FPCN39 CWLW 211342
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 FRIDAY 21 AUGUST 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       9   19     200   1     64   29    1300   6
KAMLOOPS     KEL       9   18     350   1    100   29    3350   7
OKANAGAN     KEL      11   20     500   1     64   28    1500   6
CASTLEGAR    SPOK      9   20     500   0      9   28    1300   0
CRANBROOK    SPOK      9   16     950   8    100   26    3950  13
REVELSTOKE   KEL       9   16     450   1     34   24     900   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    L/V      31015    23010
CRANBROOK    L/V      22010    21020

TODAY'S VENTING: POOR THIS MORNING BECOMING GOOD THIS AFTERNOON EXCEPT
                 BECOMING POOR IN CASTLEGAR AND REMAININGFAIR REVELSTOKE




VENTING FOR SATURDAY: 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.     10   15     950  10    100   25    3950  13
PR. GEORGE   P.G.      9   16     700   0    100   24    2550   9
SMITHERS     P.G.      9   13     500   0     65   23    1550   8
WELLS GRAY   P.G.     10   16    1000  10    100   25    4000  13
FT NLSN      F.N.      9   15     400  13     87   20    1450  12
FT STJOHN    F.N.     58   15    1200  12     92   19    1950  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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE  27022     24035    23040
SMITHERS    25020     26030    26035

TODAY'S VENTING: POOR THIS MORNING EXCEPT GOOD IN FORT ST JOHN.
                 VENTING BECOMING GOOD FOR THE WHOLE REGION THIS
                 AFTERNOON.




VENTING FOR SATURDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     68   18    1000   9     92   23    1550  10
FRASER VLY   QUIL     41   17     600   7     93   24    1600  10
SRN VRISL    QUIL      9   16     250   0     87   22    1550   8
CNTRL VRISL  QUIL      9   17     500   0     87   24    1600   8
NRN VRISL    HRDY      9   13       0  11     73   18     850  11
TERRACE      ANT      86   14    1150  13    100   22    3200  12
STEWART      ANT      58   15     650  10    100   22    1900  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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER   22020     21025    21030
PORT HARDY   L/V      22010    23010
SANDSPIT    32025     29025    28025

TODAY'S VENTING: GOOD THIS MORNING EXCEPT FAIR IN THE FRASER VALLEY
                 AND POOR OVER THE VANCOUVER ISLAND. VENTING BECOMING
                 GOOD FOR THE WHOLE AREA THIS AFTERNOON.




VENTING FOR SATURDAY: GOOD




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


END/JL