FPCN39 CWLW 111436
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 11 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      16    5     500  22     80    6    2250  22
KAMLOOPS     KEL      22    4    1000  15     75    6    1750  15
OKANAGAN     KEL      12    3     450   2     50    6    1750  11
CASTLEGAR    SPOK     26    2     850   5     36    4    1100   8
CRANBROOK    SPOK     12   -5     990   2     30    0    1200   5
REVELSTOKE   KEL      19    3     950   2     32    4    1700   8

*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    VR   5   SW  37   SW  67
CRANBROOK             W   15   W   56

TODAY'S VENTING: POOR TO GOOD.

VENTING FOR FRIDAY:  POOR TO GOOD.




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.     61    3    1200  16     80    5    1800  20
PR. GEORGE   P.G.     61    3     700  15     69    4    1800  20
SMITHERS     P.G.     61    2     500  15     69    3    1800  15
WELLS GRAY   P.G.     77    5    1350  22    100    6    1850  22
FT NLSN      F.N.      9   -2     400  10     45    0    1400  10
FT STJOHN    F.N.     66    4     700  17     69    6    1700  17

*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            SW  82   SW 109
SMITHERS              SW  56   SW 109

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR FRIDAY: FAIR TO GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     27    7     200  10     39   10    1250  12
FRASER VLY   QUIL     25    5     150  10     35    9    1200  10
SRN VRISL    QUIL     17    8     200  10     45   10    1200  15
CNTRL VRISL  QUIL     15    6     150   5     45    5    1250  12
NRN VRISL    HRDY     57    9     300  25     73   10    1200  27
TERRACE      ANT       9    1     200  12     41    3    1250  14
STEWART      ANT       9    5       0  10     39    3    1220  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   39   SW  57   SW  70
PORT HARDY   S   96   S  109   SW 104
SANDSPIT     S   11   S   33   S   67

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR FRIDAY: FAIR TO GOOD.




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


END/