FPCN39 CWLW 191400
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 19 AUGUST 1999 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   HRDY    100   25    2350  20    100   30    3200  21
KAMLOOPS     KEL      21   24     750   3    100   32    3350   7
OKANAGAN     KEL      21   24     750   3     86   30    2400   6
CASTLEGAR    SPOK     36   21     750  12     91   27    1550  14
CRANBROOK    SPOK     10   21     950  16    100   26    3950  17
REVELSTOKE   KEL      11   20     750   4     80   24    2000   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    NW   15  NW   15  SW  12
CRANBROOK             VR   15  SW  30

TODAY'S VENTING: GOOD

VENTING FOR FRIDAY: 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   18    1150   0    100   27    3950  12
PR. GEORGE   P.G.      9   19    1050   0    100   27    3700  12
SMITHERS     P.G.      9   16     700   0     20   20    1000   0
WELLS GRAY   P.G.      9   16     100   0    100   27    4000  12
FT NLSN      F.N.     12   17     500   2     78   25    1500   9
FT STJOHN    F.N.      9   19     700   7    100   26    3700  14

*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            SW  15   W   24
SMITHERS              S   26   S   24

TODAY'S VENTING:  GOOD EXCEPT POOR NEAR SMITHERS.

VENTING FOR FRIDAY: GOOD

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.

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    HRDY     47   18     450  13     96   21    1150  15
FRASER VLY   HRDY     59   19     600  13    100   22    1350  15
SRN VRISL    HRDY     17   17     150   7     85   21    1000  13
CNTRL VRISL  HRDY     58   19     500  13    100   23    1550  16
NRN VRISL    HRDY     10   15      50   1     33   18     350   9
TERRACE      ANT      11   15     250  31     45   18     450   9
STEWART      ANT      24   15     400   4     42   18     950   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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    VR   5   SW  11   SW  20
PORT HARDY   S   30   S   31   S   30
SANDSPIT     S   10   S   25   S   35

TODAY'S VENTING: GOOD SOUTH AND FAIR NORTH

VENTING FOR FRIDAY: GOOD

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

END/WJW
$$$$^^