FPCN39 CWLW 281501
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 7:00 AM PDT SUNDAY 28 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      80   13    1500  15    100   18    2050  15
KAMLOOPS     KEL      30   13     800  13     93   19    2050  13
OKANAGAN     KEL      30   13     800  10     87   18    1800  10
CASTLEGAR    SPOK     20   12     800  10    100   18    1550  22
CRANBROOK    SPOK     60   13    1500  12    100   16    2050  23
REVELSTOKE   KEL       9   12     550   3     12   14     600   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    SW   9   SW  24   W   44
CRANBROOK             W   17   W   46

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         15 C
SPOKANE          900 m         14 C

TODAY'S VENTING: GOOD.



VENTING FOR MONDAY: FAIR TO GOOD.



VENTING OUTLOOK TUESDAY THRU THURSDAY: GENERALLY 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.     80   11    1500  15    100   17    3950  25
PR. GEORGE   P.G.     60   11    1300  15    100   16    1850  24
SMITHERS     P.G.     60   10    1300  20    100   16    1500  19
WELLS GRAY   P.G.    100   12    2000  20    100   18    4000  25
FT NLSN      F.N.     20    9     600   3     83   15    1250  14
FT STJOHN    F.N.     80    9    1500  15    100   17    2900  25

*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   41   W   52
SMITHERS              W   28   W   52

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1600 m         16 C
FT. NELSON      1200 m         14 C

TODAY'S VENTING: GOOD



VENTING FOR MONDAY: GOOD




VENTING OUTLOOK TUESDAY THRU THURSDAY: GENERALLY GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     22   15     300  15     41   17     400  18
FRASER VLY   QUIL     28   15     300  15     38   17     400  18
SRN VRISL    QUIL     24   15     300  12     45   17     400  12
CNTRL VRISL  QUIL     30   14     300  12     45   16     350  12
NRN VRISL    HRDY     30   15     300  10     52   16     350  13
TERRACE      ANT     100   13    1200  12    100   15    1800  19
STEWART      ANT     100   13    1000   7    100   15    1550  15

*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    SW  24   SW  33   W   39
PORT HARDY   VR   5   SW  19   W   35
SANDSPIT     W   19   W   24   W   35

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       N/A           N/A
PORT HARDY      1600 m         16 C
ANNETTE          NONE          N/A

TODAY'S VENTING: FAIR IN THE SOUTH. GOOD IN THE NORTH.



VENTING FOR MONDAY: FAIR



VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD.



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


END/GF