FPCN39 CWLW 201316
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 20 AUGUST 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      26   22     750   3     80   31    3200   6
KAMLOOPS     KEL      28   21     850   4     80   29    3350   6
OKANAGAN     KEL       9   18     550   0     80   29    3350   6
CASTLEGAR    SPOK     17   19     800   3     80   28    3800   3
CRANBROOK    SPOK      9   18     950   3     80   27    3950   6
REVELSTOKE   KEL      18   19     750   3     80   28    3450   6

*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   VR   5   SW  15
CRANBROOK             VR   5   S   13


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.     22   12    2000  11     80   24    3000  11
PR. GEORGE   P.G.     22   14    2000  11     80   24    3000  11
SMITHERS     P.G.     22   13    2000  11     80   24    3000  11
WELLS GRAY   P.G.     22   14    2000  11     80   21    3000  11
FT NLSN      F.N.     22   16    2000  11     80   18    3000  11
FT STJOHN    F.N.     22   16    2000  11     80   23    3000  10

*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            S   17   S   24
SMITHERS              S   13   S   24


TODAY'S VENTING:  GOOD

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     55   19     350  21     70   24    1050  21
FRASER VLY   QUIL     57   19     350  21     70   27    1950  21
SRN VRISL    QUIL      9   17     250   0     70   24     950   0
CNTRL VRISL  QUIL      9   19     350   0     70   27    1850  11
NRN VRISL    HRDY     24   15     300   6     41   19     650   6
TERRACE      ANT       9   15     200  10     74   21    1900   6
STEWART      ANT      33   16     350   8     78   21    1750   6

*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   S   20   S   35
PORT HARDY   VR   5   S   17   S   20
SANDSPIT     NW  30   NW  15   W   15



TODAY'S VENTING: FAIR TO GOOD


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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