FPCN39 CWLW 251407
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 25 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      39   -3     950   4     46   -2    1200   4
KAMLOOPS     KEL      11   -6     500   1     45   -3    1350   4
OKANAGAN     KEL      11   -6     500   1     39   -4    1150   4
CASTLEGAR    SPOK      9   -6     500   2      9   -5     500   2
CRANBROOK    SPOK      9  -13     950  17      9  -11     950  17
REVELSTOKE   KEL       9   -9     450   1     10   -8     500   1

*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    VR   5   VR   5   SW   9
CRANBROOK             VR   5   W   24

TODAY'S VENTING: FAIR WEST. POOR EAST.

VENTING FOR SATURDAY: 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.      9   -9     950  13     48   -6    1450   9
PR. GEORGE   P.G.     36   -9    1000  10     39   -8    1050   9
SMITHERS     P.G.     30   -9     950   6     32   -8    1000   6
WELLS GRAY   P.G.      9   -9     950  13     44   -7    1450   9
FT NLSN      F.N.      9  -22     400   5     17  -18     550   5
FT STJOHN    F.N.      9  -22     700   5      9  -17     700   5

*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            W   39   W   48
SMITHERS              W   33   W   48

TODAY'S VENTING: FAIR TO POOR

VENTING FOR SATURDAY: FAIR TO POOR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL      9    3     100   5      9    4     100   5
FRASER VLY   QUIL      9    2      50   5      9    3      50   5
SRN VRISL    QUIL      9    7     150   5     18    8     250   4
CNTRL VRISL  QUIL      9    3      50   5     13    5     100   5
NRN VRISL    HRDY     10    3      50   5     14    5     150   4
TERRACE      ANT       9   -5     200  21      9   -4     200  21
STEWART      ANT       9   -5      20  10      9   -4      20  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
VANCOUVER    VR   5   NW   9   W   20
PORT HARDY   W   30   W   31   W   33
SANDSPIT     W   30   W   43   W   43

TODAY'S VENTING: POOR

VENTING FOR SATURDAY: FAIR

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


END/