FPCN39 CWLW 131405
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 SATURDAY 13 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    1     200   4     34    3    1000   4
KAMLOOPS     KEL       9    2     450  10     51    4    1250  15
OKANAGAN     KEL       9    1     450   4     36    4     800   6
CASTLEGAR    SPOK      9    2     450   2     38    3    1100   8
CRANBROOK    SPOK      9   -4     950   5     40    1    1350   8
REVELSTOKE   KEL      17    3     600   4     36    4    1250   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    S   13   S   43   SW  91
CRANBROOK             SW  19   SW  76

TODAY'S VENTING: FAIR.

VENTING FOR SUNDAY: 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.     32    3    1200  15     48    8    1500  15
PR. GEORGE   P.G.     32    6     800  15     48    8    1000  15
SMITHERS     P.G.      9    3     700   7     32    6    1000   7
WELLS GRAY   P.G.     30    3    1000  15     53    5    1400  15
FT NLSN      F.N.      9   -2     400   3     13    0     400   4
FT STJOHN    F.N.     17    5     750  10     44    6    1300  15

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   72   SW  93
SMITHERS              SW  48   SW  93

TODAY'S VENTING: FAIR.

VENTING FOR SUNDAY: FAIR.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL      9    5     100   5     42    9     300  21
FRASER VLY   QUIL      9    5      50   6     41    8     300  21
SRN VRISL    QUIL      9    5      50   7     42    9     300  21
CNTRL VRISL  QUIL      9    6      50   5     35    4      50  15
NRN VRISL    HRDY     21    7     150  18     56   11    1000  24
TERRACE      ANT       9    5     200   5     21    6     300  10
STEWART      ANT       9    3     100  30     17    5     250   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   67   S   87   SW  93
PORT HARDY   S   76   S   91   S   87
SANDSPIT     W   28   SW  41   SW  65

TODAY'S VENTING: FAIR

VENTING FOR SUNDAY: FAIR

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


END/MWSO