FPCN39 CWLW 251400
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 WEDNESDAY 25 AUGUST 1999 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      50   22     200  20     81   24    2000  25
KAMLOOPS     KEL      20   24     500   8     77   26    2000  12
OKANAGAN     KEL      21   25     500   8     72   28    2000  12
CASTLEGAR    SPOK     47   21     850  14     75   27    1100  16
CRANBROOK    SPOK     32   22    1050  26     90   27    2350  17
REVELSTOKE   KEL       9   19     450   8     61   22    1800  12

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W   13   W   30   W   44
CRANBROOK             W   20   W   43

TODAY'S VENTING: GOOD.


VENTING FOR THURSDAY: FAIR


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.     40   17    2600  10     88   19    2900  15
PR. GEORGE   P.G.     32   13    1050   6     72   18    2000  10
SMITHERS     P.G.     30   12    1000   5     79   17    1650   9
WELLS GRAY   P.G.     32   12    1200   6     90   19    4000  17
FT NLSN      F.N.     38   13    1000   7    100   15    1600  15
FT STJOHN    F.N.     36   13    1800   7    100   18    2800  20

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   43   W   52
SMITHERS              W   33   W   52

TODAY'S VENTING: GOOD


VENTING FOR THURSDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     70   20     900  12     90   22    1350  16
FRASER VLY   QUIL     56   19     700  10     90   21    1100  16
SRN VRISL    QUIL     58   19     600  12     92   20     800  16
CNTRL VRISL  QUIL     59   19     650  10     88   21    1050  14
NRN VRISL    HRDY     36   14     300  10     64   16     650  12
TERRACE      ANT      32   11     400   8     65   13    1200   8
STEWART      ANT      10   11      50   2     46   13     700   7

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  17   W   26   W   39
PORT HARDY   SW  13   SW  22   W   41
SANDSPIT     SW  24   SW  31   SW  41

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: FAIR




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


END/MWSO
$$$$^^