FPCN39 CWLW 121330
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 PDT SATURDAY 12 SEPTEMBER 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      17   18     550   2     68   26    1700   5
KAMLOOPS     KEL      14   17     600   2     94   27    2600   7
OKANAGAN     KEL      13   16     550   2     93   27    2550   7
CASTLEGAR    SPOK      9   17     750   0     66   27    2500   4
CRANBROOK    SPOK      9   15     950   8     93   26    3950   5
REVELSTOKE   KEL      10   14     500   2     38   21    1100   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
PENTICTON    W    9   W   22   W   35
CRANBROOK             W   11   W   28

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.      9   11     950   6    100   21    3950  16
PR. GEORGE   P.G.      9   10     700   2     95   18    2250  10
SMITHERS     P.G.      9    9     550   2     46   14    1050   8
WELLS GRAY   P.G.      9   11    1000   6    100   20    4000  16
FT NLSN      F.N.     16    9     500   7     27   16     650   7
FT STJOHN    F.N.      9    9     700   7    100   17    3700  23

*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
SMITHERS              SW  33   W

TODAY'S VENTING: GOOD.

VENTING FOR SUNDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     60   18     700  11     67   22     950   9
FRASER VLY   QUIL     58   17     650  11     71   23    1000   9
SRN VRISL    QUIL      9   17     600   0     55   22     850   7
CNTRL VRISL  QUIL      9   15     500   0     43   20     750   6
NRN VRISL    HRDY      9   13       0   3     45   19     650   9
TERRACE      ANT      10   14     450   5     50   16    1800  15
STEWART      ANT      95   12     650  25    100   15    3000  25

*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    W   11   W   28   W   39
PORT HARDY   SW  30   W   39   W   48
SANDSPIT     W   35   W   41   W   46

TODAY'S VENTING: GOOD EXCEPT FAIR OVER NORTHERN VANCOUVER ISLAND.

VENTING FOR SUNDAY: GOOD

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


END/MWSO