FPCN39 CWLW 091420
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 TUESDAY 9 SEPTEMBER 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       28   18     750   4    68   30    1950   5
KAMLOOPS     KEL       35   17     850   6    50   27    1700   5
OKANAGAN     KEL       22   16     700   4    46   26    1550   5
CASTLEGAR    SPOK      42   16     950   9    47   26    1200   6
CRANBROOK    SPOK      42   14    1250   5    54   25    1500   8
REVELSTOKE   KEL        9   11     500   5    51   24    1450   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   W   15
CRANBROOK             VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1600 m         25 C
SPOKANE         1460 m         27 C

TODAY'S VENTING: Poor this morning becoming fair in
the afternoon.

VENTING FOR WEDNESDAY: fair.

VENTING OUTLOOK THURSDAY THRU SATURDAY: Becoming good as a
trough moves through on Thursday.


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   12     950   5     48   23    1450   8
PR. GEORGE   P.G.     17   11     800   6     45   23    1400   8
SMITHERS     P.G.     12   13     800   1     33   21    1050   5
WELLS GRAY   P.G.      9   12    1000  11     70   24    1500  10
FT NLSN      F.N.      9   13     400  13     36   20     700  10
FT STJOHN    F.N.      9   15     700  13     63   22     800  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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW   9   W   24
SMITHERS              W    9   W   24

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1500 m         25 C
FT. NELSON       750 m         21 C

TODAY'S VENTING: Poor this morning becoming fair by mid afternoon.
Good over higher elevetions in more exposed areas.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY:Becoming good as a
trough moves through on Thursday.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    HRDY     11   17     450    1    44   22     750   6
FRASER VLY   HRDY     12   17     600    1    72   28    1400   7
SRN VRISL    HRDY      9   15     250    0    43   21     650   6
CNTRL VRISL  QUIL     11   17     400    1    47   24    1150   4
NRN VRISL    HRDY      9   13     100    0    36   19     550   6
TERRACE      ANT      45   15     500   15    80   22    2250  10
STEWART      ANT       9   14       0    8    80   22    2200   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   W   11
PORT HARDY   N    9   VR   5   W   11
SANDSPIT     NW  24   W   15   W   24

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      missing       missing
PORT HARDY      1800 m         30 C
ANNETTE          750 m         17 C

TODAY'S VENTING: Becoming fair to good by late afternoon. Generally
good over the north coast.

VENTING FOR WEDNESDAY: GOOD

VENTING OUTLOOK THURSDAY THRU SATURDAY: Becoming good as a
trough moves through on Thursday.


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


END/LM