FPCN39 CWLW 041434
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 4 September 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      67   20     950  11     80   24    2300  14
KAMLOOPS     KEL      72   19    1200  11     80   25    2600  10
OKANAGAN     KEL       9   17     550   0     80   24    2550  10
CASTLEGAR    SPOK     70   19    1100  15     75   25    2700   9
CRANBROOK    SPOK    100   19    2700  21     90   23    3950  11
REVELSTOKE   KEL      66   18    1200  11     84   23    2550  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW   9   SW  20
CRANBROOK             W   11   W   30

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          600 m         17 C
SPOKANE         1500 m         20 C

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: GOOD

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD EXCEPT FAIR ON MONDAY




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   15     950  13     60   22    2750   8
PR. GEORGE   P.G.      9   13     700  10     64   20    2700  12
SMITHERS     P.G.     16   13     700   4     59   19    2700   8
WELLS GRAY   P.G.      9   14    1000  13     80   22    3000   8
FT NLSN      F.N.      9   13     400  11     62   20    1900  11
FT STJOHN    F.N.      9   15     700   9     66   21    1950   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  13   SW  24
SMITHERS              SW  17   SW  24

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1100 m         20 C
FT. NELSON       800 m         20 C

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: GOOD

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD BECOMING FAIR ON MONDAY




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     28   17     300   9     95   22    2250  11
FRASER VLY   QUIL     38   18     400   9     90   23    2000  11
SRN VRISL    QUIL     14   15     100   6     97   22    2250  10
CNTRL VRISL  QUIL     56   19     700   9     97   22    2200  10
NRN VRISL    HRDY     33   15     450   6     99   18    2200  10
TERRACE      ANT     100   16    1750  16    100   20    2750  15
STEWART      ANT      82   16     950  13    100   20    2350  14

*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    SW   9   SW  13   SW  24
PORT HARDY   S   20   S   22   S   22
SANDSPIT     S   41   S   43   S   41

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m         17 C
PORT HARDY       800 m         15 C
ANNETTE         NO INVERSION

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: GOOD

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD. BECOMING FAIR TO POOR
ON MONDAY




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

END/JMS