FPCN39 CWLW 161322
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 16 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      18   22     850   1     83   29    2250   6
KAMLOOPS     KEL      21   21    1000   2     99   28    2650   7
OKANAGAN     KEL      24   22    1150   2    100   30    3350   9
CASTLEGAR    SPOK     31   21     750   9     68   27    1100  13
CRANBROOK    SPOK      9   19     950  19    100   28    3950  23
REVELSTOKE   KEL       9   17     500   0     19   20     950   2

*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    S    9   S   24   SW  44
CRANBROOK             SW  11   W   30

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.     62   15    1600  11    100   20    3950  22
PR. GEORGE   P.G.     34   16    1150   6    100   20    2200  13
SMITHERS     P.G.      9   11     500   3      9   16     550   3
WELLS GRAY   P.G.    100   17    2200  19    100   20    4000  22
FT NLSN      F.N.     33   15     550  15     95   22    1650  12
FT STJOHN    F.N.      9   14     700  13     87   20    1850  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 THURSDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE
SMITHERS              S   50   S

VENTING FOR FRIDAY: GOOD




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     77   20     650  19    100   25    1350  20
FRASER VLY   QUIL     94   21     850  20    100   26    1450  20
SRN VRISL    QUIL     26   18     300   7    100   23    1100  17
CNTRL VRISL  QUIL     23   17     250   7     54   20     500  12
NRN VRISL    HRDY     24   15     250   7     40   18     400   9
TERRACE      ANT       9   13     250   7    100   20    2350   9
STEWART      ANT      60   16    1050   6     99   20    2150   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
VANCOUVER    S   31   S   56   SW  76
PORT HARDY   S   76   S   85   S   85
SANDSPIT     NW  61   NW  35   SW   9

VENTING FOR FRIDAY: GOOD




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


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