FPCN39 CWLW 131325
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 MONDAY 13 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    5     650   3     75   12    2800   4
KAMLOOPS     KEL      28    6    1150   3     84   14    3350   4
OKANAGAN     KEL      28    6    1150   3     84   13    3350   4
CASTLEGAR    SPOK     25    5     900   4     93   12    3500   5
CRANBROOK    SPOK     14    3    1050   5     96   11    3950   5
REVELSTOKE   KEL      31    6    1350   3     84   12    3450   4


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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   VR   5
CRANBROOK             VR   5   NW   9

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          800 m          5 C
SPOKANE         1050 m          6 C

TODAY'S VENTING: BECOMING GOOD BY THIS AFTERNOON.

VENTING FOR TUESDAY: GOOD.

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: GENERALLY GOOD DURING THE
AFTERNOONS.




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.     62    3    1550  12    100    8    3950   8
PR. GEORGE   P.G.     55    4    1250  10    100    8    3700   8
SMITHERS     P.G.     18    3     800   3     83    8    2150   7
WELLS GRAY   P.G.    100    5    4000   8    100    9    4000   8
FT NLSN      F.N.     28    2     700   6    100    8    3400   6
FT STJOHN    F.N.     78    2    2250   7    100    5    3700   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NW  15   NW  17
SMITHERS              NW  11   N   17

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1300 m          7 C
FT. NELSON       800 m          3 C

TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: GENERALLY GOOD DURING
THE AFTERNOONS.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     16    7     400   2     77   11    1950   6
FRASER VLY   QUIL     14    7     300   2     92   12    2350   6
SRN VRISL    QUIL     32    9     950   3     85   12    2150   6
CNTRL VRISL  QUIL     10    7     250   1     86   12    2200   6
NRN VRISL    HRDY      9    5       0   3     80   10    1300   8
TERRACE      ANT       9    4     300   1     99   11    2750   7
STEWART      ANT      10    5      50   3     90   11    2350   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   VR   5
PORT HARDY   NW  17   NW   9   VR   5
SANDSPIT     N   20   N   20   NW  15

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       300 m          8 C
PORT HARDY       100 m          6 C
ANNETTE          100 m          6 C

TODAY'S VENTING: BECOMING GOOD BY THIS AFTERNOON.

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: FAIR.




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


END/JDG