FPCN39 CWLW 311430
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 31 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      16   19     550   2     94   27    3350  14
KAMLOOPS     KEL      19   19     800   2     76   26    3350   4
OKANAGAN     KEL      19   19     800   2     76   26    3350   4
CASTLEGAR    SPOK     24   18     800   5     70   26    3300   3
CRANBROOK    SPOK      9   17     950   1     80   25    3950   5
REVELSTOKE   KEL      10   16     500   2     75   20    3300   3

*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   VR   5   VR   5
CRANBROOK             VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1700 m         23 C
SPOKANE         1200 m         22 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.

VENTING OUTLOOK TUESDAY THRU THURSDAY: 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.     20   12    1000   6     80   21    3950   9
PR. GEORGE   P.G.     35   12    1050   8     80   21    3700   9
SMITHERS     P.G.     29   12     950   5     80   21    2850   8
WELLS GRAY   P.G.     42   13    1400  10     80   21    4000   9
FT NLSN      F.N.     34   11     650  10     90   20    2550  10
FT STJOHN    F.N.     24   10     850  10     90   18    2700  10

*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            VR   5   VR   5
SMITHERS              E    9   VR   5

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1500 m         18 C
FT. NELSON      1300 m         17 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     18   17     200   9     60   22    2700  10
FRASER VLY   QUIL     19   17     150   9     60   24    2750  11
SRN VRISL    QUIL     16   17     150   5     64   23    2300   9
CNTRL VRISL  QUIL     16   17     150   5     75   24    2600  10
NRN VRISL    HRDY     28   15     350   7     76   19    2300   7
TERRACE      ANT      20   16     350   9     71   23    2350   9
STEWART      ANT      22   17     250   6     64   23    2450   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   SE  11   S   19
PORT HARDY   VR   5   SE  13   SE  24
SANDSPIT     N   13   NE   9   E   13

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       700 m         21 C
PORT HARDY       700 m         20 C
ANNETTE         1100 m         21 C

TODAY'S VENTING: GOOD.

VENTING FOR MONDAY: GOOD.

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/JMS