FPCN39 CWLW 071432
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT Thursday 7 August 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      40   22     900   5     90   29    2000   8
KAMLOOPS     KEL      46   22    1150   6     89   28    2150   8
OKANAGAN     KEL      40   21    1000   6     85   27    1950   8
CASTLEGAR    SPOK     24   22     750   6     46   28    1200   6
CRANBROOK    SPOK      9   22     950   4     39   28    1800   4
REVELSTOKE   KEL      27   19     800   5     71   25    1800   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   W   17   W   20
CRANBROOK             W    9   W   26

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          500 m         18 C
SPOKANE         1300 m         30 C

TODAY'S VENTING: GENERALLY GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: DECREASING TO 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.    100   17    2900  26    100   23    3950  26
PR. GEORGE   P.G.    100   16    1750  22    100   21    3700  24
SMITHERS     P.G.     13   14     600   4    100   20    2600  21
WELLS GRAY   P.G.    100   15    2350  25    100   22    4000  26
FT NLSN      F.N.     48   17     650  19     88   20    1050  19
FT STJOHN    F.N.     65   17    1100  19    100   21    2050  17

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   39   W   46
SMITHERS              W   31   NW  46

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       800 m         15 C
FT. NELSON       800 m         19 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: BECOMING FAIR IN THE
SOUTH THRU THE PERIOD.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     79   19     650  19     95   23     900  19
FRASER VLY   QUIL     80   19     650  19    100   24    1050  18
SRN VRISL    QUIL      9   18     600   0     78   23     900  12
CNTRL VRISL  QUIL     57   20     650  10    100   25    1250  14
NRN VRISL    HRDY     41   16     400  10     71   19     800  11
TERRACE      ANT      55   16    1150   6    100   20    2400  10
STEWART      ANT      13   16     450   1     83   20    1800   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   26   NW  26   NW  26
PORT HARDY   NW  28   NW  33   NW  37
SANDSPIT     NW  17   W   20   NW  28

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       900 m         25 C
PORT HARDY       900 m         21 C
ANNETTE          100 m         16 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: FAIR TO GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: DECREASING TO FAIR.


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

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