE SLIGHTLY HIGHER CHANCES REMAIN OVER SOUTHERN GILA  
COUNTY. MINOR BREEZINESS WILL FOLLOW THE PASSAGE OF THIS WAVE WITH  
MINIMAL COOLING EXPECTED.  
 
A SECOND STRONGER DISTURBANCE IS FORECAST TO DIVE DOWN FROM THE  
PACIFIC NORTHWEST INTO ARIZONA WEDNESDAY. FORECAST POPS REMAIN IN  
THE SINGLE DIGITS ACROSS THE LOWER DESERTS WITH BETTER RAIN CHANCES  
OVER SOUTHERN GILA COUNTY. BEST CHANCES FOR ANY MEASURABLE PRECIP  
WILL REMAIN EAST OVER THE HIGHER TERRAIN THOUGH AMOUNTS LOOK TO  
REMAIN LOW GIVEN THE DRY INLAND TRAJECTORY OF THIS SYSTEM. THE  
BIGGEST IMPACT OF THIS SYSTEM WILL BE THE GENERATION OF STRONG GUSTY  
NORTHERLY WINDS OVER THE DESERTS WEST OF PHOENIX WITH SOME OF THE  
STRONGEST WINDS OCCURRING NEAR THE LOWER COLORADO RIVER VALLEY.  
WINDS MAY REACH ADVISORY LEVELS, BUT IT IS TOO EARLY TO SAY THIS FAR  
OUT. THURSDAY INTO FRIDAY, AMPLIFIED RIDGING BUILDS BACK INTO THE  
DESERT SOUTHWEST WITH TRANQUIL WEATHER CONDITIONS PREVAILING. FOR  
THE PHOENIX AREA OVERALL, DRY CONDITIONS ARE FAVORED TO CONTINUE  
OVER THE NEXT 7 DAYS.  
 

 
   
AVIATION
 
UPDATED AT 2310Z.  
 
SOUTH-CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT...  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
THERE ARE NO MAJOR AVIATION WEATHER CONCERNS THROUGH THE TAF  
PERIOD. WINDS WILL REMAIN LIGHT, MOSTLY AT OR BELOW 7 KTS, WITH  
DIRECTIONS FAVORING DIURNAL DIRECTIONAL TENDENCIES. THERE WILL  
ALSO BE PERIODS OF CALM/VARIABLE WINDS.  
 

 
   
FIRE WEATHER
 
 
SATURDAY THROUGH WEDNESDAY: TEMPERATURES WILL WARM TO ABOVE SEASONAL  
NORMAL LEVELS DURING THE PERIOD WITH WARMER DESERTS GENERALLY LOW TO  
MIDDLE 70S EACH DAY. CONDITIONS WILL BE MOSTLY DRY WITH MINIMUM  
HUMIDITY VALUES DROPPING INTO THE 20-30% RANGE ACROSS THE LOWER  
DESERT AND 30-40% RANGE FOR THE HIGHER TERRAIN. IT WILL BE SLIGHTLY  
DRIER NEXT TUESDAY AND WEDNESDAY AS DESERT HUMIDITY LEVELS FALL INTO  
THE UPPER TEENS IN MANY AREAS. WINDS WILL REMAIN FAIRLY LIGHT  
ALTHOUGH THE LOWER COLORADO RIVER VALLEY MAY SEE SOME GUSTS UP TO 20  
MPH THURSDAY AND FRIDAY. THERE ARE INDICATIONS THAT ANOTHER WEATHER  
SYSTEM COULD BRING A SLIGHT CHANCE FOR RAIN EARLY NEXT WEEK MAINLY  
OVER HIGH TERRAIN AREAS TO THE EAST OF PHOENIX.  
 

 
   
SPOTTER INFORMATION STATEMENT
 
 
SPOTTERS SHOULD FOLLOW STANDARD REPORTING PROCEDURES.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...NONE.  
CA...NONE.  

 
 

 
 
DISCUSSION...SMITH/CB  
AVIATION...HODGES/DEEMS  
FIRE WEATHER...DEEMS/CB  
 
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