FPCN39 CWLW 111328
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 SATURDAY 11 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      23    8     650   3     64   11    1400   6
KAMLOOPS     KEL      35    8    1350   4     80   12    1900   9
OKANAGAN     KEL      17    6     600   3     87   11    1900   8
CASTLEGAR    SPOK     18    6     800   3     83    9    1450  13
CRANBROOK    SPOK     10    4     950  17     90    8    2450  14
REVELSTOKE   KEL      32    7    1050   4     84   10    1900   8

*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   SW  13   SW  28
CRANBROOK             SW   9   SW  22

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          730 m          7 C
SPOKANE         1370 m          8 C

TODAY'S VENTING: GOOD.

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: GOOD BECOMING FAIR BY WEDNESDAY.




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.     62    2    1550   8     53    5    1850   7
PR. GEORGE   P.G.     58    3    1300  12     68    6    1950   9
SMITHERS     P.G.      9    0     500   3     83    8    2050   8
WELLS GRAY   P.G.     42    2    1550   8     54    4    1900   7
FT NLSN      F.N.      9    1     400   9     82    8    1800  11
FT STJOHN    F.N.     32    1    1000  10     75    6    1800  11

*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            VR   5   S    9
SMITHERS              VR   5   SE   9

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1280 m          8 C
FT. NELSON       700 m          4 C

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SUNDAY: GOOD

VENTING OUTLOOK MONDAY THRU WEDNESDAY: FAIR.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     74    9    1050  10     80   12    1250  12
FRASER VLY   QUIL     50    8     880  10     80   12    1250  12
SRN VRISL    QUIL     67    9     950   8     80   12    1250  11
CNTRL VRISL  QUIL     22    6     300   5     67    9     950   8
NRN VRISL    HRDY     15    6     100   7     70   10    1350   8
TERRACE      ANT       9    4     250   6     64    9    2300   4
STEWART      ANT      19    6     250   4     58    9    1800   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 SATURDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  26   SW  31   SW  31
PORT HARDY   W   19   W   19   W   17
SANDSPIT     NW  13   NW  19   NW  22

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       100 m          6 C
PORT HARDY       120 m          7 C
ANNETTE          670 m          8 C

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