FPCN39 CWLW 041400
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 4 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      52    9    1950   3     72   14    3200   3
KAMLOOPS     KEL      54    8    2200   3     72   14    3350   3
OKANAGAN     KEL      45    7    1750   3     72   14    3350   3
CASTLEGAR    KEL      45    7    1750   3     72   14    3350   3
CRANBROOK    KEL      45    7    1750   3     72   12    3350   3
REVELSTOKE   KEL      51    7    2150   3     72   12    3450   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    W   13   W   26   W   44
CRANBROOK             W   15   W   35

TODAY'S VENTING: GOOD.

VENTING FOR 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.    100    4    3950  19    100   10    3950  19
PR. GEORGE   P.G.    100    5    2350  17    100   10    3700  18
SMITHERS     P.G.      9    2     500   2    100    8    3500  14
WELLS GRAY   P.G.    100    4    3950  19    100   10    4000  19
FT NLSN      F.N.     48    5     950   8     67    8    1400   8
FT STJOHN    P.G.    100    5    2400  17    100   10    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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   26   SW  30
SMITHERS              SW  20   SW  30

TODAY'S VENTING: GOOD.

VENTING FOR WEDNESDAY: GOOD.


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    HRDY    100    9    2400  11    100   13    3100  12
FRASER VLY   HRDY    100    8    1900  10    100   12    3050  11
SRN VRISL    HRDY     94    8    1800   9    100   13    3000  11
CNTRL VRISL  HRDY    100    8    1800  10    100   13    3050  11
NRN VRISL    HRDY     40    5     650   6    100    9    2150   9
TERRACE      ANT      65    3     800  14    100    6    1850  14
STEWART      ANT      22    4     250   6     95    6    1250  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   26   W   33   W   35
PORT HARDY   W   26   W   31   W   30
SANDSPIT     W   30   SW  30   SW  28

TODAY'S VENTING: GOOD.

VENTING FOR WEDNESDAY: GOOD.


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


END/MWSO
$$$$^^