FPCN39 CWLW 061400
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 THURSDAY 6 MAY 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       9   12     650   10    30  20    2250    10

KAMLOOPS     KEL       9   13    1550   0     35  20    2350    10

OKANAGAN     KEL       9   11     700   0     40   20   2350    13

CASTLEGAR    SPOK     46   11    1100   7     90   20   2400    15

CRANBROOK    SPOK     62    9    1450  13    100   20   2850    10

REVELSTOKE   KEL       9    8     550   0     35   16    2350    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
PENTICTON    SE  13   S   35   S   72
CRANBROOK             S    9   S   26

TODAY'S VENTING: GENERALLY POOR EXCEPT GOOD IN THE KOOTENAYS.




VENTING FOR FRIDAY: POOR




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.     70   12    1900   20    100   17    2900  20

PR. GEORGE   P.G.     80   12    1800   20    100   14    1900  26

SMITHERS     P.G.      9    8     500    3     50   12    1050  10

WELLS GRAY   P.G.     70   11    1900   17    100   17    4000  36

FT NLSN      F.N.     17    4     600    4     77    8    1050  16

FT STJOHN    F.N.    100    9    2000   19    100   14    3700  18


*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            S   39   S   48
SMITHERS              S   28   S   48

TODAY'S VENTING: GENERALLY GOOD THIS AFTERNOON EXCEPT FAIR IN THE
SMITHERS AREA.




VENTING FOR FRIDAY: FAIR




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     40   10     300  05    100   14    1800  15

FRASER VLY   QUIL     20   10     300  07    100   15    1900  13

SRN VRISL    QUIL      9   11     250   0     65   13    1400 15

CNTRL VRISL  QUIL      9   11     250   0     70   15    1000  15

NRN VRISL    HRDY     46   10     400  12     99   12    1150  15

TERRACE      ANT     100    7     950  49    100   12    3200  50

STEWART      ANT     100    9     900  44    100   12    3000  47


*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    S   30   S   43   S   59
PORT HARDY   SW  20   S   31   S   54
SANDSPIT     SW  30   SW  33   S   39

TODAY'S VENTING: GOOD




VENTING FOR FRIDAY: FAIR




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


END/MWSO
$$$$^^