FPCN39 CWLW 041312
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 4 SEPTEMBER 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   19     450   4    100   32    3200   7
KAMLOOPS     KEL      14   19     500   4    100   32    3350   7
OKANAGAN     KEL      15   20     500   4    100   32    3350   7
CASTLEGAR    SPOK     24   21     750   6     56   32    1200   8
CRANBROOK    SPOK      9   17     950  14    100   30    2750  18
REVELSTOKE   KEL      11   19     500   4    100   30    3450   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   SW  15
CRANBROOK             VR   5   SW  13

TODAY'S VENTING: GOOD

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.    100   14    2650  11    100   24    3950  11
PR. GEORGE   P.G.     35   11    1150   7    100   21    3700  10
SMITHERS     P.G.      9    6     700   0     90   15    2000  10
WELLS GRAY   P.G.    100   14    2750  11    100   24    4000  11
FT NLSN      F.N.     35   11     450  31    100   20    3400  34
FT STJOHN    F.N.      9   10     700  33    100   20    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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              VR   5   VR

TODAY'S VENTING: GOOD

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     55   17     450  16     83   23     850  16
FRASER VLY   QUIL     63   19     500  16    100   28    2200  10
SRN VRISL    QUIL      9   15     350   0     59   21     800  12
CNTRL VRISL  QUIL      9   17     400   0     90   26    1450  10
NRN VRISL    HRDY     63   14     450  18    100   19    1550  16
TERRACE      ANT       9   11     250   6     99   16    2200   9
STEWART      ANT      10   12     100   1     81   16    1650   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 FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   S    9   SW  24
PORT HARDY   N   13   VR   5   SW  20
SANDSPIT     VR   5   VR   5   S   13

TODAY'S VENTING: GOOD

VENTING FOR SATURDAY: GOOD

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


END/MWSO