FPCN39 CWLW 131415
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 13 SEPTEMBER 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      20   14     750   2     54   21    2550   3
KAMLOOPS     KEL      30   14    1050   3     53   20    2650   3
OKANAGAN     KEL      16   12     700   2     51   21    2750   4
CASTLEGAR    SPOK     23   13     850   4     50   20    3500   4
CRANBROOK    SPOK      9   11     950   6    100   19    3950   9
REVELSTOKE   KEL      21   12     850   3     53   16    1900   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    VR   5   SE  11   S   17
CRANBROOK             VR   5   S   13

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          800 m         21 C
SPOKANE         1500 m         19 C

TODAY'S VENTING: fair to good.

VENTING FOR SUNDAY: fair.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: generally 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.     29    9    1300   6     80   17    3950   4
PR. GEORGE   P.G.     16    8    1050   2     56   15    2350   4
SMITHERS     P.G.     21   11    1150   2     60   15    1550   6
WELLS GRAY   P.G.     43   11    1750   6     80   16    4000   4
FT NLSN      F.N.     24    8     850   4     74   12    1900   6
FT STJOHN    F.N.     43    7    1450   5     69    9    1900   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
PR. GEORGE            VR   5   S   11
SMITHERS              VR   5   VR  11

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1700 m         15 C
FT. NELSON       800 m          8 C

TODAY'S VENTING: good.

VENTING FOR SUNDAY: good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: good.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     23   16     550   3     72   20    1950   5
FRASER VLY   QUIL     21   16     500   3     89   22    2450   6
SRN VRISL    QUIL     15   14     250   3     55   19    1400   5
CNTRL VRISL  QUIL     15   14     250   3     55   18    1450   5
NRN VRISL    HRDY     14   13     300   2     55   18    1450   5
TERRACE      ANT      15   13     400   4     56   17    1500   5
STEWART      ANT      10   13     150   1     29   17     850   3

*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    E   13   SE  17   S   22
PORT HARDY   VR   5   SE  11   SE  19
SANDSPIT     N   11   NE  11   NE  11

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m         16 C
PORT HARDY       500 m         16 C
ANNETTE          200 m         15 C

TODAY'S VENTING: good.

VENTING FOR SUNDAY: good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: generally good.

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


END/dsl