FNUS76 KPQR 212137 FWSPQR SPOT FORECAST FOR SHADOW LAKE...USFS WNF NATIONAL WEATHER SERVICE PORTLAND OR 237 PM PDT WED SEP 21 2011 FORECAST IS BASED ON REQUEST TIME OF 1400 PDT ON SEPTEMBER 21. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. ...LITTLE CHANGE EXPECTED THURSDAY... .DISCUSSION...THE OVERALL LARGE-SCALE WEATHER PATTERN THURSDAY WILL REMAIN BASICALLY UNCHANGED FROM WEDNESDAY. WEAK SURFACE GRADIENTS THURSDAY WILL LEAD TO TERRAIN-DRIVEN WIND PATTERNS OVER THE FIRE. THE UPPER RIDGE WILL CONTINUE TO WEAKEN TONIGHT AND THURSDAY IN RESPONSE TO A STRONG FRONTAL SYSTEM HEADED TOWARD NORTHWEST WASHINGTON. THUS...THURSDAY SHOULD BE A BIT COOLER WITH A LITTLE HIGHER DAYTIME HUMIDITY. THE MAIN ISSUE THURSDAY WILL BE STRONGER WIND ALOFT...WHICH COULD EASILY MIX DOWN TO THE SURFACE DURING THE AFTERNOON. IN THE EXTENDED PERIOD...THE UPPER RIDGE STRENGTHENS FRIDAY. THE LATEST COMPUTER CHARTS STILL HINT AT A WEAK SURFACE THERMAL TROUGH SETTING UP NEAR THE CASCADES FRIDAY AFTERNOON. ALTHOUGH NOT A MAJOR CONCERN FOR WIND...THE INCREASED MID-LEVEL INSTABILITY COULD BOOST HAINES VALUES TO 5. THE UPPER RIDGE SHIFTS EAST SATURDAY...ALLOWING SOUTH FLOW ALOFT TO SPREAD OVER THE WILLAMETTE NATIONAL FOREST. A FRONTAL SYSTEM APPROACHES THE COAST SUNDAY. THE INCREASED MID-LEVEL MOISTURE MAY RESULT IN A THREAT OF SHOWERS OR EVEN THUNDERSTORMS SUNDAY AFTERNOON. .TONIGHT... SKY/WEATHER.........MOSTLY CLEAR. CWR (%).............0 PERCENT. MIN TEMPERATURE.....48 TO 53...BUT 53 TO 57 ON MID/UPPER SLOPES. MAX HUMIDITY........GENERALLY AT OR ABOVE 75 PERCENT...BUT DOWN TO 50-60 PERCENT MID/UPPER SLOPES AND RIDGES. WIND (20 FT)........VALLEYS/LOWER SLOPES: SOUTHWEST TO WEST 3 TO 6 MPH THROUGH 1900 THEN EAST OR DOWN-SLOPE TO 3 MPH. RIDGES: SOUTHWEST TO WEST 3 TO 7 MPH. HAINES INDEX(HIGH)..4 (LOW). .THURSDAY... SKY/WEATHER.........PARTLY CLOUDY. CWR (%).............0 PERCENT. MAX TEMPERATURE.....75 TO 80...BUT 70 TO 75 AT 5000 FEET. MIN HUMIDITY........30 TO 40 PERCENT...BUT DOWN TO 25 PERCENT SOUTH ASPECTS AND EXPOSED RIDGES. WIND (20 FT)........VALLEYS/LOWER SLOPES: EAST TO 4 MPH IN THE MORNING THEN WEST TO SOUTHWEST 4 TO 9 MPH. AFTERNOON GUSTS UP TO 15 MPH. RIDGES: SOUTHWEST 6 TO 11 MPH IN THE MORNING THEN 7 TO 14 MPH. AFTERNOON GUSTS UP TO 23 MPH ESPECIALLY ON EXPOSED RIDGES. HAINES INDEX(HIGH)..4 (LOW). TIME (PDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM TEMP............50 51 70 73 75 77 RH..............77 68 50 38 35 35 20 FT WIND......VRB 3 VRB 3 SW 3-5 W 3-7 W 4-7 SW 4-9 MAX GUST..... 8 10 10 13 CWR.............0 0 0 0 0 0 .FRIDAY... SKY/WEATHER.........PARTLY CLOUDY. CWR (%).............0 PERCENT. MAX TEMPERATURE.....74 TO 79...BUT 70 TO 75 AT 5000 FEET. MIN HUMIDITY........31 TO 40 PERCENT...BUT DOWN TO 25 PERCENT SOUTH ASPECTS AND EXPOSED RIDGES. WIND (20 FT)........VALLEYS/LOWER SLOPES: VARIABLE LESS THAN 3 MPH IN THE MORNING THEN SOUTHWEST TO WEST 3 TO 7 MPH. RIDGES: SOUTHWEST 6 TO 10 MPH IN THE MORNING THEN 7 TO 13 MPH. AFTERNOON GUSTS UP TO 22 MPH ESPECIALLY ON EXPOSED RIDGES. HAINES INDEX(HIGH)..5 (LOW). .EXTENDED FORECAST FRIDAY NIGHT THROUGH SUNDAY... .FRIDAY NIGHT...PARTLY CLOUDY. LOWS 50 TO 55...BUT TO THE UPPER 50S ON MID/UPPER SLOPES AND MID TO UPPER 40S ELEVATED VALLEYS. .SATURDAY...PARTLY CLOUDY. HIGHS 75 TO 80...BUT 70 TO 75 NEAR 5000 FEET. MINIMUM RH 30 TO 40 PERCENT. SOUTHWEST WIND TO 10 MPH. .SATURDAY NIGHT...PARTLY CLOUDY. LOWS 50 TO 55...BUT MID TO UPPER 40S ELEVATED VALLEYS. .SUNDAY...PARTLY SUNNY. A SLIGHT CHANCE OF AFTERNOON SHOWERS. HIGHS 67 TO 73...BUT LOWER TO MID 60S AT 5000 FEET. MINIMUM RH 38 TO 48 PERCENT. SOUTHWEST WIND 6 TO 12 MPH WITH AFTERNOON GUSTS TO 18 MPH. RIDGE-TOP WIND SOUTHWEST 10 TO 15 MPH WITH GUSTS TO 25 MPH. $$ FORECASTER...COLLINS REQUESTED BY...PLANNING OPS REASON FOR REQUEST...WILDFIRE .TAG 20110921.SHADO.01/PQR