FPCN39 CWLW 091324
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 THURSDAY 9 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      33    8     750   5    100   13    2450   8
KAMLOOPS     KEL      44    7     900   7    100   13    3350   8
OKANAGAN     KEL      11    5     550   1    100   12    3350   8
CASTLEGAR    SPOK     20    5     800   4    100   12    2900   8
CRANBROOK    SPOK      9    4     950   6    100   11    3950  11
REVELSTOKE   KEL      38    6     900   7    100   12    3450   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   S   13   S   20
CRANBROOK             VR   5   S   17

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1700 m         10 C
SPOKANE         1020 m          8 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: FAIR.

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




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.     36    3    1400   8    100   10    3950   8
PR. GEORGE   P.G.     31    1    1000   8    100    9    3700   8
SMITHERS     P.G.     21    1     750   5    100    9    3500   7
WELLS GRAY   P.G.     30    2    1400   7    100   11    4000   8
FT NLSN      F.N.     41    3     600  17    100    7    2550  19
FT STJOHN    F.N.     22    3     800  17    100    8    2400  19

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

FORECAST UPPER WINDS FOR THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W    9   W   17
SMITHERS              NW  11   N   17

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1450 m          6 C
FT. NELSON       750 m          8 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: FAIR TO GOOD.

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




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     28    8     550   5     79   13    2450   5
FRASER VLY   QUIL     28    8     500   5     78   13    2400   5
SRN VRISL    QUIL     18    7     300   4     75   12    2200   4
CNTRL VRISL  QUIL     18    7     300   4     77   13    2350   4
NRN VRISL    HRDY     58    6     500  13    100   11    2250  17
TERRACE      ANT      10    3     250   9    100    9    2900  10
STEWART      ANT      38    5     600   6     94    9    2150   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   SE  11   S   19
PORT HARDY   N   15   NE   9   E    9
SANDSPIT     N   35   N   31   N   24

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       790 m         10 C
PORT HARDY       140 m          5 C
ANNETTE          200 m          4 C

TODAY'S VENTING: GOOD.

VENTING FOR FRIDAY: GOOD.

VENTING OUTLOOK SATURDAY THRU MONDAY: GOOD.




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


END/MWSO