360 
FNUS76 KPQR 210015
FWSPQR

Spot Forecast for Prairie 9...USFS WIF
National Weather Service Portland OR
515 PM PDT Tue Apr 20 2021

Forecast is based on ignition time of 0700 PDT on April 21. 
If conditions become unrepresentative...contact the National Weather
Service Portland, Oregon office.

.DISCUSSION...North to Northeast flow aloft will continue over
the site through Wednesday. A surface thermal trough was situated
over the Lane County Cascades late this afternoon, but should
retreat back into the foothills and Willamette Valley overnight.
Light offshore low-level flow continues through Wednesday morning
and then becomes onshore late in the day. Thus, expect a general
wind shift from northeast in the morning to more northwest mid to
late afternoon. Stronger onshore flow occurs Wednesday night and
Thursday, which will provide a few degrees of cooling and 
improvement in afternoon humidity. 

.WEDNESDAY...

Sky/weather.........Sunny. 
CWR.................0%. 
LAL.................1. 
Max temperature.....68-72. 
Min humidity........20-25%. 
Wind (20 ft)........ 
 Slope/valley.......Northeast to 6 mph becoming Northwest 5-10 mph 
                    mid to late afternoon. Gusts to 15 mph late in
                    the day. 
 Ridgetop...........East 7-12 mph in the morning, becoming northwest
                    to North 10-15 mph in the afternoon. 
Mixing height.......Near surface then 6000 ft AGL beginning late 
                    morning. 
Transport winds.....Northeast around 7 mph. 
Haines Index(High)..4 (low). 
Haines Index (Mid)..5 (moderate). 
Rainfall amount.....0.00 inches. 

.WEDNESDAY NIGHT...

Sky/weather.........Mostly clear. 
CWR.................0%. 
LAL.................1. 
Min temperature.....43-48. 
Max humidity........75-85%. 
Wind (20 ft)........ 
 Slope/valley.......Northwest 5-10 mph with gusts to 15 mph then
                    decreasing. Wind becoming light Southwest to
                    West overnight. 
 Ridgetop...........Northwest 10-15 mph, easing to 6-9 mph overnight. 
Mixing height.......5000 ft AGL early in the evening then near 500
                    ft AGL overnight.  
Transport winds.....Northwest around 10 mph. 
Haines Index(High)..5 (moderate). 
Haines Index (Mid)..4 (low). 
Rainfall amount.....0.00 inches. 

.THURSDAY...

Sky/weather.........Sunny. 
CWR.................0%. 
LAL.................1. 
Max temperature.....62-66. 
Min humidity........35-40%. 
Wind (20 ft)........ 
 Slope/valley.......Southwest to West to 5 mph in the morning then
                    West to Northwest 6-11 mph by the afternoon.
                    Gusts to 20 mph after 1400.  
 Ridgetop...........Northwest 6-9 mph, becoming West 8-13 mph with
                    gusts to 20 mph in the afternoon. 
Mixing height.......3500 ft AGL. 
Transport winds.....Southwest to 10 mph. 
Haines Index(High)..4 (low). 
Haines Index (Mid)..3 (very low). 
Rainfall amount.....0.00 inches. 

.FORECAST DAYS 3 THROUGH 5...
.FRIDAY...
Partly cloudy. Lows 40-45. Highs 65-70. West winds up to 5 mph.
Minimum humidity 35-40%. 
.SATURDAY...
Rain. Lows 46-51. Highs 53-58. Southwest winds up to 7 mph.
Minimum humidity 50-60%. 
.SUNDAY...
Rain. Lows 43-48. Highs 52-57. Southwest winds up to 7 mph.
Minimum humidity 60-75%. 

$$
Forecaster...Weishaar
Requested by...Matthew Pederson
Type of request...PRESCRIBED
.TAG 2109710.1/PQR
.DELDT 04/20/21
.FormatterVersion 1.0.26
.EMAIL Matthew.pederson@usda.gov