FPCN39 CWLW 101318
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 THURSDAY 10 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       9   14     500   0    100   24    2200   9
KAMLOOPS     KEL       9   14     550   0    100   25    3350  10
OKANAGAN     KEL       9   13     500   0    100   25    3350  10
CASTLEGAR    SPOK     17   18    1350   1     57   24    3500   2
CRANBROOK    SPOK     84   15    3950   4     84   24    3950   4
REVELSTOKE   KEL       9   12     500   0    100   23    2350   9

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W   11   W   15
CRANBROOK             VR   5   VR   5

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR FRIDAY: 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   10     950  20    100   19    3950  27
PR. GEORGE   P.G.      9   11     700   3    100   17    2800  20
SMITHERS     P.G.      9    8     500   3     43   15     900  10
WELLS GRAY   P.G.    100   12    1900  21    100   21    4000  27
FT NLSN      F.N.      9    9     400  10    100   17    1750  14
FT STJOHN    F.N.     10   11     700  10    100   17    3700  16

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              SW  46   SW

TODAY'S VENTING: GENERALLY GOOD THIS AFTERNOON.

VENTING FOR FRIDAY: GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     19   14     200   8     90   20    1300  12
FRASER VLY   QUIL     20   14     200   8     94   21    1350  12
SRN VRISL    QUIL     17   13     150   6     86   20    1200  11
CNTRL VRISL  QUIL     21   15     250   6     79   19    1000  11
NRN VRISL    HRDY      9   13       0   7     63   16     650  11
TERRACE      ANT      10    9     250  23     88   12     850  21
STEWART      ANT      25   11     150  11     55   12     350  15

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  13   SW  26   W   26
PORT HARDY   S   52   SW  48   W   46
SANDSPIT     SW  56   SW  63   SW  67

TODAY'S VENTING: GOOD THIS AFTERNOON.

VENTING FOR FRIDAY: GOOD.




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


END/MWSO