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 Saturday 26 July 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      54   16    1300   5    100   28    4500   6
KAMLOOPS     KEL      53   16    1450   5    100   27    4550   6
OKANAGAN     KEL      47   16    1250   5    100   27    4550   6
CASTLEGAR    SPOK     20   16     850   3    100   27    4500   9
CRANBROOK    SPOK      9   17     950   3    100   25    4500   9
REVELSTOKE   KEL      24   15     800   4    100   23    4500   6

*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    VR   5   VR   5   W   11
CRANBROOK             VR   5   W   17

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1300 m         17 C
SPOKANE         1100 m         20 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: 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.     46   12    1200   5    100   20    3950  11
PR. GEORGE   P.G.     58   14    1200   5    100   20    3700  11
SMITHERS     P.G.     13   12     750   2    100   19    3500  10
WELLS GRAY   P.G.     80   15    4000   6    100   21    4000  11
FT NLSN      F.N.     38   17     750   5     89   22    2000  11
FT STJOHN    F.N.     27   15     900   8     89   20    3700  12

*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            W   15   W   20
SMITHERS              VR   5   VR  20

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1300 m         16 C
FT. NELSON      1100 m         18 C

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     23   17     700   2     60   22    1350   7
FRASER VLY   QUIL     24   17     700   2     87   25    2100   6
SRN VRISL    QUIL     20   17     700   2     57   23    1400   5
CNTRL VRISL  QUIL     20   17     700   2     78   25    2000   5
NRN VRISL    HRDY      9   14     200   8     90   19    1300  11
TERRACE      ANT       9   14     250   4     78   18    1850   6
STEWART      ANT       9   14     150   0     51   18    1150   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   VR   5   NW   9
PORT HARDY   W    9   SW   9   W   17
SANDSPIT     SW   9   S   13   S   22

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1000 m         18 C
PORT HARDY       300 m         16 C
ANNETTE          MSG           MSG

TODAY'S VENTING: GOOD

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD




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

END/MWSO.