FPCN39 CWLW 171430
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 17 May 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     100   17    2100  22    100   22    3200  22
KAMLOOPS     KEL     100   17    2450  22    100   23    3350  22
OKANAGAN     KEL     100   17    2450  22    100   22    3350  22
CASTLEGAR    SPOK     90   15    1850  11    100   22    2150  15
CRANBROOK    SPOK     70   16    1650  15    100   20    2400  18
REVELSTOKE   KEL     100   16    2400  22    100   20    3450  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    NW  11   NW  22   N   28
CRANBROOK             NW   9   NW  24

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         NO INVERSION
SPOKANE         1188 M          17 C

TODAY'S VENTING: GOOD.

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THROUGH WEDNESDAY: GOOD IN THE AFTERNOONS.


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    9    3950  20    100   16    3950  20
PR. GEORGE   P.G.    100   10    2100  18    100   15    3700  18
SMITHERS     P.G.    100   10    1850  14    100   17    3500  16
WELLS GRAY   P.G.    100    9    4000  20    100   16    4000  20
FT NLSN      F.N.    100    8    1600  26    100   14    2650  31
FT STJOHN    F.N.    100    8    2150  31    100   13    3700  34


*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            N   31   N   33
SMITHERS              N   19   NE  33

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      NO INVERSION
FT. NELSON      1370 m          7 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THROUGH WEDNESDAY: GOOD IN THE AFTERNOONS.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     68   15     800  11     88   19    1200  12
FRASER VLY   QUIL     72   16     900  11    100   24    3050  19
SRN VRISL    QUIL     68   15     800  11     85   20    1250  10
CNTRL VRISL  QUIL     75   14     750  12    100   19    1500   8
NRN VRISL    HRDY     85   11     750  18    100   15    1400  19
TERRACE      ANT      52    8     650  12    100   15    1750  13
STEWART      ANT      67   11     800  10     99   15    1400  12


*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    NW  11   N   13   N   28
PORT HARDY   N   33   N   31   N   46
SANDSPIT     NW  37   N   31   N   43

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      3000 m         28 C
PORT HARDY      1980 m         19 C
ANNETTE         NO INVERSION

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THROUGH WEDNESDAY: GOOD.


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

END/PLJ