FPCN39 CWLW 121427
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 SATURDAY 12 DECEMBER 1998 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      19    5     500   3     50    8    1000   8
KAMLOOPS     KEL      14    4     500   3     50    6    1100   8
OKANAGAN     KEL      13    2     500   3     14    4     500   3
CASTLEGAR    SPOK      9    3     500   6      9    5     500   6
CRANBROOK    SPOK      9    0     950  22     46    4    1150  22
REVELSTOKE   KEL      11    2     500   3     11    3     500   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S   15   SW  37   SW  80
CRANBROOK             SW  20   W   69

TODAY'S VENTING: POOR TO FAIR.

VENTING FOR SUNDAY: POOR TO FAIR.




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.     45    3    1200  15     50    5    1300  15
PR. GEORGE   P.G.      9    3     700  14     50    4    1150  12
SMITHERS     P.G.      9    3     500   4     30    3     900  10
WELLS GRAY   P.G.      9    2    1000  10     50    5    1400  15
FT NLSN      F.N.      9  -10     400   0      9   -7     450   0
FT STJOHN    F.N.      9    1     700  20      9    3     700  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  59   SW  70
SMITHERS              SW  39   SW  70

TODAY'S VENTING: POOR TO FAIR EXCEPT GOOD ABOVE 1300 METRES.

VENTING FOR SUNDAY: POOR TO FAIR.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL      9    9     100  33     80   11     300  41
FRASER VLY   QUIL      9    7      50  33     50    9     150  33
SRN VRISL    QUIL      9   10       0  21     65   11     300  27
CNTRL VRISL  QUIL      9    9      50  21      9   10      50  21
NRN VRISL    HRDY     29    8     200  12     51    9     400  14
TERRACE      ANT       9    2     200  30    100    4    2500  20
STEWART      ANT       9    2     100  10    100    4    2500  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
VANCOUVER    S   44   SW  59   SW  61
PORT HARDY   SW  48   SW  67   SW  78
SANDSPIT     SW  43   SW  52   SW  61

TODAY'S VENTING: GENERALLY FAIR EXCEPT GOOD IN THE NORTH.

VENTING FOR SUNDAY: GOOD.




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


END/MWSO