FPCN39 CWLW 171431
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 Sunday 17 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      56   22    1100   6    100   30    3200   6
KAMLOOPS     KEL      50   21    1250   6     86   27    2650   6
OKANAGAN     KEL      34   19     800   6     73   26    2200   5
CASTLEGAR    SPOK     20   16     750   4    100   24    3500   6
CRANBROOK    SPOK      9   14     950  11    100   21    3950   7
REVELSTOKE   KEL      18   17     600   5     63   24    1950   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   W   13
CRANBROOK             VR   5   W   11

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         19 C
SPOKANE         1400 m         21 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: 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.     33   14    1300   7    100   23    3950  16
PR. GEORGE   P.G.     12   11     800   2    100   22    3700  13
SMITHERS     P.G.     17   15    1000   2    100   24    3500  11
WELLS GRAY   P.G.     34   14    1400   7    100   24    4000  16
FT NLSN      F.N.     29   15     600  10     80   24    1600   9
FT STJOHN    F.N.      9   11     700   9     77   18    1200   9

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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W    9   W   19
SMITHERS              W   17   W   19

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1500 m         20 C
FT. NELSON      1600 m         24 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     10   20     200   1     36   24     900   3
FRASER VLY   QUIL     11   21     200   1     41   28     900   5
SRN VRISL    QUIL     10   19     150   1     35   25     950   2
CNTRL VRISL  QUIL     10   20     200   1     37   28     900   3
NRN VRISL    HRDY     15   16     250   3     33   23     900   5
TERRACE      ANT       9   18     200   7     76   25    1700   7
STEWART      ANT      12   17      50   6     69   25    1300   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  11   SW  13   SW  11
PORT HARDY   NW  19   NW  11   NW  15
SANDSPIT     NW  35   NW  35   NW  35

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       500 m         25 C
PORT HARDY       900 m         25 C
ANNETTE          500 m         22 C

TODAY'S VENTING: FAIR SOUTH. GOOD NORTH.

VENTING FOR MONDAY: FAIR.

VENTING OUTLOOK TUESDAY THRU THURSDAY: FAIR.


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

END/JMS