FPCN39 CWLW 271451
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 27 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     100   14    2300  15    100   18    3050  15
KAMLOOPS     KEL     100   13    2300   7    100   18    3350  16
OKANAGAN     KEL     100   14    2300   7    100   18    3350  16
CASTLEGAR    SPOK     60   14    1400  12    100   18    2500  25
CRANBROOK    SPOK    100   13    2500  12    100   16    3950  26
REVELSTOKE   KEL      15   11     450   3     60   15    1850   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
PENTICTON    W   11   W   30   W   48
CRANBROOK             W   20   W   54

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          500 m         14 C
SPOKANE         1300 m         14 C

TODAY'S VENTING: GOOD.


VENTING FOR SUNDAY: GOOD.


VENTING OUTLOOK MONDAY THRU WEDNESDAY: GENERALLY GOOD AS STRONG
WESTERLY FLOW PERSISTS.



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.     80   10    1700  20    100   18    3950  29
PR. GEORGE   P.G.     80   12    1300  12    100   15    2550  27
SMITHERS     P.G.     80   10    1300   8    100   15    2100  12
WELLS GRAY   P.G.     80   10    2200  20    100   16    4000  29
FT NLSN      F.N.     40   12    1100  12    100   15    1350  33
FT STJOHN    F.N.     60   12    1300  15    100   16    2200  35


*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            W   39   W   46
SMITHERS              W   28   W   46

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      NONE           N/A
FT. NELSON      NONE           N/A

TODAY'S VENTING: GOOD.


VENTING FOR SUNDAY: GOOD


VENTING OUTLOOK MONDAY THRU WEDNESDAY: GENERALLY GOOD AS STRONG
WESTERLY FLOW PERSISTS.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL    100   14    1200  14    100   17    1550  28
FRASER VLY   QUIL    100   14    1200  15    100   18    1750  28
SRN VRISL    QUIL    100   14    1200  20    100   18    1650  27
CNTRL VRISL  QUIL     40   14    1000   4    100   17    1250  12
NRN VRISL    HRDY     40   12    1000   4     65   15    1300   4
TERRACE      ANT      60   12    1100  10    100   15    1600  17
STEWART      ANT      60   12     950   7     85   15    1000  13



*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    SW  22   SW  30   W   43
PORT HARDY   S   31   S   33   SW  48
SANDSPIT     S    9   SW  11   SW  19

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       150 m         14 C
PORT HARDY       300 m         13 C
ANNETTE          NONE          N/A

TODAY'S VENTING: GOOD.


VENTING FOR SUNDAY: GOOD.


VENTING OUTLOOK MONDAY THRU WEDNESDAY: GENERALLY GOOD AS A STRONG
WESTERLY FLOW PERSISTS.


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


END/GF