FPCN39 CWLW 111425
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 SATURDAY 11 OCTOBER 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      24    9     600   4     53   12    1050   6
KAMLOOPS     KEL      30    9     800   5     77   12    1900   7
OKANAGAN     KEL      27    8     750   5     77   12    1900   7
CASTLEGAR    SPOK     19    8     800   3     83   12    1800   9
CRANBROOK    SPOK      9    3     950  11    100   10    3950  10
REVELSTOKE   KEL      23    7     750   5     36    9     950   6

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    NW  11   NW  26   NW  37
CRANBROOK             W   11   NW  31

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          900 m          9 C
SPOKANE         1100 m         10 C

TODAY'S VENTING: Good. Unstable air over the region as upper
trough moves across.

VENTING FOR SUNDAY: Fair to good. Boundary layer winds increase
in the afternoon.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: Generally fair. Ridge of
high pressure will settle in over the area giving stable conditions.

CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   KEL       9    2     950   3     41    7    1100   5
PR. GEORGE   ANT       9   -1     691   4     50    6    1200   6
SMITHERS     ANT       9   -1     523   4     36    5     900   4
WELLS GRAY   ANT       9    3    1000   8     40    6    1800   8
FT NLSN      F.N.     32   -3     900   5     43   -2    1150   5
FT STJOHN    F.N.     50   -3    1700   5     61   -1    2050   5

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   28   W   33
SMITHERS              W   22   NW  33

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       n/a
FT. NELSON      3000 m         13 C

TODAY'S VENTING: Fair. Boundary layer circulation will increase
this afternoon.

VENTING FOR SUNDAY: Good.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: Fair to good.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     55   10     300  24    100   13    1500  23
FRASER VLY   QUIL     56   10     300  24    100   12     850  24
SRN VRISL    QUIL      9    8     150   0     90   13    1150  20
CNTRL VRISL  QUIL      9    9     250   0     91   13    1200  12
NRN VRISL    HRDY     25    8     200   9    100   11    1700  14
TERRACE      ANT       9    2     250   6     75    6    1550   7
STEWART      ANT      15    5     150   5     31    6     500   5

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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   31   NW  46   NW  65
PORT HARDY   W   15   NW  37   NW  63
SANDSPIT     S   24   W   26   W   48

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m         11 C
PORT HARDY       330 m         10 C
ANNETTE          100 m          5 C

TODAY'S VENTING: Good.

VENTING FOR SUNDAY: Good. Frontal system moving onshore.

VENTING OUTLOOK MONDAY THRU WEDNESDAY: Good. Series of frontal
systems onshore.

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


END/DB