FPCN39 CWLW 111430 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 Friday 11 July 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 41 17 1000 5 100 21 2450 11 KAMLOOPS KEL 77 16 1500 9 100 20 2600 11 OKANAGAN KEL 13 15 750 1 100 19 2400 11 CASTLEGAR SPOK 54 14 950 12 100 18 3500 15 CRANBROOK SPOK 100 14 3950 16 100 18 3950 16 REVELSTOKE KEL 9 13 550 0 95 16 2000 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 FRIDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PENTICTON W 11 W 22 NW 33 CRANBROOK W 15 W 44 INVERSION HT BREAKTHRU TEMP KELOWNA 600 m 16 C SPOKANE 1050 m 14 C TODAY'S VENTING: WEAK INVERSION AND UNSTABLE ALOFT. MODERATE TO STRONG SOUTHWEST WINDS IN THE LOW LEVELS. SURFACE HEATING WILL BE WEAK IN THE EAST. NEVERTHELESS, EXPECT GOOD VENTING ALL AREAS BY MIDDAY. VENTING FOR SATURDAY: GOOD VENTING OUTLOOK SUNDAY THRU TUESDAY: LIGHT TO MODERATE SOUTHWEST FLOW ALOFT THROUGH PERIOD. EXPECT GENERALLY GOOD VENTING TO DEVELOP IN THE AFTERNOON HOURS. CENTRAL INTERIOR/NORTHEAST UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) WILLIAMS L KEL 100 11 1950 17 100 17 3950 16 PR. GEORGE KEL 100 15 2300 14 100 19 3700 14 SMITHERS ANT 28 15 1450 2 78 23 3500 3 WELLS GRAY KEL 100 15 2850 16 100 19 4000 16 FT NLSN F.N. 9 16 400 7 49 21 1000 8 FT STJOHN F.N. 9 15 700 8 33 18 1050 8 *SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS. FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m PR. GEORGE NW 31 NW 35 SMITHERS W 20 NW 35 INVERSION HT BREAKTHRU TEMP PR. GEORGE BETWEEN 900-1200M 19 C FT. NELSON 915 m 21 C TODAY'S VENTING: PRESENCE OF NOCTURNAL INVERSION WILL SLOW DEVELOPMENT OF MIXED LAYER. EXPECT GOOD VENTING TO DEVELOP IN INTERIOR AREAS BY MIDDAY. ELSEWHERE, ONLY FAIR VENTING. VENTING FOR SATURDAY: FAIR TO GOOD VENTING OUTLOOK SUNDAY THRU TUESDAY: LIGHT TO MODERATE SOUTHWEST FLOW ALOFT THROUGH PERIOD. EXPECT GENERALLY GOOD VENTING TO DEVELOP IN THE AFTERNOON HOURS. COAST UPPER ***** MORNING ****** ***** AFTERNOON **** AIR VI Tmp MXG HT Wnd VI Tmp MXG HT Wnd (mASL) (kt) (mASL) (kt) VANCOUVER QUIL 89 17 1150 13 100 21 2250 13 FRASER VLY QUIL 99 18 1350 13 100 23 2550 12 SRN VRISL QUIL 87 18 1250 10 100 23 2500 11 CNTRL VRISL QUIL 87 18 1300 10 100 23 2500 11 NRN VRISL HRDY 91 16 1000 14 100 19 1450 15 TERRACE ANT 29 17 1050 3 53 23 2200 3 STEWART ANT 27 18 650 3 52 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 FRIDAY AFTERNOON (WINDS IN KM/H): 900m 1800m 2700m VANCOUVER W 20 W 24 NW 24 PORT HARDY W 19 NW 17 NW 20 SANDSPIT S 39 S 31 SW 28 INVERSION HT BREAKTHRU TEMP QUILLAYUTE NEAR SFC ## C PORT HARDY NEAR SFC ## C ANNETTE NEAR SFC ## C TODAY'S VENTING: WEAK OR NO INVERSION AND MODERATE NORTHWESTERLY LOW LEVEL FLOW WILL PROVIDE FAVOURABLE INGREDIENTS FOR GOOD VENTING. VENTING FOR SATURDAY: GOOD VENTING OUTLOOK SUNDAY THRU TUESDAY: FAIR TO GOOD. VENTILATION GUIDELINES: 0-33.....POOR 34-54.....FAIR 55-100.....GOOD. VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET. END/BJS