FPCN39 CWLW 211326
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 TUESDAY 21 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      20   23     650   3    100   35    3200   8
KAMLOOPS     KEL      14   20     600   2    100   34    3350   8
OKANAGAN     KEL      13   19     500   2    100   31    3350   8
CASTLEGAR    SPOK     24   21     800   5    100   32    3500   7
CRANBROOK    SPOK      9   18     950  11    100   30    3950   7
REVELSTOKE   KEL      11   18     500   2    100   27    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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   VR   5   NW   9
CRANBROOK             VR   5   VR   5

TODAY'S VENTING: POOR TO FAIR

VENTING FOR WEDNESDAY: 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   15     950   6    100   26    3950   7
PR. GEORGE   P.G.     17   14     850   5    100   23    3700   7
SMITHERS     P.G.      9   13     800   0     96   22    2800   7
WELLS GRAY   P.G.      9   15    1000   6    100   24    4000   7
FT NLSN      F.N.     30   17     550  13    100   25    2650  11
FT STJOHN    F.N.      9   16     700  13    100   22    2650  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 TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            VR   5   NW  13
SMITHERS              VR   5   N   17

TODAY'S VENTING: GOOD

VENTING FOR WEDNESDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     18   19     300   4     30   24     400   7
FRASER VLY   QUIL     26   21     350   7     87   29    1250  11
SRN VRISL    QUIL     13   17     250   2     25   24     400   4
CNTRL VRISL  QUIL     14   19     300   2     75   29    1200   8
NRN VRISL    HRDY      9   13       0   8     70   19     650  14
TERRACE      ANT      10   16     250  10    100   24    2100  10
STEWART      ANT      40   16     500   7     94   24    1750   9

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

FORECAST UPPER WINDS FOR TUESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    N   11   NE  13   NW  11
PORT HARDY   N   17   N   17   NW  17
SANDSPIT     SW  15   SW  24   SW  37

TODAY'S VENTING: FAIR TO GOOD

VENTING FOR WEDNESDAY: GOOD

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


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