FPCN39 CWLW 171446
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 WEDNESDAY 17 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      56    7     500  18     84    9     850  18
KAMLOOPS     KEL      24    5     500  10     60    7    1000  10
OKANAGAN     KEL      14    3     350   8     60    7    1000  10
CASTLEGAR    SPOK     10    4     500  10     40    6     850  10
CRANBROOK    SPOK     10    2     950  12     32    3    1150  12
REVELSTOKE   KEL       9    2     450   3      9    3     450   3

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   24   W   46
CRANBROOK             W   15   W   43

TODAY'S VENTING: GOOD TO FAIR

VENTING FOR THURSDAY: 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.     10    1     950  20    100    4    2500  20
PR. GEORGE   P.G.     10    2     700  20    100    3    2500  20
SMITHERS     P.G.      9    1     500   5     75    2    1500  10
WELLS GRAY   P.G.     10    0    1000  20    100    3    2500  20
FT NLSN      F.N.     36  -14     700  10     36  -14     700  10
FT STJOHN    F.N.     24   -7     800  15     15  -10     750  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   30   W   43
SMITHERS              SW  24   SW  43

TODAY'S VENTING: GOOD TO FAIR

VENTING FOR THURSDAY: 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    8     100   8     55    9     700   9
FRASER VLY   QUIL     23    8     350   9     48    8     600   9
SRN VRISL    QUIL      9    7       0   3     49    9     600   8
CNTRL VRISL  QUIL      9    5      50   3     50    7     600   7
NRN VRISL    HRDY     15    5     100   7     51    7     600   9
TERRACE      ANT       9    1     200   2     32    2     800   4
STEWART      ANT      14    3     150   4     12    2     100   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  20   W   28   W   33
PORT HARDY   W   26   W   31   W   35
SANDSPIT     W   35   W   37   W   39

TODAY'S VENTING: FAIR TO POOR

VENTING FOR THURSDAY: POOR

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


END/MWSO