FPCN39 CWLW 101446
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 10 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      32    3     800   4     55    7    1600   4
KAMLOOPS     KEL      24    1     750   4     50    5    1550   4
OKANAGAN     KEL      32    2     950   4     50    5    1550   4
CASTLEGAR    SPOK     22    0     850   4     29    2    1050   4
CRANBROOK    SPOK      9  -10     950   5      9   -5     950   5
REVELSTOKE   KEL      28    1     950   4     36    2    1200   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
PENTICTON    VR   5   SW  20   W   48
CRANBROOK             W    9   NW  41

TODAY'S VENTING: FAIR.

VENTING FOR THURSDAY: 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.     33   -2    1100  17     44    0    1250  15
PR. GEORGE   P.G.      9   -1     700  19     44    0    1200  15
SMITHERS     P.G.      9   -3     500   5     44   -1    1200  15
WELLS GRAY   P.G.     32   -2    1150  17     49    0    1300  17
FT NLSN      F.N.      9  -12     400   1     19  -10     400   6
FT STJOHN    F.N.      9    0     700   0     29    2     700   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   67   SW  59
SMITHERS              S   80   S   59

TODAY'S VENTING: FAIR

VENTING FOR THURSDAY: FAIR




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    HRDY     79    7     550  24     80   10    1100  21
FRASER VLY   HRDY     56    6     300  24     87    9     950  23
SRN VRISL    HRDY     85    8     550  24     80   10     900  22
CNTRL VRISL  HRDY      9    5      50  23     79    5     900  23
NRN VRISL    HRDY     85    8     550  24     80   10     900  22
TERRACE      ANT       9    1     200  25     70    3     950  25
STEWART      ANT       9    4       0  21     79    3     900  21

*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    S   57   SW  70   SW  78
PORT HARDY   S   93   SW 100   SW  93
SANDSPIT     SW  82   SW 100   S  117

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: FAIR

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


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