FPCN39 CWLW 311432 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 Saturday 31 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 9 10 200 1 74 20 1750 12 KAMLOOPS KEL 13 18 700 1 64 22 1700 5 OKANAGAN KEL 12 17 600 1 64 21 1700 5 CASTLEGAR SPOK 9 15 500 10 59 19 1350 10 CRANBROOK SPOK 9 15 950 8 29 19 1200 8 REVELSTOKE KEL 10 15 550 1 11 18 800 1 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PENTICTON W 11 W 22 W 33 CRANBROOK SW 11 SW 33 INVERSION HT BREAKTHRU TEMP KELOWNA 950 m 21 C SPOKANE 2100 m 26 C TODAY'S VENTING: A COLD FRONT NORTH TO SOUTH ACROSS VANCOUVER ISLAND THIS MORNING WILL MOVE TO LIE THROUGH CASTLEGAR BY LATE AFTERNOON. WEST OF THE FRONT THE VENTING WILL BECOME GOOD THIS AFTERNOON. EAST OF THE FRONT VENTING WILL BE POOR. VENTING FOR SUNDAY: GOOD. VENTING OUTLOOK MONDAY THRU WEDNESDAY: THE AIRMASS WILL BE UNSETTLED SO THE VENTING IS FORECAST TO BE GOOD. 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. 100 15 1800 28 100 19 3950 29 PR. GEORGE P.G. 89 16 1250 25 100 18 2050 26 SMITHERS P.G. 9 14 500 12 100 19 1800 23 WELLS GRAY P.G. 100 16 2400 28 100 18 2950 29 FT NLSN F.N. 26 14 500 17 100 22 3400 12 FT STJOHN F.N. 10 14 700 15 100 18 2550 10 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PR. GEORGE SW 24 SW 28 SMITHERS SW 31 SW 28 INVERSION HT BREAKTHRU TEMP PR. GEORGE 1000 m 16 C FT. NELSON 550 m 21 C TODAY'S VENTING: GOOD VENTING IS EXPECTED BY THIS AFTERNOON DUE TO AN UNSTABLE AIRMASS AND GUSTY WINDS. VENTING FOR SUNDAY: GOOD. VENTING OUTLOOK MONDAY THRU WEDNESDAY: THE AIRMASS WILL BE UNSETTLED SO THE VENTING IS FORECAST TO BE GOOD. COAST UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) VANCOUVER QUIL 81 18 850 15 100 20 1300 16 FRASER VLY QUIL 74 18 800 13 99 20 1250 15 SRN VRISL QUIL 19 16 200 6 99 18 1250 15 CNTRL VRISL QUIL 9 9 50 5 99 18 1250 15 NRN VRISL HRDY 11 14 100 3 99 16 1200 15 TERRACE ANT 78 15 900 15 100 19 1900 16 STEWART ANT 48 16 550 9 100 19 1600 14 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m VANCOUVER SW 26 SW 33 SW 39 PORT HARDY S 39 S 46 S 50 SANDSPIT S 46 S 48 S 48 INVERSION HT BREAKTHRU TEMP QUILLAYUTE NONE m ## C PORT HARDY 450 m 17 C ANNETTE 650 m 17 C TODAY'S VENTING: THE PASSAGE OF A COLD FRONT THIS MORNING WILL RESULT IN GOOD VENTING BY THIS AFTERNOON. VENTING FOR SUNDAY: GOOD. VENTING OUTLOOK MONDAY THRU WEDNESDAY: THE AIRMASS WILL BE UNSETTLED SO THE VENTING IS FORECAST TO BE GOOD. VENTILATION GUIDELINES: 0-33.....POOR 34-54.....FAIR 55-100.....GOOD. VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET. END/JDG