FPCN39 CWLW 141437
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 Thursday 14 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      19   27     700   2    100   33    1800  15
KAMLOOPS     KEL      14   24     600   2    100   31    1750  15
OKANAGAN     KEL      13   23     550   2    100   31    1750  15
CASTLEGAR    SPOK     28   23     750   8     70   29    1300  10
CRANBROOK    SPOK      9   19     950  15    100   27    3950  15
REVELSTOKE   KEL       9   19     450   2     70   25     750   2

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W   13   W   26   NW  41
CRANBROOK             W   19   W   50

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1000 m         21 C
SPOKANE         1500 m         23 C

TODAY'S VENTING: GOOD.




VENTING FOR FRIDAY: GOOD




VENTING OUTLOOK SATURDAY THRU MONDAY: FAIR TO GOOD.




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   20    2250  37    100   23    2500  36
PR. GEORGE   P.G.      9   19     700  20    100   20     700  20
SMITHERS     P.G.     18   21     650   8    100   26    2450  29
WELLS GRAY   P.G.     11   16    1000  34    100   23    2550  36
FT NLSN      F.N.      9   18     400  49    100   18     400  49
FT STJOHN    F.N.    100   19    2050  51    100   21    2600  51

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NW  44   NW  48
SMITHERS              NW  31   N   48

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      2300 m         21 C
FT. NELSON      Nil            18 C

TODAY'S VENTING: GOOD.




VENTING FOR FRIDAY: GOOD




VENTING OUTLOOK SATURDAY THRU MONDAY: FAIR TO GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     48   20     550  10     54   24     650  10
FRASER VLY   QUIL     49   20     550  10     60   26     700  10
SRN VRISL    QUIL      9   18     350   0      9   24     600   0
CNTRL VRISL  QUIL      9   22     600   0      9   30    1000   0
NRN VRISL    HRDY      9   19       0  19     57   20     300  21
TERRACE      ANT     100   21    1500  17    100   25    2100  22
STEWART      ANT     100   22    1450  15    100   25    1750  18

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   33   NW  46   NW  72
PORT HARDY   NW  54   NW  76   NW  83
SANDSPIT     NW  57   N   57   NW  65

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       760 m         25 C
PORT HARDY      1500 m         15 C
ANNETTE         1250 m         15 C

TODAY'S VENTING: POOR IN THE SOUTH. GOOD ELSEWHERE.




VENTING FOR FRIDAY: GOOD




VENTING OUTLOOK SATURDAY THRU MONDAY: FAIR.




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

END/MWSO