FPCN39 CWLW 041401
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 PST SATURDAY 4 APRIL 1998 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      20   11     700   2     58   15    1600   5
KAMLOOPS     KEL      26   10    1000   3     56   14    1650   5
OKANAGAN     KEL       9    8     550   0     56   14    1650   5
CASTLEGAR    SPOK     33    9     850   7     72   14    2050   6
CRANBROOK    SPOK     51    9    1900   5    100   14    3950   7
REVELSTOKE   KEL       9    6     500   0     50   12    1550   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
PENTICTON    VR   5   VR   5   VR   5
CRANBROOK             E   13   SE  30

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          500 m          8 C
SPOKANE          900 m          8 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: 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.     15    2    1050   3    100   10    4000   6
PR. GEORGE   P.G.     12    3     800   2     80    9    2500   6
SMITHERS     P.G.     15    3     700   2     70   10    2400   5
WELLS GRAY   P.G.     20    2    1200   3     75    8    2500   7
FT NLSN      F.N.     18    3     450  10    100   10    2700  11
FT STJOHN    F.N.      9    3     700  11    100    9    2800  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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            E    9   S    9
SMITHERS              SE  17   SE   9

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1000 m          4 C
FT. NELSON       500 m          5 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     12   10     300   5     64   12    1550   5
FRASER VLY   QUIL     15   11     350   5     86   14    1850   7
SRN VRISL    QUIL      9   10     300   0     65   13    1600   5
CNTRL VRISL  QUIL      9   10     200   0     64   13    1650   5
NRN VRISL    HRDY      9    6     100   2     51   11     850   6
TERRACE      ANT       9    5     150   7     71   11    1550   7
STEWART      ANT      10    6     150   6     73   11    1400   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   VR   5
PORT HARDY   VR   5   VR   5   SE  11
SANDSPIT     NW  17   VR   5   S    9

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m          8 C
PORT HARDY       200 m          8 C
ANNETTE          150 m          5 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD

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


END/MWSO