638  
FNUS75 KTWC 180056  
FWSTWC  
 
SPOT FORECAST FOR CATALINA PILES...USFS  
NATIONAL WEATHER SERVICE TUCSON AZ  
556 PM MST MON NOV 17 2025  
 
FORECAST IS BASED ON IGNITION TIME OF 0800 MST ON NOVEMBER 18.  
   
DISCUSSION  
SEVERAL ROUNDS OF STORM SYSTEMS WILL BE IMPACTING  
THE REGION TODAY AND THROUGH MOST OF THE WORK WEEK. RAIN SHOWER  
AND MOUNTAIN SNOW CHANCES ARE LOW FOR TODAY, AROUND 20 PERCENT,  
BUT THOSE CHANCES WILL BE INCREASING TONIGHT AND TOMORROW. SNOW  
LEVELS WILL DROP DOWN TO 8000 FEET BY WEDNESDAY MORNING AND  
BOTTOMING OUT TO 7500 FEET BY THE EVENING. THERE IS A 57 PERCENT  
AT LEAST 2 INCHES OF SNOW TOTALS IN A 24 WINDOW FROM WEDNESDAY  
THROUGH THURSDAY MORNING. SOUTHERLY BREEZES EXPECTED TODAY AND  
LITTLE LESS FOR WEDNESDAY. SLIGHT CHANCES FOR AFTERNOON  
THUNDERSTORMS ON WEDNESDAY WHICH CAN INCREASE RAINFALL AMOUNTS AND  
SNOW AMOUNTS BRIEFLY.  
 
***PLEASE CONTINUE TO SEND OBS TO OUR EMAIL. MUCH APPRECIATED!***  
   
TUESDAY  
 
SKY/WEATHER.........MOSTLY CLOUDY. SLIGHT CHANCE OF RAIN SHOWERS  
EARLY IN THE AFTERNOON. SLIGHT CHANCE OF SNOW  
SHOWERS AND RAIN SHOWERS LATE IN THE AFTERNOON.  
CHANCE OF PCPN......10 PERCENT INCREASING TO 20 PERCENT LATE IN THE  
AFTERNOON.  
MAX TEMPERATURE.....42-45 DEGREES.  
MIN HUMIDITY........70-73 PERCENT.  
20-FOOT WINDS.......SOUTH WINDS 12 TO 15 MPH IN THE MORNING, BECOMING  
14 TO 18 MPH WITH GUSTS UP TO 25 TO 30 MPH IN THE  
AFTERNOON.  
MIXING HEIGHT.......200 FT AGL.  
TRANSPORT WINDS.....SOUTH 12 TO 18 KNOTS.  
 
TIME (MST) 8 AM 11 AM 2 PM 5 PM  
SKY (%).........77 77 84 50  
WEATHER COV..... S CHC S CHC  
WEATHER TYPE....NONE NONE RNSHWR RNSN  
TSTM COV........  
CWR.............10 10 20 20  
TEMP............38 40 41 39  
RH..............79 71 76 78  
20 FT WIND......S 15G20 S 15G21 S 15G21 S 11G16  
MIX HGT (FT)....BLW100 BLW100 200 BLW100  
TRANSPORT WIND..S 16 S 18 S 17 S 12  
   
TUESDAY NIGHT  
 
SKY/WEATHER.........MOSTLY CLOUDY. SLIGHT CHANCE OF RAIN  
SHOWERS AND SNOW SHOWERS LATE IN THE  
THE OVERNIGHT  
CHANCE OF PCPN......20 PERCENT INCREASING TO 50 PERCENT.  
MIN TEMPERATURE.....36-39 DEGREES.  
MAX HUMIDITY........86-89 PERCENT.  
20-FOOT WINDS.......SOUTH WINDS 10 TO 15 MPH WITH GUSTS  
UP TO 25 MPH.  
MIXING HEIGHT.......100 FT AGL.  
TRANSPORT WINDS.....SOUTH AROUND 12 KNOTS.  
 
TIME (MST) 6 PM 9 PM MIDNGT 3 AM  
SKY (%).........62 55 55 60  
WEATHER COV.....S CHC CHANCE CHANCE  
WEATHER TYPE....RNSHWR NONE SNSHWR SNSHWR  
TSTM COV........  
CWR.............20 10 30 30  
TEMP............40 38 38 38  
RH..............81 80 81 85  
20 FT WIND......S 11G24 S 11G20 S 11G18 S 11G15  
MIX HGT (FT)....BLW100 BLW100 BLW100 BLW100  
TRANSPORT WIND..S 12 S 12 S 12 S 12  
   
WEDNESDAY  
 
SKY/WEATHER.........MOSTLY CLOUDY. CHANCE OF SNOW SHOWERS  
THROUGHOUT THE DAY. SLIGHT CHANCE OF  
THUNDERSTORMS LATE IN THE AFTERNOON.  
CHANCE OF PCPN......50 PERCENT INCREASING TO 60 PERCENT LATE IN THE  
MORNING.  
MAX TEMPERATURE.....38-41 DEGREES.  
MIN HUMIDITY........73-76 PERCENT.  
20-FOOT WINDS.......SOUTH WINDS 6 TO 11 MPH SHIFTING TO THE  
SOUTHWEST 8 TO 12 MPH LATE IN THE AFTERNOON.  
GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS LATE IN THE AFTERNOON.  
MIXING HEIGHT.......900 FT AGL.  
TRANSPORT WINDS.....SOUTH 11 TO 16 KNOTS SHIFTING TO THE WEST 7 TO  
10 KNOTS LATE IN THE AFTERNOON.  
 
TIME (MST) 6 AM 9 AM NOON 3 PM  
SKY (%).........66 71 77 82  
WEATHER COV.....CHANCE CHANCE LIKELY LIKELY  
WEATHER TYPE....SNSHWR SNSHWR SNSHWR SNSHWR  
TSTM COV........ S CHC  
CWR.............50 50 60 60  
TEMP............37 38 38 36  
RH..............86 77 78 94  
20 FT WIND......S 11G14 S 10G14 S 9G14 SW 7G13  
MIX HGT (FT)....BLW100 300 600 BLW100  
TRANSPORT WIND..S 12 S 13 S 14 SW 10  
   
FORECAST DAYS 3 THROUGH 5  
   
THURSDAY  
 
MOSTLY CLOUDY. SNOW SHOWERS LIKELY AND SLIGHT CHANCE OF  
THUNDERSTORMS. LOWS IN THE UPPER 20S. HIGHS IN THE LOWER 30S.  
SOUTHWEST WINDS AROUND 6 MPH.    
FRIDAY  
 
PARTLY CLOUDY. SLIGHT CHANCE OF SNOW SHOWERS. LOWS AROUND 30.  
HIGHS IN THE UPPER 30S. SOUTH WINDS AROUND 6 MPH.    
SATURDAY  
 
PARTLY CLOUDY. CHANCE OF SNOW SHOWERS. LOWS IN THE MID 30S. HIGHS  
IN THE LOWER 40S. NORTHEAST WINDS AROUND 6 MPH.  
 
 
FORECASTER...STRONGMAN  
REQUESTED BY...CHAD RICE  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2526200.0/TWC  
.DELDT 11/17/25  
.FORMATTERVERSION 2.0.0  
.EMAIL CHAD.RICE@USDA.GOV  
 
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