FPCN39 CWLW 191431
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 19 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       9   -6     200   2     65   -5    1600   6
KAMLOOPS     KEL       9   -8     350   2     68   -6    1750   6
OKANAGAN     KEL      67   -6    1750   6     85   -4    2250   7
CASTLEGAR    SPOK    100   -7    1800  18    100   -4    2150  12
CRANBROOK    SPOK     10  -16     950  20     60  -13    2150  12
REVELSTOKE   KEL      80   -6    2150   7     80   -6    2150   7


*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    N    9   NE  24   NE  35
CRANBROOK             E   13   E   24

TODAY'S VENTING: GOOD.



VENTING FOR SUNDAY: 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.     30  -18    1000  10     68  -11    1700  12
PR. GEORGE   P.G.     30  -18     700  10     72   ##    1600  10
SMITHERS     P.G.     10  -22     600   2     10   ##     600   4
WELLS GRAY   P.G.     30  -20    1000  12     65   ##    1700  14
FT NLSN      F.N.     10  -26     400   3     11  -22     450   3
FT STJOHN    F.N.      9  -19     700  10     26  -17     850  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            N   31   N   69
SMITHERS              N   41   N   69

TODAY'S VENTING: GENERALLY GOOD. POOR IN THE NORTHWEST AND THE
NORTHEAST.


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     40   -1    1000  21     78    1    2000  11
FRASER VLY   QUIL     50   -2    1200  21     90   -1    2100  21
SRN VRISL    QUIL     45    0    1000  11    100    1    2000  11
CNTRL VRISL  QUIL     45    0     100  11     68    2    1500  19
NRN VRISL    HRDY     55    1      50  12    100    2    1250  18
TERRACE      ANT      45   -8     200   7     80   -6    1200   7
STEWART      ANT      40   -8     200   7     80   -6    1200   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    NE  41   NE  50   NE  43
PORT HARDY   NE  28   NE  67   NE  85
SANDSPIT     N   33   N   46   N   63

TODAY'S VENTING: GOOD.


VENTING FOR SUNDAY: GOOD


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


END/GF