FPCN39 CWLW 271435
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 Wednesday 27 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      15   18     750   1    100   23    2000  10
KAMLOOPS     KEL      18   18     900   2    100   23    2550  11
OKANAGAN     KEL      12   15     650   1    100   22    2350  11
CASTLEGAR    SPOK     41   18     950   8     97   23    2000  11
CRANBROOK    SPOK     86   18    1900   8    100   23    2600  15
REVELSTOKE   KEL      15   16     800   2     84   20    1800   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  17   SW  28
CRANBROOK             SW  11   SW  30

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         900  m         18 C
SPOKANE        1040  m         18 C

TODAY'S VENTING: Generally poor this morning except fair
to good in the southeast. Venting becoming good
by noon.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY: Good as unsettled
conditions continue.

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   13    2150  21    100   17    2900  22
PR. GEORGE   P.G.    100   14    1600  20    100   17    2400  21
SMITHERS     P.G.     38   13     750  14    100   16    1800  18
WELLS GRAY   P.G.    100   15    2600  22    100   18    4000  22
FT NLSN      F.N.     20   16     450  15     57   22     800  15
FT STJOHN    F.N.      9   15     700  15     13   18     700  15

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  28   SW  39
SMITHERS              W   39   W   39

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1040 m         15 C
FT. NELSON       780 m         23 C

TODAY'S VENTING: Becoming good in the afternoon.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY:Good as unsettled
conditions continue.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     54   17     650  11    100   20    3100  23
FRASER VLY   QUIL     38   16     560   8    100   20    1400  22
SRN VRISL    QUIL     45   16     350  13    100   19    1100  19
CNTRL VRISL  QUIL     16   15     150   6     84   18     750  17
NRN VRISL    HRDY     12   15     200   2     48   17     650   5
TERRACE      ANT      74   15    1150  11    100   18    1800  13
STEWART      ANT      35   15     500   6     95   18    1450  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   19   SW  26   SW  37
PORT HARDY   S   19   S   19   SW  17
SANDSPIT     W   19   W   15   W   15

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      none            none
PORT HARDY      none            none
ANNETTE         none            none

TODAY'S VENTING: Becoming good by this afternoon except only
fair over northern Vancouver Island.

VENTING FOR THURSDAY: GOOD

VENTING OUTLOOK FRIDAY THRU SUNDAY:Good as unsettled
conditions continue.

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

END/lm