FPCN39 CWLW 041342
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 MONDAY 4 MAY 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   18     550   3     90   27    2150   7
KAMLOOPS     KEL      21   19     750   3    100   28    3350   8
OKANAGAN     KEL      14   15     500   3    100   27    3350   8
CASTLEGAR    SPOK     21   17     800   4     92   27    3500   5
CRANBROOK    SPOK      9   16     940   7     93   24    3950   5
REVELSTOKE   KEL      14   16     600   3    100   26    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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    VR   5   N    9   VR   5
CRANBROOK             VR   5   VR   5

           INVERSION HT    BREAKTHRU TEMP
KELOWNA         1480 m         21 C
SPOKANE          900 m         19 C

TODAY'S VENTING: GOOD

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU 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.     10   13     950  11    100   22    3950  14
PR. GEORGE   P.G.     24   12     850  11    100   21    2300  12
SMITHERS     P.G.     11   11     750   1     93   21    2100   9
WELLS GRAY   P.G.     10   12    1000  11    100   23    4000  14
FT NLSN      F.N.     29    9     550  11     37   15     650  15
FT STJOHN    F.N.      9   11     700  11    100   19    3700  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            W   20   W   35
SMITHERS              W   26   W   35

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE      1420 m         18 C
FT. NELSON       700 m         17 C

TODAY'S VENTING: GOOD LOCALLY FAIR

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: GOOD

COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     22   16     750   2     78   21    1250   9
FRASER VLY   QUIL     22   15     750   2     68   27    1700   5
SRN VRISL    QUIL     20   16     650   2     64   23    1500   5
CNTRL VRISL  QUIL     22   17     750   2     67   25    1600   5
NRN VRISL    HRDY     12   12     600   2     21   17     750   2
TERRACE      ANT      51   14     750  10    100   23    2100  13
STEWART      ANT      53   15     700   8    100   23    1950  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 MONDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    N   13   NE  15   NE  11
PORT HARDY   N    9   N   11   N   13
SANDSPIT     N   33   NW  30   NW  33

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       950 m         20 C
PORT HARDY      1580 m         30 C
ANNETTE         1070 m         19 C

TODAY'S VENTING: GOOD LOCALLY FAIR

VENTING FOR TUESDAY: GOOD

VENTING OUTLOOK WEDNESDAY THRU FRIDAY: GOOD TO FAIR

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


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