FPCN39 CWLW 301321
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 30 JULY 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      22   28     600   3     84   38    3200   4
KAMLOOPS     KEL      12   26     600   1     84   36    3350   4
OKANAGAN     KEL      10   23     500   1     84   35    3350   4
CASTLEGAR    SPOK     21   25     800   4     84   33    3400   4
CRANBROOK    SPOK     20   25     700   4     84   33    3400   4
REVELSTOKE   KEL      11   25     600   1     84   33    3450   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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   VR   5
CRANBROOK    VR   5   VR   5   VR   5

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: 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.      9   21     950   9    100   33    3950   6
PR. GEORGE   P.G.      9   21     700   3    100   32    3700   6
SMITHERS     P.G.      9   21     550   3    100   33    3500   6
WELLS GRAY   P.G.      9   23    1000   9    100   34    4000   6
FT NLSN      F.N.     75   17     850  21    100   22    1300  24
FT STJOHN    F.N.     44   15     900  21    100   23    2200  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE   VR 5     SW  15   S 10
SMITHERS     VR 5     SW  15   S 20

TODAY'S VENTING: GOOD

VENTING FOR THURSDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     43   21     550   8     57   28     900   8
FRASER VLY   QUIL     49   24     650   8     89   34    1600   9
SRN VRISL    QUIL     38   18     500   7     49   25     700   7
CNTRL VRISL  QUIL     44   22     600   7     64   31    1150   7
NRN VRISL    HRDY     30   16     250   9     53   22     600  10
TERRACE      ANT      81   20     750  21    100   32    2700  17
STEWART      ANT      78   21     650  17    100   32    2400  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW   9   W    9   W    9
PORT HARDY   N   19   NW   9   W    9
SANDSPIT     N   44   NW  22   W   17

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: GOOD


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


END/LEC