FPCN39 CWLW 211349
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 TUESDAY 21 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       9    5     400   1     39   10    1150   4
KAMLOOPS     KEL      21    6     500   4     36    9    1200   4
OKANAGAN     KEL       9    5     500   1     34    8    1100   4
CASTLEGAR    SPOK     20    6     750   3     24   11    1000   3
CRANBROOK    SPOK      9    5    1050   4     27   11    1600   3
REVELSTOKE   KEL      26    5     950   4     33    8    1200   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  11   W   17
CRANBROOK             W    9   W   24

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1600 m         20 C
SPOKANE         1000 m         12 C

TODAY'S VENTING: POOR TO FAIR

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY: 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.      9    4    1050   5     38    9    1250   7
PR. GEORGE   P.G.     12    4     750   1     25    7     900   6
SMITHERS     P.G.     14    6     800   2     29    8     850   7
WELLS GRAY   P.G.      9    5    1100   6     44    9    1350  10
FT NLSN      F.N.      9   -2     500   3     12    3     500   5
FT STJOHN    F.N.     16    6     800  10     60    8    1100  15

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  20   SW  31
SMITHERS              SW  43   SW  31

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1100 m         13 C
FT. NELSON       700 m         11 C

TODAY'S VENTING: POOR TO FAIR

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY: FAIR TO GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     14    7     150   6     33   12     450   7
FRASER VLY   QUIL     16    8     150   6     42   15     600   7
SRN VRISL    QUIL     15    8     150   4     34   13     450   6
CNTRL VRISL  QUIL     14    7     150   4     25   11     300   6
NRN VRISL    HRDY     19    8     350   3     27   12     650   3
TERRACE      ANT      10    8     250   8     20   10     350  10
STEWART      ANT       9    7     100   5     17   10     200   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W    9   W   20   W   30
PORT HARDY   SW  37   W   46   W   56
SANDSPIT     W   43   W   46   W   54

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       600 m         15 C
PORT HARDY      1000 m         17 C
ANNETTE          700 m         13 C

TODAY'S VENTING: POOR TO FAIR

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY: FAIR TO GOOD


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


END/MWSO