FPCN39 CWLW 261433
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 26 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      21   18     700   3     42   23    1300   3
KAMLOOPS     KEL      25   18     900   3     48   23    1500   4
OKANAGAN     KEL      13   15     550   2     40   22    1350   3
CASTLEGAR    SPOK     17   16     750   3     32   22    1050   4
CRANBROOK    SPOK      9   15     950   6     35   21    1400   6
REVELSTOKE   KEL      11   14     550   2     22   17     900   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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   S   26   SW  50
CRANBROOK             S   13   S   39

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1430 m         22 C
SPOKANE         1430 m         24 C

TODAY'S VENTING: Poor this morning becoming fair late
this afternoon as cloud cover keeps temperatures from
exceeding the inversion too early.

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY:Fair to good
as unsettled conditions persist.

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.     11   15     950  32    100   20    3950  15
PR. GEORGE   P.G.      9   14     700  15     88   18    1250  15
SMITHERS     P.G.     10   14     600   1     32   18     850   8
WELLS GRAY   P.G.     11   15    1000  32    100   21    4000  21
FT NLSN      F.N.     15   16     550   4     28   22     850   4
FT STJOHN    F.N.      9   15     700   4     32   21    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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SE  30   SE  44
SMITHERS              E   19   SE  44

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      700 m         17 C
FT. NELSON      820 m         22 C

TODAY'S VENTING: Poor this morning becoming fair to good in the
central interior.  Poor in the Peace District and extreme western
sections as low cloud restricts heating.

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY: Fair to good as unsettled
conditions persist.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
VANCOUVER    HRDY     64   17     450  20     70   19    2700  11
FRASER VLY   HRDY     69   19     550  17     70   21    2450  11
SRN VRISL    HRDY     59   17     400  17     68   19    2400  10
CNTRL VRISL  HRDY     59   17     400  17     63   19    2450  10
NRN VRISL    HRDY     11   15     100   4     18   17     250   4
TERRACE      ANT       9   10     200  16    100   19    1600  20
STEWART      ANT      18   16     150   8     94   19    1000  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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   26   SW  37   SW  50
PORT HARDY   S   24   S   30   S   35
SANDSPIT     VR   5   VR   5   SE  11

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      missing      missing
PORT HARDY      300 m         18 C
ANNETTE         none         none

TODAY'S VENTING: Poor this morning becoming good
by early to mid afternoon in most areas. Venting staying
poor over northern Vancouver Island due to cloud cover and onshore
flow keeping temperatures from breaking the inversion.

VENTING FOR WEDNESDAY: FAIR

VENTING OUTLOOK THURSDAY THRU SATURDAY:Fair to good as unsettled
conditions persist.

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

END/lm