FPCN39 CWLW 261505
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 7:00 AM PDT FRIDAY 26 SEPTEMBER 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      ##   ##     ###  ##    100   20    3950  20
KAMLOOPS     KEL      ##   ##     ###  ##     56   21    1200   7
OKANAGAN     KEL      ##   ##     ###  ##     56   21    1200   7
CASTLEGAR    SPOK     ##   ##     ###  ##     35   20     750  11
CRANBROOK    SPOK     ##   ##     ###  ##    100   20    3950  33
REVELSTOKE   KEL      ##   ##     ###  ##     10   16     500   2

*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    SW  15   SW  33   SW  57
CRANBROOK             SW  19   SW  54

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         18 C
SPOKANE          900 m         21 C

TODAY'S VENTING: fair to good.

VENTING FOR SATURDAY: fair to good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: decreasing to poor.


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   18    2450  24
PR. GEORGE   P.G.     ##   ##     ###  ##    100   16    2450  24
SMITHERS     P.G.     ##   ##     ###  ##    100   17    2450  24
WELLS GRAY   P.G.     ##   ##     ###  ##    100   18    2550  24
FT NLSN      F.N.     ##   ##     ###  ##     18   16     500   9
FT STJOHN    F.N.     ##   ##     ###  ##      9   17     700  16

*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            SW  44   SW  56
SMITHERS              SW  30   SW  56

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1200 m         19 C
FT. NELSON      1100 m         27 C

TODAY'S VENTING: good in the Interior but poor in the Northeast.

VENTING FOR SATURDAY: fair to good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: decreasing to fair.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     ##   ##     ###  ##    100   19    1850  29
FRASER VLY   QUIL     ##   ##     ###  ##    100   19    1750  28
SRN VRISL    QUIL     ##   ##     ###  ##    100   19    1650  25
CNTRL VRISL  QUIL     ##   ##     ###  ##    100   18    1450  25
NRN VRISL    HRDY     ##   ##     ###  ##    100   17    1200  24
TERRACE      ANT      ##   ##     ###  ##    100   15    2200  15
STEWART      ANT      ##   ##     ###  ##    100   15    2200  15

*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    SW  57   SW  74   SW  83
PORT HARDY   SW  46   SW  56   SW  59
SANDSPIT     SW  30   SW  26   SW  22

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       200 m         17 C
PORT HARDY       400 m         16 C
ANNETTE          400 m         15 C

TODAY'S VENTING: good.

VENTING FOR SATURDAY: good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: decreasing to fair.


VENTILATION GUIDELINES:
          0-33.....POOR
          34-54.....FAIR
          55-100.....GOOD.
VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET.


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