FPCN39 CWLW 121324
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 WEDNESDAY 12 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   23     550   0     94   33    2700   6
KAMLOOPS     KEL       9   21     500   0     98   33    2850   7
OKANAGAN     KEL       9   21     500   0     98   33    2850   7
CASTLEGAR    SPOK     17   23     750   3    100   34    3500   7
CRANBROOK    SPOK      9   20     950   6    100   32    3950   8
REVELSTOKE   KEL       9   21     550   0     96   32    2850   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W   13   W   22
CRANBROOK             W   11   W   20

TODAY'S VENTING: GOOD




VENTING FOR THURSDAY: 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  15    100   24    3950  22
PR. GEORGE   P.G.      9   15     700   1     20   19     850   7
SMITHERS     P.G.      9   13     500   1      9   15     550   1
WELLS GRAY   P.G.     10   18    1000  15    100   25    4000  22
FT NLSN      F.N.      9   15     400   7    100   22    3400   8
FT STJOHN    F.N.      9   15     700   7    100   21    3700   8

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              W   22   W

TODAY'S VENTING: GOOD EXCEPT POOR IN THE NORTHWEST AND PRINCE GEORGE




VENTING FOR THURSDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     57   19     600  11     94   26    1450  11
FRASER VLY   QUIL     69   21     800  11    100   31    2000  11
SRN VRISL    QUIL     49   19     600   8     88   26    1350  10
CNTRL VRISL  QUIL     71   22     900  10    100   30    1800  10
NRN VRISL    HRDY      9   17       0   3     25   20     450   4
TERRACE      ANT      10   13     250  15     77   17     900  15
STEWART      ANT      40   16     350  10     51   17     550  10

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   11   NW  13   W   20
PORT HARDY   SW  15   W   22   W   35
SANDSPIT     SW  22   SW  26   W   30

TODAY'S VENTING: GOOD EXCEPT NORTHERN VANCOUVER ISLAND.




VENTING FOR THURSDAY: GOOD




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


END/MWSO