FPCN39 CWLW 241351
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 24 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       9   -6     500   0      9   -6     500   0
KAMLOOPS     KEL      11   -7     750   1     23   -6    1250   2
OKANAGAN     KEL      11   -7     750   1     23   -6    1250   2
CASTLEGAR    SPOK     31   -8     900   6     46   -7    1050   8
CRANBROOK    SPOK      9  -17     950  12     10  -14     950  12
REVELSTOKE   KEL       9  -10     450   0      9   -9     450   0

*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    9   W   37   W  106
CRANBROOK             SW  28   SW  85

TODAY'S VENTING: POOR TO FAIR.

VENTING FOR FRIDAY: 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.     34   -8    1200  10     54   -7    1500  11
PR. GEORGE   P.G.      9  -12     700   7      9  -12     700   7
SMITHERS     P.G.     22   -9     900   3     27   -8     950   5
WELLS GRAY   P.G.      9   -9    1000   7     41   -8    1350  10
FT NLSN      F.N.      9  -25     400   0      9  -24     400   0
FT STJOHN    F.N.      9  -18     700  15     42  -16     950  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            E   44   E   30
SMITHERS              E   46   E   30

TODAY'S VENTING: POOR TO FAIR.

VENTING FOR FRIDAY: 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    0     100  23     41    2     250  23
FRASER VLY   QUIL      9   -1      50  23      9    1      50  23
SRN VRISL    QUIL     33    2     150  18     41    2     250  23
CNTRL VRISL  QUIL      9    1      50  13     34    2     200  18
NRN VRISL    HRDY     33    2     150  18     41    2     250  23
TERRACE      ANT       9   -7     200  25      9   -7     200  25
STEWART      ANT       9   -7      50  15      9   -7       0  20

*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   W   80   W   87
PORT HARDY   W   54   W   65   W   61
SANDSPIT     N   24   N   28   NW  31

TODAY'S VENTING: POOR TO FAIR.

VENTING FOR FRIDAY: POOR TO FAIR.


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


END/DSL