FPCN39 CWLW 021431
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 Saturday 2 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      21   23     800   2     75   30    1900   6
KAMLOOPS     KEL      20   22     900   2     82   30    2450   6
OKANAGAN     KEL      20   22     900   2     76   29    2100   6
CASTLEGAR    SPOK     23   21     800   5     71   28    1450   9
CRANBROOK    SPOK      9   20     950  15    100   27    3950   5
REVELSTOKE   KEL      12   19     600   2     54   26    1550   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
PENTICTON    VR   5   SW  15   SW  24
CRANBROOK             W   11   W   26

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1600 m         21 C
SPOKANE         1500 m         27 C

TODAY'S VENTING: Becomn good to fair in the mid afternoon.

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: 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   13     950   7     83   20    2850   6
PR. GEORGE   P.G.     36   14     850  17     81   20    1950   9
SMITHERS     P.G.     25   13     750   7     61   19    1100  12
WELLS GRAY   P.G.      9   14    1000   7    100   21    4000   6
FT NLSN      F.N.      9   16     400  12    100   24    3400  11
FT STJOHN    F.N.      9   14     700  12    100   21    3700  11


*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            S   24   S   33
SMITHERS              S   17   S   33

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       1000 m         19 C
FT. NELSON        640 m         16 C

TODAY'S VENTING: good by in the afternoon.

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     45   19     750   6     77   22    1500   7
FRASER VLY   QUIL     44   19     700   6     89   25    1700   8
SRN VRISL    QUIL     20   17     200   6     78   23    1500   7
CNTRL VRISL  QUIL     42   19     650   6     77   22    1450   7
NRN VRISL    HRDY     15   15     150   4     45   18    1200   6
TERRACE      ANT       9   15     200   7     60   19    1300   6
STEWART      ANT      15   16     100   6     31   19     400   6


*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   13   S   22   S   35
PORT HARDY   S   30   S   37   S   43
SANDSPIT     SE   9   SE  15   S   20

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1650 m         25 C
PORT HARDY       450 m         18 C
ANNETTE          520 m         20 C

TODAY'S VENTING: Good most areas by the afternoon.
Poor over northern Vancouver Island except briefly fair in the
afternoon.

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: Fair  to good as a number of
weak troughs move across the coasts.

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

END/lm