FPCN39 CWLW 181432
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 Friday 18 July 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      19   22     950   1     67   27    2550   3
KAMLOOPS     KEL      15   19     750   2     80   27    3350   4
OKANAGAN     KEL      13   18     600   2     80   27    3350   4
CASTLEGAR    SPOK     26   19     850   5     67   26    2100   5
CRANBROOK    SPOK      9   17     950  12    100   24    3950  13
REVELSTOKE   KEL      14   18     750   2     48   23    2150   3

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W    9   W   13
CRANBROOK             VR   5   W   15

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1000 m         21 C
SPOKANE         1700 m         24 C

TODAY'S VENTING: generally good.

VENTING FOR SATURDAY: generally good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: gnerally 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.    100   16    2250  16    100   23    3950  15
PR. GEORGE   P.G.     79   15    1550  12    100   22    3700  13
SMITHERS     P.G.     22   15     900   4    100   20    2200  12
WELLS GRAY   P.G.    100   17    4000  15    100   24    4000  15
FT NLSN      F.N.     48   18     700  14    100   24    3400  10
FT STJOHN    F.N.     38   16     950  13    100   24    3700   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   19   W   26
SMITHERS              SW  20   SW  26

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1800 m         21 C
FT. NELSON      1700 m         23 C

TODAY'S VENTING: good.

VENTING FOR SATURDAY: good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: good.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     83   18    1100  12     93   22    1350  12
FRASER VLY   QUIL     82   17    1050  12    100   25    3050  11
SRN VRISL    QUIL     78   18    1100  10     89   23    1350  10
CNTRL VRISL  QUIL     77   18    1100  10     92   24    1450  10
NRN VRISL    HRDY     31   14     400   7     69   18    1100   8
TERRACE      ANT     100   15    1200  28    100   19    1950  23
STEWART      ANT     100   15     800  23    100   19    1600  22

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   13   NW  13   NW  13
PORT HARDY   SW  11   SW  13   W   22
SANDSPIT     S   39   SW  39   SW  48

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       200 m         14 C
PORT HARDY       200 m         14 C
ANNETTE          none

TODAY'S VENTING: generally good.

VENTING FOR SATURDAY: generally good.

VENTING OUTLOOK SUNDAY THRU TUESDAY: generally good.


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

END/dsl