FPCN39 CWLW 271700
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 PST THURSDAY 27 NOVEMBER 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    7    1150  40    100    8    1250  40
KAMLOOPS     KEL      89    4     800  30    100    7    1300  30
OKANAGAN     KEL      11    3     350  15    100    6    1200  30
CASTLEGAR    SPOK     80    2    1100  15    100    5    1400  25
CRANBROOK    SPOK     48   -1    1150  22     86    2    1500  22
REVELSTOKE   KEL      16    3     800   2    100    4    1100  30

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S   11   SW  37   W   93
CRANBROOK             W   30   W   83

TODAY'S VENTING: Good.

VENTING FOR FRIDAY: 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.     71    2    1200  36     86    4    1300  36
PR. GEORGE   P.G.     87    3    1100  30     95    5    1200  30
SMITHERS     P.G.      9    1     500  12     10    2     550  21
WELLS GRAY   P.G.     73    3    1250  36    100    5    1500  36
FT NLSN      F.N.      9  -14     400   9      9  -12     400   9
FT STJOHN    F.N.     62   -1    1100  17     93    1    1650  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  50   SW  74
SMITHERS              SW  48   SW  74

TODAY'S VENTING: Good.

VENTING FOR FRIDAY: Good.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     10    8     100  23     66   10     400  23
FRASER VLY   QUIL     28    8     150  23     90   11     650  23
SRN VRISL    QUIL     20    9     200   6     89   11     550  20
CNTRL VRISL  QUIL     14    8     100   6     54    9     250  20
NRN VRISL    HRDY     36    8     300  11     42    9     350  11
TERRACE      ANT      10    3     200  17     10    4     200  17
STEWART      ANT       9    5       0   8      9    4       0   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  56   SW  83   SW  93
PORT HARDY   SW  52   SW  67   SW  78
SANDSPIT     SW  57   SW  63   SW  69

TODAY'S VENTING: Good.

VENTING FOR FRIDAY: Good.

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


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