FPCN39 CWLW 181431
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 18 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      24   15     800   3    100   24    3200  13
KAMLOOPS     KEL      82   15    1550  10    100   23    3350  13
OKANAGAN     KEL      14   11     600   2    100   21    3350  13
CASTLEGAR    KEL      57   13    1300   8    100   22    3500  14
CRANBROOK    KEL      96   10    1900  17    100   18    3950  17
REVELSTOKE   KEL      37   13    1100   5    100   20    3450  13


*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   NW   9   W   15
CRANBROOK             VR   5   SW  13

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         12 C
SPOKANE         MISSING

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: 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.     29    9    1350   5    100   18    3950   8
PR. GEORGE   P.G.     24    8    1000   5    100   16    3700   8
SMITHERS     P.G.     23    9     950   3     65   15    1900   4
WELLS GRAY   P.G.     20    8    1250   5    100   17    4000   8
FT NLSN      F.N.     37    8     600  14     85   14    1550  11
FT STJOHN    F.N.      9    6     700  12     91   13    2400   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
PR. GEORGE            W   22   W   35
SMITHERS              W   35   W   35

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1150 m         12 C
FT. NELSON       940 m         11 C

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: 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     16   14     200   6     52   19     600  11
FRASER VLY   QUIL     21   17     250   6    100   25    2550  19
SRN VRISL    QUIL     14   15     200   3    100   22    2250  17
CNTRL VRISL  QUIL     15   17     250   3    100   24    2450  17
NRN VRISL    HRDY     26   10     150  15     64   16     500  15
TERRACE      ANT      36   12     500  12    100   19    1700  13
STEWART      ANT      15   11     100   8     89   19    1200  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   NE   9   N   19
PORT HARDY   NW  24   N   26   NW  30
SANDSPIT     NW  46   NW  54   NW  69

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m         18 C
PORT HARDY       760 m         18 C
ANNETTE         1030 m         17 C

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THROUGH THURSDAY: GENERALLY GOOD.

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

END/PLJ