FPCN39 CWLW 311340
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 WEDNESDAY 31 MARCH 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   KEL       9    5     500   0    100   12    3200   9
KAMLOOPS     KEL      50    6    1300   5    100   12    3350   9
OKANAGAN     KEL      23    5     700   4    100   12    3350   9
CASTLEGAR    SPOK     45    4    1050   8    100    9    2750   8
CRANBROOK    SPOK     76    2    1950  10    100    7    3950   7
REVELSTOKE   KEL       9    3     500   0     81    7    2100   7

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   N   15   N   22
CRANBROOK             VR   5   E   19

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: 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.     54    2    2050   5    100    9    3950   6
PR. GEORGE   P.G.     62    4    1900   6    100    9    3700   6
SMITHERS     P.G.      9    1     500   2     91    5    3700   4
WELLS GRAY   P.G.     54    2    2050   5    100    9    4000   6
FT NLSN      F.N.     66   -6    1300   9     43    0    1550   5
FT STJOHN    F.N.     81   -3    1550  13     49    1    1600   7

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

FORECAST UPPER WINDS FOR WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   15   W   17
SMITHERS              SW  17   SW  17

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR THURSDAY: FAIR TO GOOD.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     74    7     750  14    100   12    2600  11
FRASER VLY   QUIL     61    6     600  13    100   13    3050  11
SRN VRISL    QUIL     44    5     450  10    100   12    2400  11
CNTRL VRISL  QUIL     18    4     200   6    100   11    2150  11
NRN VRISL    HRDY     10    4      50   1     93   10    1850   8
TERRACE      ANT      43    4     600  10    100    8    2300  12
STEWART      ANT      43    4     600  10     93    8    1400  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 WEDNESDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    NW  13   N   11   NE  17
PORT HARDY   VR   5   VR   5   SW  13
SANDSPIT     S   30   S   30   SW  19

TODAY'S VENTING: GOOD.

VENTING FOR THURSDAY: GOOD.




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


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