825  
FNUS76 KPQR 202045  
FWSPQR  
 
SPOT FORECAST FOR COLLINS SLIDE PILES...USFS  
NATIONAL WEATHER SERVICE PORTLAND OR  
1245 PM PST MON JAN 20 2025  
 
FORECAST IS BASED ON IGNITION TIME OF 1000 PST ON JANUARY 21.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION  
A WEAK UPPER LEVEL TROUGH WILL RESULT IN BREEZY  
WESTERLY WINDS THROUGH THE COLUMBIA RIVER GORGE ON TUESDAY WITH NO  
PRECIPITATION EXPECTED. DAYTIME HUMIDITY WILL BE WELL-ABOVE  
CRITICAL THRESHOLDS THROUGH THE TIME PERIOD, BUT EXPECT MODERATE  
TO HIGH OVERNIGHT HUMIDITY RECOVERIES. SURFACE HIGH PRESSURE WILL  
RE-BUILD EAST OF THE CASCADES TUESDAY NIGHT, RETURNING LIGHT  
EASTERLY WINDS THROUGH THE GORGE BY EARLY WEDNESDAY MORNING.  
UPPER LEVEL HIGH PRESSURE RE-BUILDS OVER THE REGION ON WEDNESDAY,  
MAINTAINING DRY WEATHER.  
   
TUESDAY  
 
SKY/WEATHER.........PARTLY CLOUDY THEN BECOMING MOSTLY SUNNY THEN  
BECOMING PARTLY CLOUDY.  
CWR.................0 PERCENT.  
MAX TEMPERATURE.....AROUND 46.  
MIN HUMIDITY........44-49 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......WEST WINDS 8 TO 11 MPH WITH GUSTS TO AROUND 20 MPH.  
MIXING HEIGHT.......3200 FT AGL.  
TRANSPORT WINDS.....WEST 12 TO 17 MPH.  
HAINES INDEX........4 (LOW).  
HAINES INDEX (MID)..4 (LOW).  
 
TIME (PST) 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........27 33 21 26 36 37 42 42  
CWR.............0 0 0 0 0 0 0 0  
TEMP............38 40 43 44 45 46 44 43  
RH..............56 55 52 50 49 49 52 54  
20 FT WIND DIR..NW W W W W W W W  
20 FT WIND SPD..10 11 11 11 11 10 8 8  
20 FT WIND GUST.17 18 18 18 18 17 16 16  
RIDGE WIND DIR..M M M M M M M M  
RIDGE WIND SPD..M M M M M M M M  
MIX HGT (KFT)...2.5 2.9 2.9 3.2 3.0 2.6 2.1 2.0  
TRANSP WIND DIR.W W W W W W W W  
TRANSP WIND SPD.13 14 15 17 16 15 12 12  
HAINES INDEX....4 4 4 4 4 4 4 4  
HAINES MID LVL..4 4 4 4 4 4 4 4  
   
TUESDAY NIGHT  
 
SKY/WEATHER.........PARTLY CLOUDY.  
CWR.................0 PERCENT.  
MIN TEMPERATURE.....AROUND 33.  
MAX HUMIDITY........58-63 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......WEST WINDS 5 TO 8 MPH WITH GUSTS TO AROUND 16  
MPH SHIFTING TO THE EAST AROUND 5 MPH AFTER  
3-5 AM.  
MIXING HEIGHT.......1900 FT AGL.  
TRANSPORT WINDS.....WEST 6 TO 12 MPH SHIFTING TO THE EAST AROUND 6  
MPH AFTER 3 AM.  
HAINES INDEX........4 (LOW).  
HAINES INDEX (MID)..4 (LOW).  
 
TIME (PST) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM  
SKY (%).........42 17 18 18 18 17  
CWR.............0 0 0 0 0 0  
TEMP............42 39 37 36 35 35  
RH..............56 59 61 63 62 61  
20 FT WIND......W 8 W 6 W 6 W 6 W 5 E 5  
20 FT WIND GUST.16 12 11 11 10 10  
MIX HGT (FT)....2000 2000 1900 2000 2000 2000  
TRANSPORT WIND..W 12 W 10 W 8 W 7 NW 6 E 6  
HAINES INDEX....4 4 4 4 4 4  
HAINES MID LVL..4 4 4 4 4 4  
   
WEDNESDAY  
 
SKY/WEATHER.........MOSTLY SUNNY THEN BECOMING PARTLY CLOUDY.  
CWR.................0 PERCENT.  
MAX TEMPERATURE.....AROUND 42.  
MIN HUMIDITY........49-54 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......EAST WINDS 5 TO 7 MPH.  
MIXING HEIGHT.......3000 FT AGL.  
TRANSPORT WINDS.....EAST 7 TO 13 MPH.  
HAINES INDEX........4 (LOW).  
HAINES INDEX (MID)..4 (LOW).  
 
TIME (PST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........17 20 20 20 22 22 22 19 19 19 33 33  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............34 34 35 35 36 38 39 41 41 41 41 40  
RH..............63 63 63 62 60 58 56 54 54 54 55 56  
20 FT WIND DIR..E E E E E E E E E E E E  
20 FT WIND SPD..5 6 6 6 7 7 7 7 7 7 7 7  
20 FT WIND GUST.10 10 10 10 13 13 13 13 13 13 13 13  
MIX HGT (KFT)...1.9 2.0 2.1 2.3 2.5 2.7 2.9 3.0 2.8 2.6 2.3 2.2  
TRANSP WIND DIR.E E E E E E E E E E E E  
TRANSP WIND SPD.7 8 9 12 13 13 13 13 13 13 13 12  
HAINES INDEX....4 4 4 4 4 4 4 4 4 4 4 4  
HAINES MID LVL..4 4 4 4 4 4 4 4 4 4 4 4  
 
 
FORECASTER...ALVIZ  
REQUESTED BY...LAUREN CLARK  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2500929.0/PQR  
.DELDT 01/20/25  
.FORMATTERVERSION 2.0.0  
.EMAIL LAUREN.CLARK@USDA.GOV  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab OR Page
The Nexlab WA Page
Main Text Page