FPCN39 CWLW 211453
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 Monday 21 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      60   27    1000  20     64   32    1450  15
KAMLOOPS     KEL      45   24     600   7    100   32    3350  12
OKANAGAN     KEL      45   21     600   5    100   32    3350  12
CASTLEGAR    SPOK     25   20     600   4    100   31    3500   7
CRANBROOK    SPOK     25   21    1000   3    100   28    3950   7
REVELSTOKE   KEL      25   18     500   5     51   29    1350   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   S   19   SW  31
CRANBROOK             SW   9   SW  22

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          900 m         30 C
SPOKANE         1130 m         28 C

TODAY'S VENTING: Poor in the east this morning becoming
good by the mid afternoon. Fair to good elsewhere this morning
becoming

good by the afternoon.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:Fair to good  becoming only
fair

by the end of the week as a ridge builds into the region.

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.     42   20    1070   6    100   26    3950  12
PR. GEORGE   P.G.     47   18     900   6     80   25    1750  10
SMITHERS     P.G.     60   15    2000   8     88   21    3000   7
WELLS GRAY   P.G.     30   17    1000  10    100   26    4000  12
FT NLSN      F.N.     32   18     400   6    100   24    2150  16
FT STJOHN    F.N.     39   18     700   6    100   24    2800  14

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            S   26   S   37
SMITHERS              SW  20   SW  37

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE     1400 m          26 C
FT. NELSON       970 m          22 C

TODAY'S VENTING:  fair becoming good.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:Fair to good  becoming only
fair

by the end of the week as a ridge builds into the region.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     70   18     950  10     85   23    1650   8
FRASER VLY   QUIL     70   18     950   8     87   24    1700   8
SRN VRISL    QUIL     70   19     950   8     82   23    1600   7
CNTRL VRISL  QUIL     70   18     950   5     82   23    1600   7
NRN VRISL    HRDY     54   17     600   7     16   18     700   1
TERRACE      ANT      64   16     200  16    100   20    1700  12
STEWART      ANT      64   16     200  16     97   20    1250  10

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  13   SW  20   SW  39
PORT HARDY   SW  19   S   28   SW  33
SANDSPIT     SW  19   SW  19   SW  22

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1900 m         27 C
PORT HARDY       760 m         18 C
ANNETTE         none  m        none

TODAY'S VENTING: fair to good this morning.
Good this afternoon.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:Fair becoming only poor tofair
by the end of the week as a ridge builds into the region.

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

END/lm