FPCN39 CWLW 111501
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT Monday 11 August 1997 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      24   23     850   2     94   33    2850   6

KAMLOOPS     KEL      19   21     800   2     85   30    2700   5

OKANAGAN     KEL      13   19     600   2     69   29    2150   5

CASTLEGAR    SPOK     16   20     850   2    100   29    3500   6

CRANBROOK    SPOK      9   18     950   5    100   27    3950   8

REVELSTOKE   KEL      12   18     600   2     41   27    1800   3


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

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

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1100 m         23 C
SPOKANE          910 m         22 C

TODAY'S VENTING:
Strong inversion will limit mixing heights. Light winds will combine
with this to provide only short time window for good venting in the
afternoon.

VENTING FOR TUESDAY: FAIR TO GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:
Little change Wednesday. Generally good venting Thursday and Friday
as low level winds increase and inversion weakens somewhat.

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.      9   18     950  10    100   27    3950   7

PR. GEORGE   P.G.     21   19     850   8    100   28    3700   8

SMITHERS     P.G.     24   19     850   5     55   28    1300   7

WELLS GRAY   P.G.      9   17    1000  10    100   28    4000   7

FT NLSN      F.N.     76   19    1000  16    100   24    1950  15

FT STJOHN    F.N.     71   17    1250  16    100   23    2200  14


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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   11   W   15
SMITHERS              W    9   W   15

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1100 m         26 C
FT. NELSON       800 m         18 C

TODAY'S VENTING:
Good venting in the northeast. Strong inversion elsewhere will limit
amount of time for good venting.

VENTING FOR TUESDAY: FAIR TO GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:
Little change Wednesday. Generally good venting Thursday and Friday
as low level winds increase and inversion weakens somewhat.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     18   21     300   4     31   27     700   4

FRASER VLY   QUIL     19   22     300   4     76   31    2200   5

SRN VRISL    QUIL      9   19     250   0      9   26     500   0

CNTRL VRISL  QUIL      9   25     450   0     68   33    2400   4

NRN VRISL    HRDY     20   16     200   7     37   21     350   9

TERRACE      ANT       9   17     200  16      9   19     200  16

STEWART      ANT       9   15       0   7      9   19       0   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   E    9
PORT HARDY   VR   5   VR   5   VR   5
SANDSPIT     N   24   NW  11   W   13

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       640 m         26 C
PORT HARDY       980 m         29 C
ANNETTE          nil m         ## C stable to 1040

TODAY'S VENTING:
Breakthrough temperature remains high. Expect only good venting in
inland areas where temperatures climb above the 25 degree mark.

VENTING FOR TUESDAY: FAIR

VENTING OUTLOOK WEDNESDAY THRU FRIDAY:
Fair on Wednesday. Fair to good Thursday and Friday.

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

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