FPCN39 CWLW 271437
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 27 DECEMBER 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      24    1     550   4     45    4     850   7
KAMLOOPS     KEL      17   -1     550   4     30    1     700   7
OKANAGAN     KEL      15   -2     500   4     30    1     700   7
CASTLEGAR    SPOK     53   -1     950  12     41    0     950   9
CRANBROOK    SPOK      9   -4     950  22     25   -2    1050  15
REVELSTOKE   KEL      15   -1     600   4     24    0     700   7

*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    VR   5   W   26   NW  50
CRANBROOK             NW  19   NW  52

TODAY'S VENTING: POOR TO FAIR.


VENTING FOR SUNDAY: 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.     10   -4     950  12     10   -1     950  12
PR. GEORGE   P.G.      9   -2     700  16     23    0     800  12
SMITHERS     P.G.      9   -3     500   8     21   -1     650  10
WELLS GRAY   P.G.      9   -6    1000  12     10   -1    1000  12
FT NLSN      F.N.     23  -10     550   8     29   -8     600  10
FT STJOHN    F.N.     41    0    1000  12     48    1    1000  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  37   W   48
SMITHERS              SW  63   SW  48

TODAY'S VENTING: POOR LOCALLY FAIR

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    3     100  13     17    7     150  13
FRASER VLY   QUIL      9    4      50  13      9    7      50  13
SRN VRISL    QUIL     11    6     100   3     12    7     100   3
CNTRL VRISL  QUIL      9    2      50   3     10    5     100   3
NRN VRISL    HRDY      9    5       0  17      9    6       0  17
TERRACE      ANT      10    2     250  12     10    3     250  12
STEWART      ANT       9    4       0   4      9    3       0   4

*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    SW  22   W   35   W   57
PORT HARDY   S   74   SW  82   SW  85
SANDSPIT     SW  76   SW  72   SW  80

TODAY'S VENTING: POOR

VENTING FOR SUNDAY: POOR

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


END/MWSO