FPCN39 CWLW 301435
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 TUESDAY 30 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      89   17     750  30     89   19     800  30
KAMLOOPS     KEL      52   15     700  10     66   19     850  10
OKANAGAN     KEL      18   14     650   3     45   18     800   7
CASTLEGAR    SPOK     28   14     750   8     32   17     800   8
CRANBROOK    SPOK      9   12     950   8      9   16     950  12
REVELSTOKE   KEL      11   12     550   2     15   13     650   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S    9   SW  28   SW  59
CRANBROOK             SW  22   SW  69

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          900 m         20 C
SPOKANE         1200 m         25 C

TODAY'S VENTING: poor in the east this morning but good in strong
winds western sections.  Becoming fair to good in the afternoon except
remaining poor in the east.

VENTING FOR WEDNESDAY: POOR

VENTING OUTLOOK THURSDAY THRU SATURDAY:fair 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.     47   12    1750   5    100   14    2450  15
PR. GEORGE   P.G.     40   10    1050  10     99   14    1550  10
SMITHERS     P.G.     12    8     600   3     37   12    1100   6
WELLS GRAY   P.G.     48   10    1300  12    100   14    2550  15
FT NLSN      F.N.      9    6     400  11     76   10    1550   9
FT STJOHN    F.N.     78    9    1900   9    100   13    3700  12

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  43   SW  56
SMITHERS              S   52   S   56

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1300 m         14 C
FT. NELSON       700 m          8 C

TODAY'S VENTING:Poor to fair thi morning becoming fair to good by
mid afternoon except remaining poor in the west.

VENTING FOR WEDNESDAY: POOR

VENTING OUTLOOK THURSDAY THRU SATURDAY:Fair to poor.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     11   17     100   5     70   18     850  10
FRASER VLY   QUIL     11   16      50   5     70   18     800  10
SRN VRISL    QUIL     21   15     100   4     74   17     500  10
CNTRL VRISL  QUIL      9   14      50   4     56   16     350  10
NRN VRISL    HRDY      9   14      80  10     33   15     200  10
TERRACE      ANT      10    9     200  15    100   13    1700  14
STEWART      ANT       9   13    1400   4     99   13    1400   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   22   SW  41   SW  63
PORT HARDY   S   43   S   52   SW  59
SANDSPIT     W   39   W   39   SW  39

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      none         n/a C
PORT HARDY      1300 m        17 C
ANNETTE          600 m        11 C

TODAY'S VENTING: Poor becoming generally good in the afternoon except
remaing fair to poor over northern Vancouver Island and the central
coast.

VENTING FOR WEDNESDAY: POOR

VENTING OUTLOOK THURSDAY THRU SATURDAY: Fair to poor.

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


END/lm