FPCN39 CWLW 071343
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 7 APRIL 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      79   10    2500  30     80   13    2500  15
KAMLOOPS     KEL      24   11    1050   2     97   15    2300   8
OKANAGAN     KEL       9    8     500   0     96   14    2200   8
CASTLEGAR    SPOK     48    8     950  10    100   12    1850  13
CRANBROOK    SPOK    100    8    1950  18    100   12    2800  15
REVELSTOKE   KEL       9    6     500   3     10    9     650   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  19   SW  44
CRANBROOK             SW  15   SW  37

TODAY'S VENTING: GOOD

VENTING FOR 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.     71    3    1950  12     75    8    2950  12
PR. GEORGE   P.G.     10    4     700   3     65    8    2050   8
SMITHERS     P.G.      9    3     500   1     42    6    1250   5
WELLS GRAY   P.G.      9    2     700   5     65    8    3000  12
FT NLSN      F.N.     23    3     800   0     45    9    2400  11
FT STJOHN    F.N.    100    5    3700  11    100    8    3700  11

*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            SW  20   SW  31
SMITHERS              SW  19   W   31

TODAY'S VENTING: FAIR TO 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     65    8     600  14     65   11    1250   8
FRASER VLY   QUIL     55   10    1050   5     65   13    1450   5
SRN VRISL    QUIL     50   10     950   5     65   13    1400   5
CNTRL VRISL  QUIL     65   10     950  15     65   13    1450   8
NRN VRISL    HRDY      9    6      50   2     42    7     500   8
TERRACE      ANT      93    3    1400   0     75    5    2200   8
STEWART      ANT      12    3     100   3     75    5    1400  11

*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    S   24   SW  44   SW  59
PORT HARDY   NW  26   W   22   SW  20
SANDSPIT     W   17   W   22   NW  26

TODAY'S VENTING: GOOD

VENTING FOR THURSDAY: GOOD

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

END/WJW