FPCN39 CWLW 251433 SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF ENVIRONMENT CANADA AT 8:00 AM PDT Sunday 25 May 1997 FOR TODAY. VENTILATION INDICES (TEMPERATURE) AND MIXING HEIGHTS. MIXING HEIGHTS IN METRES ABOVE SEA LEVEL. AVERAGE WINDS IN KNOTS. SPOT INDICES ARE DETERMINED BY THE ASPECT AND ELEVATION OF THE SITES. COMPARE WINDS, TEMPERATURES AND ELEVATION WITH THE SITES HERE TO DETERMINE THE INDEX IN ANY OTHER AREA. SOUTHERN INTERIOR UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) FRSR CANYN KEL 29 16 800 3 80 21 3000 3 KAMLOOPS KEL 29 16 1050 3 100 22 3350 6 OKANAGAN KEL 15 15 750 2 100 21 3000 5 CASTLEGAR SPOK 20 13 1050 7 60 18 1800 6 CRANBROOK SPOK 20 11 1250 5 50 14 2150 5 REVELSTOKE KEL 14 14 750 2 100 22 3450 6 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PENTICTON NW 9 N 19 N 24 CRANBROOK NE 13 NE 37 INVERSION HT BREAKTHRU TEMP KELOWNA 750 m 15 C SPOKANE 1100 m 11 C TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON OVER MOST AREAS DUE TO AN UNSTABLE AIRMASS. THE SOUTHEAST HOWEVER WILL REMAIN FAIR DUE TO AN OVERCAST CLOUD LAYER. VENTING FOR MONDAY: GOOD VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD BECOMING FAIR BY THURSDAY DUE TO A RIDGE OF HIGH PRESSURE. CENTRAL INTERIOR/NORTHEAST UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) WILLIAMS L P.G. 9 11 950 8 100 19 3950 7 PR. GEORGE P.G. 16 11 750 11 100 21 3700 8 SMITHERS P.G. 27 13 800 7 100 22 3500 8 WELLS GRAY P.G. 9 11 1000 8 100 22 4000 7 FT NLSN F.N. 30 1 500 7 50 6 1100 13 FT STJOHN F.N. 50 10 1000 9 80 14 2700 9 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PR. GEORGE NW 11 VR 5 SMITHERS W 13 W 5 INVERSION HT BREAKTHRU TEMP PR. GEORGE 1400 m 20 C FT. NELSON 1400 m 8 C TODAY'S VENTING: POOR TO FAIR BECOMING GOOD NEAR MID AFTERNOON DUE TO A SOMEWHAT UNSTABLE AIRMASS. THE EXTREME NORTHEAST WILL REMAIN FAIR DUE TO A MODIFIED ARCTIC AIRMASS. VENTING FOR MONDAY: GOOD VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD BECOMING FAIR BY THURSDAY DUE TO A RIDGE OF HIGH PRESSURE. COAST UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) VANCOUVER QUIL 40 15 1000 5 50 19 1100 6 FRASER VLY QUIL 40 16 1000 5 60 20 1150 7 SRN VRISL QUIL 40 16 1000 5 50 20 1050 6 CNTRL VRISL QUIL 40 15 1000 5 50 20 1000 6 NRN VRISL HRDY 49 13 850 6 50 17 1000 6 TERRACE ANT 23 15 950 2 40 23 2000 3 STEWART ANT 29 16 900 2 40 23 2000 3 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m VANCOUVER W 15 NW 19 N 15 PORT HARDY NW 15 NW 11 VR 5 SANDSPIT NW 9 VR 5 W 9 INVERSION HT BREAKTHRU TEMP QUILLAYUTE 2100 m 23 C PORT HARDY 1100 m 22 C ANNETTE 1150 m 21 C TODAY'S VENTING: ONLY FAIR THIS AFTERNOON DUE TO A RIDGE OF HIGH PRESSURE. HOWEVER INLAND AREAS OF THE SOUTH COAST MAY JUST REACH THE GOOD CATEGORY. VENTING FOR MONDAY: FAIR. VENTING OUTLOOK TUESDAY THRU THURSDAY: FAIR. VENTILATION GUIDELINES: 0-33.....POOR 34-54.....FAIR 55-100.....GOOD. VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET. END/JDG