FPCN39 CWLW 251448
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 25 OCTOBER 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      45   10     400  15     73   11    1200   20
KAMLOOPS     KEL      30    5     500  10     69   11    1600    7
OKANAGAN     KEL      20    5     500   2     56   11    1350    5
CASTLEGAR    SPOK     15    5     600   3     56    9    1150    9
CRANBROOK    SPOK     18    2    1100   2     66    7    1800    7
REVELSTOKE   KEL      18    5     500   2     49    7     950   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
PENTICTON    SW   9   SW  26   W   52
CRANBROOK             W   19   W   59

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1000 m          8 C
SPOKANE         1100 m          9 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: FAIR

VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR TO 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.     26    3    1000   8     76    6    1500  14
PR. GEORGE   P.G.     35    3     750  10     76    6    1300  14
SMITHERS     P.G.     30    4     600   8     72    7    1250  10
WELLS GRAY   P.G.     36    3    1050  10     78    7    1650  16
FT NLSN      F.N.     12   M2     400   2     17    4     650   3
FT STJOHN    F.N.     25    4     800  10     56    8    1300  18

*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            SW  63   W   76
SMITHERS              SW  54   SW  76

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1600 m         13 C
FT. NELSON       800 m          9 C

TODAY'S VENTING: GOOD EXCEPT POOR FAR NORTH

VENTING FOR SUNDAY: FAIR

VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR TO GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     11    8     100   5     26   11     300   8
FRASER VLY   QUIL     12    8     100   5     23   11     200   8
SRN VRISL    QUIL     12    8     100   5     22   12     250   6
CNTRL VRISL  QUIL     12    8     100   5     21   11     200   3
NRN VRISL    HRDY     26    9     200  13     58   11     600  15
TERRACE      ANT      26    7     200  12     50   10     250  20
STEWART      ANT      13    4     100   3     21   10     200  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
VANCOUVER    S   24   SW  37   W   57
PORT HARDY   SW  70   SW  67   SW  69
SANDSPIT     SW  46   SW  54   SW  57

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       350 m         12 C
PORT HARDY      NO LOW LEVEL INVERSION
ANNETTE         NO INVERSION

TODAY'S VENTING: POOR EXCEPT FAIR NORTH

VENTING FOR SUNDAY: FAIR

VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR TO GOOD

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


END/MWSO