FPCN39 CWLW 191446
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 FRIDAY 19 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       9    3     500  15     66    4     700  15
KAMLOOPS     KEL       9    1     350   5     37    2     600   8
OKANAGAN     KEL       9    1     350   5     45    3     900  10
CASTLEGAR    KEL       9    0     500   7     50    3    1350   6
CRANBROOK    KEL       9   -6     950   7      9   -4     950   7
REVELSTOKE   KEL       9    0     450   0     25    2     900   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S   11   SW  30   W   59
CRANBROOK             W   19   W   61

TODAY'S VENTING: FAIR.

VENTING FOR SATURDAY: FAIR TO 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.    100   -1    1400  43    100    0    1450  43
PR. GEORGE   P.G.     99    0    1250  30    100    1    1400  30
SMITHERS     P.G.      9   -1     500  13     45    0     500  13
WELLS GRAY   P.G.    100    0    1500  43    100    1    1500  43
FT NLSN      F.N.     44  -15     550  27     59  -10     600  27
FT STJOHN    F.N.     33   -5     800  28     92   -3    1300  24

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  56   W   70
SMITHERS              SW  56   SW  70

TODAY'S VENTING: GOOD LOCALLY FAIR.

VENTING FOR SATURDAY: FAIR.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL      9    6     100  22     75    8     450  28
FRASER VLY   QUIL      9    4      50  22     60    6     350  22
SRN VRISL    QUIL     19    7     150   8     59    8     350  21
CNTRL VRISL  QUIL     20    7     150   8     60    8     350  21
NRN VRISL    HRDY      9    5       0  17     64    6     450  18
TERRACE      ANT       9    0     200  32     60    1     500  32
STEWART      ANT       9    3       0  16     45    1     300  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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   57   SW  69   SW  70
PORT HARDY   SW  31   SW  44   SW  56
SANDSPIT     W   44   W   50   SW  57

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: POOR NORTH. FAIR SOUTH.


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


END/KAL