FPCN39 CWLW 211414
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 PST MONDAY 21 DECEMBER 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       9  -10     550   0     53   -8    1350   4
KAMLOOPS     KEL      48  -10    1450   4     53   -8    1400   6
OKANAGAN     KEL      48  -10    1450   4     51   -9    1450   6
CASTLEGAR    SPOK     40  -11    1800   5     54   -8    1950   4
CRANBROOK    SPOK     40  -22    1800   4     54  -12    2000   4
REVELSTOKE   KEL      12  -12     750   1     54  -10    1550   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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   W    9   NW  22
CRANBROOK             NW   9   NW  35

TODAY'S VENTING: FAIR.

VENTING FOR TUESDAY: POOR




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.     39  -14    1400  14     34  -13    1250  10
PR. GEORGE   P.G.     20  -16     900   5     32  -14    1200   5
SMITHERS     P.G.     28  -13    1100   4     44  -12    1250   6
WELLS GRAY   P.G.     30  -15    1300   4     33  -13    1500  14
FT NLSN      F.N.      9  -17     400   0      9  -16     400   0
FT STJOHN    F.N.      9  -17     700  18      9  -16     700  18

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NW  20   N   39
SMITHERS              N   24   N   39

TODAY'S VENTING: POOR.

VENTING FOR TUESDAY: POOR.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     77   -3     450  29     50    0     550  15
FRASER VLY   QUIL     10   -5      50  27     50   -3     400  15
SRN VRISL    QUIL     87   -1     600  23     50    1     800  15
CNTRL VRISL  QUIL     87   -1     600  23     50    1     850  15
NRN VRISL    HRDY     29    0     450   5     41    2     800   5
TERRACE      ANT       9  -10     200   8      9   -9     200   8
STEWART      ANT       9  -12     100   5      9   -9     100   5

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

FORECAST UPPER WINDS FOR MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    E   20   N   13   N   24
PORT HARDY   E   15   NE  24   N   35
SANDSPIT     N   24   NE  33   NE  44

TODAY'S VENTING: FAIR EXCEPT POOR IN THE NORTH.




VENTING FOR TUESDAY: POOR TO FAIR.




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


END/MWSO