FPCN39 CWLW 261333
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 SUNDAY 26 APRIL 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      74   13    1650   7     97   18    2400   7
KAMLOOPS     KEL      87   13    2150   7    100   21    3350   8
OKANAGAN     KEL      14    9     600   2    100   18    3350   8
CASTLEGAR    SPOK     33    9     950   6     87   17    2700   6
CRANBROOK    SPOK     27    8    1250   6    100   17    3950   6
REVELSTOKE   KEL      12    8     600   2     91   15    2400   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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   SW  19   W   30
CRANBROOK             W    9   NW  26

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          850 m         10 C
SPOKANE         1000 m         10 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD TO FAIR

CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   KEL      85    8    2250   9    100   13    3950  10
PR. GEORGE   F.N.    100   10    2050  20    100   13    3700  21
SMITHERS     ANT     100    6    1550  22    100    9    2600  21
WELLS GRAY   F.N.    100   10    4000  22    100   14    4000  22
FT NLSN      F.N.     51    6     850  11     97   12    1350  17
FT STJOHN    F.N.     88    9    1400  18    100   14    3700  21

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

FORECAST UPPER WINDS FOR SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            SW  57   SW  80
SMITHERS              SW  50   SW  80

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      MISSING
FT. NELSON      1340 m         12 C

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD TO FAIR

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     76   11     700  17    100   14    1250  16
FRASER VLY   QUIL     47   10     350  16    100   16    1550  16
SRN VRISL    QUIL     55   11     500  12    100   15    1300  14
CNTRL VRISL  QUIL     78   12     800  13    100   15    1300  14
NRN VRISL    HRDY     35   10     250  14    100   12     950  19
TERRACE      ANT      10    4     250  20    100    8    1200  21
STEWART      ANT      41    4     250  15     74    8     600  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 SUNDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    S   13   SW  28   SW  44
PORT HARDY   S   67   SW  70   SW  85
SANDSPIT     SW  50   SW  59   SW  69

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE      1460 m         13 C
PORT HARDY       300 m         11 C
ANNETTE          NONE

TODAY'S VENTING: GOOD

VENTING FOR MONDAY: GOOD

VENTING OUTLOOK TUESDAY THRU THURSDAY: GOOD TO FAIR

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


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