FPCN39 CWLW 111334
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 11 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      59   20     900  15     85   22    2250  20
KAMLOOPS     KEL       9   19     350   2     75   22    2200  12
OKANAGAN     KEL       9   19     350   2     75   22    2200  10
CASTLEGAR    SPOK     23   19     850   4     70   24    2250  10
CRANBROOK    SPOK      9   17     950   8     70   24    2250  10
REVELSTOKE   KEL       9   16     450   2     79   19    2250  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    W    9   W   22   W   37
CRANBROOK             W    9   W   26

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         NO INVERSION
SPOKANE         1100 m         21 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: 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.     79   13    2100   9     90   17    2900  12
PR. GEORGE   P.G.     40   13    1000  11     96   17    3200  11
SMITHERS     P.G.      9   12     500   6     84   16    3250  10
WELLS GRAY   P.G.     85   14    2200  10     90   18    3000  13
FT NLSN      F.N.     75   14     850  20     90   19    2750   9
FT STJOHN    F.N.     44   11     900  20     92   13    2800   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            W   17   W   22
SMITHERS              W   15   W   22

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1200 m         16 C
FT. NELSON       800 m         13 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     84   18    1100  12     80   20    2550  12
FRASER VLY   QUIL     93   19    1300  12     80   23    2700  12
SRN VRISL    QUIL     75   18     950  11     78   20    2500  11
CNTRL VRISL  QUIL     12   16     100   6     78   20    2500  11
NRN VRISL    HRDY      9   13     300   7     78   17    3000  11
TERRACE      ANT      26   15    1300   2     86   18    2100  11
STEWART      ANT      13   13     200   2     84   18    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
VANCOUVER    W   20   W   28   W   37
PORT HARDY   W   15   W   22   W   33
SANDSPIT     W   15   W   15   W   13

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      NO INVERSION
PORT HARDY       100 m         13 C
ANNETTE         NO INVERSION

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD.




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


END/JMS