FPCN39 CWLW 261359
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 FRIDAY 26 DECEMBER 1997 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    2     300   5     81    6    1650  15
KAMLOOPS     KEL       9    0     400   5     62    1    1350   9
OKANAGAN     KEL       9    0     450   5     61    2    1550  10
CASTLEGAR    SPOK      9   -1     800   0     30    0     950   5
CRANBROOK    SPOK     10   -4     950   2     46   -3    1350   8
REVELSTOKE   KEL      11    0    1300  12     57    0    1300  12

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    SW  13   SW  41   W   93
CRANBROOK             W   22   W   78

TODAY'S VENTING: GOOD.

VENTING FOR SATURDAY: 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.     14   -1    1050   7     33    1    1250  14
PR. GEORGE   P.G.     42    2    1000  14     47    3    1350  14
SMITHERS     P.G.      9    1     500   4     29    1    1250   8
WELLS GRAY   P.G.      9    1    1000  15     37    2    1400  15
FT NLSN      F.N.      9   -4     400   5     21   -5     500   7
FT STJOHN    F.N.     10    4     700  15     81    5    2000  15

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            W   56   W   61
SMITHERS              W   44   W   61

TODAY'S VENTING: FAIR EXCEPT GOOD BC PEACE.

VENTING FOR SATURDAY: GOOD


COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     14    5     200   4     64    8    1000  10
FRASER VLY   QUIL      9    2      50   4     50    6     750   8
SRN VRISL    QUIL     19    7     250   5     66    9    1000  10
CNTRL VRISL  QUIL     17    5     200   5     45    5     600   8
NRN VRISL    HRDY     21    6       0  12     57    7     700  21
TERRACE      ANT      14    3     200  10     57    5    1000  12
STEWART      ANT       9    5       0   6     45    5       0  13

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

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    SW  54   W   83   W   93
PORT HARDY   W   48   W   57   W   61
SANDSPIT     W   44   W   50   W   54

TODAY'S VENTING: FAIR TO GOOD.

VENTING FOR SATURDAY: GOOD


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


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