FPCN39 CWLW 111426
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 11 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      40    5     700   7     81    7    1500   9
KAMLOOPS     KEL      70    5    1350   9     80    7    1500  10
OKANAGAN     KEL      28    3     650   7     54    5    1300   4
CASTLEGAR    SPOK      9    2     500   6     45    4    1200   6
CRANBROOK    SPOK      9   -1     950  16     45    2    1200  16
REVELSTOKE   KEL      32    3     850   7     44    4    1100   9

*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   S   31   SW  67
CRANBROOK             SW  17   SW  56

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: 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.      9    2     950  15    100    4    2650  24
PR. GEORGE   P.G.      9    2     700  17     51    4     950  20
SMITHERS     P.G.      9    2     500   3     54    3    1300  10
WELLS GRAY   P.G.      9    0    1000   3    100    5    4000  24
FT NLSN      F.N.      9   -7     400   0      9   -4     400   0
FT STJOHN    F.N.     20    3     800  10     20    4     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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   69   SW  93
SMITHERS              S   56   SW  93

TODAY'S VENTING: POOR TO FAIR EXCEPT GOOD ABOVE 1000 METRES OVER
EASTERN SECTIONS.

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     31    8     250  13     54   10     600  17
FRASER VLY   QUIL     24    7     200  13     54    9     400  17
SRN VRISL    QUIL     48    9     350  13     54   10     550  15
CNTRL VRISL  QUIL     27    8     200  10     50    9     400  13
NRN VRISL    HRDY     59    7     350  20    100    9    1050  20
TERRACE      ANT      10    3     200  10     89    5    1050  12
STEWART      ANT      10    0     200  20     89    5    1050  12

*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   54   S   67   SW  72
PORT HARDY   S   54   SW  70   SW  78
SANDSPIT     SW  46   SW  59   SW  69

TODAY'S VENTING: FAIR IN THE SOUTH. GOOD IN THE NORTH.

VENTING FOR SATURDAY: FAIR TO GOOD.




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


END/MWSO