FPCN39 CWLW 131400
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 TUESDAY 13 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      67   10    1000  10    100   15    3200  14
KAMLOOPS     KEL     100   10    3350  14    100   15    3350  14
OKANAGAN     KEL     100   10    3350  14    100   15    3350  14
CASTLEGAR    SPOK     44    7     900  11    100   14    3500  14
CRANBROOK    SPOK      9    6     950  16    100   10    3950  14
REVELSTOKE   KEL      13    6     500   5    100   10    3450  14

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W    9   NW  26   NW  37
CRANBROOK             W   13   W   30

TODAY'S VENTING: GOOD.

VENTING FOR WEDNESDAY: 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.    100    3    3950  26    100   10    3950  26
PR. GEORGE   P.G.    100    3    2400  26    100    9    3700  25
SMITHERS     P.G.    100    3    1550  19    100    9    3500  21
WELLS GRAY   P.G.    100    3    4000  26    100   10    4000  26
FT NLSN      F.N.      9    3     400   0    100    9    3400  30
FT STJOHN    F.N.    100    3    2800  33    100    8    3700  34

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   37   W   50
SMITHERS              W   28   W   50

TODAY'S VENTING: GOOD.

VENTING FOR WEDNESDAY: FAIR.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL    100    9    1800  18    100   12    2050  18
FRASER VLY   QUIL    100    9    1800  18    100   12    2050  18
SRN VRISL    QUIL     94    8    1150  14    100   13    2050  16
CNTRL VRISL  QUIL     80    7     900  12    100   12    2050  16
NRN VRISL    HRDY     11    5     250   1    100    9    1950  15
TERRACE      ANT      92    4    1300  14    100    8    2950  16
STEWART      ANT      61    5     800   9    100    8    2200  13

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   17   NW  20   NW  37
PORT HARDY   VR   5   VR   5   NW  22
SANDSPIT     S   19   S   15   W   17

TODAY'S VENTING: GOOD.

VENTING FOR WEDNESDAY: FAIR.


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


END/MWSO
$$$$^^