FPCN39 CWLW 191330
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 SATURDAY 19 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      33   16    1050   3    100   20    2350   8
KAMLOOPS     KEL      25   14     900   3    100   21    2850  12
OKANAGAN     KEL      40   15    1400   3    100   20    2700  10
CASTLEGAR    SPOK     55   14    1350   7    100   19    3500  11
CRANBROOK    SPOK     53   11    1550   9    100   18    3950  13
REVELSTOKE   KEL      22   13     900   3     95   17    2300   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    NW  11   NW  24   N   37
CRANBROOK             NW  11   NW  30

TODAY'S VENTING: BECOMING GOOD THIS AFTERNOON.

VENTING FOR SUNDAY: FAIR TO 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.     24   11    1450   3     70   17    2050   8
PR. GEORGE   P.G.     31   11    1250   4     54   17    1700   6
SMITHERS     P.G.     33   11    1100   4     54   20    1700   6
WELLS GRAY   P.G.     47   12    1850   5     70   18    2100   8
FT NLSN      F.N.     25   10     500  16     61   21    1050  10
FT STJOHN    F.N.      9    8     700  15     46   17    1400   5



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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              VR   5   VR

TODAY'S VENTING: BECOMING FAIR TO GOOD THIS AFTERNOON.

VENTING FOR SUNDAY: FAIR.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     51   15     500  12    100   19    1850  12
FRASER VLY   QUIL     79   16    1000  11    100   21    2150  13
SRN VRISL    QUIL      9   13       0   0    100   19    1700  11
CNTRL VRISL  QUIL      9   13      50   0    100   21    2100  11
NRN VRISL    HRDY      9   12       0   6     76   16    1150   9
TERRACE      ANT      36   13     950   4     49   19    1600   4
STEWART      ANT      42   14     900   4     52   19    1300   4


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

FORECAST UPPER WINDS FOR SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    W   11   NW  17   N   22
PORT HARDY   NW  19   N   24   N   26
SANDSPIT     VR   5   S    9   S    9

TODAY'S VENTING: GOOD THIS AFTERNOON EXCEPT FAIR IN THE NORTH.

VENTING FOR SUNDAY: FAIR.




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


END/MWSO