FPCN39 CWLW 111431
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 11 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      23   16     750   3    100   26    2350   8
KAMLOOPS     KEL      21   15     850   3     95   24    2300   8
OKANAGAN     KEL      19   14     750   3    100   25    2450   9
CASTLEGAR    SPOK     19   14     750   4     91   25    2100   9
CRANBROOK    SPOK      9   13     950  13    100   23    3950   8
REVELSTOKE   KEL      16   13     750   3     90   22    2200   8


*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   VR   5
CRANBROOK             VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1450 m         21 C
SPOKANE         1450 m         20 C

TODAY'S VENTING: BECOMING GOOD BY LATE MORNING.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: BECOMING GOOD EACH
AFTERNOON.

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.      9   11     950   1    100   21    3950   6
PR. GEORGE   P.G.     18   10     950   4     98   20    3700   6
SMITHERS     P.G.     20   11     900   3     58   20    2100   4
WELLS GRAY   P.G.      9   10    1000   1    100   20    4000   6
FT NLSN      F.N.     14   11     500   5    100   20    3400   9
FT STJOHN    F.N.     48   12    1600   5    100   19    3700  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            VR   5   W   15
SMITHERS              SW   9   SW  15

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1066 m         16 C
FT. NELSON       790 m         15 C

TODAY'S VENTING: BECOMING GOOD BY LATE AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: GENERALLY 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     12   16     150   7     43   21     400  13
FRASER VLY   QUIL     21   20     250   7     73   27     800  12
SRN VRISL    QUIL     11   15     100   2     43   23     450   9
CNTRL VRISL  QUIL     11   17     150   2     51   26     600   9
NRN VRISL    HRDY     22   11     200   7     41   18     500   8
TERRACE      HRDY     26   14     450   8     64   22    1000   9
STEWART      HRDY     26   14     400   8     55   20     900   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
VANCOUVER    E   19   E   19   E   11
PORT HARDY   VR   5   E   13   VR   5
SANDSPIT     VR   5   SW  11   SW  24

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       800 m         25 C
PORT HARDY      1490 m         26 C
ANNETTE         MISSING

TODAY'S VENTING: FAIR TO GOOD THIS AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: FAIR TUESDAY AFTERNOON.
GOOD WEDNESDAY AND THURSDAY AFTERNOONS.


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

END/mwso