FPCN39 CWLW 231443
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 TUESDAY 23 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      75    4    1450   8     79    5    1550   8
KAMLOOPS     KEL       9    0     350   4     42    2    1000   6
OKANAGAN     KEL       9    0     350   4     40    1    1000   4
CASTLEGAR    SPOK     18   -2     800   3     21    0     900   3
CRANBROOK    SPOK      9   -3     950  16     39   -2    1150  16
REVELSTOKE   KEL       9   -2     450   4      9   -1     450   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W   17   NW  31
CRANBROOK             NW  15   NW  48

TODAY'S VENTING: FAIR TO POOR.


VENTING FOR WEDNESDAY: 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.      9   -2     950  32      9    0     950  32
PR. GEORGE   P.G.     25    0     800  16     33    1     850  16
SMITHERS     P.G.      9    0     500   8     21    1     700   8
WELLS GRAY   P.G.     62    1    1200  32    100    2    1800  35
FT NLSN      F.N.     15  -13     450  14     20  -10     450  14
FT STJOHN    F.N.     10    1     700  19     10    1     700  19

*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            W   57   W   63
SMITHERS              W   54   W   63

TODAY'S VENTING: FAIR TO POOR.


VENTING FOR WEDNESDAY: POOR


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL      9    4     100  10     65    6    1100  10
FRASER VLY   QUIL      9    3      50  10     65    5    1050  10
SRN VRISL    QUIL     11    5     100   3     60    7     950   7
CNTRL VRISL  QUIL      9    2      50   3     55    3     750   3
NRN VRISL    HRDY      9    4       0  10     60    5     800  10
TERRACE      ANT       9    1     200  21     60    1     800  21
STEWART      ANT       9    2       0  10     60    1     800  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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   17   NW  30   NW  37
PORT HARDY   W   31   NW  41   NW  59
SANDSPIT     W   41   W   54   W   74

TODAY'S VENTING: GOOD.


VENTING FOR WEDNESDAY: POOR


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


END/GF